{"1": {"fulltext": "I", "height": "4924", "width": "3384", "jp2-path": "handbookofpracti00berg_0001.jp2"}, "2": {"fulltext": "LIBRARY OF CONGRESS.\\nCopyright N\\nShelfJ A\u00c2\u00a3\\nK r\\nChape. Copyright No.\\nUNITED STATES OF AMERICA.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0002.jp2"}, "3": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0003.jp2"}, "4": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0004.jp2"}, "5": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0005.jp2"}, "6": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0006.jp2"}, "7": {"fulltext": "Handbook of Practical Hygiene", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0007.jp2"}, "8": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0008.jp2"}, "9": {"fulltext": "HANDBOOK\\nOF\\nPractical Hygiene\\nBY\\nD. H. BERGEY, A.M., M.D.,\\nFirst Assistant, Laboratory of Hygiene,\\nUniversity of Pennsylvania,\\nPhiladelphia, Pa.\\nEASTON, PA. I\\nChe Chemical publishing Company.\\n1899.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0009.jp2"}, "10": {"fulltext": "TWO COPIES RECEIVED,\\n48537\\nLibrary of C\u00c2\u00abngr\u00c2\u00ab\u00c2\u00ab%\\nOfflc. ,f t\\nNOV 1 7 ?WM\u00c2\u00bb\\nft\u00c2\u00bbfl*Ur of Copyrights\\nk W 3 7.\\nCopyright, 1899, by Eiward Hart,\\nSECOND COPY,", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0010.jp2"}, "11": {"fulltext": "PREFACE.\\nThe lack of a convenient handbook for the guidance\\nof students in the sanitary analysis of air, water, soil,\\nand the principal food materials, and in testing the\\nventilation of buildings, is my apology for the prepa-\\nration of this little work. There are several excellent\\nhandbooks in German that cover about the same field,\\nas well as a number of general treatises on hygiene in\\nEnglish that contain some of the methods incorporated\\nin this work, but there is no short and concise* labora-\\ntory guide, in the English language, that satisfactorily\\nmeets the wants of the student in practical hygiene.\\nI have felt this want as a student and as an instruc-\\ntor and I trust, therefore, that this work may be a\\nmeans of lightening the labor of others in this line of\\nstudy.\\nAs a general rule only the more simple and ready\\nmethods now in use have been here incorporated as it\\nis expected that when once a good foundation for re-\\nsearch has been laid the student will be stimulated to\\nmake use of the more extensive treatises relating to\\nthe subject.\\nThe subject of food analysis has been gone into just\\nfar enough to permit of the detection of the more com-\\nmon forms of adulteration that are likely to be en-\\ncountered, while the subject of general food analysis\\nhas been omitted entirely because, as a rule, medical\\nstudents are not prepared to take up such a difficult\\nsubject in chemistry. For the same reason the sub-\\nject of examination of clothing has been omitted.\\nPhiladelphia, Pa., May 25, z8pp.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0011.jp2"}, "12": {"fulltext": "CONTENTS.\\nPage.\\nIntroducti\\non\\nI\\nPart I.\\nAtmospheric air\\n6\\nPart II.\\nWater\\n63\\nPart III.\\nSoil\\n114\\nPart IV.\\nSanitary Analysis of Foods\\n!25\\nPart V.\\nVentilation and Heating\\nI50", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0012.jp2"}, "13": {"fulltext": "INTRODUCTION\\nThe practical hygiene of to-day is the logical out-\\ngrowth of observations in sanitary science as the re-\\nsult of the experiences of the peoples of different coun-\\ntries, cities, and towns. These observations were made\\nchiefly during the present century since sanitary science\\nhad made very little progress from the empirical pro-\\ncedures of the ancients until these procedures had been\\ntested through the means and measures afforded by\\nmodern chemistry and physics.\\nIt will be of interest to trace briefly the more im-\\nportant steps in the development of sanitary science\\nwhich gave rise to what is known as practical hygiene\\nto-day, before taking up the various steps in the de-\\nvelopment of practical hygiene. The earlier discov-\\neries which have been of immense value to sanitary\\nscience are those of Jenner with regard to vaccinia\\nthose of Howard with regard to the relation of filth\\nand insufficient air-supply to the high death-rate in\\nprisons those of Bowditch, of Boston, and Middleton,\\nof England, with regard to the relation of dampness\\nof the soil of a locality to the prevalence of tubercu-\\nlosis; those of Gerhard, of Philadelphia, with regard\\nto the differentiation between typhus and typhoid\\nfever; and those of von Pettenkofer, of Munich, with\\nregard to the relation of ground-water to the preva-\\nlence of typhoid and cholera.\\nThe discovery of the etiological factors in infectious\\ndiseases, the definite determination of the relation of\\ncertain diseases to polluted water-supplies, and of the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0013.jp2"}, "14": {"fulltext": "2 PRACTICAL HYGIENE\\nintimate relation of certain respiratory diseases with\\nthe ventilation and general sanitary condition of build-\\nings, mark the beginning of the practical application\\nof scientific methods to sanitary science. Practically\\nall of these discoveries have been made within the\\nlast two or three decades. The influence of the sev-\\neral sanitary commissions of England, as the Health\\nof Towns Commission, the Barracks Commission, and\\nthe Rivers Pollution Commissions, in stimulating in-\\nvestigations and in the collection of valuable data, has\\nbeen very great.\\nThe discoveries made during this period w T hich\\nstand out prominently and mark important steps in\\nthe development of practical hygiene, are those of Pas-\\nteur, of Paris, and of Koch, of Berlin, upon the rela-\\ntion of micro-organisms to disease; those of Lister\\nupon the aseptic treatment of wounds the experi-\\nments of Paul Bert on the influence upon life and\\nhealth of various atmospheric conditions those of von\\nPettenkofer and Voit on expired air, and the latter s\\naccurate methods for the determination of carbon\\ndioxid in air.\\nOf the discoveries and adaptations of methods em-\\nployed in chemistry and physics to sanitary science\\nwhich mark the rise of practical hygiene, it is impos-\\nsible to speak with any great definiteness, since the\\nadvancement has been so gradual that it would be\\ndifficult to trace out the various steps in order to make\\nspecial mention of them. Several of these methods,\\nhowever, stand out quite prominently, in addition to\\nthose already mentioned, so that it is possible to", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0014.jp2"}, "15": {"fulltext": "INTRODUCTION 3\\ntrace their birth and evolution. Among others the\\nfollowing should receive special mention The method\\nfor the determination of organic matter in water by\\nmeans of potassium permanganate, published by Fore-\\nhammer, of Copenhagen, in 1849, and modified since\\nby Kubel and by Tiemann, and others; the method for\\nthe determination of the hardness of water by means\\nof an alcoholic solution of soap, published by Mm.\\nBoutron and Felix Boudet in Comptes rendu s, March\\n26, 1855, and elaborated by Dr. Thomas Clark, of\\nAberdeen the perfection of Levol s method of deter-\\nmining chlorin, by Mohr, in 1856, by the use of po-\\ntassium chromate solution as indicator and the appli-\\ncation of the method to the determination of chlorin in\\nwater the discovery of a delicate reagent for the detec-\\ntion of ammonia, by Nessler, in 1 856; the method for the\\ndetermination of the nitrogenous organic matter in water\\nas free and albuminoid ammonia, published by YVank-\\nlyn, Chapman, and Smith before the Chemical Society,\\nof London, June 20, 1867; the discovery of a satisfac-\\ntorv method for the determination of nitrogen as ni-\\ntrites in water, by Griess, in 1881, and its improve-\\nment by Warrington the discovery of a delicate test\\nfor nitrates in water, by Grand val and Lajoux, in 1885.\\nThe methods in use for the determination of organic\\nmatter in air had their origin in the ingenuity of\\nAugus Smith, Chapman, Moss, and Remsen.\\nThe evolution of practical hygiene has been very\\nrapid during the last two or three decades, so much\\nso that the student of to-day rarely realizes how re-\\ncently all of the different methods employed in the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0015.jp2"}, "16": {"fulltext": "4 PRACTICAL HYGIENE\\nanalysis of water have come into use. If we go back\\nto the year 1855 we find that the only chemical methods\\nknown by means of which organic contamination of\\nwater could be detected were Loss on ignition Fore-\\nhammer s permanganate test the distillation of enor-\\nmous quantities of water, as much as 50 gallons, in\\norder to estimate the ammonia, which was done by\\ntitration with standard acid. This procedure has long\\nsince been very much simplified through the introduc-\\ntion of the Nessler process and the Wanklyn method\\nof distillation. The development of practical hygiene\\nhas been of such recent date that so far it has failed\\nto receive the consideration in educational institutions\\nwhich it really merits from its immense practical\\nutility.\\nThe opinion that the medicine of the future must\\nbe largely preventive medicine is rapidly gaining\\nground, consequently the study and application of all\\nthe preventive measures known becomes of the great-\\nest importance in the training of medical men.\\nSince pure air, pure water and food, and sanitary\\nhabitations and environment are of primary import-\\nance in the maintenance and restoration of health, the\\nstudy of the character and sources of impurities in\\nthese, of whatever nature, is highly essential in the\\npractical training of the physician of to-day.\\nThe testimony of experts before recent sessions of\\ngovernment and legislative investigation commissions,\\nhas shown that food adulterations of a character which\\nis as yet practically unknown to the general public\\nare becoming quite frequent. Such disclosures as", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0016.jp2"}, "17": {"fulltext": "INTRODUCTION 5\\nthose made by Dr. Wiley, chief chemist of the De-\\npartment of Agriculture, before the Senatorial Pure\\nFood Investigation Committee, in which he stated\\nthat articles of food were imported from abroad, adul-\\nterated to such a degree that they would not be used\\nin the countries where they were produced, should\\narouse us to more active supervision of the character\\nof the food materials exposed for sale in our markets.\\nWhile many of the adulterations specified in the testi-\\nmony before these investigation commissions are not\\nnecessarily dangerous or even injurious to health, they\\nare nevertheless fraudulent and should not be tolerated\\nunder any circumstances. On the other hand the use\\nof highly injurious food preservatives is far from un-\\ncommon and is rarely suspected. Some of these pre-\\nservatives act in such a manner as to render the food\\npractically indigestible aside from any injurious effect\\nwhich they may exert upon the digestive organs them-\\nselves. In order to properly control the healthfulness\\nof food supplies it is necessary to have more general\\ninvestigation into the nature and composition of the\\ndifferent food materials offered for sale in the markets.\\nIn order to make such a supervision feasible it is nec-\\nessary to have a considerable force of trained analysts\\nin all the larger cities and towns, in addition to a more\\ngeneral supervision of the mode of preparation and\\nsystem of marketing of the different forms of prepared\\nfoods. In this manner it would be possible to protect\\nthe common people, at least more effectually than is\\ndone at present, against gross fraud and against injury\\nto health from adulterated food.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0017.jp2"}, "18": {"fulltext": "PART I\\nATMOSPHERIC AIR\\nThe air, when pure, is composed of 20.99 per cent,\\nby volume of oxygen, 0.03 to 0.04 per cent, of carbon\\ndioxid, about 78 per cent, of nitrogen, 1.0 per cent, of\\nargon, and varying proportions of watery vapor.\\nTraces of ammonia and organic vapors are also gener-\\nally present. The relative proportion of the two prin-\\ncipal gases, oxygen and nitrogen, remains quite con-\\nstant in all portions of the globe, while the carbon\\ndioxid, aqueous and organic vapors, and the ammonia\\nvary quite perceptibly in different localities and under\\nvarious modifying influences.\\nFor the hygienist, therefore, the constituents of the\\natmosphere which vary in their relative proportions,\\nthe carbon dioxid, aqueous and organic vapors, and\\nammonia, are of primary interest. It is these con-\\nstituents, along with the temperature, barometric pres-\\nsure, and the force and direction of the wind, that will\\nengage our attention.\\nThe nitrogen serves merely as a diluent for the\\noxygen of the air, and, so far as known, has no other\\ninfluence upon man. The amount of aqueous vapor\\nin the air of dwellings is a most important factor in\\nrelation to the comfort and health of the occupants.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0018.jp2"}, "19": {"fulltext": "CHAPTER I. PHYSICAL EXAMINATION OF AIR-METEOROLOGY\\nA. OBSERVATION OF TEMPERATURE\u00e2\u0080\u0094 THER-\\nMOMETERS\\nThe observation of temperature in the laboratory is\\ncommonly made by means of a mercurial thermometer.\\na. Control of the zero-point. The zero-point of a\\nmercurial thermometer should be verified from time\\nto time, and all new thermometers must be verified\\nbefore they are brought into use, to avoid any error\\nfrom variations which are liable to take place as the\\nresult of contraction of the glass bulb.\\nProcess. The verification of the zero-point of a ther-\\nmometer is made by placing the bulb into a small glass\\nfunnel filled with cracked ice, when, if the thermometer\\nis properly constructed, it will register o\u00c2\u00b0 C. in about five\\nminutes.\\nb. Testing the boiling-point of water as registered\\nby a thermometer. The thermometer is placed in a\\nso-called hypsometer, in which it is quite surrounded\\nwith streaming steam, so that only the upper part of\\nthe scale is visible outside of the apparatus.\\nThe water in the apparatus is boiled for ten min-\\nutes and then the reading of the thermometer is taken.\\nIt is to be remembered that the boiling-point of water\\nis influenced by the barometric pressure the greater\\nthe pressure the higher the boiling-point of water, and\\nvice versa. For instance a correct centigrade ther-\\nmometer will indicate ioo\u00c2\u00b0 C. only when the baromet-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0019.jp2"}, "20": {"fulltext": "8 PRACTICAL HYGIENE\\nric pressure at o\u00c2\u00b0 C. is 760 mm. Consequently it is\\nnecessary to observe, at the time of reading the ther-\\nmometer, the barometric pressure and the temperature\\nat the barometer. The observed barometric pressure\\nmust then be corrected for o\u00c2\u00b0 C, according to the\\nformula, b l where a the coefficient of ex-\\npansion for mercury for each degree of temperature,\\nor 0.00018.\\nThe normal boiling-point for the corrected baromet-\\nric pressure is then taken from Regnault s table (see\\nTable I) and if this coincides with the boiling-point\\nas indicated by the thermometer that is being tested,\\nthen the latter is correct, otherwise the difference is\\nto be noted as the correction for the boiling-point.\\nExample. A new thermometer registers the boiling-\\npoint at 98. 2 C, with the barometric pressure at 713\\nmm., and the temperature at the barometer 15 C. The\\nbarometric reading is reduced to o\u00c2\u00b0 C. according to the\\nformula\\nbt\\nb 711.08 mm.\\n1 ^-a.t\\nAccording to the table the temperature of boiling water\\nat 711 mm. =98.-15\u00c2\u00b0 C, and at 712 mm. =98.19\u00c2\u00b0 C.\\nDifference 0.04\u00c2\u00b0 for 1\u00c2\u00b0 of temperature, and for 0.01\u00c2\u00b0\\nthe difference is 0.0004\u00c2\u00b0, aG d for 0.08\u00c2\u00b0 it is 0.0032\u00c2\u00b0,\\nhence the temperature of boiling water at 711.08 mm.\\n98.1532\u00c2\u00b0 C. Since our thermometer registered 98.2\u00c2\u00b0 C.\\nit registers 0.046 8\u00c2\u00b0 too high, and the correction for the\\nboiling-point is 0.0468\u00c2\u00b0.\\nTesting the accuracy of the thermometer between\\nthe two fundamental points\\nThe accuracy of the scale between the zero- and", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0020.jp2"}, "21": {"fulltext": "METEOROLOGY 9\\nboiling-point is determined by comparison with a nor-\\nmal thermometer. This is done by placing both in a\\nwooden vessel containing distilled water and gradually\\nraising the temperature of the water. The two ther-\\nmometers must be placed at equal distances from the\\nsides and bottom of the vessel. At intervals of several\\ndegrees the reading is taken of each thermometer. In\\ncase there is a difference between the readings of the\\nthermometers between two points another observation\\nshould be made about half way between those points,\\nor one proceeds as follows: It has been found, for in-\\nstance, that the thermometer to be tested varies from\\nthe normal thermometer -o.i\u00c2\u00b0 at io\u00c2\u00b0, and at 20 it\\nvaries 0.4 Undoubtedly the thermometer changes\\nbetween io\u00c2\u00b0 and 20 We may assume that .the de-\\ngree of variation is evenly distributed between the two\\npoints, and there are points at which the correction is\\n0.2 and 0.3 These points may be determined by\\ncalculation by dividing the space between io\u00c2\u00b0 and 20\\ninto four parts of 2.5 each; after each 2.5 the cor-\\nrection changes by o.i\u00c2\u00b0.\\nThe correction\\nO.\\n1\u00c2\u00b0\\nreaches from\\n10\\n,o\u00c2\u00b0\\nto\\n12\\n\u00e2\u0080\u00a25\\na\\nO.\\n,2\u00c2\u00b0\\na a\\n12.\\n6\u00c2\u00b0\\ni\\n15\\n,o\u00c2\u00b0\\na\\no.\\n3\u00c2\u00b0\\nct n\\ni5-\\ni\u00c2\u00b0\\n17\\n\u00e2\u0080\u00a25\u00c2\u00b0\\nit\\n0.\\n4\u00c2\u00b0\\nH I\\n17-\\n6\u00c2\u00b0\\n20,\\n,o\u00c2\u00b0\\nFor these corrections, however, such great differ-\\nences in temperature, as io\u00c2\u00b0 to 20 should not be\\nused, but a reading should be made at least once be-\\ntween the two points preferably at 15 or better\\nstill at each degree of the scale.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0021.jp2"}, "22": {"fulltext": "IO\\nPRACTICAL HYGIENE\\nTable I.\\nRegnault s Table Showing the Boiling-point of Water ac-\\ncording to the Degree of Barometric Pressure.\\nBarom-\\nTemper-\\nBarom-\\nTemper-\\nBarom-\\nTemper-\\neter.\\nature.\\neter.\\nature.\\neter.\\nature.\\n5 8o\\n92.6\\n650\\n95-7\\n715\\n98.3\\n585\\n92\\n8\\n655\\n95\\n9\\n720\\n98.5\\n590\\n93\\n1\\n660\\n96\\n1\\n725\\n98.7\\n595\\n93\\n3\\n665\\n96\\n3\\n730\\n98.9\\n600\\n93\\n5\\n670\\n96\\n5\\n735\\n99.I\\n605\\n93\\n7\\n675\\n96\\n7\\n740\\n99.3\\n610\\n94\\n680\\n96\\n9\\n745\\n99-4\\n615\\n94\\n2\\n685\\n97\\n1\\n750\\n99.6\\n620\\n94\\n4\\n690\\n97\\n3\\n755\\n99.8\\n625\\n94\\n6\\n695\\n97\\n5\\n760\\n1 00.0\\n630\\n94\\n8\\n700\\n97\\n7\\n765\\n100.2\\n635\\n95\\n1\\n705\\n97\\n9\\n770\\n100.4\\n640\\n95\\n3\\n710\\n98\\n1\\n775\\n100.5\\n645\\n95\\n5\\nB. SPECIAL THERMOMETERS\\n1. Spirit thermometer. For temperatures below\\no\u00c2\u00b0 C. especially below 20 C. a spirit thermom-\\neter is used. These are similar in construction to the\\nordinary mercurial thermometer but contain alcohol\\ncolored with some anilin dye, usually eosin, as the\\nthermometric fluid.\\n2. Thermometers for high temperatures. For the\\nobservation of temperatures over ioo\u00c2\u00b0 C. a long-\\nstemmed mercurial thermometer is used. In this\\nmanner the scale may be lengthened so as to register\\nup to 300 C. For temperatures ranging from 300\\nto 450 C. the capillary tube of the thermometer con-\\ntains nitrogen gas instead of a partial or complete", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0022.jp2"}, "23": {"fulltext": "METEOROLOGY I I\\nvacuum. In this manner the mercury is prevented\\nfrom boiling by the increased pressure within the cap-\\nillary tube. At still higher temperatures air ther-\\nmometers are used, air being the thermometric sub-\\nstance.\\n3. Pyrometer. Pyrometers are constructed of a\\nbar of metal or graphite which is fastened to a support\\nat one extremity. Variations in temperature bring\\nabout alterations in the length of this bar and these\\nchanges are measured by means of a movable pointer\\nattached to the free end of the bar in such a manner\\nthat the temperature is indicated on a fixed scale over\\nwhich the pointer moves. These instruments are\\ngraduated by making comparative observations with\\nan air thermometer. The pyrometers are less accurate\\nthan the air thermometers for the observation of high\\ntemperatures.\\n4. Thermograph. By means of mechanical or electri-\\ncal devices the variations in the temperature, curve, as\\nindicated by the pointer of the pyrometer, are recorded\\non a revolving chart having appropriate rulings for\\ndifferent degrees of temperature and also for definite\\nperiods of time, as a day, a week, or a month. By\\nmeans of a pen or small piece of graphite attached to\\nthe tip of the pointer, a permanent record of its to-\\nand-fro movements, under the influence of fluctuations\\nin the temperature, is produced.\\n5. Maximum-minimum thermometer.\u00e2\u0080\u0094 These in-\\nstruments record both the highest and the lowest", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0023.jp2"}, "24": {"fulltext": "12 PRACTICAL HYGIENE\\npoints reached by the temperature during a definite\\nperiod of time, as twenty-four hours. The form of\\ninstrument in common use is that of Six, consisting\\nof a U-shaped, capillary glass tube, the upper portions\\nof both arms being of somewhat larger caliber than\\nthe body of the tube. A thermometer scale is attached\\nto each arm of the tube, the one arm forming the\\nmaximum, the other the minimum, thermometer. The\\nupper portion of the arm corresponding to the maxi-\\nmum thermometer is expanded into a small, pointed\\nbulb and contains a little alcohol and vapor of alcohol.\\nThe low r er portion or body of the tube contains mer-\\ncury. In addition to this each arm also contains an\\nindex consisting of a small, barbed bar of steel, one\\nend of which rests on the surface of the column of\\nmercury forming the two thermometers. The ther-\\nmometric substance in this instrument is the alcohol\\nin the upper arm of the tube, while the mercury in\\nthe body of the tube is the propeller of the indices.\\nBoth indices are carried upward by the contraction on\\nthe one hand, and the expansion on the other, of the\\nmercurial column as the result of a fall or rise in the\\ntemperature, and each of them is arrested at the point\\ncorresponding to the lowest temperature reached dur-\\ning the period of time under observation in the one\\ncase, and at the point corresponding to the highest\\ntemperature reached during the same time on the\\nother hand, thus recording the two extremes in tem-\\nperature for that period of time. The indices are pre-\\nvented from falling w r ith the receding column of mer-\\ncury by the feathery projections along their sides.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0024.jp2"}, "25": {"fulltext": "METEOROLOGY 1 3\\nAfter reading the thermometers the indices are again\\nbrought in contact with the surface of the mercurial\\ncolumn by drawing a small horseshoe magnet down-\\nward along the side of each arm of the instrument.\\n6. Measurement of solar radiation. The ordinary\\nmercurial thermometer indicates only the heat com-\\nmunicated to it by the surrounding media and is but\\nlittle influenced by the heat radiating from the sun\\ndirectly. To measure the amount of heat radiating\\nfrom the sun a maximum thermometer, with blackened\\nbulb, is commonly employed. This instrument is en-\\nclosed in a larger glass tube exhausted of air, one\\nend of which is expanded into a bulb. The bulb of\\nthis thermometer is influenced by the solar radiations\\nalone, reflecting the solar heat against the outer bulb\\nwhose temperature is the same as that of the surrounding\\natmosphere. The instrument is placed in a horizontal\\nposition and registers higher than one that is exposed\\nto the air, the increase in temperature indicating the\\namount of heat radiating from the sun.\\n7. Terrestrial radiation. For the purpose of meas-\\nuring the radiation of heat from the earth at night a\\nminimum thermometer is placed in a horizontal posi-\\ntion, on wooden supports, in an exposed place. The\\nreading of this thermometer is compared with that of\\nanother minimum thermometer at the same place, but\\nprotected from such influence a higher reading of the\\nlatter indicates the amount of heat radiating from the\\nearth.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0025.jp2"}, "26": {"fulltext": "14 PRACTICAL HYGIENE\\nC. THERMOMETER SCALES\\ni. The centigrade scale. The centigrade scale is\\nthe one most commonly used in scientific investiga-\\ntions. It has for its zero-point the melting-point of\\nice, while ioo\u00c2\u00b0 represents the boiling-point of water\\nwith the barometer at 760 mm.\\n2. The Fahrenheit scale. In this scale the zero-\\npoint is 32 below the melting-point of ice, and the\\nboiling-point of water is at 21 2\u00c2\u00b0 with the barometer\\nat 29.905 inches in the latitude of London. This is\\nthe standard scale in the United States, but, for ob-\\nvious reasons, the centigrade scale is preferable to it.\\n3. The Reaumur scale, In this scale the melting-\\npoint of ice also corresponds to the zero-point, while\\nthe boiling-point of water is at 80 This scale has\\nnever been used very extensively and is now falling\\ninto disuse.\\n4. Relative values of the degrees on the three\\nscales.\\n5 C.=9\u00c2\u00b0F.\\n4\u00c2\u00b0R-\\ni\u00c2\u00b0 C. =-5- \u00c2\u00b0F.\\n5\\n\u00c2\u00b0R.\\n5\\n1\u00c2\u00b0 F. \u00c2\u00b0C.\\n9\\n9\\ni\u00c2\u00b0R.=^ \u00c2\u00b0C.\\n\u00c2\u00b0F.\\n4 4\\nTo convert centigrade degrees into Fahrenheit degrees,\\nmultiply by and add 32. (C. X 32 F.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0026.jp2"}, "27": {"fulltext": "METEOROLOGY 1 5\\nTo convert centigrade degrees into Reaumur degrees,\\nmultiply by C. X R.\\n5 5\\nTo convert Fahrenheit degrees into centigrade degrees,\\nsubtract 32, and multiply by (F. 32) X C.\\nTo convert Fahrenheit degrees into Reaumur degrees,\\nsubtract 32, and multiply by (F. 32) X R.\\nTo convert Reaumur degrees into centigrade degrees,\\nmultiply by R. X C.\\n4 4\\nTo convert Reaumur degrees into Fahrenheit degrees,\\nmultiply by and add 32. (R. X 32 F.\\n4 4\\nD. ATMOSPHERIC PRESSURE\\nThe atmosphere having weight exerts, therefore, a\\nconstant but variable amount of pressure upon the\\nearth s surface. The amount of pressure exerted by\\nthe atmosphere is dependent upon the quantity of\\nmoisture it is holding and upon its temperature. The\\ndegree of pressure which it exerts is subject to con-\\nstant fluctuations through the incessant movements\\noccurring between its higher and lower strata, as well\\nas through its movements from one point to another\\nover the earth s surface, the latter movements giving\\nrise to what are known as winds. The movements\\nof the atmosphere are produced by an increase or a\\ndecrease in the amount of moisture at one point of the\\nearth s surface as compared with other surrounding\\npoints, such increase or decrease in the amount of\\nmoisture being brought about through precipitation", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0027.jp2"}, "28": {"fulltext": "1 6 PRACTICAL HYGIENE\\nfrom the clouds, or through evaporation of moisture\\nfrom the earth s surface. On the other hand move-\\nments of the atmosphere are also brought about by an\\nincrease or decrease in its temperature as the result of\\na greater amount of, heat radiation at one point than\\nat another, but more particularly through the influence\\nof the high temperature of the torrid zone and the\\ninfluence of the low temperature of the polar regions.\\nThe barometer is high (a) when the air is cold, be-\\ncause it is then more dense than it is when warm (6)\\nwhen the air is dry, because it is then also more dense\\nthan when it is moist (c) when an upward current\\nsets in towards a certain point, because in consequence\\nof this movement, the lower strata are compressed.\\nThe barometer is low (a) when the lower strata are\\nheated there is an upward movement, as the density\\nof these strata decreases, and the upper or lighter\\nstrata are displaced laterally (A) when the air is damp,\\nbecause the density of aqueous vapor, at 760 mm. and\\no\u00c2\u00b0 C. is 0.622, air being 1, therefore the mixture be-\\ncomes lighter the more moisture it contains; (V) when\\nthe air has a gradual upward movement without a\\nsimultaneous lateral movement to replace the air that\\nis moving upward.\\nAs the density of the atmosphere influences the\\namount of pressure which it is capable of exerting it\\nis evident that the pressure must bear an inverse rela-\\ntion to the altitude the higher the altitude the greater\\nthe rarification of the air and, consequently, the higher\\nthe barometer. On the other hand the density of the\\nair increases as we descend to the level of the sea, or", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0028.jp2"}, "29": {"fulltext": "METEOROLOGY I 7\\npenetrate into the interior of the earth, and the ba-\\nrometric reading is lower, being at 760 mm. at the\\nsea-level, and gradually falling as we descend below\\nthat level.\\n1. Mercurial Barometers\\na. Cistern barometer. Observations of barometric\\npressure are commonly made with the cistern barom-\\neter. It consists of a glass tube, 80 cm. in length,\\nsealed at one end. This is filled with mercury and\\ninverted in a small metal cistern containing mercury,\\nwhen a portion of the mercury in the tube escapes,\\nleaving a vacuum in the upper part of the tube. The\\ngreater portion of the mercury in the tube is retained\\nthrough the pressure exerted on the surface of the\\nmercury in the cistern by the atmosphere. The top\\nof the cistern is partly closed in and has a small ivory\\npoint projecting from the roof which serves as the\\nzero-point of the scale, and is called the fiducial\\npoint. The bottom of the cistern is composed of\\nleather and can be raised or lowered as required, so\\nthat the surface of the mercury is always brought in\\ncontact with the ivory point projecting from the roof.\\nIn this manner the zero-point of the scale is regulated\\nat each reading. The barometer tube is enclosed in\\na metal tube having a ring attached to its upper ex-\\ntremity from which it is suspended. It must hang\\nperpendicularly, but is prevented from swinging by\\nmeans of four small screws projecting from the inner\\nsurface of the metal ring surrounding the cistern.\\nThese screws are adjusted in such a manner that they", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0029.jp2"}, "30": {"fulltext": "1 8 PRACTICAL HYGIENE\\nprevent any marked swinging of the instrument, and\\nyet avoid communicating the influence of any jarring\\nfrom the supports to which it is attached.\\nThe barometer scale. For scientific observations\\nthe metric scale is most commonly employed. In this\\nscale the standard pressure at sea-level is taken as 760\\nmm., with the temperature at o\u00c2\u00b0 C. In the standards\\nof the United States and Great Britain measurement\\nis made in inches, tenths, and hundredths, with the\\ntemperature at 32 F. The standard pressure at sea-\\nlevel is 30 inches.\\nThe vernier. In order to facilitate the accurate\\nreading of the barometer, a small movable scale, called\\na vernier, is attached at the side of the fixed scale,\\nand is moved upward and downward by means of a\\nrack-and-pinion arrangement. This allows the read-\\ning of the fractional parts of the millimeter. 1\\nTo read the fractional parts of a millimeter of the\\npressure recorded by the barometer, the zero-point of\\nthe vernier is brought on a level with the top of the\\nmeniscus of the column of mercury in the barometer\\ntube to the point at which it cuts off the light pass-\\ning between it and the top of the meniscus. The line\\non the vernier scale that is on a level with, or nearest\\nto, one of the lines on the fixed scale indicates the\\nnumber of tenths of a millimeter to be added to the\\n1 The principle of the vernier is this, that a given length con-\\ntaining n divisions of the fixed scale is divided into n -j- 1 divisions\\non the vernier usually representing the length of one millimeter\\non the fixed scale.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0030.jp2"}, "31": {"fulltext": "METEOROLOGY I 9\\nreading of the fixed scale e. g., the reading of the\\nfixed scale is 764 mm., and the line on the vernier\\nscale that is on the same level with, or nearest to, one\\nof the lines on the fixed scale is the eighth, then the\\ncorrect reading of the barometer is 764.8 mm.\\nTemperature at the barometer. Attached to the\\nmetal case surrounding the barometer tube is a small\\nmercurial thermometer which records the temperature\\nat the barometer. The reading of this thermometer\\nshould always be taken before reading the barometer\\nitself, otherwise the breath of the observer and the\\nheat given off from his body might change its read-\\ning-, and thus affect the accuracv of his observations.\\nManner and place of hanging a barometer. Ba-\\nrometers should be hung in a room protected from di-\\nrect sunlight and removed from marked temperature\\nfluctuations.\\nReading of the barometer. The first point to be\\nobserved in reading the barometer is to note and record\\nthe temperature at the thermometer attached to it.\\nThe next point to observe is whether the instrument\\nis properly suspended, after which the zero-point of\\nthe scale is adjusted by bringing the surface of the\\nmercury in the cistern to the u fiducial point, by either\\nraising or lowering the bottom of the cistern, as may-\\nbe required, by means of the screw attached beneath\\nit. The vernier is now raised above the top of the\\ncolumn of mercury in the tube and then carefully\\nbrought down on a level with the top of the meniscus.\\nIn regulating the vernier it is very essential that the\\neye of the observer is also on a level with the top of", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0031.jp2"}, "32": {"fulltext": "20 PRACTICAL HYGIENE\\nthe meniscus. The number of millimeters pressure is\\nshown on the fixed scale and the tenths of a millimeter\\non the vernier scale.\\nCorrections of barometric readings. To obtain ac-\\ncurate results, as well as for purposes of comparison,\\nseveral corrections of the readings of the barometer\\nare necessary (a) for variations in the meniscus ac-\\ncording to the diameter of the barometer tube. For\\na tube of 12 mm. diameter the correction is so small\\nthat it has but little influence on the results and may\\nbe ignored. For the same reasons (b) variations in the\\nbarometer scale, as well as (c) variations in the glass\\ntube under different conditions, may be ignored. The\\nonly important influence on the barometric reading for\\nwhich correction must be made is that which is due\\nto the expansion and contraction of the mercury at\\ndifferent degrees of temperature. With an increase of\\ni C. of temperature, mercury expands at the rate of\\n0.00018 times its volume, consequently the influence\\nof varying degrees of heat on the height of the column\\nof mercury in the barometer tube must be eliminated\\nfrom every observation. Correction of the barometric\\nreading for temperature is made according to the for-\\nmula bjo reducing the reading to o\u00c2\u00b0 C.\\ntemperature.\\nbjo the barometer reduced to o\u00c2\u00b0 C,\\nb\\\\t as read,\\na constant, 0.00018, the coefficient of expansion\\nof mercury for each degree of temperature.\\nt temperature at the barometer.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0032.jp2"}, "33": {"fulltext": "METEOROLOGY 2 1\\nExample. The barometer stands at 768.4 mm., with\\nthe temperature at 18.3 C. Then\\n#/o= 4\\n1 0.00018 X 18.3\\nor b/o 765.8 mm.\\nWith the temperature below o\u00c2\u00b0 C. the formula is\\nb/o\\n1 a.t\\nb. Stationary barometer. In the stationary barom-\\neter the bottom of the cistern is fixed and the zero-\\npoint of the scale cannot be adjusted at each reading\\nas in the cistern barometer. The scale is also fixed,\\nbut it is arranged in such a manner, however, that its\\nzero-point indicates a barometric pressure of 760 mm.\\nc. Differential barometer. This form of barometer\\nconsists of a glass tube, of equal diameter throughout,\\nand which is bent in the form of the letter S. It is\\nsealed at its upper end, but the lower arm of the tube,\\nwhich is U-shaped, is open to the air. The tube is\\nsomewhat constricted at the middle whereby the move-\\nment of the mercury is impeded, to a slight degree.\\nThe upper portion of the tube contains a vacuum,\\nhence the contraction and expansion of the mercury\\nlowers and raises the level of the column in both arms\\nof the tube. The scale is either fixed or movable, the\\nmethod of reading the barometer depending on this\\npoint. The distance between the upper and lower\\nlevels of the mercury is the height of the mercurial\\ncolumn. This form of barometer is used principally\\nin determining degrees of altitude and the height of\\nmountains.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0033.jp2"}, "34": {"fulltext": "22 PRACTICAL HYGIENE\\n2. Aneroid Barometer\\nThe aneroid barometer consists of a thin-walled,\\nmetallic chamber which has been nearly exhausted of\\nair, its sides being held apart by a strong spring. The\\npressure of the atmosphere on the sides of the cham-\\nber is indicated by means of a pointer which is at-\\ntached to the spring and moves over a dial. Aneroid\\nbarometers are also so constructed as to be self-regis-\\ntering like the thermograph.\\nCorrection of the readings. Three corrections of\\nthe aneroid barometer are necessary (a) for tempera-\\nture, (b) for the divisions on the dial, and (c) for the\\naltitude of the place of observation. For each instru-\\nment these factors must be ascertained, for the loca-\\ntion in which it is to be used, by comparison with a\\nmercurial barometer.\\nE. HUMIDITY OF THE ATMOSPHERE\\nAt different temperatures air is capable of taking up\\nvariable amounts of moisture, there being a saturation\\npoint for each degree of temperature. The point of\\nsaturation rises with the elevation of the temperature\\nof the air, so that when the air is saturated at a high\\ntemperature and is then cooled, there is a precipitation\\nof moisture in the form of rain or dew, or in the form\\nof sleet, snow, or hail.\\na. Dew-point. The point of saturation at a certain\\ndegree of temperature is known as the dew-point.\\nb. Absolute humidity. The absolute humidity de-\\nnotes the amount of moisture, in grains, which i cubic", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0034.jp2"}, "35": {"fulltext": "METEOROLOGY 23\\nmeter of air, of a certain temperature, may be holding.\\nThe absolute humidity varies with the temperature,\\nincreasing in amount with increase of the temperature\\nof the air.\\nc. Maximum of saturation. The maximum satu-\\nration of air is the maximum amount of moisture, in\\ngrams, which i cubic meter of air, at a certain tem-\\nperature, is capable of holding.\\nd. Deficiency of saturation. Deficiency of satura-\\ntion denotes the amount of moisture, in grams, which\\n1 cubic meter of air, at a certain temperature, is capa-\\nble of taking up, in addition to that which it already\\ncontains, to become fully saturated. It is the differ-\\nence between the maximum saturation for that degree\\nof temperature and the absolute humidity.\\ne. Relative humidity. The relative humidity de-\\nnotes the quantity of moisture contained in the air, at\\na certain temperature, expressed in per cent, of the\\nquantity of moisture that can be taken up at that tem-\\nperature, or the absolute humidity expressed in per\\ncent, of the maximum of saturation. It is the great-\\nest near the surface of the earth during night when\\nthe temperature approaches the dew-point, and it is\\nleast during the middle of the day when the heat is\\ngreatest.\\nF. ESTIMATION OF MOISTURE IN THE AIR\\n1. Direct hygrometers. There are three forms of\\ndirect hygrometer all depending on the same princi-\\nple: (a) Daniell s, (b) Regnault s, an improved form of", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0035.jp2"}, "36": {"fulltext": "24 PRACTICAL HYGIENE\\nDanielPs instrument, and (c) Dines s. Dante/Ps hygrom-\\neter consists of two glass bulbs connected by a glass\\ntube bent twice at right angles. The instrument is\\nattached to a samll wooden stand to which is fixed a\\nsmall mercurial thermometer. One of the bulbs is\\nmade of black glass and contains a thermometer; the\\nother bulb is made of ordinary glass and is covered\\nwith muslin. The bulbs contain some ether vapor.\\nBy holding the covered bulb in the hand for a minute,\\nthe ether contained in it evaporates and passes over\\ninto the black bulb; some ether is then dropped on the\\nmuslin, and, by its rapid evaporation, reduces the\\ntemperature of this bulb, causing the ether vapor in\\nthe black bulb to contract and distil over into the\\nother bulb. The temperature of the black bulb is now\\nreduced until the dew-point is reached and the mois-\\nture! in the air surrounding it is deposited on the shi-\\nning black bulb. The instant this occurs the tempera-\\nture shown by the thermometer inside the bulb is noted\\n(the dew-point), as well as the temperature of the air\\nas shown by the thermometer on the stand.\\nRegnaulf s hygrometer is an improvement on Dan-\\niell s, having a bright silver cup in place of a glass\\nbulb to contain the ether, and the ether is evaporated\\nby means of an aspirator or air-pump attached to the\\ncup.\\nDines^s hygrometer consists of a vessel, containing\\nice-cold water, and a black glass attached to a wooden\\nstand. The vessel containing the ice-cold water has\\na tube attached that connects it with a small, closed\\nchamber underneath the glass plate, so that the water", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0036.jp2"}, "37": {"fulltext": "METEOROLOGY 25\\npassing into this chamber cools the bulb of a ther-\\nmometer within the chamber, just beneath the glass\\nplate. The flow of water is controlled by means of a\\nstop-cock. At the moment when dew begins to de-\\nposit on the glass plate the temperature at the ther-\\nmometer, attached to the instrument, is noted, the\\nair temperature being noted at the same time.\\n2. Indirect hygrometers. There are two principal\\nkinds of indirect hygrometer (a) the hair hygrometer,\\nand (b) the wet- and dry-bulb thermometer.\\nThe hair hygrometer, of Wolpert, consists of a hu-\\nman or horse hair that has been freed from oily mat-\\nter, one end of which is fixed, while a light weight is\\nsuspended from the other end. A portion of the hair\\npasses over a pulley to which is attached a pointer\\nthat moves over a scale and indicates the relative hu-\\nmidity of the air in per cent, of saturation. The scale\\nof each instrument is graduated by wetting the hair\\nto complete saturation and marking the point ioo\u00c2\u00b0,\\nthen placing the instrument over sulphuric acid of\\nknown strength and marking the point indicated 15\\nof saturation. The intervening space is divided into\\neighty-five equal parts, each of which denotes a de-\\ngree of relative humidity/\\nThe wet- and dry -bulb thermometer, or psychrometer.\\nThis consists of two ordinary mercurial thermometers,\\nas nearly alike as possible, and registering tenths of a\\ndegree centigrade, which are attached to a small frame\\nor to a strip of wood. The bulb of one of the ther-\\nmometers is covered with a jacket of cotton threads", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0037.jp2"}, "38": {"fulltext": "26 PRACTICAL HYGIENE\\nwhich extend into a small cup of water attached to\\nthe bottom of the frame of the instrument, thus keep-\\ning the bulb continuously moist through capillary at-\\ntraction. This is known as the u wet-bulb and the\\nother as the u dry-bulb thermometer.\\nAs long as the atmosphere is not saturated, mois-\\nture continues to evaporate from the wet-bulb and, in\\nconsequence, the mercury cools and contracts and\\nshows a lower temperature than the dry-bulb ther-\\nmometer, which registers the temperature of the sur-\\nrounding atmosphere. The difference between the\\ntemperature registered by the two thermometers is\\ngreatest when the atmosphere contains the least mois-\\nture, and when it is saturated they show the same\\ntemperature, since there is no evaporation from the\\nwet bulb. When the temperature is below freezing\\ncapillary action ceases and the readings of the wet-\\nbulb thermometer are unreliable.\\nA form of this instrument that is in common use is\\nthe u sling psychrometer. The two thermometers\\nare fastened on opposite sides of a small strip of wood,\\nhaving a handle attached to its upper end by means\\nof which the instrument can be made to revolve. The\\nwet-bulb thermometer projects three or four cm. be-\\nyond the lower end of the wooden support, and the\\njacket surrounding it is thoroughly moistened with\\ndistilled water whenever an observation is to be made.\\nInformation derived from hygrometer observations.\\nThe important items of information to be derived\\nfrom hygrometer observations are (a) the dew-point,\\n(f?) the tension of aqueous vapor, or the absolute hu-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0038.jp2"}, "39": {"fulltext": "METEOROLOGY 27\\nmidity, and (V) the relative humidity of the atmos-\\nphere. Each of these may be calculated from the dif-\\nference between the temperature of the wet- and dry-\\nbulb thermometers, either by formulae, or from tables.\\nThe dew-point of the atmosphere is determined\\ndirectly by means of one of the three forms of direct\\nhygrometers.\\nThe absolute humidity can be calculated from the\\nreadings of the wet- and dry-bulb thermometers accord-\\ning to the formula: m M cd, where m the ab-\\nsolute humidity of the air at the temperature indicated\\nby the dry-bulb thermometer, t, and Tkf the maximum\\nof saturation at the temperature of the wet-bulb ther-\\nmometer, f, which is found by reference to Fliigge s\\ntable (see Table II).\\nc a constant, usually 0.65, but in the winter, when\\nthe bulb is covered with ice, 0.56, and\\nd the difference between the wet- and dry-bulb\\nthermometer readings.\\nThe product cd can also be taken directly from the\\ntable.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0039.jp2"}, "40": {"fulltext": "28 PRACTICAL HYGIENE\\nTable II.\\nTable of the Water Capacity of Air at Different Tempera-\\ntures. (From Emmerich and Trillich.)\\nTemp.\\nof o o.i 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9\\nthe Air.\\n20\\n1.06\\n15\\n1.57\\n14\\n1.70\\n1.69\\n1.68\\n1.67\\n1.65\\n1.64\\n1.62\\n1.61\\n1.60\\n1.58\\n13\\n1.84\\n1.82\\n1. 81\\n1.80\\n1.78\\n1-77\\n1.76\\ni-74\\ni-73\\n1. 71\\n12\\ni-97\\n1.96\\n1-95\\n1.94\\n1-93\\n1. 91\\n1.90\\n1.89\\n1.87\\n1.85\\nII\\n2.13\\n2.10\\n2.08\\n2.07\\n2.05\\n2.04\\n2.03\\n2.01\\n2.00\\n1.98\\nIO\\n2.30\\n2.28\\n2.27\\n2.25\\n2.23\\n2.21\\n2.20\\n2.18\\n2.16\\n2.15\\n9\\n2.49\\n2.47\\n2.45\\n2.43\\n2.41\\n2.39\\n2.38\\n2.36\\n2-34\\n2.32\\n8\\n2.67\\n2.65\\n2.63\\n2.62\\n2.60\\n2.58\\n2.56\\n2.54\\n2.53\\n2.51\\n7\\n2.88\\n2.86\\n2.84\\n2.82\\n2.80\\n2.77\\n2.75\\n2-73\\n2.71\\n2.69\\n6\\n3-w\\n3.09\\n3.06\\n3.o4\\n3.02\\n2-99\\n2.97\\n2.95\\n2.93\\n2.90\\n5\\n3.36\\n3-33\\n3-31\\n3.28\\n3.26\\n3-23\\n3.21\\n3.18\\n3.i6\\n3.13\\n4\\n3.6i\\n3.58\\n3.56\\n3-53\\n3.5i\\n3-48\\n3.46\\n3-43\\n3.4i\\n3.38\\n3\\n3-90\\n3.87\\n3.84\\n3.81\\n3.78\\n3-75\\n3-73\\n3-70\\n3-67\\n3- 6 4\\n2\\n4.19\\n4.16\\n4.13\\n4.10\\n4.07\\n4.05\\n4.02\\n399\\n3-96\\n3.93\\n1\\n4.52\\n4-49\\n4-45\\n4.42\\n4.39\\n4-35\\n4.32\\n3.29\\n4.26\\n4.22\\n4.87\\n4.83\\n4.80\\n4.76\\n4-73\\n5.69\\n4.66\\n4.62\\n4-59\\n4.55\\n-j- 1\\n5-21\\n525\\n5.28\\n5-32\\n5-35\\n5-39\\n5-43\\n5.46\\n5.50\\n553\\n2\\n5-57\\n5.6i\\n5.65\\n5.69\\n5-73\\n5.76\\n5.8o\\n5.84\\n5.88\\n592\\n3\\n5.96\\n6.00\\n6.04\\n6.08\\n6.12\\n6.16.\\n6.21\\n6.25\\n6.29\\n6.33\\n4\\n6-37\\n6.41\\n9-45\\n6.50\\n6.54\\n6.58\\n6.62\\n6.66\\n6.71\\n6.75\\n5\\n6.79\\n6.84\\n6.88\\n6.93\\n6.98\\n7.02\\n7.07\\n7. 11\\n7.16\\n7.21\\n6\\n7.26\\n7-3i\\n7-35\\n7.40\\n7-45\\n7-49\\n7-54\\n7-59\\n7.64\\n7.68\\n7\\n7-73\\n7.78\\n7-83\\n7.89\\n7-94\\n7-99\\n8.04\\n8.09\\n8.15\\n8.20\\n8\\n8.25\\n8.30\\n8.36\\n8.41\\n8.47\\n8.52\\n8-57\\n8.63\\n8.68\\n8-73\\n9\\n8.79\\n8.85\\n8.91\\n8.96\\n9.02\\n9.07\\n9-13\\n9.19\\n9.24\\n9-3\u00c2\u00b0\\n10\\n9-37\\n9-43\\n9-49\\n9-55\\n9.61\\n9.67\\n9-74\\n9.80\\n9.86\\n9.92\\n11\\n9.98\\n10.04\\n10. 11\\n10.17\\n10.24\\n10.30\\n10.36\\n10.43\\n10.49\\n10.56\\n12\\n10.62\\n10.69\\n10.75\\n10.82\\n10.88\\n10.95\\n11.02\\n11.08\\n11. 15\\n11. 21\\n13\\n11.28\\n11-35\\n11-43\\n11.50\\n11.58\\n11.65\\n11.72\\n11.80\\n11.87\\nif -95\\n14\\n12.02\\n12.09\\n12.17\\n12.24\\n12.32\\n12.39\\n12.46\\n12.54\\n12.61\\n12.69\\n15\\n12.76\\n12.84\\n12.92\\n13.00\\n13.08\\n13-15\\n13.23\\n13.31\\n13-39\\n13-47\\n16 13.54 13.63 13.72 13.80 13.89 13.97 14.05 14.14 14.22 14.31", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0040.jp2"}, "41": {"fulltext": "METEOROLOGY 29\\nTemp.\\nof o 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9\\nthe Air.\\n1; 14.39 M.48 I4-5 8 M.67 14-77 M-S6 14.95 15.05 15.14 15.24\\niS 15.35 15.42 15.50 15.59 15.68 15.76 15.85 15.94 16.03 16.11\\n19 16.20 16.39 16.44 16.49 16.58 16.68 16.78 16.87 16.97 17.06\\n20 17.16 17.26 17.37 17.47 17-58 17.68 17.78 17.89 17.99 18.10\\n21 1S.20 18.31 18.41 18.52 18.63 J 8.73 18.84 18.95 19.06 19.17\\n22 19.29 19.41 19.52 19.64 19.75 19.87 19.99 20.10 20.22 20.33\\n23 20.45 20.56 20.68 20.79 20.91 21.02 21.14 2I 2 5 21.37 21.48\\n24 21.60 21.73 21.85 21.98 22.11 22.23 22.36 22.49 22.62 22.74\\n25 22.87 23.00 23.13 23.27 23.40 23.53 23.66 23.79 23.93 24.06\\n26 24.19 24.33 2447 24.61 24.75 24.88 25.02 25.16 25.30 55.44\\n27 25.58 25.72 25.86 26.01 26.15 26.29 26.43 26.57 26.72 26.86\\n28 27.00 27. 15 27.31 27.46 27.61 27.76 27.92 28.07 28.22 28.38\\n29 28.53 28.69 28.85 29.01 29.17 29.33 29.50 29.66 29.82 29.98\\n30 30.14 30.31 30.47 30.64 30.81 30.97 31.14 3 I -3 I 3 I -48 31-64\\n31 31.81 31.98 32.16 32.33 32.51 32.67 32.86 33.03 33.21 33.38\\n32 33-56 33-74 33-92 34.10 34.28 34.45 34.63 34.81 34.99 35.17\\n33 35-35 35-54 35-73 35-93 36.12 36.31 36.50 36.69 36.87 37.08\\n34 37 27\\nThe constant c varies indirectly according to the\\nbarometric pressure and the air-movement, but, for\\nhygienic purposes, it is not necessary to make correc-\\ntions because the slight difference between the results\\nobtained with the above formula, and those obtained\\nby taking into consideration the influence of baro-\\nmetric pressure, are of no vital importance.\\nProcess. Temperature at the drv-bulb thermometer\\n(0 32-5\u00c2\u00b0C.\\nTemperature at the wet-bulb thermometer\\n18. o\u00c2\u00b0 C.\\nd the difference between the two thermometers\\n14.5 c.\\nAccording to the table we find the maximum-satura-\\ntion of air at the temperature of the wet-bulb thermome-\\nter (_/*) is 15.33 grams of water in 1 cubic meter.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0041.jp2"}, "42": {"fulltext": "30 PRACTICAL HYGIENE\\nThe formula m M cd is now as follows\\n15-33 6 5 X 14-5), or\\n15-33 9-425. or\\nm 5.905, the absolute humidity of the air.\\nCalculation of the relative humidity. According to\\nthe table we find the maximum-saturation at the tem-\\nperature of the dry-bulb thermometer, 32. 5 C. 34.45\\ngrams, and the absolute humidity at 32. 5 C. 5.905\\ngrams. The difference betw r een the two, or deficiency\\nof saturation 28.545 grams. Therefore, at 32. 5 C,\\nthe air under observation is capable of taking up\\n28.545 grams per cubic meter, in addition to the\\nmoisture it already holds.\\nThe maximum-saturation is in proportion to the ab-\\nsolute humidity as 34.45 5.905 100 x.\\nTheiefore ^=17.14 per cent. the relative hu-\\nmidity of the air.\\n3. Estimation of moisture in the air by chemical\\nmethods. A quantitative estimation of the moisture\\nin the air is made by aspirating a known volume of\\nair through some absorbent material, the weight of\\nwhich has been carefully determined, and thus any\\nincrease in its weight will represent the amount of\\nmoisture, in grams, absorbed from the measured vol-\\nume of air aspirated through it. Pumice stone, sat-\\nurated with concentrated sulphuric acid, is used for\\nthis purpose. It is placed in an absorption flask\\nthrough which the air is aspirated, the volume of air\\naspirated being determined by means of a graduated\\naspirator.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0042.jp2"}, "43": {"fulltext": "METEOROLOGY 31\\n4. The hygroscope. The hygroscope is employed\\nfor the qualitative study of changes in the amount of\\nmoisture in the air. The operation of these instru-\\nments depends on the expansion and contraction of\\ncertain substances, as straw, the bristles of chaff, etc.,\\nor on changes in the color of certain salts, as cobalt,\\nnickel, or chromium salts, as the result of changes in\\nthe humidity of the atmosphere. These instruments\\nare, however, not adapted for hygienic observations.\\n5. Evaporation of moisture from the earth s sur-\\nface.\\na. Evapo7Hmete7 r The evaporation of moisture\\nfrom the earth s surface can be estimated quantita-\\ntively by means of an instrument known as an evapo-\\nrimeter. It consists of a square tin chamber the sur-\\nface area of which is 100 sq. cm,, and is about\\n4 cm. in height. It is closed at the top by means\\nof a conical wire cover of w T ide mesh. The chamber\\nis filled with distilled water to two-thirds its height,\\nits weight accurately determined, and then placed\\nwhere the observation is to be made. After twenty-\\nfour hours it is again weighed when the loss in\\nweight will represent the amount of water evaporated.\\nThe loss in weight, in grams, divided by 100, the\\nsurface area of the chamber, gives the amount of evap-\\noration for 1 cm. in height, or multiplying this amount\\nby 10 the result is expressed in millimeters.\\nExample. Grams.\\nWeight of chamber, Aug. 20, with water 650\\n21, =578\\nwater evaporated in 24 hours 72", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0043.jp2"}, "44": {"fulltext": "32 PRACTICAL HYGIENE\\nThe air must have free access to the instrument from\\nall sides, but it must be protected from direct sunlight\\nand rain. The amount of moisture evaporated is de-\\npendent upon the relative humidity of the atmosphere\\nand upon the relative, amount of moisture in the soil.\\nThe rate at which evaporation takes place is depend-\\nent upon the temperature, the higher the temperature\\nthe greater the rapidity, and the larger the amount of\\nevaporation.\\nb. Pische s atmometer. This instrument consists of a\\ngraduated glass tube, sealed at one end, which is filled\\nwith water and suspended in the air. The lower end\\nof the tube is closed by means of a piece of paper of\\ndefinite size which has a small perforation to allow the\\nwater to evaporate slowly.\\nThe water in the tube of the apparatus passes\\nthrough the fine opening in the paper as fast as evap-\\noration takes place, and air enters to take its place,\\nthus forming the index of the volume of water evap-\\norated from the paper, the amount varying with the\\nsize of the paper. The amount of evaporation is in-\\ndicated on the graduated scale of the glass tube.\\nG. PRECIPITATION OF MOISTURE\\nMoisture is precipitated either in the form of rain,\\nsnow, hail, or sleet.\\na. Rain. The amount of precipitation in the form\\nof rain is estimated by means of the rain-gauge. This\\ninstrument consists of a cylindrical tin chamber meas-\\nuring 500 sq. cm., or 1/20 sq. m. at the top, and has a\\nfunnel-shaped bottom which terminates in a short tube", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0044.jp2"}, "45": {"fulltext": "METEOROLOGY 33\\nthrough which the rain-water collected by the cham-\\nber is conducted into a vessel placed beneath it. The\\nrain is prevented from splashing over the sides of the\\nchamber by the vertical rim, about 15 mm. in height,\\nwhich projects from the upper edge of the funnel.\\nThe water collected by the apparatus in an hour, or\\nduring the observation period, is measured in the\\ngraduated cylinder and the amount calculated for a\\nmillimeter in depth, the result obtained indicating the\\namount of rainfall in millimeters.\\nExample. Quantity of water collected in 24 hours\\n2 is cc, 0.4^ mm. of rainfall.\\nD 500\\nb. Snow, hail, and sleet. The amount of snowfall\\nis also estimated by means of the rain-gauge. The\\nsnow that collects in the vessel beneath the cylinder,\\nduring the observation period, is first melted and the\\nwater formed from it is then measured and the amount\\nper millimeter calculated as in the case of rain.\\nThe amount of precipitation as hail and sleet may\\nbe estimated in the same manner as in the estimation\\nof snowfall.\\nPosition of the rain-gauge, The rain-gauge should\\nbe at least 1.5 m. above ground and placed in such a\\nposition as to escape the influence of eddying air-cur-\\nrents, and must, therefore, not be near any object. It\\nmay be placed on the middle of the roof of a building,\\nhigh enough from its surface to escape the influence\\nof eddying currents.\\n3", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0045.jp2"}, "46": {"fulltext": "34 PRACTICAL HYGIENE\\nH. WIND FORCE, RAPIDITY, AND DIRECTION OF\\nCURRENTS OF AIR\\nAs the result of changes in temperature the den-\\nsity of the air is changed and sets in motion large\\nmasses of air, that having the greatest density dis-\\nplacing that which is less dense. The direction in\\nwhich the movement takes place is always along the\\nline of least resistance and toward the point of least\\ndensity. The rapidity of the movement is directly\\nproportional to the magnitude of the change in den-\\nsity i. e. to the rise in the temperature. These move-\\nments of masses of air we call winds, and the most\\nimportant cause of winds is variations in the amount\\nof heat transmitted from the sun in different latitudes,\\nand at different altitudes on the earth s surface, and\\nthe variations in temperature arising from the daily\\nrevolutions of the earth on its axis.\\na. Qualitative Estimation of Air Movements\\ni. In closed rooms candles, smoke, air-balloons or\\ndynamic manometers may be used to determine the\\namount and direction of air movement, but a move-\\nment of less than 0.2 meter per second cannot be esti-\\nmated by these means.\\n2. Wind vane. In the open air the senses and wind\\nvanes are employed. The wind vane indicates the\\ndirection in which the air is moving. It consists of a\\nwooden or metallic pointer the exact shape of which\\nis not of vital importance, an arrow, or a representa-\\ntion of some afiimal, being the most common form in\\nuse. It is placed in a horizontal position on the end", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0046.jp2"}, "47": {"fulltext": "METEOROLOGY 35\\nof a vertical rod so that it can revolve with the great-\\nest facility. The point of suspension is not quite at\\nthe center of gravity, one end being slightly heavier,\\nand this end is also expanded somewhat on its verti-\\ncal plane so as to afford a point of contact for the\\nwind, while the lighter end is generally more compact\\nin structure so as to offer as little impediment to its\\nmovements as possible. The lighter end points in the\\ndirection from which the wind is coming. The direc-\\ntion of the air movement, i. e., from which the wind\\ncomes, is expressed in points of the compass.\\nb. Quantitative Estimation of Air Movements\\nThe designations in common use to describe\\nthe velocity of the wind denote movements rang-\\ning from calm, when no movement is perceptible,\\nto the movement of greatest velocity which is known\\nas hurricane. The designations denoting veloci-\\nties between these two extremes, as the velocity in-\\ncreases, are weak, perceptible, fresh, strong, and\\nstorm. The velocity of the air movements is usually\\nexpressed so as to indicate the distance traveled in a\\ndefinite period of time, as meter per second. Instead\\nof expressing the air movement in terms representing\\nthe distance traveled in a definite period of time, we\\nalso express it in terms of the degree of force which\\nit exerts when coming in contact with an object, as\\nkilograms per square meter. The velocity of the air\\nmovements may also be expressed so as to designate\\nthe effect produced by it upon different objects, with\\nwhich it comes in contact, as, when there is a calm\\nsmoke rising and the leaves are undisturbed, a slightly", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0047.jp2"}, "48": {"fulltext": "36\\nPRACTICAL HYGIENE\\ngreater movement causes leaves to move, and as the\\nvelocity of the current increases the effects are the\\nmovement of small branches, of larger branches, whole\\nbranches, until we have the effects of a hurricane in\\nthe unroofing of houses and the uprooting of large\\ntrees. All the different modes of expressing the amount\\nof air movement have been arranged into a scale of\\nthirteen degrees from o to 12 by Beaufort. (See\\nBeaufort s scale.)\\nBeaufort s Scale of Different Degrees of\\nAir Movement.\\nBeau- j^ Velocity Pressure\\nfort s de- in m. per in kg.\\ntion.\\ngrees. second, per sq. m.\\nEffect of the wind.\\nO\\nI\\n2\\n3\\n4\\n5\\n6\\n7\\nCalm\\nWeak\\nBreeze\\nFresh\\n8 Strong\\n9\\n10\\n11\\nStorm\\ni-5\\n3-5\\n6.0\\n8.0\\n10. o\\n12.5\\n15.0\\n18.0\\n21.5\\n25.0\\n29.0\\n33-5\\no.3\\n1-5\\n4.4\\n7.8\\n12.2\\n19.0\\n27.4\\n40.0\\n56.0\\n76.0\\n103.0\\n137.0\\n12 Hurricane 40.0 195.0\\nSmoke rises leaves\\nare undisturbed.\\nPerceptible to the\\nsenses, moves leaves\\nand sails.\\nMoves leaves and the\\nsmaller branches\\nstretches sails.\\nMoves the smaller\\nbranches of trees.\\nMoves whole branch-\\nes and weaker stems,\\nand hinders one in\\nwalking.\\nShakes whole trees,\\nbreaks branches and\\nstems, and uproots\\nsmaller trees.\\nUnroofs houses,\\nblows down chim-\\nneys, breaks and up-\\nroots trees.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0048.jp2"}, "49": {"fulltext": "METEOROLOGY 37\\nAnemometer. The determination of the rapidity\\nof the air movements is made by means of the anem-\\nometer. One form of this instrument consists of\\ntwo bars crossing at right angles to each other, the\\ndistal ends of which bear a small cup-shaped vessel,\\narranged in such a manner that each in turn presents\\nits concave face toward the wind. These bars are\\nplaced on the top of a vertical revolving shaft. The\\nrevolutions of the shaft are communicated to a set of\\npointers revolving over dials. The velocity of the\\nwind, expressed in meters per second, is registered on the\\ndials and mav be at once read off bv observing- the in-\\nstrument for a minute.\\nThe form of anemometer which is used in estima-\\nting air movements in the ventilating shafts of build-\\nings consists of a small wheel bearing a number of\\nflat blades radiating from its axis and placed at such\\nan angle that each, in turn, receives the impulse of\\nthe air current and consequently causes the wheel to\\nrevolve. The revolutions of the wheel are transmitted\\nto a set of indices, each revolving over the face of the\\ndial, and registering the velocity of the current in\\nmeters or feet.\\nDirection of the wind wind vane. The direction\\nof the air movements are denoted by points of the\\ncompass. The designations adopted by international\\nagreement are as follows\\nN.\\nfor north\\nS.\\nfor south\\nNNE.\\n1 north-northeast\\nssw.\\n1 south-southwest\\nNE.\\n1 northeast\\nsw.\\n1 southwest\\nENE.\\neast-northeast\\nwsw.\\nwest-southwest", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0049.jp2"}, "50": {"fulltext": "38 PRACTICAL HYGIENE\\nE. for east W. for west\\nESE. east-southeast WNW. west-northwest\\nSE. southeast NW. northwest\\nSSE. south-southeast NNW. north-northwest\\nI. FOG AND CLOUDS\\na. Fog. Fog results from the cooling of moist air\\nbelow the dew-point and consists of fine droplets of\\nwater.\\nb. Clouds. When the condensed moisture of the\\nair collects as fog in the lower strata and rises into\\nthe upper strata it takes the form and appearance\\nwhich we call clouds. According to the different forms\\nwhich clouds assume under different atmospheric\\nconditions they have been divided into four principal\\ntypes (a) cirrus light and feathery which rise to a\\ngreat height, 4000 to 6000 meters or more (6) cumu-\\nlus hemispherical or conical heaps like mountains\\nrising from a horizontal base\u00e2\u0080\u0094 which rise to a height\\nof 500 to 2000 meters; (c) stratus widely extended\\ncontinuous horizontal sheets, often forming at sunset\\n{d) nimbus or rain-cloud is a horizontal sheet of\\ngrayish color, and is a mixture of the first two types,\\nand rises to a height of less than 500 meters.\\nBetween the three principal types we have compo-\\nsition forms, as cirro-cumulus, cirro-stratus, and cumu-\\nlostratus.\\nEstimation of the amount of cloud. This is done\\nby a system of numbers o, indicates a cloudless sky,\\nand 10, a fully clouded sky, and the intermediate num-\\nbers indicate the various intermediate degrees of cloudi-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0050.jp2"}, "51": {"fulltext": "M KTKOROLOGY 39\\nness. In making an observation the eye is directed\\ntoward a point midway between the horizon and\\nzenith, then slowly turning round the eye is carried\\nalong that plane and the relative amount of clear and\\nclouded sky noted.\\nDesignation of Amount of Cloud Formation.\\ncloudless o\\nhalf covered 5\\nJ three-quarters covered 7\\nentirely covered 10,\\nRepresentations of results of observations. The\\nresults of meteorological observations can be presented\\nin a tabulated form or they can be presented graphic-\\nally, though the latter method may unduly magnify\\nslight variations, or, on the other hand, it may imper-\\nfectly represent the variations that exist.\\nWeather prognostication. From the observation of\\nmeteorological conditions the following principles have\\nbeen established which give a definite insight into the\\nchanges of the weather\\n1. The condition of the weather is influenced di-\\nrectly by the direction of the wind.\\n2. The direction of the wind is influenced directly\\nby the barometric pressure, which again is directly\\ninfluenced by\\na, the altitude of the location,\\nb, the specific gravity of the air, according\\nr, to the humidity of the atmosphere, and\\nd, the temperature.\\n3. The air flows from an area with high barometric", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0051.jp2"}, "52": {"fulltext": "40 PRACTICAL HYGIENE\\npressure towards such areas that have a lower baro-\\nmetric pressure, or from anticyclone toward cyclone,\\nor depression areas.\\n4. The rapidity of this movement of the atmosphere\\nis directly dependent upon the magnitude of the dif-\\nference in the barometric pressure in adjacent areas.\\n5. In consequence of the earth s movements the\\nmovement of the atmosphere is not in a vertical direc-\\ntion from the isobars, but in such a manner that the\\nobserver (in north latitude), with his back toward the\\nwind, has the anticyclone area before and to the left\\nof him, and the cyclone area back of him and to the\\nright.\\n6. The weather in the anticyclone area is settled,\\ndry, and clear; in the cyclone area it is variable, cloudy,\\nand rainy.\\n7. The areas of anticyclone change their form and\\nposition more slowly than those of cyclone, while the\\nlatter nearly always pass to the right of the former in\\ntheir movements.\\n8. Low temperature is indicative of the approach\\nof the anticyclone area and high temperature of cyclone\\nareas.\\nThe meteorological conditions of the country are\\ntelegraphed twice daily 8 a.m., and 8 p.m. to the\\nseat of government where they are tabulated and rep-\\nresented graphically upon a map of the entire country.\\nLocalities that have the same barometric pressure are\\nconnected by means of lines isobars in like manner\\nthe localities having the same temperatures these\\nlines are termed isotherms.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0052.jp2"}, "53": {"fulltext": "ANALYSIS OF AIR 4 1\\nJ. IMPURITIES IN THE AIR\\nThe impurities in the air are both gaseous and solid.\\na. Gaseous impurities. The more important gase-\\nous impurities in air that are of interest to the hygi-\\nenist are carbon monoxid, carbon dioxid, hydrogen\\nsulphid, marsh-gas, and gaseous organic substances\\nand ammoniacal compounds. The air of manufactur-\\ning establishments may contain other gaseous impuri-\\nties.\\nb. Solid impurities. The solid impurities in air\\nare living organisms, such as bacteria, etc., and va-\\nrious forms of dust. The solid impurities in the air\\nwhich we recognize as dust particles consist of various\\nforms of debris arising from the disintegration of por-\\ntions of animal and vegetable life, and minute parti-\\ncles of mineral matter.\\nCHAPTER II. CHEMICAL ANALYSIS OF AIR\\nThe normal and abnormal constituents of atmos-\\npheric air which are of hygienic interest and for the\\npresence of which it is necessary to make air analyses\\nare the relative proportion of oxygen, carbon dioxid,\\naqueous vapor, and the determination of the presence\\nof hydrogen sulphid, marsh gas, carbon monoxid, and\\norganic matter. Under special conditions, as in the\\nair of manufacturing establishments, air analyses must\\nalso be made to determine the presence of poisonous\\nmetals and their compounds, as phosphorus, zinc,\\narsenic, mercury, sulphur dioxid, nitrous, hydrochlo-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0053.jp2"}, "54": {"fulltext": "42 PRACTICAL HYGIENE\\nric, and sulphurous acids, chlorin, and of carbon di-\\nsulphid.\\nA. OXYGEN\\nThough the relative proportion of oxygen in the air\\nvaries within very narrow limits under ordinary con-\\nditions, it is, however, at times desirable to make\\nquantitative estimations of the amount of oxygen in\\nthe air of confined spaces.\\nProcess. A ready method for the estimation of the\\noxygen in the air is by means of the Bunte gas-burette.\\nThis consists of a large graduated burette of over 160 cc.\\ncapacity, closed at each end by means of a glass stop-\\ncock, the upper portion being expanded into a bulb. The\\nupper end of the burette is closed by means of a three-\\nw T ay stop-cock through which communication can be made\\neither with the small cup-shaped reservoir at the top\\nand the interior of the burette, or with the outside air.\\nIn order to prevent rapid changes in the temperature of\\nthe sample of air under analysis the body of the burette,\\nbetween the upper and lower stop-cocks, is surrounded\\nby a glass tube of larger calibre than the burette, the\\nends of which are hermetically sealed to the outside\\nof the burette and the intervening space is filled with\\nwater, forming a water-jacket for the body of the burette.\\nThe capacity of the burette is shown on a scale engraved\\non the stem of the tube, the zero-point being some dis-\\ntance above the lower stop-cock. From the zero-point\\nthe scale extends downward for 10 cc. nearly to the lower\\nend of the tube, and upward for ioo cc, which is just\\nbelow the expanded portion. From the ioo cc. mark to\\nthe upper stop-cock the capacity is 50 cc. The cup-\\nshaped reservoir at the top of the burette serves to hold\\nthe solutions of the reagents used in the analysis and is\\ngraduated at 20 cc. and at 25 cc.\\nBefore collecting a sample of air for analysis the burette\\nis filled with distilled water, and the reservoir at the top\\nto the 20 cc. mark. The large three-way stop-cock at", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0054.jp2"}, "55": {"fulltext": "ANALYSIS OF AIR 43\\nthe top is now turned so as to establish communication\\nwith the interior of the burette and the outside air, when,\\non opening the lower stop-cock, the water in the burette\\nflows out and the air enters through the stem of the three-\\nway stop-cock. As soon as about 150 cc. of the water\\nhave escaped the lower stop-cock is closed, and then the\\nupper stop-cock is turned so as to establish communica-\\ntion between the reservoir and the interior of the burette.\\nWith 20 cc. of water in the reservoir the volume of air in\\nthe burette will adapt itself to the pressure which it ex-\\nerts by either allowing some of the water to pass into the\\nburette if it is under less pressure, or by forcing some of\\nthe air out of the burette if it is under greater pressure.\\nAs soon as the sample of air in the burette has been\\nplaced under the pressure of the 20 cc. of water in the\\nreservoir, the three-way stop-cock is turned so as to shut\\noff all communication with the outside and the burette is\\nset aside for several minutes to allow all the water to set-\\ntle to the bottom of the tube. The volume of the sample\\nof air taken is then read off on the scale.\\nA portion of the water remaining in the burette is now\\nwithdrawn, by cautiously opening the lower stop-cock,\\nthus lessening the density of the air in the burette. A\\nlarger portion of water can be removed by connecting the\\nlower end of the burette with a filter-pump. The w T ater\\nin the reservoir is poured out and about 10 cc. of a 25\\nper cent, solution of potassium hydroxid is poured into\\nthe cup the three-way stop-cock is carefully turned so\\nas to allow the reagent to flow into the burette. To fa-\\ncilitate the action of the reagent the burette is turned up-\\nside down several times during five minutes. The potas-\\nsium hydroxid solution combines with the carbon di-\\noxid in the air and it also renders the water in the burette\\nstrongly alkaline. After the air has again been brought\\nunder the pressure of 20 cc. of water in the reservoir, and\\nthe burette has been set aside for two or three minutes,\\nanother reading is made, the decrease in the volume of\\nthe sample of air indicating the amount of carbon dioxid\\ncontained in it.\\nThe density of the air in the burette is now again de-\\ncreased by removing some of the liquid through the lower", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0055.jp2"}, "56": {"fulltext": "44 PRACTICAL HYGIENK\\nstop-cock. The .water in the reservoir is poured out and\\n10 cc. of a 25 per cent, solution of pyrogallic acid, in\\nwater, is poured into the cup and, turning the three-way\\nstop-cock, it is allowed to pass into the burette. In\\nstrongly alkaline solutions this reagent combines with\\nthe oxygen very readily. By turning the burette upside\\ndown several times during five minutes the reagent is\\nbrought in contact w r ith every portion of the air. The\\npressure within the burette is now again brought to the\\nstandard adopted for the other readings that of 20 cc.\\nof water in the reservoir and the volume of the sample\\nof air noted. The decrease in the volume as shown by\\nthe second and third readings of the burette indicates the\\namount of oxygen in the sample of air. The results in\\nair analyses are usually expressed in per cent. less fre-\\nquently in parts per 1000 or 10,000 parts of air. The\\nportion of the sample of air remaining in the burette after\\nthe absorption of the carbon dioxid and oxygen may\\nusually be considered as nitrogen.\\nExample.\\ncc.\\nVolume of the sample of. air taken for analysis 148.7\\nSecond reading 148.6\\nDifference carbon dioxid o. 1\\n148.7 o. 1 100 x 0.06 per cent, carbon dioxid.\\ncc.\\nSecond reading 148.6\\nThird =119.2\\nDifference oxygen 29.5\\n148.7 29.5 100 x 19.83 per cent, oxygen.\\ncc.\\nFirst reading =148.7\\nVolume of carbon dioxid and oxygen 29.6\\nDifference nitrogen 1 19. 1\\n148.7 1 19. 1 100 x 80.09 P er cent, nitrogen.\\nB. CARBON DIOXID\\n1. Qualitative Estimation\\nFrom the fact that carbon dioxid is always present", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0056.jp2"}, "57": {"fulltext": "ANALYSIS OF AIR 45\\nin the air, qualitative determinations have no scientific\\nvalue.\\n2. Quantitative Estimation\\nThe most reliable methods for the quantitative es-\\ntimation of carbon dioxid in air are the two introduced\\nby Prof, von Pettenkofer.\\nThe Pettenkofer flask method. This method is\\nbased upon the reaction of carbon dioxid with a solu-\\ntion of barium, strontium, or calcium hydroxid in\\nwater, producing an insoluble carbonate of the base.\\nThe reduction in the alkalinity of the hydroxid solu-\\ntion indicates the amount of carbonate that has been\\nformed, and is determined through titration against\\nan acid solution, usually a solution of oxalic acid since\\nthis reacts upon the hydroxid solution in a similar\\nmanner as the carbon dioxid the formation of an in-\\nsoluble salt of the base. The barium hydroxid solu-\\ntion is now generally employed in the estimation of\\ncarbon dioxid in air. The solution of oxalic acid em-\\nployed is made of a definite strength i cc. oxalic\\nacid 0.25 cc. carbon dioxid.\\nOxalic acid solution. One molecule oxalic acid\\none molecule carbon dioxid, hence\\n1 molecule carbon dioxid 44 parts by weight.\\n1 oxalic acid 126 parts by weight.\\n1 mg. carbon dioxid 0.5084 cc. carbon dioxid (at\\no\u00c2\u00b0 C. and 760 mm.).\\n44 mg. carbon dioxid 22.3696 cc. carbon dioxid.\\nTherefore 126 mg. C.,H 4 4 2H 2 22.3696 cc. carbon\\ndioxid.\\nSince 1 cc. of the oxalic acid solution 0.25 cc. of\\ncarbon dioxid, the equation", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0057.jp2"}, "58": {"fulltext": "46 PRACTICAL HYGIENE\\n22.3696 126 0.25 x 1405 nig. oxalicacid,\\nshows that 1.405 grams oxalic acid must be dissolved\\nin a liter of distilled water. It is necessary to meas-\\nure the water accurately and therefore the solution\\nmust be made up in a graduated flask of a liter capac-\\nity. This solution must be protected from light in\\ndark, glass-stoppered bottles.\\nBarium hydroxid solution. This solution is pre-\\npared of such strength that 25 cc. of it are about equal to\\n25 cc. of the oxalic acid solution. For this purpose\\n3.5 grams of pure, alkali-free barium hydroxid are dis-\\nsolved in 1 liter of distilled water. In case the hy-\\ndroxid should not be entirely alkali-free it is best to\\nadd 0.2 gram barium chlorid to each liter of the solu-\\ntion. In order to protect the barium hydroxid solu-\\ntion from the carbon dioxid of the air, the solution is\\npreserved in a flask having two glass tubes passing\\nthrough the cork stopper. One of the glass tubes\\nreaches almost to the bottom of the flask and is bent\\nover above the stopper and passes down along the\\noutside of the flask nearly to the bottom when it\\nagain bends upward. The mouth of this tube is closed\\nwith a short piece of rubber tubing closed by means\\nof a pinch-cock. The second glass tube is cut off just\\nbelow the inner edge of the cork, and outside of the\\nflask it is twice bent at right angles and extends down\\nto the neck of the flask where it passes through the\\ncork stopper of a small wide-mouthed bottle contain-\\ning pumice stone saturated with strong potassium or\\nsodium hydroxid solution. The cork stopper of the\\nsmall wide-mouthed bottle carries another glass tube", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0058.jp2"}, "59": {"fulltext": "ANALYSIS OF AIR 47\\nwhich reaches nearly to the bottom of the bottle, while\\nthe portion outside the bottle is about 20 cm. in length,\\nand is bent at right angles above the cork. The mouth\\nof this tube is also closed with a short piece of rubber\\ntubing closed with a pinch-cock. This arrangement\\nallows the barium hydroxid solution to be withdrawn\\nfrom the store bottle by inserting the point of a\\npipette into the end of the rubber tubing attached to\\nthe glass tube that reaches nearly to the bottom of the\\nflask, while the air that enters to take its place, passes\\nthrough the wide-mouthed bottle containing the pum-\\nice stone, and then through the second tube in the\\ncork stopper of the store bottle into the flask. In\\npassing through the small wide-mouthed bottle the\\nair is freed of carbon dioxid by the solution of caustic\\nwith which the pumice stone is saturated, thus pre-\\nserving the alkalinity of the barium hydroxid solu-\\ntion.\\nIndicators. For the purpose of sharply defining\\nthe point of neutralization of the barium hydroxid so-\\nlution in titrating it with the oxalic acid solution we\\nemploy a solution of some substance which undergoes\\na change in color when its reaction is altered.\\na. Rosalie acid solution. A solution of rosolic acid\\nis commonly employed for this purpose. It gives a\\ndelicate rose tint to the alkaline solution of barium\\nhydroxid which gradually fades as the point of neu-\\ntralization approaches and is completely decolorized\\nby a drop of the acid solution in excess.\\nThe rosolic acid solution is made by dissolving 1\\ngram in 500 cc. of 80 per cent, alcohol. This solu-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0059.jp2"}, "60": {"fulltext": "48 PRACTICAL HYGIENE\\ntion is slightly acid in reaction, yellow in color, and\\nis neutralized by the addition of barium hydroxid so-\\nlution until its color changes to red.\\nb. Phenolphthalein solution. Another indicator\\nthat is also frequently used is an alcoholic solution (i\\nto 30) of phenolphthalein. In acid solution this indi-\\ncator is colorless, but the least trace of alkali changes\\nit to a deep violet color.\\nApparatus required.\\na. Four-liter flask. The samples of air are col-\\nlected in a flask of about four liters capacity that has\\nbeen accurately tared. This is done by thoroughly\\ncleansing it and, when dry, weighing it empty. It\\nis then filled with distilled water at 15 C. so that\\nthe water stands level with the mouth of the flask\\nwhen it is again weighed, the increase in weight, in\\ngrams, indicating its capacity in cubic centimeters.\\nExample.\\nGrams.\\nWeight of flask with water =5250\\nempty 1250\\nCapacity 4000\\nor 4000 cc. 4 liters.\\nThe mouth of the flask is closed with a closely-fitting\\nrubber cap.\\nb. Hand bellows. A hand bellows with a long rub-\\nber tube attached to its nozzle is used to force the air\\nto be examined into the flask, thus replacing that con-\\ntained in the flask, for which about 100 strokes of the\\nbellows are necessary.\\nc. Thermometer. A mercurial thermometer, regis-\\ntering tenths of a degree centigrade, is required to ob-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0060.jp2"}, "61": {"fulltext": "ANALYSIS OF AIR 49\\nserve the temperature of the air at the place where the\\nsample is collected.\\nd. Barometer. It is necessary to observe the baro-\\nmetric pressure at the time the sample is collected.\\nThe barometer may be at a convenient place in the\\nlaboratory and need not be taken to the place where\\nthe sample of air is collected.\\ne. Pipettes. A ioo cc, and a 25 cc, pipette are re-\\nquired, the former to measure the barium hydroxid\\nsolution used to precipitate the carbon dioxid in the\\nair, and the latter to measure the barium solution in\\nmaking the titrations.\\nf. Burette. A Mohr s burette with glass stop-cock,\\ngraduated in tenths of a cubic centimeter, is employed\\nto hold the oxalic acid solution.\\ng. Florence flasks. Several Florence flasks of 100\\ncc. capacity are required to hold the barium hydroxid\\nsolution for the titrations.\\nh. Glass-stoppered bottles. Several small glass-stop-\\npered bottles, of 125 cc. capacity, are needed in which\\nthe barium solution is preserved, after it has been ex-\\nposed to the sample of air, to allow the precipitated\\nbarium carbonate to subside.\\nCollection of the sample of air. The four-liter flask\\nis carefully dried and taken to the place where the\\nsample of air is to be collected and allowed to remain\\nabout fifteen minutes if the temperature differs con-\\nsiderably from that of the laboratory. The thermom-\\neter should be placed near the flask at the same time.\\nThe rubber tube attached to the nozzle of the bellows\\n4", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0061.jp2"}, "62": {"fulltext": "50 PRACTICAL HYGIENE\\nis now placed into the mouth of the flask, extending\\nalmost to the bottom. Care must be taken to prevent\\nthe entrance of expired air, and, in collecting samples\\nout of doors, it is best to place the bottle to windward,\\nholding the bellows as far as convenient from the\\nbody, and with the open side of the bellows turned\\ntoward the wind. About ioo strokes of the bellows\\nare sufficient to completely change the air in the flask.\\nThe mouth of the flask is then closed with a rubber\\ncap and the temperature of the air, as recorded by the\\nthermometer, is noted.\\nThe flask containing the sample of air is now\\nbrought into the laboratory and ioo cc. of the barium\\nhydroxid solution is at once placed in the flask by\\ncarefully lifting the edge of the rubber cap sufficiently\\nto permit the introduction of the ioo cc. pipette into\\nthe flask as far as the bulb, then carefully replacing\\nthe rubber cap. When there is much difference be-\\ntween the temperature of the sample of air and that of\\nthe laboratory, it is preferable to introduce the barium\\nsolution into the flask before it is removed from the\\nplace where the sample has been collected, in order to\\navoid the loss of a part of the air, or the entrance of\\nlaboratory air, while introducing the barium solution,\\nbecause some alteration takes place in the density of\\nthe air in the flask as the result of the higher or lower\\ntemperature in the laboratory.\\nThe barometer should now be read and the temper-\\nature indicated by the thermometer attached to the\\nbarometer must also be noted. The barium solution\\nin the flask should be agitated from time to time by", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0062.jp2"}, "63": {"fulltext": "ANALYSIS OF AIR 5 1\\nrolling the flask on the table, or rotating it with the\\nhands, care being taken to avoid the splashing of the\\nsolution against the rubber cap. After half an hour\\nthe barium solution is transferred to a 125 cc. glass-\\nstoppered bottle and set aside for the precipitate to\\nsubside.\\nTitrations of the solutions. While the barium so-\\nlution is being agitated with the air in the flask, the\\nalkalinity of this reagent should be determined. By\\nmeans of a pipette 25 cc. of the barium solution are\\ntaken from the store bottle and placed in a 100 cc.\\nFlorence flask and several drops of the indicator solu-\\ntion added to it. The Mohr s burette having been\\nfilled with the oxalic acid solution, the acid solution\\nis slowly added to the barium solution until the indi-\\ncator, by its changed color, shows that the point of\\nneutralization has been reached. The burette is then\\nread and denotes the number of cubic centimeters of\\noxalic acid solution that are required to neutralize 25\\ncc. of the barium solution.\\nReading the burette. It is necessary to deduct 0.1\\ncc. from the reading of the burette because it required\\nthe further addition of 0.1 cc. of oxalic acid solution\\nto change the color of the indicator, after all the ba-\\nrium had been neutralized, the greater affinity of the\\nbarium for the acid preventing the reaction on the in-\\ndicator until all the barium had first been acted upon.\\nThe alkalinity of the barium solution must be de-\\ntermined each day when a sample of air is collected,\\nand the results obtained are then used subsequently", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0063.jp2"}, "64": {"fulltext": "52 PRACTICAL HYGIENE\\nfor comparison with those obtained for the alkalinity\\nof the barium solution that has been exposed to the\\nsample of air collected at the same time. Unless the\\nalkalinity of the barium solution is determined for\\neach analysis the results may be unreliable on account\\nof its great liability to undergo change.\\nAfter standing for three or four hours the precipi-\\ntated barium carbonate has subsided leaving a clear\\nsupernatant liquid. To determine the reduction in the\\nalkalinity of the barium solution through the action\\nof the carbon dioxid in the air, 25 cc. of the clear su-\\npernatant liquid are carefully removed with a pipette\\nand transferred to a Florence flask of 100 cc. capacity\\nand several drops of the indicator added to it. It is\\nthen titrated with the oxalic acid solution as before,\\nwhen the difference between the amount of oxalic acid\\nsolution now required and that for the fresh barium\\nsolution at the time the sample was collected, will\\nrepresent the reduction in the alkalinity, in one-fourth\\nof the barium solution employed in the analysis. From\\nthis result can be calculated the proportion of carbon\\ndioxid in the air. It is best to make duplicate, or\\ntriplicate titrations, and then take the mean of the\\nresults obtained.\\nExample. At the time the sample of air was collected\\n25 cc. barium hydroxid 24.8 cc. oxalic acid solution:\\nnow, 25 cc. barium hydroxid 23.6 cc. oxalic acid solu-\\ntion therefore in each 25 cc. barium hydroxid solution\\nthe equivalent of 1.2 cc. oxalic acid solution have been\\nprecipitated by the carbon dioxid in the air, or the total\\namount of carbon dioxid in the sample is equivalent to\\n4 X 1.2=4.8 cc. of oxalic acid solution. Since 1 cc.\\noxalic acid solution =0.25 cc. carbon dioxid, we have", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0064.jp2"}, "65": {"fulltext": "ANALYSIS OF AIR 53\\n4.8 X 0.25 1.2 cc. of carbon dioxid in the sample of\\nair.\\nCalculation of the results.\\na. Correction for barometric pressure. The baro-\\nmetric reading is reduced to o\u00c2\u00b0 C. according to the\\nformula: b n\\n1 a. t\\nExample. The barometer at the time the sample of\\nair was collected stood at 764.7 mm., the thermometer\\nattached registering 21.3 C.\\nTherefore b n 761.77 mm.\\n1 -h 0.00018 X 21.3\\nb. Reduction of the air volume to nor mal conditions.\\nAt o\u00c2\u00b0 C, and 760 mm., according to the formula\\nV\\n760 XU+a.t)\\nExample. The capacity of the flask employed, the\\nair volume, is 3814 cc, and the temperature of the air\\nat the place where the sample was collected was 14. 6\u00c2\u00b0 C.\\nThe air volume is, therefore, 3814 100 Ba(OH) 2\\n37 14 cc\\nTherefore\\nthe air volume at o\u00c2\u00b0 C, and at 760 mm.\\nc. Calculation of- per cent, of carbon dioxid found.\\nThe amount of carbon dioxid found is 1.2 cc.\\nTherefore 3628.96 1.2 100 0.03306 per\\ncent, or 3.306 parts of carbon dioxid in 10,000 parts\\nof air.\\nPettenkofer s tube method. Another method for\\nthe estimation of carbon dioxid in the air is that known", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0065.jp2"}, "66": {"fulltext": "54 PRACTICAL HYGIENE\\nas Pettenkofer s tube method. In this method spe-\\ncially devised absorption tubes are employed.\\nInto each of these absorption tubes is placed ioo cc.\\nof barium solution and a measured quantity of air as-\\npirated through them. The quantity of air flowing\\nfrom the aspirator represents the volume of air aspi-\\nrated. A thermometer is placed adjacent to the tubes\\nto register the temperature of the air. This ther-\\nmometer should be read at the beginning and at the\\nend of the aspiration of air, and the mean of the two\\nobservations taken as the temperature of the air vol-\\nume aspirated. The barometer must also be read dur-\\ning the time that aspiration is going on.\\nC. AQUEOUS VAPOR\\nThe method for the quantitative estimation of mois-\\nture in air has already been considered.\\nD. HYDROGEN SULPHID\\nHydrogen sulphid is detected by its characteristic\\nodor and by its action (blackening) on paper moistened\\nwith solution of lead acetate, forming black sulphid\\nof lead.\\nFor its quantitative estimation a known volume of\\nair is aspirated through a titrated solution of iodin,\\nthe hydrogen sulphid being reduced as follows\\nH 2 S 2! 2HI -f- S. The uncombined iodin re-\\nmaining in solution is then estimated through titra-\\ntion with a standard (;//io) solution of sodium thio-\\nsulphate, using starch paper as an indicator, the iodin", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0066.jp2"}, "67": {"fulltext": "ANALYSIS OF AIR 55\\ncoloring the starch papei a deep blue color. The re-\\naction which takes place is as follows\\n2Na S 2l 2NaI NaS 6\\n2 2 3 24O\\nIodin solution. A i/io normal iodin solution, con-\\ntaining 12.685 grams of pure iodin, dissolved in i\\nliter of distilled water with the aid of 18 grams of pure\\npotassium iodide, i cc. of this solution 1.7 mil-\\nligrams hydrogen sulphid.\\n2. Sodium thiosulphate solution. A 1/10 normal solu-\\ntion of sodium thiosulphate (Na 2 S 2 is made by dis-\\nsolving 24.808 grams of pure, crystalline sodium thio-\\nsulphate in 1 liter of distilled water. 1 cc. of this\\nsolution 1-7 milligrams hydrogen sulphid.\\nBoth of these solutions must be protected from the\\nair in glass-stoppered bottles.\\nj. Starch paste. Freshly boiled starch paste is\\nmade by boiling 1 gram of potato starch in 100 cc. of\\nwater.\\nProcess. The air is aspirated through 100 cc. of the\\nnormal iodin solution contained in an absorption flask,\\nor a Pettenkofer absorption tube. After several hundred\\nliters of air have been slowly aspirated through the iodin\\nsolution it is transferred to a small glass-stoppered bottle,\\nthen 25 cc. of it are placed in a 100 cc. Florence flask\\nwith 1 cc. of the starch paste. The normal sodium thio-\\nsulphate solution is then added from a burette until the\\niodin solution becomes colorless. The difference be-\\ntween the amount of sodium thiosulphate solution re-\\nquired to decolorize 25 cc. of the iodin solution, before\\nand after its exposure to the air, indicates the amount of\\nhydrogen sulphid in the air. The results are expressed\\nso as to show the number of milligrams of hydrogen sul-\\nphid in 1 cubic meter of air.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0067.jp2"}, "68": {"fulltext": "56 PRACTICAL HYGIENE\\nE. CARBON MONOXID\\na. Qualitative tests. The spectroscope is usually\\nemployed to determine the presence of carbon monoxid\\nin air. For this purpose 10 cc. of fresh blood are di-\\nluted with 40 cc. of distilled water and poured into a\\nflask of 6 to 10 liters capacity. The flask is then\\nfilled with the air under examination by means of a\\nhand bellows and closed with a rubber cap. The di-\\nluted blood is agitated with the air for fifteen to twenty\\nminutes so as to bring it in contact with all the carbon\\nmonoxid in the air. The carbon monoxid displaces\\nthe oxygen in the oxy-haemoglobin of the blood and\\nforms CO-haemoglobin.\\nTen drops of this blood, as well as a like quantity\\nof normal blood, are each diluted to about 20 cc. and\\ncompared by means of the spectroscope. Oxy-haemo-\\nglobin, or normal blood, shows in the yellow and\\ngreen lines of the normal spectrum (Fraunhof s lines\\nD and E [b] two absorption bands with well-defined\\nmargins. CO-haemoglobin also shows these bands,\\nbut closer together, and with indistinct margins.\\nFor absolute differentiation the action of some re-\\nducing agent on both specimens of blood is to be noted;\\nfor instance, the influence of ammonium sulphid. The\\noxy-haemoglobin is reduced while the CO-haemoglobin\\nremains unchanged. This differentiation is readily\\nmade with the spectroscope. One or two drops of\\nammonium sulphid are added to the diluted blood\\nthis is then gently agitated and again examined spec-\\ntroscopically. The reduced oxy-haemoglobin now\\nshows an indistinct band lying about midway between", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0068.jp2"}, "69": {"fulltext": "ANALYSIS OF AIR 57\\nthe two haemoglobin bands, while the CO-haemoglo-\\nbin shows very little change.\\nb. Chemical tests. In order to detect carbon mon-\\noxid in the air by chemical means, the CO-haemo-\\nglobin that is formed when the diluted blood is agi-\\ntated with the air, is coagulated by heat, and the car-\\nbon monoxid that is given off is conducted into a i to\\n500 solution of palladium chlorid. The diluted blood\\nis passed into a flask closed with a doubly perforated\\ncork through which fresh air is aspirated. The air is\\nfirst conducted through an absorption flask containing\\npalladium chlorid in order to free it of carbon mon-\\noxid or any other bodies capable of reducing palla-\\ndium chlorid. It is then conducted through the flask\\ncontaining the CO-haemoglobin which has been placed\\non a boiling water-bath. The air takes up the carbon\\nmonoxid, as it is liberated from the haemoglobin, and\\nthen passes through the absorption flask containing\\nsulphuric acid where it is freed from moisture. It is\\nthen conducted through another absorption flask con-\\ntaining a solution of lead acetate where the ammonia\\nand hydrogen sulphid are taken up, as these would\\nvitiate the reaction. Finally the air passes into the\\nabsorption flask containing the palladium chlorid so-\\nlution where the carbon monoxid is absorbed. The\\nwarming of the blood on the water-bath, and the aspi-\\nration of air must be continued for at least half an\\nhour. The carbon monoxid precipitates the palladium\\nchlorid as black metallic palladium.\\nWhile the spectroscopic method shows the presence", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0069.jp2"}, "70": {"fulltext": "58 PRACTICAL HYGIENE\\nof 2.5 per cent, of carbon monoxid in the air the chem-\\nical method shows 0.2 per cent.\\nF. ORGANIC MATTER\\na. Nitrogenous organic matter (Remsen s method\\nFree and albuminoid ammonia). The method for\\nthe determination of organic matter in the air that is\\nopen to least objection is that devised by Prof. Rem-\\nsen. It consists in aspirating a measured volume of\\nair through a small glass absorption tube containing\\nfreshly-ignited, granular pumice stone which has been\\nmoistened with pure distilled water. After several\\nhundred liters of air have been aspirated through the\\ntube the pumice stone is transferred to a clean, glass-\\nstoppered retort, 500 cc. of water that is practically\\nfree from ammonia is added, and then the free and\\nalbuminoid ammonia is determined by the Wanklyn\\nand Chapman method.\\nb. Oxidizable organic matter. The organic matter\\nin air may also be estimated as oxidizable matter by\\nboiling the pumice stone, used in the Remsen absorp-\\ntion tube, with a weak, acid solution of potassium per-\\nmanganate and titrating with solution of oxalic acid\\nas for oxidizable matter in water.\\nG. ESTIMATION OF DUST IN AIR\\n1. By weight. The amount of organic matter in\\nair in the form of dust particles may be estimated by\\naspirating a measured volume of air through an ab-\\nsorption tube containing freshly-ignited asbestos. The\\nincrease in weight of the absorption tube will repre-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0070.jp2"}, "71": {"fulltext": "ANALYSIS OF AIR 59\\nsent the weight of the dust particles collected from the\\nknown volume of air aspirated. The relative propor-\\ntion of organic and inorganic matter in the dust may\\nbe determined by carefully transferring the asbestos to\\na weighed platinum crucible and incinerating the or-\\nganic matter contained in the dust. The loss in weight\\nwill represent the organic matter in the dust while the\\ndifference between the first and second weighing will\\nrepresent the inorganic matter.\\n2. The number of dust particles (Aitken s dust\\ncounter). The number of dust particles in a definite\\nvolume of air may be estimated by means of Aitken s\\ndust counter. This instrument consists of a small\\nmetallic chamber with glass top and bottom. A small\\nlens is placed over the glass top of the chamber while\\nthe glass forming the bottom of the chamber is divided\\ninto squares of i/io millimeter each. The inner walls\\nof the chamber are lined with bibulous paper which\\nis moistened before making an analysis. To the side\\nof the chamber is attached a small vacuum pump by\\nmeans of which the air in the chamber can be rarefied,\\nwhen, on turning a small, three-way stop-cock at the\\ntop of the pump, the outside air rushes into the cham-\\nber. The stop-cock is then turned so as to close the\\nchamber and connect it with the pump. When the\\npiston of the pump is now rapidly lowered and raised\\nat short intervals, the tension of the air in the cham-\\nber is alternately increased and diminished, thus\\ncausing the moisture in the paper to vaporize and con-\\ndense on the dust particles in the air. On looking\\nthrough the small lens at the top of the chamber the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0071.jp2"}, "72": {"fulltext": "60 PRACTICAL HYGIENE\\ndust particles are seen to fall within the chamber as\\nminute droplets of water and rest on the ruled glass\\nat the bottom. The total number of droplets falling\\non one of the squares, after the air in the chamber has\\nbeen rarefied eight or nine times, with the proportion\\nof impure and pure air in the chamber, afford the data\\nfrom which the number of dust particles in the air\\nmay be estimated.\\nH. SULPHUROUS ACID\\na. Qualitative test. The presence of sulphurous\\nacid in air may be detected by its peculiar penetrating\\nodor.\\nb. Quantitative estimation.\u00e2\u0080\u0094 For the quantitative\\nestimation of this gas the air is aspirated through i/io\\nnormal iodin solution whereby it is oxidized to sul-\\nphuric acid\\n2l SO 2H O 2HI H SO\\n1 2 i 2 24\\nThe i/io normal iodin solution is titrated with 1/10\\nnormal sodium thiosulphate solution as in the estima-\\ntion of hydrogen sulphid. 1 cc. 1/10 normal sodium\\nthiosulphate solution 3.2 milligrams of sulphurous\\nacid.\\nI. HYDROCHLORIC ACID\\na. Qualitative test. The fumes or vapor of hydro-\\nchloric acid in air are detected by their reaction upon\\nsilver nitrate in solution, producing a white precipi-\\ntate of silver chlorid.\\nb. Quantitative estimation. In the quantitative\\nestimation of hydrochloric acid the air is drawn through", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0072.jp2"}, "73": {"fulltext": "ANALYSIS OF AIR 6 1\\na i/io normal solution of sodium hydroxid which is\\nthen titrated with i/io normal sulphuric acid. The\\ndecrease in the alkalinity of the soda solution repre-\\nsents the quantity of hydrochloric acid in the known\\nvolume of air aspirated.\\nJ. CHLORIN\\nIn the quantitative estimation of chlorin, known\\nvolumes of air are conducted through a solution of\\npotassium iodid (i gram in 20 cc. of water) whereby\\nthe iodin is liberated KI CI I KC1. The\\namount of iodin that has been liberated is then deter-\\nmined by titration with 1/10 normal solution of sodium\\nthiosulphate 1 cc. 3.55 milligrams chlorin.\\nK. AMMONIA\\na. Qualitative test. Ammonia, when present in\\nthe air, in considerable quantities, can be detected by\\nits characteristic odor. When present in smaller quan-\\ntities it may be detected by means of a strip of litmus,\\nhaemotoxylon, or curcuma paper placed between two\\nglass plates, in such a manner that one-half of it pro-\\njects from the margin of the plates and is the only\\nportion acted upon by the ammonia in the air. The\\npresence of ammonia is showm by the changed color\\nof the portion of the paper exposed to the air, the ex-\\ntent to which the color is changed indicating the rela-\\ntive amount of ammonia present.\\nb. Quantitative estimation.\\nGravimetric method. For the quantitative esti-\\nmation of ammonia large volumes of air are aspirated", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0073.jp2"}, "74": {"fulltext": "62 PRACTICAL HYGIENE\\nthrough dilute hydrochloric acid with which it unites\\nto form ammonium chlorid. This salt is then pre-\\ncipitated with platinic chlorid and the resulting dou-\\nble chlorid of ammonium and platinum is collected on\\na filter, dried, and weighed.\\n2, Volumetric method. By this method large quan-\\ntities of air are aspirated through pure water acidu-\\nlated with sulphuric acid which retains all the ammo-\\nnia. The quantity of ammonia retained is then de-\\ntermined by means of Nessler s reagent.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0074.jp2"}, "75": {"fulltext": "PART II\\nWATER\\nCHAPTER I. THE NATURE AND COMPOSITION OF WATER\\na. Physical properties. Pure water is a colorless,\\ntasteless, and odorless liquid of neutral reaction. At\\n760 mm. barometric pressure, and at the temperature\\nof its greatest density (4 C), its specific gravity is\\ntaken as 1000, one liter weighing one kilogram. At\\no\u00c2\u00b0 C. it changes into ice, and at ioo\u00c2\u00b0 C. it is converted\\ninto steam. Its density decreases as the temperature\\nrises above 4 C, and also as the temperature falls\\nbelow that point. At o\u00c2\u00b0 C, in the form of ice, it has\\na specific gravity of 0.91674.\\nb. Chemical composition. Pure water (H 2 0) con-\\nsists of 2 parts by weight of hydrogen and 16 parts by\\nweight of oxygen, having a molecular weight of 18.\\nTwo volumes of hydrogen are combined with one vol-\\nume of oxygen and form two volumes of water-gas,\\n1 8\\nhaving a density of =9- The percentage compo-\\nsition of water, by weight, is p e r cent.\\nHydrogen, n.il\\nOxygen, 88.89\\n100.00\\nWater, as it is found in nature, is not chemically", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0075.jp2"}, "76": {"fulltext": "64 PRACTICAL HYGIENE\\npure, but contains various substances in solution and\\nsuspension which it derives from the air and soil.\\nMany of these substances are present in variable quan-\\ntities in nearly all waters and are therefore not looked\\nupon as impurities, from a hygienic point of view.\\nThe substances which fall under this class are the\\ngases of the atmosphere oxygen, nitrogen, and car-\\nbon dioxid which all waters hold in solution the\\nsalts of different metals and the alkaline earths, vary\\nin their nature with the character and composition of\\nthe soil of the locality principally chlorid, sulphate,\\nnitrate, carbonate, and silicate of sodium, potassium,\\ncalcium, and magnesium.\\nOn the other hand, those substances in water which\\nare called impurities from their detrimental influence\\non health, do not originate from the natural constitu-\\nents of the soil but arise from the refuse matter around\\nhuman habitations, lying within, or on the surface of\\nthe soil traversed by the water. The most important\\nof the impurities in water is organic matter, in the\\nform of living and dead vegetable and animal organ-\\nisms, and their products. As the result of the chem-\\nical and vital processes of nature s laboratory, the or-\\nganic matter in water is constantly being destroyed,\\nthe resulting products being ammonia, nitrous and\\nnitric acids, chlorids, carbonates, etc.\\nCHAPTER II. SANITARY ANALYSIS OF WATER\\ni. Collection of the Sample\\nA bottle of about four liters capacity is cleansed\\nwith hot water, then repeatedly rinsed with distilled", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0076.jp2"}, "77": {"fulltext": "NATURE AND COMPOSITION OF WATER 65\\nwater, and, finally, it is rinsed several times with the\\nwater to be examined. It is then filled with the water\\nand closed with a clean, new cork that has also first\\nbeen rinsed in the water, The cork should be held\\nin place with a heavy cord.\\nIn collecting a sample from a pond, lake, or stream\\nthe bottle should be immersed for 20 or 30 cm. below\\nthe surface of the water in order to avoid the entrance\\nof refuse matter that may be floating on the surface.\\nThe sample should be collected at a sufficient distance\\nfrom the shore to avoid impurities lodged along the\\nbanks of the stream or pond. A sample of well water\\nor hydrant water should be collected only after it has\\nbeen flowing for several minutes. In collecting a\\nsample from a town supply, the end of the supply-pipe\\nshould be avoided in order to secure a sample that is\\nfairly representative of the condition of the water.\\n2. Data on the Label\\nAfter the sample of water has been procured, a label\\nshould be attached to the bottle giving the following\\ndata (a) the source of the sample, and date of collec-\\ntion (b) the presence of any contaminating influences,\\nas the general character of the drainage the presence\\nor absence of sewers, density of the population, the\\npresence or absence of epidemic diseases.\\n3. The Physical Examination of the Water\\na. Clearness. Note whether the water is clear,\\nopalescent, or cloudy whether it contains any sus-\\npended particles, and their nature.\\n5", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0077.jp2"}, "78": {"fulltext": "66 PRACTICAL HYGIENE\\nb. Color. This is determined by comparison with\\ndistilled water by filling a glass cylinder, 50 cm. in\\nheight, with the water, and holding it over a white\\nsurface. The color may also be estimated by placing\\n50 cc. of water in a long Nessler tube and comparing\\nit with the standards used in determining the free and\\nalbuminoid ammonia. The result is expressed as 0.1\\nor 0.2 according to the particular standard to which\\nthe color corresponds.\\nc. Odor. A marked odor can be detected at once\\non opening the bottle containing the sample of water.\\nWhen there is only a slight odor a liter flask may be\\nhalf filled with the water and strongly agitated for\\nseveral minutes when the odor may be detected on\\nremoving the stopper. If this procedure fails a por-\\ntion of the water should be warmed to 40 C. when,\\nif any odoriferous substances are present, their pres-\\nence will be manifested by a faint or distinct odor ac-\\ncording to their nature. The addition of some potas-\\nsium hydroxid, before warming, at times hastens the\\nliberation of the odors.\\nd. Taste. Aside from organic matter the taste of\\nwater is influenced by its temperature and by the\\nquantity of carbon dioxid which it contains.\\ne. Reaction. Most waters are of neutral reaction\\nor very slightly acid, an alkaline reaction being com-\\nparatively rare. The reaction may be determined\\nwith litmus paper, but for accuracy and delicacy the\\nphenolphthalein test is preferable.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0078.jp2"}, "79": {"fulltext": "ANALYSIS OF WATER 67\\nProcess. Take 100 cc. of the water and add 1 cc. of\\nthe phenolphthalein solution; then add from a burette a\\ndilute (w/10) solution of either sodium or potassium hy-\\ndroxid. The violet tint of the water, showing the neu-\\ntralization of the acid, is readily noticeable.\\n4. Chemical Analysis for Impurities\\nThe chemical analysis of water for hygienic pur-\\nposes consists, ordinarily, in the quantitative estima-\\ntion of the total solids, of chlorin, free and albuminoid\\nammonia, nitrates and nitrites, oxidizable organic\\nmatter, and the hardness of the water.\\nThe chemical analysis of water may be either quali-\\ntative or quantitative in character.\\nI. QUALITATIVE CHEMICAL ANALYSIS OF WATER\\na. Gases\\n1, Free carbonic acid (Pettenkofer s Method). To\\n100 cc. of the water add 10 drops of rosolic acid solu-\\ntion. Note the color, as compared with sample of dis-\\ntilled water. Free carbon dioxid turns color to yellow.\\n2. Hydrogen sulphid. Warm ioo cc, of water in a\\nflask in the neck of which is a strip of filter-paper\\nmoistened with solution of lead acetate, and held in\\nplace by a loosely fitting cork. Black color indicates\\nhydrogen sulphid.\\nb. Salts in Solution\\n1. Silicic acid. 250 cc. of water are evaporated to\\ndryness. The residue is dissolved in a few drops of\\nhydrochloric acid, again evaporated to dryness, and", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0079.jp2"}, "80": {"fulltext": "68 PRACTICAL HYGIENE\\nagain dissolved in dilute hydrochloric acid. The sil-\\nicic acid remains undissolved in the form of white\\nflakes, and can be washed, dried, and weighed.\\n2. Sulphurous acid, To 50 cc. of water add a few\\ndrops of hydrochloric acid and 1 cc. barium chlorid\\nsolution. Sulphurous acid is precipitated as heavy\\nwhite barium sulphate.\\nNa 2 S0 4 BaCl 2 BaS0 4 2NaCl.\\n3. Chlorin. To 50 cc. of water add 5 drops of di-\\nlute nitric acid and a few drops of silver nitrate solu-\\ntion. An insoluble, white, flaky precipitate of silver\\nchlorid is formed, dissolving in excess of ammonia.\\nNaCl AgNO s AgCl NaN0 3\\n4. Nitric acid. Dissolve a few crystals of diphenyl-\\namin in 2 cc. sulphuric acid. Float 10 drops of the\\nwater on the acid. A blue color indicates the pres-\\nence of nitric acid.\\n5. Nitrous acid. Place 50 cc. of water in a tall\\nglass cylinder, add 5 drops concentrated sulphuric acid,\\nand 1 cc. of zinc-iodin-starch solution. Shake. A\\nblue color indicates the presence of nitrous acid.\\nZnl 2 2KN0 2 2H,S0 4\\n2NO K 2 S0 4 ZnS0 4 2H 2 I 2\\n6. Phosphoric acid. Evaporate 250 cc. of water\\ndown to 50 cc. in a platinum crucible. Acidify with\\nnitric acid. Add ammonium molybdate solution. A\\nyellow precipitate forms within twenty-four hours.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0080.jp2"}, "81": {"fulltext": "ANALYSIS OF WATER 69\\nc. Bases\\n1. Potassium and sodium. (See page 101).\\n2. Calcium. Acidify ioo cc. water with hydro-\\nchloric acid, boil, render alkaline with ammonia, and\\nadd 1 cc. ammonium oxalate solution. A white pre-\\ncipitate rapidly forms calcium oxalate.\\nCaCl 2 (NH 4 ),CA 2(NH 4 )C1 CaC 2 4\\nIt is necessary to first remove iron and the earthy\\nbases.\\n3. Magnesium. The precipitate of the oxalate of\\nlime is filtered off, the filtrate again treated with 10\\ndrops ammonium oxalate solution to remove all the\\nlime. Then add ten drops sodium phosphate solution.\\nStir. White crystalline precipitate of magnesium am-\\nmonium phosphate forms.\\nMgCl 2 Na 2 HP0 4 NH 4 HO\\nMg(NH 4 )P0 4 2NaCl H 2 0.\\n4. Iron. The residue of 250 cc. of water is dis-\\nsolved in hot dilute nitric acid, and 5 drops of potas-\\nsium ferrocyanid solution added. A green to blue\\ncolor is produced.\\n2Fe 2 Cl 6 3 K 4 Fe(CN) 6 Fe 7 (CN) 18 12KCI.\\n5. Heavy metals. Five liters of water are treated\\nwith a few drops of nitric acid, and ammonium nitrate\\nsolution. This is evaporated to 50 cc, then treated\\nwith hydrogen sulphid.\\nA black precipitate may be lead or copper.\\nFilter and wash with hydrogen sulphid solution.\\nDissolve in hot dilute nitric acid, filter, and add a few", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0081.jp2"}, "82": {"fulltext": "70 PRACTICAL HYGIENE\\ndrops of sulphuric acid. If lead is present there is a\\nwhite precipitate of lead sulphate.\\na. PbN 2 6 H 2 S PbS 2HN0 3\\nb. PbS 2HNO3 PbN 2 6 H 2 S.\\nc. PbN.O, H 2 S0 4 PbS0 4 2HNO a\\nCopper, The filtrate is then treated with potas-\\nsium ferrocyanid solution. Reddish brown, flaky-\\nprecipitate is copper in form of ferrocyanid.\\nZinc. The filtrate of the copper serves to show the\\npresence of zinc. Boil to drive off hydrogen sulphid.\\nAdd excess of sodium hydroxid. Zinc hydroxid is\\nformed. Filter and treat with hydrogen sulphid gas.\\nWhite precipitate is zinc sulphid.\\na. ZnN 2 O e 2NaOH Zn0 2 H 2 2NaN0 3\\nb. Zn0 2 H 2 H 2 S ZnS 2H 2 0.\\n6. Ammonia* Nessler s reagent, 1 cc, added to 50\\ncc. of the water.\\nNH 4 C1 2HgKI 3 4KHO\\nHg 2 NH 2 OI 5KI KC1 3 H 2 0.\\nA yellowish color indicates the presence of ammonia.\\nII. QUANTITATIVE CHEMICAL ANALYSIS OF WATER\\n1. Total Solids\\nA definite quantity of the water (100 to 1000 cc.)\\nis placed in a weighed porcelain capsule and evapo-\\nrated to dryness on a water-bath. The capsule is then\\ndried for an hour, at ioo\u00c2\u00b0 C, allowed to cool in a des-\\niccator, and again weighed. For very accurate re-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0082.jp2"}, "83": {"fulltext": "ANALYSIS OF WATER 7 1\\nsuits the residue must be dried to a constant weight.\\nThe increase in the weight of the capsule represents\\nthe weight of the solids in the amount of water evap-\\norated.\\nIncineration of the residue, In order to determine\\nthe proportion of organic and inorganic matter in the\\nsolids obtained from the w 7 ater evaporation, the residue\\nis carefully incinerated, and, after cooling in a desicca-\\ntor, the capsule is again weighed. The loss in weight\\nrepresents approximately the organic matter and the\\nremainder the inorganic matter. From the color of\\nthe residue, and the odors given off during incinera-\\ntion, we derive some information as to the nature of\\nthe organic matter whether of vegetable or of animal\\norigin; an odor resembling burning hair indicates\\nanimal matter. A dark and greasy residue usually\\nindicates the presence of sewage.\\n2. Chlorin\\nFrom the fact that chlorin is found in practically\\nall waters, in variable quantities, quantitative estima-\\ntions are always necessary. Chlorin in water is esti-\\nmated by means of a solution of silver nitrate, using a\\nfew drops of a solution of potassium chromate as an\\nindicator.\\na. Solution of silver nitrate. The solution of silver\\nnitrate used in the estimation of chlorin in water is\\nmade of such strength that i cc. i milligram chlorin.\\nThe molecular weight of silver nitrate 170,\\nli chlorin 35.5,", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0083.jp2"}, "84": {"fulltext": "72 PRACTICAL HYGIENE\\nTherefore 35.5 170 1 x 4.788 milligrams silver\\nnitrate are equal to 1 milligram of chlorin, and 4.788\\ngrams silver nitrate must be dissolved in a liter of\\nwater in order that 1 cc. of solution 1 milligram\\nchlorin.\\nb. Solution of sodium chlorid. The solution of sil-\\nver nitrate is standardized by titrating against a solu-\\ntion of sodium chlorid of such strength that each cubic\\ncentimeter represents 1 milligram chlorin.\\n35-5 5 8 -5 1 1.647 m g- Na Cl. 1 mg. CI.\\nTherefore 1.647 g rams sodium chlorid must be dis-\\nsolved in a liter of water. The reaction which takes\\nplace between these two solutions is as follows\\nNaCl AgN0 3 AgCl NaN0 3\\nand, as soon as all the chlorin in the solution has been\\nprecipitated by the silver the further addition of a\\nslight excess of the silver solution produces a reaction\\nbetween it and the indicator, potassium chromate, and\\nis manifested by a change in the color of the solution\\nfrom the precipitate of red chromate of silver which\\nis now produced, the reaction being\\nK s Cr0 4 2 AgNO, Ag,Cr0 4 -f 2KN0 3\\nc. The indicator. This consists of a 10 per cent,\\nsolution of potassium chromate which has been freed\\nfrom chlorin, three or four drops being used for each\\ntitration.\\nProcess. Before each determination of chlorin in\\nwater the solution of silver nitrate must be standardized\\nby titrating it against a standard solution of sodium\\nchlorid. Then 100 cc. of the water are placed in a half-\\nliter Florence flask with three or four drops of the indi-\\ncator, and the silver solution added from a burette, con-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0084.jp2"}, "85": {"fulltext": "ANALYSIS OF WATER 73\\nstantly agitating the water in the flask, until the reddish\\ntint produced by the silver chromate remains permanent.\\nIn order to avoid adding an excess of the silver solution\\nthe flask should be placed in a porcelain capsule, com-\\nparing the color of the solution from time to time with\\nthat of a duplicate sample in another flask placed under\\nsimilar conditions, and in which the end-reaction was\\naccurately determined. The number of cubic centimeters\\nof silver solution required to precipitate the chlorin in\\nthe water will represent the number of milligrams of\\nchlorin in ioo cc. of the water. From the fact that the\\nend-reaction requires the addition of an excess of silver\\nsolution it is necessary to deduct o. i cc. from the reading\\nof the burette.\\nExample. ioo cc. of water required 1.3 cc. silver ni-\\ntrate solution therefore, deducting 0.1 cc. for the end-\\nreaction, we have 1.2 cc. silver nitrate 1.2 milligrams\\nchlorin in 100 cc. of water. If, however, the silver ni-\\ntrate solution varies from the normal strength, as shown\\nby its titration against the sodium chlorid solution, it is\\nnecessary to make a corresponding correction of the\\nresults obtained. For example\\n10 cc. NaCl 10. 1 cc. AgN0 3\\nHence 10. 1 10. o 1.2 x 1.188 mg. CI.\\nor if 10 cc. NaCl 9.8 cc. AgN0 3\\nthen 9.8 10 1.2 x= 1.224 m g- CI.\\nIn waters containing much organic matter the color\\nof the water may interfere with the satisfactory detec-\\ntion of the end-reaction when potassium chromate is\\nused as an indicator. In such instances Salkowski s\\nmodification of Volhard s method of using ammonium\\nthiocyanate as an indicator should be employed.\\nSolutions required\\n1. Pure nitric acid, of 1.20 specific gravity.\\n2. Concentrated solution of ammonioferric alum.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0085.jp2"}, "86": {"fulltext": "74 PRACTICAL HYGIENE\\n3. A standard sodiiim chlorid solution, 1 cc. 1\\nmilligram chlorin.\\n4. A standard silver nitrate solution, 1 cc. 1 mil-\\nligram chlorin.\\n5. A titrated solution of ammonium thiocyanate.\\nThis is made by dissolving 2 grams of pure ammonium\\nthiocyanate in water and diluting it to 1100 cc. A\\nburette is filled with this solution, and 10 cc. of the\\nsilver nitrate solution are placed in a flask, diluted to\\n100 cc, and 5 cc. of nitric acid and 5 cc. of the alum so-\\nlution are added. The mixture is agitated and the\\nthiocyanate solution added in small portions until\\nthe red color remains permanent, but still weak. This\\ntitration is repeated and then a liter of the thio-\\ncyanate solution is diluted until 10 cc. of it are equiv-\\nalent to 10 cc. of the silver nitrate solution.\\nProcess. 1000 cc. of the water are acidulated with nitric\\nacid, and a known amount of the standard silver nitrate\\nsolution is added, enough to leave a small excess. This\\nis well shaken and then filtered through a dry filter. To\\na measured portion of the clear filtrate (100 cc. a little\\nalum solution is added, and finally the standard ammo-\\nnium thiocyanate solution is dropped from a burette\\nuntil the red color of ferric thiocyanate makes its ap-\\npearance. The quantity of ammonium thiocyanate\\nsolution used (calculated for the entire quantity of water\\ntaken) gives the amount of excess of silver solution in\\nthe liquid, and this by subtraction from the whole amount\\nof silver solution used, gives the amount corresponding\\nto the chlorin present in the water.\\n3. Free and Albuminoid Ammonia\\nThe nitrogenous organic impurities in water are\\ngenerally estimated by the Wanklyn and Chapman\\nprocess as free and albuminoid ammonia.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0086.jp2"}, "87": {"fulltext": "ANALYSIS OF WATER 75\\na. Nessler s reagent. Nessler s reagent is prepared\\nby dissolving 62.5 grains of potassium iodid in 250\\ncc. of water, and to this a hot saturated solution of\\nmercuric chlorid is added until a slight permanent\\nprecipitate of red mercuric iodid is formed. Solid\\ncaustic potash, 150 grams, dissolved in 150 cc. of\\nwater, is then added to the mixture and the solution\\nrendered sensitive to ammonia by the addition of a\\nsmall amount of the saturated mercuric chlorid solu-\\ntion. It is then filtered through asbestos and pre-\\nserved in a glass-stoppered bottle.\\nb. Alkaline potassium permanganate solution.\\nThis solution is prepared by dissolving 8 grams of po-\\ntassium permanganate in 600 cc. of distilled water,\\nand 200 grams of caustic potash in 500 cc. of water.\\nAs soon as each of these has become entirely dissolved\\nthe two solutions are mixed and the mixture evapo-\\nrated to a liter, thereby freeing it of ammonia.\\nc. Standard ammonium chlorid solution. A strong\\nsolution of ammonium chlorid is prepared by dissolv-\\ning 3. 141 grams of ammonium chlorid in a liter of dis-\\ntilled water. The standard solution is prepared from\\nthis strong solution by diluting it 1 100 with dis-\\ntilled water when each cubic centimeter will contain\\n0.01 milligram of ammonia, or 0.0082 milligram of\\nnitrogen.\\nd. Ammonia-free water. In making up the stand-\\nards containing definite amounts of the ammonium\\nchlorid solution, it is necessary to employ distilled\\nwater that is practically free from ammonia. This", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0087.jp2"}, "88": {"fulltext": "76 PRACTICAL HYGIENE\\nwater must be specially prepared as it is not on the\\nmarket. The best way to secure such a water is by\\nredistillation of pure distilled water or spring water.\\nAt times it has been found almost impossible to ob-\\ntain a satisfactory water from the city water supply\\nbecause of the large amounts of sewage contained in\\nit. In preparing ammonia-free water from pure dis-\\ntilled water the first portion of the distillate is always\\ndiscarded, usually about a third of the distillate. The\\nwater distilling over, after the first third has been dis-\\ncarded, is tested with Nessler s reagent, and if found\\nammonia-free, is collected in a clean glass-stoppered\\nflask. Where this method fails to yield satisfactory\\namounts it may be advisable to add a few drops of\\npure, concentrated sulphuric acid to the water before\\ndistilling, so as to convert the ammonia into the sul-\\nphate, when the distillate will come over fairly free\\nfrom ammonia.\\nProcess. A glass-stoppered retort of 1250 cc. capac-\\nity, and a Iyiebig s condenser, with constant water-sup-\\nply, are required to carry out this process. The retort\\nis thoroughly cleansed and partly filled with pure dis-\\ntilled water. The water is then distilled over until it\\ncomes off free from ammonia, as shown by testing 50 cc.\\nof the distillate with 1 cc. of the Nessler reagent. As\\nsoon as the distillate is found to be free of ammonia the\\ndistillation is stopped, the retort disconnected from the\\ncondenser, and the remainder of the distilled water poured\\nout leaving the last drops to drain away. Then, without\\nrinsing, it is again connected with the condenser and 500\\ncc. of the water to be examined placed in it. The dis-\\ntillation of the water is now begun and each 50 cc. of the\\ndistillate collected separately in short glass cylinders and\\ntransferred to long Nessler tubes of 50 cc. capacity, which", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0088.jp2"}, "89": {"fulltext": "ANALYSIS OF WATER 77\\nhave been thoroughly cleansed by rinsing repeatedly with\\npure water, and allowed to drain in a suitable rack or\\nframe. When four portions of 50 ee. each, or 200 ce.\\naltogether, have been distilled over the free ammonia has\\nusually all been removed, and the distillation is arrested.\\n50 ee. of the alkaline potassium permanganate solution\\nare now added to the remainder of the water in the retort\\nand the distillation resumed. Five portions of 50 ce.\\neach of the distillate are collected as before, these repre-\\nsenting the so-called albuminoid ammonia.\\nA set of standards is now prepared by placing o. 1, 0.2,\\n0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 cc. of the stand-\\nard ammonium chlorid solution into Nessler tubes of 50\\ncc. capacity and diluting with water that is practically\\nfree of ammonia. These are then placed in a suitable\\nrack in regular order according to the strength of the\\nstandards they represent. The standards and distillates\\nare now nesslerized by adding 1 cc. of Nessler s rea-\\ngent to the contents of each tube. After standing for\\nten minutes the comparisons may be made. The total\\namount of ammonia found in the first four distillates rep-\\nresents the amount of free ammonia in 500 cc. of the\\nwater. The total quantity of ammonia found in the last\\nfive distillates represents the amount of albuminoid am-\\nmonia in the same amount of the water. By multiplying\\neach of these amounts by two we learn the number of\\nmilligrams of free and of albuminoid ammonia in a liter\\nof the water.\\nExample. The first 50 cc. of distillate =0.3 cc. of\\nthe standard ammonium chlorid solution, or 0.003 m g- or\\nammonia; the second 50 cc. =0.15 cc. of the standard\\nsolution, or 0.0015 mg. of ammonia the third 50 cc.\\n0.005 cc or 0.0005 m OI ammonia and the fourth 50\\ncc. 0.000 cc. of the standard solution. The total\\namount of free ammonia found in the 500 cc. of water is\\n0.005 m g- or 01 m g- \u00c2\u00b0f ammonia in a liter of the water.\\nThe distillates containing the albuminoid ammonia\\nare as follows", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0089.jp2"}, "90": {"fulltext": "78 PRACTICAL HYGIENE\\nFirst 0.4 cc, or 0.004 m \u00c2\u00b0f ammonia\\nSecond =0.3 cc, or 0.003 m g- \u00c2\u00b0f ammonia\\nThird =0.2 cc, or 0.002 mg. of ammonia\\nFourth =0.1 cc, or 0.001 mg. of ammonia\\nFifth 0.05 cc, or 0.0005 m g- \u00c2\u00b0f ammonia.\\nThe total quantity of albuminoid ammonia found in the\\n500 cc. of water is 0.0105 mg., or 0.021 mg. of ammonia\\nin a liter of the water.\\n4. Oxidizable Organic Matter\\na. Oxalic acid solution. This solution is made of\\nsuch strength that each cubic centimeter of it will\\nrepresent o. 1 milligram of oxygen.\\nTherefore 16 126 0.1 .r 0.7875 milligram\\noxalic acid in each cubic centimeter, or 0.7875 gram\\nof oxalic acid are dissolved in a liter of distilled water,\\nso that 1 cc of the solution 1 milligram of oxygen.\\nb. Potassium permanganate solution. This is like-\\nwise made of such strength that 1 cc. of it will equal\\nabout 0.1 milligram of oxygen, and therefore, 0.4 gram\\nof potassium permanganate are dissolved in a liter of\\nwater.\\nc. Sulphuric acid of 25 per cent, strength.\u00e2\u0080\u0094\\nCleansing the casserole. A porcelain casserole of\\nabout 200 cc. capacity is freed from organic matter by\\nintroducing 100 cc. of distilled water, 5 cc. of the 25\\nper cent, sulphuric acid, and several cubic centimeters\\n,of the potassium permanganate solution and boiling\\nfor five minutes. This water is then poured out leav-\\ning the last few drops to drain away.\\nInto the clean casserole is now introduced 100 cc. of\\nthe water to be examined, 5 cc. of the 25 per cent, sul-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0090.jp2"}, "91": {"fulltext": "ANALYSIS OF WATER 79\\nphtiric acid, and 6 to 8 cc. of the potassium perman-\\nganate solution and boiled for five minutes. Into the\\nhot liquid is now introduced 10 cc. of the oxalic acid\\nsolution by means of a pipette, and then the potas-\\nsium permanganate solution is carefully added, drop\\nby drop, from a Gay-Lussac burette, until the liquid\\nassumes a faint rose tint. The total quantity of the\\npotassium permanganate solution added represents the\\namount necessary to oxidize the 10 cc. of oxalic acid\\nsolution and the organic matter in the ioo cc. of water.\\nStandardizing the solutions. In order to ascertain\\nthe amount of potassium permanganate solution re-\\nquired to oxidize the 10 cc. of oxalic acid solution, it\\nis necessary to again introduce 6 or 8 cc. of the potas-\\nsium permanganate solution into the liquid in the\\ncasserole, which is now free of organic matter, and heat\\nit to boiling, again adding io cc. of the oxalic acid\\nsolution, and finally the potassium permanganate so-\\nlution, drop by drop, until the faint rose tint is repro-\\nduced. The amount of potassium permanganate so-\\nlution required now for the io cc. of oxalic acid solu-\\ntion alone will indicate the amount of potassium per-\\nmanganate solution required to yield i milligram of\\noxygen.\\nExample. The ioo cc. of water examined and the io\\ncc. of oxalic acid solution required 13.4 cc. of the potas-\\nsium permanganate solution to bring about the rose tint\\nof the liquid in the first instance. In the second instance\\nthe 10 cc. of oxalic acid solution alone required only 10.4\\ncc. of the potassium permanganate solution to bring about\\nthe same result. It is necessary to deduct o. 1 cc. from\\neach of these results as that amount of potassium per-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0091.jp2"}, "92": {"fulltext": "80 PRACTICAL HYGIKNE\\nmanganate solution is necessary to bring about the end-\\nreaction. Therefore 10.3 cc. of the potassium permanga-\\nnate solution represent 1 milligram of oxygen, and the\\norganic matter in the 100 cc. of water under examination\\nrequired 3.0 cc. of the potassium permanganate solution\\nfor its oxidation. From these data we can calculate the\\namount of oxygen required to oxidize the organic matter\\nin a liter of the water under examination.\\n10.3 1 30 x 2.912 milligrams O.\\nThe role of the sulphuric acid.- The necessity for\\nthe addition of the sulphuric acid in this process is\\ntwofold. The reaction of the potassium permanga-\\nnate is more energetic in acid solutions, and in the sec-\\nond place, the potassium permanganate in breaking\\nup will unite with the sulphuric acid to form mangan-\\nous sulphate, a colorless salt 2KMnO 3H 2 SO\\n2MnS0 4 K S0 4 3HO 5O.\\nBoiling for five minutes. In carrying out this pro-\\ncess it is highly important to boil the water for a defi-\\nnite period of time. Some authors recommend boil-\\ning for ten minutes and there may be instances where\\nit would be necessary to do so in order to oxidize cer-\\ntain organic substances present in the water, but for\\nmost substances boiling for five minutes is considered\\nsufficient. In making comparative estimations it is\\nessential to boil for the same length of time in each\\ndetermination always counting from the beginning\\nof ebullition.\\n5. The Hardness of Water\\nThe hardness of water is due to the presence of lime\\nand magnesia in the form of carbonates, chlorids, sul-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0092.jp2"}, "93": {"fulltext": "ANALYSIS OF WATER 8 1\\nphates, or nitrates. In exceptional instances the hard-\\nness of water is also in part due to the presence of\\nsalts of iron.\\nThe hardness of water is usually determined by\\nmeans of a standard soap solution. The fatty acids in\\nthe soap solution form insoluble stearates, palmitates,\\netc., of lime and magnesia. As long as any of the\\nlime and magnesia is unprecipitated the soap solution\\nfails to produce a permanent lather with the water.\\nAs soon as a distinct lather is formed, and remains\\npermanent for five minutes, all the lime and magnesia\\npresent in the water have been precipitated, and the\\nlather, therefore, forms the indicator of the end-reac-\\ntion.\\na. Standard soap solution. The standard soap so-\\nlution is made by softening 150 grams of lead plaster\\n(U. S. P.) on a water-bath and thoroughly mixing it\\nwith 40 grams of pure potassium carbonate until a\\nhomogeneous mixture is obtained. This mixture is\\nthen diluted with dilute alcohol and transferred to a\\nglass-stoppered bottle and agitated at intervals for sev-\\neral days. The solution is then filtered and standard-\\nized by means of a solution of barium nitrate 0.559\\ngram dissolved in a liter of distilled water of which\\n100 cc. contain an amount of barium equivalent to 12\\nmilligrams of lime. The standard soap solution is\\nmade of such strength that 45 cc. of it are required to\\nform a lather with 100 cc. of the barium solution\\ntherefore 45 cc. are equal to 12 milligrams of lime.\\nThe filtered alcoholic soap solution is diluted with\\ndilute alcohol until the required strength is attained.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0093.jp2"}, "94": {"fulltext": "82 PRACTICAL HYGIENE\\nb. Degrees of hardness. The hardness of water is\\nexpressed in degrees. In England a degree of hard-\\nness Clark s scale represents i grain calcium car-\\nbonate in a gallon of water. In Germany i degree of\\nhardness represents i part by weight of calcium oxide\\nin 100,000 parts by weight of water, or 1 milligram\\ncalcium oxide in 100 cc. of water. In France 1 de-\\ngree of hardness represents 1 part of calcium carbon-\\nate in 100,000 parts of w 7 ater, or 1 milligram calcium\\ncarbonate in 100 cc. of water. This is also known as\\nthe metric scale. In America the metric scale is com-\\ning into more general use as being preferable to\\nClark s scale. One degree of hardness in the metric\\nscale represents 0.7 degree of Clark s scale, and from\\nthese data results expressed in either of these systems\\nmay readily be converted into the other.\\nThe hardness of water is expressed as total hardness\\n(the hardness resulting from the action of all the lime\\nand magnesium salts present in the water) and as per-\\nmanent and removable hardness. The removable\\nhardness represents the proportion of the salts of lime\\nand magnesium in the form of carbonates and bicar-\\nbonates. The carbon dioxid combined with the lime\\nand magnesium in this manner is liberated by boiling\\nthe water for half an hour. The permanent hardness\\nrepresents salts of lime and magnesium present in the\\nwater as sulphates, chlorids, or nitrates and is deter-\\nmined by applying the soap test to a part of the water\\nthat has been subjected to boiling, while the remova-\\nble hardness is determined by taking the difference\\nbetween the total and permanent hardness.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0094.jp2"}, "95": {"fulltext": "ANALYSIS OF WATER 83\\nProcess. To determine the total hardness of water\\n50 ec. of the sample are placed into a glass-stoppered\\nbottle of 125 ec. capacity and the standard solution of\\nsoap is added from a burette graduated in tenths of a\\ncubic centimeter. The soap solution is added, at first,\\nin amounts of about 0.5 cc, and the water agitated thor-\\noughly after the addition of each portion of the soap so-\\nlution. As soon as a slight lather begins to form the soap\\nsolution is added drop by drop, until the lather is 1 cm.\\nin thickness and remains unchanged for five minutes. It\\nis customary to deduct 0.2 cc. from the quantity of soap\\nsolution used in the determination as that amount is\\nnecessary to produce a permanent lather in distilled\\nwater.\\nVery hard waters that require more than 45 cc. of the\\nstandard soap solution, must be diluted with distilled\\nwater, because of the formation of double salts of lime\\nand magnesium with the fatty acids in the presence of\\nexcessive amounts of these bases, and, in consequence of\\nwhich, the reaction is irregular and the results unsatis-\\nfactory.\\nTo determine the permanent hardness of water, 100 cc.\\nof the sample are placed into a suitable vessel and boiled\\nfor half an hour, but without evaporating to dryness.\\nAfter cooling the concentrated water is diluted to 100 cc.\\nwith distilled water and the hardness determined in the\\nsame manner as for the total hardness, or, if the evapo-\\nration has removed half of the water, then the whole of\\nthis may be used, if the degree of hardness is low, in\\nmaking the determination of the permanent hardness.\\nThe removable hardness of water is determined by de-\\nducting the amount of soap solution required for the per-\\nmanent hardness from the amount required for the total\\nhardness, the remainder representing the removable\\nhardness.\\nCalculation of the results. As each o.i cc, or\\nmeasure, of the standard soap solution represents 0.25\\nmilligrams calcium carbonate, and all the results are", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0095.jp2"}, "96": {"fulltext": "84 PRACTICAL HYGIENE\\nexpressed in terms of calcium carbonate because it is\\nthe principal agent producing the hardness of water,\\nthe calculation is very easily made. Two measures of\\nsoap solution are deducted from each reading for the\\nend-reaction. The number of measures required X\\n0.25 milligram calcium carbonate the number of\\nmilligrams of calcium carbonate in 50 cc. of the water\\ntested. This result is multiplied by 2, converting it\\ninto milligrams calcium carbonate per 100 cc. of water,\\nor parts per 100,000, or degrees of hardness according\\nto the metric scale. This result multiplied by 0.7\\nconverts it into grains per gallon, or degrees of hard-\\nness of Clark s scale.\\nExample. 50 cc. of water required 32 2 30 meas-\\nures of soap solution. Then 30 X 2 X 0.25 15.0 de-\\ngrees of hardness according to the metric scale or 15 X 0.7\\n10.5 degrees of hardness of Clark s scale. This repre-\\nsents the total hardness of the water. 100 cc. of the\\nsame water, after being boiled down to 50 cc. required\\n20 2 18 measures of soap solution. Then 18 X 0.25\\n4.5 degrees of permanent hardness according to the\\nmetric scale, or 4.5 X 0.7 3. 15 degrees of Clark s scale.\\nThe removable hardness is determined by finding the\\ndifference in the two amounts of soap solution required\\nfor the total and permanent hardness 60 18 42\\nmeasures, then 42 X 0.25= 10.5 degrees in the metric\\nscale, or 7.35 degrees of Clark s scale.\\nHehner s method of determining the hardness of\\nwater. The solutions required in this method are a\\nn/50 sodium carbonate solution and n/50 sulphuric\\nacid. Each cubic centimeter of the standard acid ex-\\nactly neutralizes 1 milligram of calcium carbonate,\\nand each cubic centimeter of the sodium carbonate so-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0096.jp2"}, "97": {"fulltext": "ANALYSIS OF WATER 85\\nlution represents alike amount of calcium carbonate,\\nor its equivalent of magnesia, when present in a sam-\\nple of water.\\nThe sodium carbonate solution is prepared by dis-\\nsolving 1.06 grams of recently ignited pure sodium\\ncarbonate in a liter of water, i cc. 1.06 milligrams\\nsodium carbonate 1.0 milligram calcium carbonate.\\nThe standard sulphuric acid is prepared by adding\\n1 cc. of pure concentrated sulphuric acid to about a\\nliter of water. 50 cc. of the standard sodium carbon-\\nate solution is placed in a porcelain dish, heated to\\nboiling, a few drops of indicator added (phenacetolin\\nor lacmoid), and the sulphuric acid cautiously run in\\nfrom a burette until a change of color is produced. From\\nthe result obtained the degree of dilution required for\\nthe sulphuric acid may be calculated so that 1 cc. of\\nthe sulphuric acid 1 cc. of the sodium carbonate\\nsolution.\\nProcess Temporary hardness. 100 cc. of the water\\nis tinted with 1 cc. of the indicator and heated to boiling,\\nand the sulphuric acid cautiously added until a change of\\ncolor is produced. Each cubic centimeter of acid required\\nrepresents one part of calcium carbonate, or its equiva-\\nlent in 100,000 parts of water, or the number of degrees\\nof hardness according to the metric scale.\\nPermanent hardness. To 100 cc. of the water is added\\nan amount of sodium carbonate solution in excess of that\\nrequired to decompose the calcium and magnesium sul-\\nphates, chlorids, and nitrates present usually 50 cc. of\\nthe solution will be all that is required. The mixture is\\nevaporated to dryness in a platinum dish and the residue\\n\u00e2\u0096\u00a0dissolved in distilled water. The solution is filtered\\nthrough a very small filter, washed, and the filtrate and\\nwashings titrated while hot with sulphuric acid. The", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0097.jp2"}, "98": {"fulltext": "86 PRACTICAL HYGIENE\\ndifference between the amount of sodium carbonate added\\nand the sulphuric acid required for the residue, will give\\nthe permanent hardness.\\nIf the water contains sodium or potassium carbonate\\nthere will be no permanent hardness, and there will be\\nmore acid required for the filtrate than the equivalent of\\nthe sodium carbonate added. From this excess the quan-\\ntity of sodium carbonate in the water may be determined.\\nThe amount of sodium carbonate found in the water must\\nbe deducted from the result obtained for the temporary\\nhardness.\\nThe indicator. The lacmoid solution is made by\\ndissolving 2 grams of lacmoid in a liter of 50 per cent,\\nalcohol. When the test is carried out in the cold\\nmethyl orange may be used as the indicator. It is\\nwell to use a second flask containing water colored to\\nthe same depth with the indicator for comparison, in\\norder to determine the first change of color which\\nmarks the end-reaction.\\nHehner s method is far more satisfactory than Clark s\\nmethod by means of standard soap solution in testing\\nhard waters. It is also preferable to Clark s method\\nbecause it gives more definite information as to the\\nnature of the constituents causing the hardness of\\nwater. It is customary to speak of the temporary\\nhardness of water as determined by this method as\\nthe u alkalinity of the water, and the permanent\\nhardness as the incrusting constituents of the water,\\nexpressed in terms of calcium carbonate.\\nGravimetric determination of the hardness of wa-\\nter. For the more exact determination of the hard-\\nness of water the quantities of lime and magnesia\\npresent are determined gravimetrically.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0098.jp2"}, "99": {"fulltext": "ANALYSIS OF WATER 87\\nEstimation of lime. The amount of lime is deter-\\nmined by concentrating 50 cc. of the water through\\nevaporation and treating the residue with ammonium\\nchlorid, an excess of ammonium oxalate, and a\\nsmall amount of ammonia. The lime is precipitated\\nin the form of calcium oxalate while the magnesia re-\\nmains in solution as magnesium oxalate. The pre-\\ncipitated calcium oxalate is collected on a filter,\\nwashed, dried and heated strongly, whereby it is con-\\nverted into caustic lime and then weighed as such.\\nEstimation of magnesia. The magnesia, which is\\nnow 7 in the filtrate in the form of oxalate, is treated\\nwith ammonium chlorid, ammonia, and w T ith sodium\\nphosphate, when it is precipitated as ammonium-mag-\\nnesium phosphate. The precipitate is collected on a\\nfilter, dried and fused, and is then weighed as mag-\\nnesium pyrophosphate.\\n6. Determination of Nitrogen as Nitrates\\nI, Marx-Tromsdorf method, In this method the\\nwater is titrated with indigo solution in hot acid solu-\\ntion. The water is mixed with an equal volume of\\nconcentrated sulphuric acid free of nitrogen, when a\\nheat of i20\u00c2\u00b0-i25\u00c2\u00b0 C. is generated, which. favors the\\nconversion of the nitrates into nitric acid and sulphates,\\ncausing the indigo solution to be decolorized. As\\nsoon as all the nitrates have been so changed the\\nfurther addition of indigo solution will change the\\nliquid to a yellowish-green color.\\na. The indigo solution. About 3 grams commercial\\nindigotin are pulverized in a mortar and digested with", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0099.jp2"}, "100": {"fulltext": "88 PRACTICAL HYGIENE\\nabout 60 cc. concentrated sulphuric acid. Indigodi-\\nsulpho acids are formed, besides some indigomonosul-\\npho acids. After standing twenty-four hours the reac-\\ntion is completed and the solution is poured into four\\ntimes the quantity of distilled water, when, on stand-\\ning, the insoluble indigomonosulpho acids are precipi-\\ntated. The solution is now filtered and preserved in\\na glass-stoppered bottle. This solution is diluted with\\ndistilled water, before using, so that 6 to 8 cc. will be\\ndecolorized by 1 milligram of nitrogen pentoxid.\\nb. Standard potassium nitrate solution. To stand-\\nardize the indigo solution a solution of potassium ni-\\ntrate is prepared of which 25 cc. 1 milligram of\\nnitrogen pentoxid (1 liter 40 milligrams nitrogen\\npentoxid), but since such a small quantity cannot be\\nweighed accurately we dissolve 7.5037 gram of potas-\\nsium nitrate in a liter of water, and dilute this solution\\n1 100 before using it. 25 cc. of the dilute solution\\n1 milligram of nitrogen pentoxid, and it should re-\\nquire from 6 to 8 cc. of the indigo solution to neutral-\\nize 25 cc. of the standard potassium nitrate solution.\\nProcess. It is important that the operation be car-\\nried out under the same conditions each time, especially\\nas to the temperature of the solutions. 25 cc. of the di-\\nlute potassium nitrate solution are placed in a 100 cc.\\nFlorence flask with 25 cc. (nitrogen-free) concentrated\\nsulphuric acid, quickly mixing them, when the tempera-\\nture will rise to 120 to 125 C, and the nitrates are\\nchanged into nitric acid and sulphuric acid salts. Into\\nthis boiling solution the indigo solution is added drop by\\ndrop, at first, from a burette measuring tenths of a cubic\\ncentimeter, then in quantities of about a cubic centimeter,\\nshaking the flask after each addition of indigo solu-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0100.jp2"}, "101": {"fulltext": "ANALYSIS OF WATER 89\\ntiou. Not more than 8 cc. of the indigo solution should\\nbe required. If more is required the solution is too weak.\\nThe examination of a sample of water is conducted in the\\nsame manner only that 25 cc. of the water are used in-\\nstead of 25 cc. of the potassium nitrate solution. If more\\nthan 8 cc. of the indigo solution are required the water\\nmust be diluted.\\nExample. For 25 cc. of potassium nitrate solution 7.5\\ncc. of indigo solution are required, therefore 7.5 cc. of\\nindigo solution 1 milligram of nitrogen pentoxid. For\\n25 cc. of the water 6.4 cc. of indigo solution were re-\\nquired, and for 1000 cc. of water 40 X 6.4= 256 cc. of\\nindigo solution, or 34.13 milligrams of nitrogen\\npentoxid in a liter of water.\\n2. Method of Grandval and Lajoux. Five cc. of\\nthe water are placed in a porcelain dish of about 35 cc.\\ncapacity, two or three drops of a 1 per cent, solution\\nof sodium carbonate added, and then evaporated to\\ndryness on the water-bath. The steam should not be\\nallowed to come in contact with the dish itself. The\\nevaporation residue is treated with about 0.5 cc. of\\nphenolsulphuric acid (made by digesting 23 grains of\\npure crystallized phenol in 200 cc. of pure sulphuric\\nacid for some hours). By appropriate manipulation\\nthe acid is worked well over the bottom and sides of\\nthe dish. After some time a few cc. of distilled water\\nare added and then a solution of caustic potash until\\nthe yellow color is well brought out. The strength\\nof the caustic potash solution should be 10 per cent,\\nor more. It is important that too great an excess of\\nthis reagent be not added, for if this occurs crystals of\\npotassium sulphate are thrown down, a result which\\nis not desirable.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0101.jp2"}, "102": {"fulltext": "90 PRACTICAL HYGIENE\\nA set of standards is made up for each analysis from\\ni, 2, 3, 4, 5, and 6 cc. of a solution of potassium ni-\\ntrate, of which i cc. contains o.ooi milligram of nitro-\\ngen as nitrate. These portions of the potassium ni-\\ntrate solution are placed in small porcelain dishes of\\n35 cc. capacity and treated in the same manner as de-\\nscribed for the sample of water. (In making up the\\nstandard solution of potassium nitrate 0.7215 gram is\\ndissolved in a liter of water, and this solution is then\\ndiluted 1 100 before using.)\\nAfter treating the sample of water and the stand-\\nards as already described, the contents of the dishes\\nare transferred to the long Nessler tubes of 50 cc. ca-\\npacity. More distilled water is added until they are\\nfilled to within 2 or 3 cm. of the top, and the readings\\nare then made.\\n3. The Schultze-Tiemann method. By boiling with\\nferrous chlorid the nitrogen pentoxid is reduced to ni-\\ntric oxid gas, which is measured and calculated to\\nN 2 5 The reduction is as follows: 6FeCl 2 8HC1\\n+V 2 ON 2 5 3Fe 2 Cl 6 2NO JhTo 2KCI. From\\n108 parts nitrogen pentoxid result 60 parts nitric oxid,\\nor from 9.67689 (108 X 0.0896) nitrogen pentoxid re-\\nsult 4 liters nitric oxid; L e., 1 liter nitric oxid\\n2.419 grams nitrogen pentoxid.\\nApparatus required\\n100 cc. flask.\\nGlass tubing.\\nPinch-cocks.\\nBeaker, 30 cc. capacity.\\nGlass dish, 10 cm. diameter, and 5 to 6 cm. in height.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0102.jp2"}, "103": {"fulltext": "ANALYSIS OF WATER 91\\nMeasuring tube of 30 to 50 ec. capacity, scale divided\\ninto 1/10 cc.\\nA vessel somewhat higher than the measuring tube.\\n20 per cent, sodium hydroxid solution, boiled. Satu-\\nrated solution of ferric chlorid.\\nConcentrated hydrochloric acid.\\nSufficient water must be taken to yield 10 to 20 cc. of\\nnitric oxid gas. This will depend on the richness of the\\nwater in nitrates,\\no 50 milligrams nitrogen pentoxid use 250 cc. water.\\n50 250 100 cc.\\nThe water is concentrated to about 5 cc. on a water-\\nbath, and then transferred to the 100 cc. flask and\\nthe dish washed with about 15 cc. distilled water, and\\nthis added to the water. It is not necessary to add\\nthe precipitated alkaline earths. The stopper is now\\nput in position, and boiling commenced with both\\npinch-cocks open, until the quantity of water is re-\\nduced to about 10 cc, whereby all the air is removed\\nfrom the apparatus. The glass tube is now inserted\\nunder the mouth of the measuring tube, which has\\nbeen filled with sodium hydroxid and inverted over\\nthe dish containing the sodium hydroxid. 15 cc. fer-\\nrous chlorid solution, and 10 cc. hydrochloric acid, are\\nnow placed in the beaker. The flame is now removed\\nand the pinch-cocks closed, so that on cooling there is\\nnegative pressure in the flask. When cooled the pinch-\\ncock is carefully opened when the ferrous chlorid\\nand hydrochloric acid is drawn over into the flask.\\nCare must be taken that no air gains entrance at the\\nsame time, closing the pinch-cock before all the liquid\\nhas passed over. The flame is now again applied,\\nheating with the pinch-cocks closed at first, until the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0103.jp2"}, "104": {"fulltext": "92 PRACTICAL HYGIENE\\nnegative pressure in the flask is entirely removed,\\nthen the pinch-cock is carefully opened to allow\\nthe nitric oxid gas to escape into the measuring tube.\\nAny carbon dioxid formed is absorbed by the sodium\\nhydroxid. When no more bubbles of gas are given\\noff the pinch-cock is closed and the flame removed,\\nwhen negative pressure again develops and the re-\\nmainder of the nitric oxid gas is liberated. The flame\\nis now again applied and the pinch-cock opened\\nto allow the gas to escape into the measuring tube.\\nThe nitric oxid gas is measured at o\u00c2\u00b0 C. and 760 mm.\\nThe sodium hydroxid is allowed to cool, the cyl-\\ninder is filled with boiled water, and the measuring\\ntube is carefully transferred to the cylinder, where\\nit is allowed to remain for several hours at room tem-\\nperature. The measuring tube is raised, by means of\\na pair of tongs, so that the level of the water within\\nand without the tube are the same. The temperature\\nof the water is taken, as well as the barometric pres-\\nsure and the temperature at the barometer. It must\\nbe remembered that the gas is moist and correction\\nmust be made for the increased volume due to the\\ntension of the aqueous vapor, and deducted from the\\nobserved barometric pressure.\\nThe reduction is made according to the following\\nformula\\nV VX(*-T)\\n760 x (1 0.00366 x\\nT the tension of the aqueous vapor in millimeters\\nat the observed temperature. This must be taken\\nfrom tables of tension of aqueous vapor.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0104.jp2"}, "105": {"fulltext": "ANALYSIS OF WATER 93\\n4. The aluminum method. A 50 cc. tube is filled\\nwith the water, and an excess (about 2 grams) of alu-\\nminum wire is added, with 2 cc. of a strong solution\\nof sodium hydroxid free from nitrogen. It is then\\nallowed to stand over night in a warm place, and a\\nmeasured portion, usually from 2 to 10 cc, removed\\nand made up with distilled water (free from nitrates),\\nof the same temperature as the ammonia standards, to\\n50 cc, and nesslerized.\\nThe ammonia carried off by the evolved hydrogen\\nhas frequently been caught in a trap and determined,\\nbut with 2 cc of the caustic soda and at temperatures\\nbelow 30 C, the loss will not exceed 2 per cent, in\\nany case. Using too little caustic soda, or keeping\\nthe tubes at too low a temperature, the nitrate is not\\nall reduced, while with the opposite conditions an ap-\\npreciable amount of ammonia is carried away by the\\nhydrogen. Taking due care as to these conditions\\nvery satisfactory results may be obtained.\\nIn calculating the nitrate, reduction is made for the\\nfree ammonia and nitrites, but when the ammonia\\namounts to a considerable fraction of the total nitro-\\ngen, it is first removed by boiling with the caustic\\nsoda and thoroughly cooled before adding- the alumi-\\nnum. When waters do not give good colors by direct\\nnesslerization it is necessary to distil. This can be\\nmost conveniently done indirectly by a current of\\nsteam.\\nPreparation of nitrate-free water. Eight liters of\\nordinary distilled water are treated with 100 cc of a\\n50 per cent, solution of sodium hydroxid and 5 grams", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0105.jp2"}, "106": {"fulltext": "94 PRACTICAL HYGIENE\\nof pure aluminum foil. After some hours the water\\nis placed in a still with 3 grams of potassium perman-\\nganate and distilled the middle portion of the dis-\\ntillate is free from nitrates.\\nSodium hydroxid solution. One liter of nitrate-free\\nwater and 50 grams of the purest sodium hydroxid\\nobtainable are brought together in a porcelain dish\\nwith about 2 grams of pure aluminum foil. When\\nthe foil is all dissolved, the solution is boiled down to\\na volume of 500 cc, and after being allowed to settle,\\nfiltered through asbestos. Two cc. of this solution\\nwith 50 cc. of water and 0.35 gram of aluminum foil,\\nshould indicate the presence of only a very slight\\namount of ammonia when treated in the same manner\\nas samples for analysis.\\n7. Determination of Nitrogen as Nitrites\\n1. Warrington s modification of the Griess method.\\nThe process consists in adding to 45 cc. of the water\\nto be tested two or three drops of hydrochloric acid\\n(50 cc. strong acid in 50 cc. water), then 2 cc. of a sat-\\nurated solution of sulphanilic acid, and finally 2 cc.\\nof a saturated solution of naphthylamin hydrochlorid\\n(8 grams naphthylamin, 8 cc. strong hydrochloric acid\\nand 992 cc. of water). The presence of nitrites is in-\\ndicated by the production of a most intense and beau-\\ntiful rose-red color due to the formation of azobenzol-\\nnaphthylaminsulphuric acid. The rose color produced\\nwhen nitrites are present is compared with the depth\\nof color obtained from known amounts of a standard\\nsodium nitrite solution under the same conditions. The", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0106.jp2"}, "107": {"fulltext": "ANALYSIS OF WATER 95\\nstandards are made up from a dilute solution of sodium\\nnitrite. 1.815 grams of sodium nitrite are dissolved\\nin a liter of distilled water. 10 cc. of this solution\\nare diluted to a liter with distilled water before using\\n1 cc. 0.01 milligram of nitrogen tetroxid. With\\nthis dilute solution ten standards are made up con-\\ntaining from 0.1 cc. to 1.0 cc. each. These standards\\nare treated in the same manner as the sample of water,\\nand the readings are made in the long Nessler tubes\\nafter allowing them to stand for one-quarter of an hour\\nto permit the color to fully develop.\\nWater containing more than 0.002 part of nitrogen\\nas nitrogen tetroxid per 100,000, must be diluted with\\na known amount of distilled water free from nitrites.\\nSurface waters having a color above 0.1 must be de-\\ncolorized by shaking with aluminum hydroxid and\\nrapidly filtering before testing for nitrites.\\n2. Schuy ten s method, When 5 cc. of a 1 per\\ncent, solution of antipyrin in acetic acid (1/10) is added\\nto a solution containing nitrites, a green color is pro-\\nduced.\\nAntipyrin solntioit. Dissolve 10 grams of antipyrin\\nin dilute acetic acid (1 to), and add water sufficient\\nto make a liter.\\nProcess. To 45 cc. of the sample of water in one\\nof the long Nessler tubes, 5 cc. of the antipyrin solution\\nare added. After standing for about half an hour the\\nreading is made. The same standards of sodium nitrite\\nsolution may be used for comparison as in the former\\nmethod. This method will show the presence of 1 part\\nof nitrogen as N0 2 in 20,000 parts. It is therefore not\\nas delicate as the former method but it is not hindered", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0107.jp2"}, "108": {"fulltext": "96 PRACTICAL HYGIENE\\nby the presence of any of the ordinary contaminations in\\nwater.\\n8. Detection of Lead in Water\\na. Method. The presence of lead in water may be\\ndetermined by taking 200 cc. of the water and precipi-\\ntating the lead with acetic acid and then passing hy-\\ndrogen sulphid gas through the mixture and convert-\\ning it into the sulphid, the presence of lead being in-\\ndicated by the black precipitate which forms. To dis-\\ntinguish the precipitate thus formed from the sulphid\\nof some of the other metals, it is necessary to collect\\nthe precipitate on a filter, dissolve it in warm nitric\\nacid, dilute with water, and then precipitate with sul-\\nphuric acid. A white precipitate forming on the ad-\\ndition of sulphuric acid shows the presence of lead in\\nthe water, and is now in the form of lead sulphate.\\nb. Colorimetric method. The estimation of lead\\ncan be made colorimetrically if it is shown that the\\nwater contains no copper.\\nA solution of lead of known strength is prepared,\\nby dissolving o. 1 gram of pure lead in excess of acetic\\nacid and diluting with distilled water to a liter.\\n1 cc. 0.000 1 gram lead.\\nFive narrow cylinders of colorless glass are rilled\\nwith\\n99 97) 95) an( i 93 cc water,\\nto which are added\\ni, 3, 5, and 7 cc. lead solution,\\nrepresenting\\n1, 3, 5, and 7 milligrams lead,\\nin a liter of the mixture.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0108.jp2"}, "109": {"fulltext": "ANALYSIS OF WATER 97\\nIn a fifth cylinder is placed ioo cc. of the water\\nacidified with a few 7 drops of acetic acid.\\nTo each cylinder is now added 20 cc. of freshly pre-\\npared hydrogen snlphid w T ater, shaking well, and com-\\nparing the intensity of the brown color formed in the\\nwater with that of the cylinders of lead solution. If\\nit compares with the cylinder containing 5 cc. of the\\nlead solution, then 100 cc. of water contain 0.5 milli-\\ngram of lead, or a liter contains 5 milligrams.\\n9. Detection of Zinc in Water\\nThe presence of zinc in water may be determined\\nby treating some of the water with ammonium sul-\\nphid, when any zinc that may be present will be pre-\\ncipitated as zinc sulphid. When lead and iron are\\nalso present they are likewise precipitated as sulphids,\\nand these must be removed by boiling with sodium\\nacetate in weak acid solution and filtering. The zinc\\nis then recovered from the filtrate.\\n10. Estimation of Carbon Dioxid\\n1. Free carbon dioxid. 100 cc. of water are placed\\nin an Erlenmeyer flask and 10 drops of phenolphthal-\\nein solution are added and titrated with 1/10 normal\\nsodium hydroxid solution until the liquid is distinctly\\nred. The titration should be repeated and nearly the\\nentire amount of sodium hydroxid added at once, the\\ntitration being completed under constant agitation of\\nthe liquid.\\n1 cc. 1/10 normal sodium hydroxid 4.4 milligrams\\ncarbon dioxid.\\nNaOH C0 2 NaHC0 3\\n7", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0109.jp2"}, "110": {"fulltext": "98 PRACTICAL HYGIENE\\n2. Partially combined and free carbon dioxid\\n(Trillick s modification of Pettenkofer s method). The\\nfree and partially combined carbon dioxid are com-\\nbined by the addition of barium hydroxid, thereby\\nprecipitating the whole of the carbon dioxid, the ex-\\ncess of the barium hydroxid being determined by\\ntitration.\\nThe solutions required are\\ni. Barium hydroxid of the same strength as that\\nused in carbon dioxid determination in air.\\n2. Barium chlorid solution i io; neutral.\\n3. Hydrochloric acid, of which 1 cc. 1 milligram\\ncarbon dioxid. About 7 cc. of hydrochloric acid of\\n1. 1 24 specific gravity are diluted to 1 liter with water,\\nso that 22 cc. of the acid will neutralize 10 cc. 1/10\\nnormal sodium hydroxid.\\n4. The indicator solution of phenolphthalein, or\\ncochineal.\\nIn a determination flask of 200 cc. capacity, closed\\nwith a rubber stopper, is placed, by means of a pipette,\\n100 cc. water, 45 cc. barium hydroxid, and 5 cc. barium\\nchlorid this is then well shaken and allowed to stand\\nfor twelve hours. Through the addition of the barium\\nhydroxid (1) the free and half-combined carbon dioxid\\nin the water is changed into insoluble barium carbon-\\nate (2) the calcium carbonate in the water, being now\\nrobbed of its solving material through the operation\\nin (1), also becomes insoluble; (3) the alkaline car-\\nbonate in the water is changed into alkaline chlorid\\nthrough the action of the barium chlorid and is con-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0110.jp2"}, "111": {"fulltext": "ANALYSIS OF WATER 99\\nverted into insoluble barium carbonate; (4) all the\\nmagnesium in the water is precipitated as magnesium\\nhydroxid, and the magnesium carbonate, which is con-\\nverted into insoluble barium carbonate and magnesium\\nchlorid by the action of the barium chlorid, is precipi-\\ntated finally as magnesium hydroxid; and (5) all the\\nsulphur trioxid is combined with barium, and in place\\nof the same the equivalent quantities of sulphur tri-\\noxid combined with bases.\\nThe resulting precipitate contains all the carbon\\ndioxid contained in the water in the form of barium\\nand calcium hydroxid, and all the magnesium as hy-\\ndroxid, and all the sulphur trioxid as barium sulphate.\\nDuring the sedimentation the strength of the barium\\nhydroxid is determined by taking 100 cc. of distilled,\\ncarbon dioxid free (boiled) water, 45 cc. barium hy-\\ndroxid, and 5 cc. barium chlorid solulion, mixing well,\\nand taking by means of a pipette 50 cc. 1/3 the\\ntotal amount), placing it in a flask with several drops\\nof phenolphthalein solution, then adding the hydro-\\nchloric acid from a burette until the red color has dis-\\nappeared.\\nAfter twelve hours the precipitate in the flask has\\nbecome crystalline 50 cc. are then taken of the clear\\nsupernatant solution by means of a pipette and titrated\\nas above. The difference in the amount of hydro-\\nchloric acid required, expresses the quantity of barium\\nrequired (1) to precipitate the free and half-combined\\ncarbon dioxid, and (2) to precipitate the magnesium.\\nThe magnesium in the water must then be deter-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0111.jp2"}, "112": {"fulltext": "JOO PRACTICAL HYGIENE\\nmined gravimetrically and by multiplication with\\ni.i, calculated to carbon dioxid.\\n40\\nIf for example for 50 cc. of the mixed solution a\\ncc. hydrochloric acid have been required, and for the\\nwater b cc, and the amount of magnesium in the wa-\\nter is m milligram in 100 cc, then 1 liter of water\\ncontains [3 X (a b) 1.1 X nt\\\\ X 10 milligrams\\nfree and half-combined carbon dioxid.\\nExample. A water contains in 100 cc 3.3 milligrams\\nMgO m.\\n50 cc of the mixed solution 12.7 cc. hydrochloric acid.\\n50 cc water 7.0 cc\\nThen 1 liter of the water contains [3 X (12.7 7.0)\\ni.i X 3.3] X 10 milligrams free combined carbon\\ndioxid [3 X 5.7 3.63] X 10 134.7 milligrams free\\nand half-combined carbon dioxid.\\n3. Total carbon dioxid. After the removal of the\\n50 cc. the sedimentation flask still contains 100 cc.\\nand the precipitate. This remainder is now titrated\\nwith hydrochloric acid, from the amount of hydro-\\nchloric acid required is subtracted the amount re-\\nquired for the 100 cc which is known form the deter-\\nmination of the free and half-combined carbon dioxid.\\nThe remainder is the amount of hydrochloric acid re-\\nquired for the precipitate which contains all the car-\\nbon dioxid and all the magnesium.\\nAn excess of the hydrochloric acid is added (e. g.,\\n100 cc), and the flask is placed in warm water, then\\nin hot water, when all the carbon dioxid is driven off.\\nCochineal solution is now added and the solution ti-\\ntrated with 1/10 normal sodium hydroxid until it be-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0114.jp2"}, "113": {"fulltext": "ANALYSIS OF WATER IOI\\ncomes red, i. e., alkaline. If for the ioo cc. of solu-\\ntion precipitate, d cc. hydrochloric acid were used,\\nthen d 2b cc. of hydrochloric acid were required for\\nthe precipitate alone, and 1 liter of water contains\\nthen \\\\_(d 2b) 1.1 X m\\\\ X 10 milligrams total car-\\nbon dioxid.\\nExample. 100 cc. solution precipitate, required 43.3\\ncc. hydrochloric acid. 1 liter of water contains then\\n[(43-3 2 X 7.0) 1.1 X 3.3] X 10 milligrams total\\ncarbon dioxid [29.3 3.63] X 10 256.7 milligrams\\ntotal carbon dioxid.\\n4. Combined carbon dioxid. 100 cc. of the water\\nare placed in an Erlenmeyer flask and 5 drops of phe-\\nnolphthalein solution are added, the water is heated\\nto boiling and titrated with hydrochloric acid (1 cc.\\n1 milligram carbon dioxid) until after boiling for five\\nminutes the decolorized liquid does not again redden.\\n11. Alkalies Potassium and Sodium\\nThe estimation of potassium and sodium is necessary\\nonly in rare instances. Usually the indirect method\\nwill suffice, wherein the potassium and sodium is es-\\ntimated as sodium sulphate.\\n250 cc. of water are evaporated to dryness after ad-\\ndition of excess of sulphuric acid, the residue is incin-\\nerated to drive off the excess of sulphuric acid, then\\nadding some ammonium carbonate and again incin-\\nerating.\\nThe residue now contains only sulphates and silicic\\nacid. The calcium and magnesium is calculated to\\nsulphate, the silicic acid is added to it, and the whole", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0115.jp2"}, "114": {"fulltext": "102 PRACTICAL HYGIENE\\nsubtracted from the total weight. The remainder is\\nsulphate of potassium and sodium, the former being\\nexpressed as sodium sulphate.\\ni gram sodium sulphate 0.437 g ram sodium oxid.\\n12. Iron\\nIron is estimated according to the following method: 1\\nThe following are the solutions required\\ni. An oxid of iron solution of known strength,\\n0.4306 gram pure crystalline ammonio-ferrous sulphate\\nis diluted to a liter, and some hydrochloric acid\\nadded. 1 cc. 0.00005 g ram iron, or 0.00035 gram\\nferrous oxid.\\n2. Ammonium thiocyanate solution. 7.5 grams\\nammonium thiocyanate dissolved in 1 liter of water.\\n3, Hydrochloric acid (1 3). The method is based\\non the comparison of the intensity of the red color of\\na water treated with acid ammonium thiocyanate\\nsolution with the red color of a ferrous oxid solution\\nof known strength. It is a colorimetric method.\\nMethod, 500 cc. of water are placed in a porcelain\\ndish, nitric acid added, and then evaporated to about\\n50 cc, transferred to a measuring cylinder, and diluted\\nto 100 cc.\\nThe liquid is now brought into a narrow cylinder\\nof colorless glass, set on white paper, and 5 cc. of the\\nammonium thiocyanate solution and 1 cc. of diluted\\nhydrochloric acid are added to it.\\nBesides the cylinder are placed four other cylinders\\nA. Jolles Arch. f. Hygiene, 8, 402.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0116.jp2"}, "115": {"fulltext": "ANALYSIS OF WATER 103\\nof the same kind into the first is placed i, into the\\nsecond 3, into the third 5, and into the fourth 7,\\ncc. of the ferrous oxid solution. These cylinders are\\nnow filled with distilled water to 100 cc. and the color\\ncompared after several minutes with that containing\\nthe sample of water.\\nIf its color compares with that of the fourth cylin-\\nder, there are in the 100 cc. concentrated water 7 X\\n0.00005 gram of iron, or 7 X 0.00035 g ram ferrous\\noxid. This quantity of iron is contained in the 500\\ncc. of the water, or in a liter of the water there are\\n0.0007 gram or 0.7 milligram of iron, or 0.0049 g ram\\nferrous oxid.\\nQuantitative estimation of iron in water, 1 A stand-\\nard solution of iron is made by dissolving 0.7 gram of\\npure ammonia-ferrous sulphate in half a liter of water,\\nacidulating with sulphuric acid, adding sufficient per-\\nmanganate solution to convert the iron exactly into\\nferric salt, then diluting to a liter. Hydrogen peroxid\\nmay also be used in place of permanganate, taking\\ncare to dissipate the excess by boiling. 1 cc. of this\\nsolution contains 1/10 milligram of iron.\\nProcess. Evaporate 100 cc. of the water to dryness\\non a water-bath. Pour 1 cc. 50 per cent, nitric acid\\nover the residue and evaporate to dryness. Dissolve the\\nresidue in 1 cc. 10 per cent, hydrochloric acid and add\\nabout 10 cc. distilled water, filter and wash through a\\nsmall filter. Make up the filtrate to 50 cc. in a Nessler\\ntube. 1 cc. nitric acid is added and then tested with 1\\n1 According to Sutton s Volumetric Analysis, sixth edition, p.\\n194.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0117.jp2"}, "116": {"fulltext": "104 PRACTICAL HYGIENE\\ncc. potassium ferrocyanid solution. The presence of free\\nacid facilitates the process.\\nA second Nessler tube is prepared containing i cc.\\nstandard iron solution, i cc. nitric acid, enough distilled\\nwater to fill up to the 50 cc. mark, and treated with 1 cc.\\npotassium ferrocyanid solution. If the color in the two\\ntubes is not the same other tubes are prepared, with more\\nor less of the iron solution, until one is found to compare\\nin color with that containing the sample of water.\\nExample. The sample of water compared in color with\\na tube containing 2.5 cc. of the standard iron solution,\\nhence it contained 2.5 X 1/10 milligram or 1/4 milli-\\ngram of iron in 100 cc. of the water, or 2.5 milligrams of\\niron per liter of the water.\\n13. Oxygen\\nThe estimation of oxygen in water is made accord-\\ning to the method of L. M. Winkler. 1 It is based on\\nthe fact that manganous chlorid in alkaline solution\\nis oxidized to manganic chlorid through the action of\\noxygen, and with the manganic chlorid an equivalent\\nquantity of iodin is set free from an alkaline solution\\nof potassium iodid, the iodin liberated being deter-\\nmined by means of a titrated solution of sodium thio-\\nsulphate (Na 2 S 2 3\\nThe processes of the operation are as follows\\n1. MnCl 2NaOH MnO H 2NaCl\\n2Mnd H O H O Mn CXH,.\\n22 1 2 266\\n2. Mn 6 H 6 6HC1 Mn Cl 6 6H O\\nMn CL 2KI 2MnCl 2 I 2KCI.\\n2 o 2 2\\n3. I 2Na SO Na S CX 4- 2NaI.\\n*J 2 223 246\\nThe following solutions are required\\n1. Manganous chlorid solution of 40 per cent,\\nstrength.\\n1 Ber. d. chem. Ges., (1888), 2843.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0118.jp2"}, "117": {"fulltext": "ANALYSIS OF WATER IO5\\n2. Alkaline potassium iodid solution. 32 grains\\nnitrogen-free potassium hydroxid dissolved in 100 cc.\\ndistilled water, to which are added 10 grams potassium\\niodid.\\n3. Concentrated hydrochloric acid.\\n4. 1/100 normal sodium thiosulphate solution. 2.48\\ngrams sodium thiosulphate dissolved in a liter of dis-\\ntilled water.\\n1 cc. 0.055825 cc. O, at o\u00c2\u00b0 C. and 760 mm.\\n5. Starch solution as indicator.\\nThe capacity of a glass-stoppered flask of about 500 cc.\\nis carefully determined when filled with distilled water\\nat 1 5 C. up to the stopper. This flask is then filled\\nwith the water to be examined in such a manner as to\\navoid bringing it too much in contact with air.\\nWith a long pipette 4 cc. of the manganous chlorid\\nsolution and 4 cc. of the alkaline potassium iodid\\nsolution are introduced into the bottom of the flask,\\nthe stopper put in place and then the flask shaken.\\nThe yellowish-brown precipitate is allowed to sub-\\nside, and then 5 cc. of concentrated hydrochloric acid\\nare added, the stopper replaced and the flask shaken,\\nwhen the precipitate is again dissolved, but the liquid\\nbecomes brown from the iodin.\\nThe solution of sodium thiosulphate is now placed\\ninto a burette graduated to 1/10 cc. 100 cc. of the\\nbrown liquid are taken from the flask and placed\\nin an Erlenmeyer flask, and 2 cc. of starch solu-\\ntion are added when the liquid becomes bluish green.\\nThe sodium thiosulphate solution is now added from", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0119.jp2"}, "118": {"fulltext": "106 PRACTICAL HYGIENE\\nthe burette until the liquid becomes colorless. The\\ntitration is controlled by a second titration.\\nIf the volume of the flask is a cc, then the oxygen\\nin {a 8) cc. of water has been determined.\\nIf ioo cc. of the liquid required \u00c2\u00a3cc. of sodium thio-\\nsulphate solution, then a cc. require cc. of sodi-\\n1 a SXd\\num thiosulphate, or X 0.0558 cc. oxygen.\\nThis quantity was contained in a 8 cc. then a\\nr 1000 X a X b X 0.0558\\nliter 01 water contains rr cc. otox-\\n100 X (a 8)\\nygen at o\u00c2\u00b0 C. and 760 mm.\\n14. Phosphoric Acid\\nA colorimetric method for the estimation of phos-\\nphoric acid in water, 1 Since we know that the pro-\\ntoplasm of the cells does not consist of albumin, in\\nthe usual sense of the word, but of nucleo-proteids rich\\nin phosphorus, and that consequently, in the decom-\\nposition of animal and vegetable excreta, we have not\\nonly nitrogenous substances but also phosphorous com-\\npounds gaining access to water.\\nIn the method usually given for the determination\\nof phosphoric acid in water, the water (three liters) is\\nconcentrated to a small volume, treated with nitric\\nacid, treated with ammonium phosphomolybdate\\nand the phosphoric acid precipitated from the water\\nis then estimated as magnesium pyrophosphate. In\\nthis process the presence of organic matter causes the\\nDr. Adolf Jolles Arch. f. Hygiene, 34, 22.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0120.jp2"}, "119": {"fulltext": "ANALYSIS OF WATER 107\\nresult to express only from 65 to 80 per cent, of the\\nphosphoric acid present. By evaporating the water\\nto dryness and treating the residue with nitric acid,\\nand again evaporating to dryness, then dissolving the\\nresidue in 10 cc. of dilute nitric acid, a much higher\\nresult is obtained than in the former process.\\nJolles method is based on the fact that small amounts\\nof phosphoric acid salts produce a yellow color with\\npotassium molybdate, which color is increased in in-\\ntensity with increased temperature up to about 8o\u00c2\u00b0 C,\\nwhere the maximum intensity is obtained. The method\\nis extremely sensitive and allows the detection of\\n0.000025 g* ram phosphorus pentoxid, in the cold in\\n20 cc. of liquid, and in warm solutions 0.0000025\\ngram can be detected.\\nReageitt. Dissolve 8 grams chemically pure potas-\\nsium molybdate in 50 cc. of water and add 50 cc.\\nchemically pure nitric acid of 1.20 specific gravity and\\nfilter.\\nSolution of sodium phosphate for comparisons,\\nNaHPO 12HO.\\n2 4 2\\nSolution A. Fresh uncrystallized sodium phosphate,\\n53.23 grams, dissolved in a liter of water. This is a 1\\nper cent, solution. From this a series of dilute solutions\\nare prepared.\\nSolution B.\u00e2\u0080\u0094 10 cc. Sol. A -f 90 cc. H,0 0.1 P,0 5\\nC\u00e2\u0080\u0094 10 cc. Sol. B 4- 90 cc. H,0 0.01 P. 2 5\\nD.\u00e2\u0080\u0094 10 cc. Sol. C 90 cc. H 2 0.001 P 2 5\\nE to cc. Sol. D 90 cc. H 2 0.0001 P,0 5", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0121.jp2"}, "120": {"fulltext": "io8\\nPRACTICAL HYGIENE\\nIO.O cc.\\nSol.\\nC 0.00 1\\n7-5\\nC 0.00075\\n5.0\\ni i\\nC 0.0005\\n2-5\\ni i\\nC 0.00025\\n10.0\\ni i\\nD 0.0001\\n7,5\\nD 0.000075\\n5-o\\ni i\\nD 0.00005\\n2-5\\ni 1\\nD 0.000025\\n10.0\\ni i\\nE 0.0000 1\\n7-5\\ni i\\nE 0.0000075\\n5.o\\n1 1\\nE 0.000005\\n2-5\\ni i\\nE 0.0000025\\nper cent. P 2 5\\nIt is necessary to thoroughly remove all silicic acid\\nfrom the water as it is capable of yielding a yellow\\ncolor with the potassium molybdate. To accomplish\\nthis a liter of the water to be examined is evaporated\\nto dryness in a platinum dish, the residue treated with\\nnitric acid, and again evaporated to dryness, at 130\\nC, then dissolved in dilute nitric acid and again evap-\\norated to dryness, dissolved in nitric acid and filtered.\\nThe filtrate is diluted to 20 cc, and then tested for\\nphosphoric acid the resulting color is compared with\\nthe sodium phosphate solution.\\n15. Recording the Results in Water Analyses\\nThe results obtained in the analysis of water for\\nsanitary purposes are recorded either according to the\\nEnglish system (in grains per gallon of water) or ac-\\ncording to the metric system (in parts per 100,000 or\\nper 1,000,000 parts of water).\\nThe metric system is the preferable one for our pur-\\nposes inasmuch as the metric system of weights and\\nmeasures has been employed exclusively in the de-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0122.jp2"}, "121": {"fulltext": "ANALYSIS OF WATER 109\\nscription of the various methods of analysis and in the\\npreparation of the standard solutions.\\nIn the different examples given under the various\\nmethods the results have always been calculated to\\nmilligrams per liter of water. With such a basis it\\nwill be easy to express the results either in parts per\\n100,000 or in parts per 1,000,000, since the number of\\nmilligrams per liter at once represent the parts in\\n1,000,000 parts of water, and, in consequence, this\\nmethod of recording the results is given the prefer-\\nence.\\nIf it is desired to express the results in grains per\\ngallon this is readily done by multiplying the results\\nin parts per 100,000 by 0.7 and the result obtained is\\nthe number of grains per gallon.\\n16. Interpretation of the Results in Water Analyses\\nThe form of the most serious pollution of water is\\norganic matter. This may be present as living orga-\\nnisms and the product of organic life, or the matter may\\nbe present in various stages of decomposition. It is\\ncustomary to classify the condition of the organic mat-\\nter by means of the condition of the nitrogenous or-\\nganic matter. In this way the albuminoid ammonia\\nis taken as an indication of the amount of undecom-\\nposed organic matter. When decomposition has be-\\ngun its extent is indicated by the presence of so-called\\nfree ammonia. Further changes result in converting\\nthe free ammonia into nitrites, and finally into nitrates,\\nthe last stage in the process of alteration by which", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0123.jp2"}, "122": {"fulltext": "IIO PRACTICAL HYGIENE\\norganic matter is converted again into a form suited\\nfor assimilation by organic life.\\nIt. is imprudent to state that because a water con-\\ntains unusually large amounts of any of these com-\\npounds of nitrogen that it is necessarily polluted. The\\nsignification of each compound may be stated briefly\\nas follows, it being understood that only surface wa-\\nters are now under consideration Albuminoid ammo-\\nnia was formerly considered as an indication of the\\npresence of an equivalent amount of organic matter\\nliable to decay, but within recent years it has been\\nfound that this is not necessarily so. The lesson to\\nbe learned from this compound is indicated most clearly\\nby successive analyses of a water, for if the albuminoid\\nammonia remains unchanged for months without de-\\nvelopment of free ammonia, a comparatively large\\namount may be harmless. This is especially the case\\nwith brown coloring-matter which water dissolves\\nfrom grasses, leaves, and roots, according to Dr. T. M.\\nDrown, who instances the very dark water of Acushuel\\nRiver, the source of New Bedford s supply, as a water\\ncontaining enough albuminoid ammonia to be classi-\\nfied as a polluted water according to most European\\nstandards.\\nFree ammonia is a characteristic ingredient of sew-\\nage, but the conditions which influence its develop-\\nment and accumulation in natural waters are so vari-\\nous that one must be extremely cautious in deciding\\nwhat is the signification of its presence in individual\\ncases. It may be safely said that if an analysis shows a\\nlarge amount of free ammonia in a water from a catch-\\nment area having dwellings upon it, further investiga-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0124.jp2"}, "123": {"fulltext": "ANALYSIS OF WATER I I I\\ntion should be made into the causes of its presence.\\nNitrites are compounds of much interest, as their\\namount is generally found to vary less with the sea-\\nsons than the other organic derivatives, and they are\\ntherefore a better index of sewage pollution. High\\nfree ammonia and high nitrites together are character-\\nistic of recent pollution, and when they are uniformly\\nhigh in a surface water they point to continuous pol-\\nlution.\\nNitrates indicate the complete change of organic to\\ninorganic matter, and their importance can only be\\nsettled satisfactorily when the surface from which they\\nwere derived is known. The organic matter that is\\ndischarged into a w r ater is rarely dangerous if it is\\ngiven time to change to nitrates, but the disease germs\\nthat may have been discharged at the same time may\\nstill be a source of danger when the chemical changes\\nare over. Chemical analysis, by indicating the amount\\nof albuminoid and free ammonia, nitrites, and nitrates,\\npoints to the possibility of such germs being in the\\nwater and the time that has elapsed since they were\\ndischarged into it. The time is probably least when\\nthe albuminoid ammonia is high, and greatest when\\nthe nitrates are high in the analysis.\\nChlorin is also a valuable indication of sewage pol-\\nlution. The amount of chlorin found in natural wa-\\nters varies greatly according to the proximity of the\\nocean, deposits of salt, or the proximity of natural gas\\nand oil regions. In Massachusetts the chlorin content\\nof surface waters decreases as the distance from the\\nseashore increases. It is therefore necessary to know", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0125.jp2"}, "124": {"fulltext": "112 PRACTICAL HYGIENE\\nalways the normal chlorin content of surface waters of\\nthe locality from which the sample is derived before\\ndeciding upon the signification of the amount found\\nin the sample analyzed. The chlorin in the reservoirs\\nof the Boston water system has been found to vary di-\\nrectly with the population upon the respective water-\\nsheds. High free ammonia, high nitrites, and high\\nchlorin are considered to afford complete proof of sew-\\nage pollution. Dr. Drown has pointed out, however,\\nthat when the chlorin is not much above the normal\\nin waters containing high free ammonia and nitrites,\\nthe inference is that the pollution comes from farm-\\nyards or manured fields, a distinction that is often im-\\nportant to make.\\nWanklyn gives the following rules for the interpre-\\ntation of the results obtained in a water analysis: If\\na water yield o.oo part per 1,000,000 of albuminoid\\nammonia it may be passed as organically pure, despite\\nmuch free ammonia and chlorin, and if, indeed, the\\nalbuminoid ammonia amount to 0.02, or to less than\\n0.05 part per 1,000,000, the w^ater belongs to the\\nclass of pure waters. When the albuminoid ammonia\\namounts to 0.05 parts, then the proportion of free am-\\nmonia becomes an element in the calculation and I\\nshould be inclined to regard with some suspicion a\\nwater yielding a considerable quantity of free ammo-\\nnia, along with 0.050 part of albuminoid ammonia.\\nFree ammonia, however, being absent or small, a wa-\\nter should not be condemned unless the albuminoid\\nammonia reaches something like 0.10 part per 1,000,-\\n000. Albuminoid ammonia above 0.10 per 1,000,000", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0126.jp2"}, "125": {"fulltext": "ANALYSIS OF WATER\\n113\\nbegins to be a very suspicious sign; and over 0.15\\npart ought to condemn a water absolutely.\\n17. Limits of Impurity in Water\\nAccording to the amounts of impurity in water we\\nmay form four classes into which we classify the wa-\\nters according to the degree of pollution. These classes\\nare pure, usable, suspicious, and impure. In the fol-\\nlowing table these classes of water are given with the\\ndegrees of impurities in each.\\nTable III.\\nApproximate Composition of Drinking-water.\\n(Stated in parts per million.\\nChemical Con-\\nstituents.\\nPure.\\nUsable.\\nSuspicious.\\nImpure.\\nTotal Solids\\n70.000\\n430.000\\n430.000 to\\n710.000\\n710.000\\nChlorin\\n14.000\\n40.000\\n40.000 to\\n70.000\\n70.000\\nX. as Nitrates\\n0.140\\n1. 120\\n1 200 to\\n2.400\\n2.400\\nN. as Nitrites\\nnil\\nnil\\n0.500\\n0.500\\nN. as free NH 3\\n0.020\\n0.050\\n0.050 to\\nO.IOO\\nO.IOO\\nN. as alb. NH 3\\n0.050\\nO.IOO\\n0. 100 to\\n0.125\\n0.125\\nOrganic matter\\n0.250\\n1. 000\\n1. 000 to\\n1.500\\n1.500", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0127.jp2"}, "126": {"fulltext": "PART III\\nSOIL\\ni. MECHANICAL ANALYSIS\\na. Collection of the Sample\\nIn collecting a sample of soil for analysis it is im-\\nportant to exercise care in order that the portion col-\\nlected represent, as far as possible, the average com-\\nposition of the soil of the locality. The surface cov-\\nering is carefully removed and then, by means of a\\nspade, portions of equal thickness and extending to\\nthe same depth are taken up and thoroughly mixed.\\nFrom the mixture obtained in this manner samples\\nmay be taken for the analysis. In instances where it\\nis desired to ascertain the porosity and filtering capac-\\nity of the soil in situ a sample may be taken by\\nmeans of a metal cylinder.\\nb. Separation of the Different Sized Grains\\nFor hygienic purposes it is usually considered nec-\\nessary to separate the soil particles into a number of\\ngroups corresponding to their size, because of the great\\nimportance of the relative proportions of the number\\nof particles belonging to these different groups in a\\nparticular soil from the influence it would exert upon\\nthe health of the locality. The porosity and drainage\\ncapacity of a soil are almost wholly dependent upon", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0128.jp2"}, "127": {"fulltext": "MECHANICAL ANALYSIS 115\\nthe relative proportions which the size of the different\\ngroups of soil particles bear to each other. A rela-\\ntively large quantity of soil particles falling within\\nthe groups representing the smaller sized grains will\\nlessen, to a considerable degree, the adaptability of such\\nsoil for a building site. Soil is damp or dry accord\\ning to the preponderance of the smaller or larger sized\\ngrains making up its structure.\\nSieving the soil, The separation of the soil parti-\\ncles into groups according to their sizes is accom-\\nplished most readily by means of a set of sieves hav-\\ning meshes of different sizes. Knopp has devised a\\nscale in which the soil particles are separated into six\\ngroups according to their size, as follows:\\n1st group particles coarser than 7 mm.\\ncoarse gravel.\\n2nd ranging from 4 to 7 mm.\\nmedium gravel.\\n3rd 2 4 mm.\\nfine gravel.\\n4th l 1 2 mm.\\ncoarse sand.\\n5th 0.3 1 mm.\\nmedium sand.\\n6th finer than 0.3 mm.\\nfine sand.\\nProcess. An average sample of the soil is taken, iooo\\ngrams are carefully weighed, dried at ioo\u00c2\u00b0 C, and then\\nsieved. The quantity remaining in each of the sieves is\\nthen weighed, as follows\\nCoarse gravel 544 grams. Coarse sand 55 grams.\\nMedium =156 grams. Medium --=64 grams.\\nFine 90 grams. Fine 90 grams.\\nTotal 999 grams, loss 1 gram.\\nElutriation. The separation of the different sized\\ngrains of soil into groups may also be accomplished\\nby the process known as elutriation. This is a very\\ndelicate and tedious operation and is rarely employed\\nin the analysis of soil for hygienic purposes. This", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0129.jp2"}, "128": {"fulltext": "Il6 PRACTICAL HYGIENE\\nprocess is more generally employed in the analysis of\\nsoil for agricultural purposes.\\nKnopp has devised a small apparatus for the further\\nseparation of the soil particles comprising the sixth\\ngroup of his scale, those finer than 0.3 mm. in diame-\\nter. This apparatus consists of a glass cylinder 55\\ncm. in height which is fitted with four glass tubes\\nwith stop-cocks coming off from the side, the first at\\n10 cm. from the bottom, and the others 10 cm. above\\neach other.\\nProcess. The soil particles forming the sixth group\\nin the mechanical analysis described above, are placed\\ninto the apparatus. Distilled water is then added until\\nit rises to a point 10 cm. above the highest glass tube.\\nThe contents of the cylinder are now agitated thoroughly\\nfor five minutes, then, after standing undisturbed for five\\nminutes, the stop-cock of the upper glass tube is opened\\nand the dirty water collected in a porcelain capsule. After\\nagain agitating the contents of the cylinder for five min-\\nutes, and allowing another five minutes for the subsidence\\nof the coarser particles, the second stop-cock is opened\\nand this portion of dirty water is also collected in a por-\\ncelain capsule. In like manner a third and fourth por-\\ntion are collected from the third and fourth tubes. The\\ncylinder is then again filled with distilled water, and, in\\nlike manner, the dirty water from each of the tubes col-\\nlected in the capsules containing that portion previously\\ncollected from each of the tubes. The dirty water col-\\nlected in each of the four porcelain capsules, as well as\\nthe portion remaining in the bottom of the apparatus, is\\nthen carefully evaporated to dryness and weighed.\\n2. PHYSICAL ANALYSIS OF SOIL\\na. The Porosity of Soil\\nThe porosity of a soil is dependent upon several dif-\\nferent factors, as the looseness or compactness with", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0130.jp2"}, "129": {"fulltext": "MECHANICAL ANALYSIS 117\\nwhich the soil particles are packed together, the pre-\\nponderance of the larger or smaller sized soil particles,\\nand also what is known as the separate grain struc-\\nture of the different soil particles; t. e., whether they\\nare distinctly angular or distinctly spherical in form,\\nand the amount of gradation between these two ex-\\ntremes. All these factors have a direct bearing upon\\nthe amount of air and water that the soil is capable of\\ntaking up and also on the movement of the air and\\nwater within the soil. It is evident that the volume\\nof the pores varies within wide limits in different soils.\\nEstimation of the porosity. For the estimation of\\nthe porosity of soil as it occurs in nature a metallic\\ncylinder 20 cm. in height and 5 cm. in diameter is\\npressed into the soil and a corresponding portion of\\nthe soil thus removed. The bottom of the cylinder is\\nclosed with wire gauze or with a perforated metal\\nplate. According to the formula r 2 X 3.14 X// the\\nvolume of soil taken is 2.5 X 2.5 X 3.14 X 20 392.5\\ncc. This same cylinder may also be used to estimate\\nthe porosity of a sample of soil taken from a mixture.\\nIt is carefully filled with the soil and well packed by\\ntapping the cylinder on the work table. After the\\nsample of soil has been thus carefully collected it is\\ntransferred from the cylinder to a 1000 cc. measuring\\ncylinder containing 500 cc. of distilled water. The\\nvolume of the mixture of soil and water is then read\\noff, and this amount deducted from the sum of the\\nvolume of soil and water employed 500 -j- 392.5 cc.\\n892.5 cc. For instance, if the volume of the mix-\\nture of soil and water is 840 cc, then the volume of", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0131.jp2"}, "130": {"fulltext": "Il8 PRACTICAL HYGIENK\\nthe pores is 52.5 cc, or 392.5 52.5 100 x\\n13.37 per cent., the porosity of the soil.\\nPettenkofer s method, Another method for esti-\\nmating the porosity of the soil, devised by v. Petten-\\nkofer, consists in placing the dried soil into a glass\\ntube 30 cm. in length, a portion 18 cm. in length\\nhaving a diameter of 25 mm., and the remaining 12\\ncm. only 5 mm. in diameter, which is graduated at 50\\ncc. The narrow portion of the tube is connected be-\\nlow T with a burette by means of rubber tubing on\\nwhich is fastened a screw-clamp, the burette and rub-\\nber tubing containing distilled water. The tube is\\nfilled with the soil to be examined, up to the 50 cc.\\nmark then on opening the screw-clamp the water\\npasses into the tube, and when it appears just above\\nthe column of the 50 cc. of soil in the tube the clamp\\nis closed and the quantity of water so used is noted by\\nreading the burette.\\nCalculation of the results. 50 cc. of the dry soil ab-\\nsorbed 9.5 cc. of water; then 50 9.5 100 x 19 per\\ncent., the porosity of the soil.\\nb. Water Capacity of Soil\\nAccording to the relative size of the soil particles,\\nand consequently the porosity of the soil, different\\nsoils take up and retain varying quantities of water.\\nWhen the porosity is great the amount of w 7 ater re-\\ntained is small as compared with soil composed of\\nsmaller particles. The water capacity of soil is ex-\\npressed in per cent, of the volume of the pores.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0132.jp2"}, "131": {"fulltext": "MECHANICAL ANALYSIS 119\\ni. Estimation with the metal cylinder. The wa-\\nter capacity of soil may be estimated by means of the\\nmetal cylinder used in estimating the porosity. The\\ncylinder is weighed, and then filled with the sample\\nof soil and again weighed. The soil is now saturated\\nwith water by holding the cylinder in a beaker of dis-\\ntilled water, whereby the water passes through the\\nperforated bottom of the cylinder and gradually dis-\\nplaces all the air and fills the pores of the soil. As\\nsoon as the surface of the soil is covered by the water\\nwithin the cylinder, and every portion of the soil has\\nbeen thoroughly saturated, the cylinder is removed\\nfrom the beaker and the excess of the water allowed\\nto drain away. When the water has ceased dropping\\nthe exterior of the cylinder is carefully dried. The\\nweight of the cylinder and moistened soil are now as-\\ncertained, when the increase in the weight of the\\ncylinder will represent the weight of the water re-\\ntained in the soil.\\nExample. The porosity of the soil has been found to\\nbe 13.37 P er cent.\\nWeight of cylinder and soil 1050 grams,\\nempty 250 grams.\\nthe soil 800 grams.\\nVolume of the soil 39 2 -5 cc.\\nAfter saturation with water\\nWeight of cylinder and moistened soil 1095 grams.\\ndry 1050 grams.\\nIncrease in weight of the soil 45 grams.\\nTherefore 800 grams, or 392.5 cc. of soil have retained\\n45 grams, or 45 cc. of water. The 392.5 cc. of soil, have\\npores equal to 52.5 cc, or 13.37 P er cent. Of the 52.5\\ncc. of pores 45 cc. remained filled with water, or\\n52.5 45 100 ^=85.81 cc, or 85.81 per cent.\\nthe water capacity.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0133.jp2"}, "132": {"fulltext": "120 PRACTICAL HYGIENE\\nThe soil may also be moistened by slowly pouring\\nthe water into the top of the cylinder until it pene-\\ntrates through the soil and flows out at the bottom.\\nThe results obtained by these two methods are not\\nexactly the same the former method gives somewhat\\nhigher results and seems most likely to afford results\\nthat are satisfactory.\\n2. The Pettenkofer apparatus. The water capac-\\nity of the soil may also be estimated by means of the\\nPettenkofer apparatus. After the soil has been mois-\\ntened with water, as in the determination of the po-\\nrosity, the reading of the burette is taken. The rubber\\ntubing is now removed and the excess of water allowed\\nto drain away and collected in a graduated measur-\\ning cylinder. The difference between the reading of\\nthe burette and the water drained away will represent\\nthe water capacity, or the amount of water retained\\nin the soil.\\nc. The Drainage Capacity of Soil\\nThe drainage capacity of a soil is of great hygienic\\nimportance, and, like the porosity and water capacity,\\nis dependent upon the separate grain structure of\\nthe soil. It is directly dependent upon the water ca-\\npacity since it represents the quantity of water that is\\ncapable of penetrating through it. The unit of meas-\\nurement of the drainage capacity of soil is the amount\\nof water that is capable of penetrating through a defi-\\nnite volume of clean, coarse sea gravel. If, for in-\\nstance, 50 cc. of coarse sea gravel absorb 40 cc. of wa-\\nter, as estimated by the Pettenkofer method, of which", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0134.jp2"}, "133": {"fulltext": "MECHANICAL ANALYSIS 121\\n35 cc. drain away, equal to 70 cc. of water for 100\\ncc. of gravel. The 70 cc. of water draining away\\nfrom 100 cc. of gravel are represented as 1 in the com-\\nparison of the drainage capacity of any soil with coarse\\nsea gravel, the result being expressed in decimal frac-\\ntions of 1, the unit of comparison.\\nExample. 50 cc. of a sample of soil are placed in the\\nglass tube of the Pettenkofer apparatus and the water\\nallowed to pass slowly from the burette until it covers\\nthe column of soil to the extent of several centimeters,\\nw r hen the excess of water is allowed to flow 7 back until it\\nis just on a level with the surface of the column of soil.\\nThe quantity of water absorbed by the soil is then noted,\\nindicating the porosity of the soil. The water is now al-\\nlowed to drain away from the soil and is collected in a\\n100 cc. measuring cylinder, representing the drainage\\ncapacity of the soil, while the amount of water retained\\nrepresents the water capacity. If the 50 cc. of soil used\\nabsorbed 25 cc. of water, its porosity is equal to 50 per\\ncent. Of the 25 cc. of water absorbed 15 cc. drained\\naway, or 30 cc. with 100 cc. of the soil. Therefore the\\ndrainage capacity is 70 30 1 .r 0.428, coarse sea\\ngravel being taken as unity.\\nd. Estimation of Moisture in Soil\\nSoil moisture is estimated by taking a known quan-\\ntity of the soil, 10 or 100 grams, drying it at ioo\u00c2\u00b0\\nC, and again weighing it. The loss in weight repre-\\nsents the amount of moisture driven off. The result\\nis expressed in per cent, of the volume of soil taken.\\ne. Estimation of the Level of the Ground-water\\nAt varying depths below the surface of the soil all\\nthe interstices are filled with water, the level of which\\nis subject to fluctuation from various causes, as the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0135.jp2"}, "134": {"fulltext": "122 PRACTICAL HYGIENE\\namount and frequency of rainfall, the proximity to\\nstreams and bodies of water either above or below the\\nsurface, the amount of evaporation that takes place\\nfrom the surface, the nature of the surface covering,\\netc. The movement of the ground-water takes place\\nboth vertically and horizontally. Since it has been\\nsupposed that the height of the level of the ground-\\nwater influences to some extent the propagation and\\nspreading of certain diseases, as typhoid fever and\\ncholera, it is considered necessary for the hygienist to\\nstudy the movements and fluctuations in the level of\\nthe ground-water.\\nThe height of the level of the ground-water may be\\ndetermined by ascertaining the depth at which water\\nstands in a well, or in special borings made for the\\npurpose. The measurement is made either by means\\nof a long rod or a weighed tape-measure. A special\\napparatus devised by Pettenkof er for this purpose con-\\nsists of a number of small cups fixed to a rod which\\nis lowered into the water when the uppermost cup that\\ncontains water indicates the level of the water. Sev-\\neral other mechanical devices have been constructed\\nfor this purpose. The measurement must be made\\nfrom a fixed point at the top of the well and the ele-\\nvation of this point above the sea-level accurately de-\\ntermined. For purposes of comparison it is also nec-\\nessary to make a number of observations on other\\nwells or on borings in the vicinity. It is also neces-\\nsary to determine the effect, upon the level of the wa-\\nter, of pumping water from the well for some hours.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0136.jp2"}, "135": {"fulltext": "MECHANICAL ANALYSIS 1 23\\nCourse of the ground-water. The direction in\\nwhich the ground-water moves is influenced by the\\ndirection in which surface streams are flowing, since,\\nlike these, it usually tends toward the sea. The direc-\\ntion and degree of movement which it undergoes may\\nbe determined by placing some substance in one of a\\nseries of borings and noting the direction and rapidity\\nof the movement by computing the time required to\\nconvey the substance used to the surrounding borings\\nin succession whereby the direction of the movement\\nwill also be indicated.\\nf. Estimation of the Amount of Carbon Dioxid in\\nSoil Air\\nThe amount of carbon dioxid in soil air is obtained\\nby means of the Pettenkofer tube method. The ab-\\nsorption tube containing barium hydroxid solution of\\ndouble strength is attached to the top of a driven well,\\nby means of glass and rubber tube connections: The\\nair is aspirated through the absorption tube by means\\nof an aspirator. The driven wells used for this pur-\\npose consist of an iron cylinder, closed at the lower\\nend, about 2 meters in length, which are driven into\\nthe soil. The lower end of the tube is closed with a\\npointed metal cap, above which are the perforations\\nfor the entrance of the soil air. The top of the tube\\nis closed by means of a metal screw-cap. In order to\\nprocure the sample of air from the bottom of the well\\na glass tube is lowered into the well and held in place\\nby a closely fitting perforated cork, so that the top of\\nthe tube is on a level with the top of the well and may\\nbe connected with the Pettenkofer absorption tube.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0137.jp2"}, "136": {"fulltext": "124 PRACTICAL HYGIENE\\ng. Estimation of the Soil Temperature\\nThe soil temperature is estimated by constructing a\\nwell 3 meters in depth, lined with wood, into which\\na block of wood of the same size will slide easily. At-\\ntached to this sliding block of wood are several ther-\\nmometers, one above the other, penetrating to definite\\ndepths of the soil. The block of wood carrying the\\nthermometers may be so constructed as to allow its\\nbeing raised and lowered by means of a weight and\\npulley.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0138.jp2"}, "137": {"fulltext": "PART IV\\nSANITARY ANALYSIS OF FOODS\\nCHAPTER 1. MILK\\nNature and composition of milk, Milk, the secre-\\ntion of the mammary glands of mammels, is an aque-\\nous solution of casein, lactose, and small quantities\\nof mineral matter, and holds in suspension a quantity\\nof fat in the form of minute globules. Normal milk\\nis an opaque, white or yellowish-white liquid, of some-\\nwhat sweetish taste, and possesses an odor resembling\\nthat of the animal from which it has been derived.\\nThe reaction of fresh milk is amphioteric i. e., it turns\\nred litmus blue and blue litmus red. Its specific grav-\\nity ranges from 1028 to 1035.\\nComposition of Milk (Hirt).\\nWater\\nCasein\\nA1UU-\\nmin\\nJLUlcU p\\nAlbumin\\nLactose\\nSalts\\nHuman\\n87.09\\n0.63\\n2-35\\n2.48 3.90\\n6.04\\n0.49\\nCow\\n87.41\\n3.01\\n0.75\\n3.41 3.66\\n4.82\\n0.70\\nEwe\\n81.63\\n4.09\\n1.42\\n6.95 5-83\\n4.86\\n0.73\\nAss\\n90.04\\nO.60\\ni-55\\n2.00 I.39\\n6.25\\n0.31\\nMare\\n90.71\\n1.24\\n0.75\\n2.05 1. 17\\n5-70\\n0.37\\nGoat\\n89.91\\n2.87\\n1. 19\\n3.69 4.09\\n4-45\\nO.86\\nEXAMINATION OF MILK\\na. Physical Examination\\nThe physical examination of milk embraces the de-\\ntection, through the senses, of such variations in its", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0139.jp2"}, "138": {"fulltext": "126 PRACTICAL HYGIENE\\ncharacter as are denoted by its appearance, taste, and\\nodor when compared with a sample of fresh milk.\\ni. Specific gravity. The specific gravity of milk\\nvaries with the temperature, the average at 15 C.\\nbeing 1030; at 37.5 C, the specific gravity of the\\nsame milk is 1024. The specific gravity of milk is\\nlowered by the addition of w r ater, while the removal\\nof fat raises its specific gravity, and, consequently, the\\nnormal specific gravity of good milk may be main-\\ntained by the simultaneous addition of water and the\\nremoval of fat. This is a common form of adultera-\\ntion of market milk.\\nDetermination of the specific gravity. The specific\\ngravity of milk may be determined by means of the\\nlactodensimeter of Quevenne. The scale of this in-\\nstrument shows the specific gravity in degrees Que-\\nvenne by using only the second and third decimal, as\\n32 Quevenne indicates a specific gravity of 1032.\\nThe sample of milk is well mixed by pouring it\\nseveral times from one vessel into another, or by gen-\\ntly agitating it for several minutes, w T hen it is trans-\\nferred to the cylinder of the instrument, filling it up to\\nthe mark near the top. The temperature of the milk\\nis now noted with a small mercurial thermometer.\\nThe lactodensimeter is then dried and floated in the\\nmilk. When it has become quiet the eye is brought\\non a level with the surface of the milk and the de-\\ngrees Quevenne read off on the scale, using the kwer\\nmeniscus. A second, or control, observation should\\nalways be made.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0140.jp2"}, "139": {"fulltext": "ANALYSIS OF FOODS 1 27\\nThe reading of the specific gravity is, however, only\\ncorrect when the temperature of the milk is at 15 C.\\nIf this is not the case a correction of the reading is\\nnecessary. For each degree above 15 C, 0.2 degree\\nQuevenne must be added to the observed reading,\\nwhile a corresponding amount must be subtracted from\\nthe reading for each degree below 15 C.\\nThe specific gravity of milk increases during the\\nfirst twenty-four hours from 1 to 1.5 degrees Que-\\nvenne, and it is preferable, therefore, to place the sam-\\nple of milk on ice for several hours before making the\\nobservation. The specific gravity of milk is also\\nreadily determined by means of a Westphal balance.\\nIn this determination the temperature of the milk\\nshould be, as nearly as possible, at 15 C.\\n2. Estimation of fat in milk. In the examination\\nof market milk by inspectors the fat is usually deter-\\nmined by means of optical methods.\\na, Lactoscope. The lactoscope of Feser is com-\\nmonly employed for this purpose in Germany. The\\nprinciple on which this instrument operates rests upon\\nthe fact that the degree of opacity of milk is depend-\\nent upon the percentage of fat that it contains, the\\nhigher the percentage of fat the larger the amount of\\nwater that has to be added to the milk to render it\\ntransparent.\\nThe lactoscope consists of a glass tube 3 cm. in di-\\nameter and 17 cm. long, the lower 5 cm. of the tube\\nbeing only 2.3 cm. in diameter. Within this lower\\nportion is a cylinder of white, opaque glass on which", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0141.jp2"}, "140": {"fulltext": "128 PRACTICAL HYGIENE\\nis a scale of six black lines. The expanded portion\\nof the tube also bears a scale which denotes the per-\\ncentage of fat in the milk. Each instrument is ac-\\ncompanied with a small pipette graduated at 4 cc.\\nWith this pipette 4 cc. of milk, well mixed, are trans-\\nferred to the lactoscope, when the dark lines on the\\ncylinder of opaque glass in the bottom of the tube\\ncannot be seen. Water is now added, in small quan-\\ntities, after repeated agitation, until the dark lines are\\njust visible and can be counted when the instrument\\nis held between the eye of the observer and a white\\nwall. The amount of diluted milk in the tube is then\\nread off on the larger scale, denoting the per cent, of\\nfat in the milk.\\nb. Cremometer. This instrument consists of a glass\\ncylinder into which 150 cc. of milk are placed and\\nallowed to stand in a warm room for twenty-four hours.\\nThe cylinder bears a scale at the top on which the\\namount of cream is denoted. The reading of the\\namount of cream is made on the scale of the instru-\\nment, each division of the scale representing one per\\ncent, of cream when the instrument is filled to the\\nhighest mark of the scale.\\nThese instruments are even less accurate than the\\nlactoscope, though they afford definite knowledge,\\nwithin fairly narrow limits, of the fat content of a\\nsample of milk.\\nb. Chemical Analysis of Milk\\n1. Total solids. 10 cc. of milk are placed in a\\nweighed porcelain crucible and carefully weighed.\\nThe milk is then evaporated to dryness in the drying", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0142.jp2"}, "141": {"fulltext": "ANALYSIS OF FOODS 1 29\\noven at ioo\u00c2\u00b0 C. When cool the residue is weighed.\\nExample. Grams.\\nWeight of empty crucible I2 -73\\nmilk and 22.84\\nalone io.ii\\nft residue 1.32\\nPer cent, of solids in the milk 13.056\\n2. Ash. The evaporation residue is carefully in-\\ncinerated at a low temperature until it is fully white\\nwhen the crucible is again cooled and weighed.\\nExample. Grams.\\nWeight of crucible and residue 1 4-\u00c2\u00b05\\nash 12.781\\nash 0.051\\nPer cent, of ash in the milk 0.504\\n3- Fat.\u00e2\u0080\u0094\\na. The Extraction Method, About 10 grams of\\nmilk are carefully weighed in a glass or porcelain cap-\\nsule and mixed with about 10 grams of freshly ignited\\nsand, pumice stone, or asbestos, and evaporated to dry-\\nness on a water-bath.\\nThe dish, with its contents, is then finely pulver-\\nized and transferred to a Soxhlet extraction apparatus,\\nand the fat extracted with ether for at least five hours.\\nThe ether extract of the flask is then evaporated to\\ndryness on a water-bath and the residue dried to con-\\nstant weight (at ioo\u00c2\u00b0 C.) and weighed. The increased\\nweight of the flask will represent the fat in the 10\\ngrams of milk.\\nb. Estimation of fat by means of the lactobutyrom-\\neter. The method depends on the solution of the\\nfat in ether through the action of alcohol. From the\\n9", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0143.jp2"}, "142": {"fulltext": "13\u00c2\u00b0\\nPRACTICAL HYGIENE\\nvolume of the ethereal fat solution is calculated the\\nper cent, of fat in the milk.\\nProcess. The lactobutyrometer consists of a glass\\ntube of 40 cc. capacity, closed at its lower end. 10 cc.\\nof milk are first placed into the tube, then 10 cc. of ether\\n(sp. gr. 0.725-0.730, at 1 5 C.) are added thereto. The\\nmouth of the tube is closed with the thumb or a soft cork\\nand the solutions gently mixed until a homogeneous mix-\\nture is obtained, carefully lifting the stopper from time\\nto time. Now 10 cc. of 91 per cent, alcohol (sp. gr.\\n0.8203) are added and again agitated for several minutes,\\nuntil the small clumps of casein are evenly distributed,\\nwhen the tube is placed in a cylinder containing water at\\n40 C. After fifteen or twenty minutes, when the clear,\\nyellowish ethereal fat solution has risen to the top of the\\ntube, the tube is placed in a cylinder filled with w r ater at\\n20 C, when further portions of fat will rise to the sur-\\nface. The amount of ethereal fat solution is now noted\\nby reading the scale of the instrument, when the per\\ncent, of fat can be determined by reference to Table IV.\\nTable IV\\nLactobutyrometer Table of Tollens and Schmidt\\n(From Lehmann s Handbuch.)\\nA\\nB\\nA\\nB\\nA\\nB\\n1/10 cc.\\nFat\\n1 10 cc.\\nFat\\n1 10 cc.\\nFat\\n1.0\\n1-339\\n8.0\\n2.767\\n14.5\\n4-093\\n1.5\\n1. 441\\n8.5\\n2.869\\n15.0\\n4\\n195\\n2.0\\n1.543\\n9.0\\n2.971\\n15-5\\n4\\n297\\n2.5\\n1.645\\n9-5\\n3.073\\n16.0\\n4\\n399\\n3-0\\n1.747\\nIO. O\\n3.175\\n16.5\\n4\\n501\\n3-5\\nI.849\\n10.5\\n3.277\\n17.0\\n4\\n628\\n4.0\\nI-95I\\nII. O\\n3-379\\n17-5\\n4\\n792\\n4-5\\n2.053\\n11. 5\\n3.481\\n18.0\\n4\\n956\\n5-o\\n2.155\\n12.0\\n3o83\\n18.5\\n5\\n129\\n5-5\\n2.257\\n12.5\\n3.685\\n19.0\\n5\\n306\\n6.0\\n2-359\\n13.0\\n3.787\\n19-5\\n5\\n483\\n6.5\\n2.461\\n13.5\\n3.889\\n20.0\\n5\\n660\\n7.0\\n2.563\\n14.0\\n3.991\\n20.5\\n5\\n837\\n7.5\\n2.665", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0144.jp2"}, "143": {"fulltext": "ANALYSIS OF FOODS 131\\nc. The Babcock method. A method of determining\\nfat in milk which is in very general use by dairymen\\nand creameries, and which is giving very general sat-\\nisfaction, is known as the Babcock method. In this\\nmethod a centrifugal machine is used which is capa-\\nble of making from 700 to 1200 revolutions per min-\\nute. In this method the casein is dissolved by sul-\\nphuric acid and the separation of the fat is then aided\\nby the centrifugal apparatus. The test-bottles con-\\ntaining the samples of milk are revolved in a tank\\nfilled w T ith hot water (about 95 C). The acid and\\ndissolved casein in the milk being heavier than the\\nfat are thrown outward (to the bottom of the test-bot-\\ntle) by the rapid motion of the machine, while the fat\\nrises to the top and collects in the graduated neck of\\nthe test-bottle. The separation of the fat is rapid and\\nvery complete. If the whirling is carried out as soon\\nas the acid is mixed with the milk it will not be nec-\\nessary to fill the tank with hot water, as the addition\\nof the strong acid to the milk generates enough heat\\nto cause the fat to rise to the top.\\nProcess. With the graduated pipette measure off\\n17.6 cc. of milk and place it into the test-bottle. Great\\ncare must be exercised to have the milk and cream uni-\\nformly mixed before taking the sample. Add to the milk\\nin the test-bottle 17.5 cc. of commercial sulphuric acid,\\nspecific gravity 1.82. If too little acid is added the casein\\nis not all dissolved or is not all held in solution through-\\nout the test and an imperfect separation of fat results.\\nIf too much acid is added the fat itself is attacked. After\\nadding the acid to the milk they should be thoroughly\\nmixed together by gently shaking with a rotary motion.\\nThere is a large amount of heat evolved on mixing the\\nacid and milk, and the solution, at first nearly colorless,", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0145.jp2"}, "144": {"fulltext": "132 PRACTICAL HYGIENE\\nsoon changes to a very dark brown, owing to the char-\\nring of the milk-sugar and perhaps some other constitu-\\nents of the milk.\\nAs soon as the bottles have been whirled for five min-\\nutes they are filled up to the neck with hot distilled water\\nand whirled for one minute, then filled up to the seven\\nper cent, mark with hot water and again whirled for two\\nminutes, after wdiich the amount of fat is read off on the\\ngraduated neck of the test-bottle. The fat, when meas-\\nured, should be warm enough to flow readily, so that the\\nline between the acid liquid and the column of fat will\\nquickly assume a horizontal position when the bottle is\\nremoved from the machine. Any temperature between\\n45 C. and 65 C. will answer, but the higher temperature\\nis to be preferred. The slight difference in the length of\\nthe column of fat due to the difference in temperature is\\nnot sufficient to materially affect the results.\\nTo measure the fat, take the bottle from its socket in\\nthe machine, and, holding it in a perpendicular position,\\nwith the scale on a level with the eye, observe the divi-\\nsions which mark the highest and lowest limits of the\\nfat. The difference between these gives the per cent, of\\nfat directly. Five of the divisions on the scale on the\\nneck of the test-bottle are equal to 1 per cent, of fat when\\n17.6 cc. of milk are used in the test, it being assumed\\nthat the specific gravity of the butter-fat, at the temper-\\nature at which the reading is made (about 48 C), is 0.9.\\nThe reading can easily be taken to the half division, or\\nto one-tenth per cent. In reading the position of the\\nupper level of the column of fat it is important to select\\nthe point where the upper surface of the fat meets the\\nside of the tube.\\nThe Babcock method can also be employed to deter-\\nmine the fat in cream, in skim-milk, buttermilk, and in\\nwhey. In testing the fat in cream 18 cc. should be taken\\ninstead of 17.6 cc. The reason for this is that cream is\\nlighter than milk and more of the former always adheres\\nto the pipette. A special cream te^t-bottle is to be used\\nfor the purpose of making the determination. For skim-\\nmilk a test- bottle of twice the ordinary size is usually\\nemployed.", "height": "4605", "width": "2877", "jp2-path": "handbookofpracti00berg_0146.jp2"}, "145": {"fulltext": "ANALYSIS OF FOODS 1 33\\nThe test -bottles should always be cleaned out as soon\\nas the reading has been recorded. If the bottles are al-\\nlowed to cool before cleaning it will prove far more diffi-\\ncult. It is best to rinse them thoroughly with hot water,\\nor hot water containing caustic soda solution.\\nd. The Leff man-Beam method. This method is\\nsomewhat similar to the Babcock method inasmuch\\nas the fat is separated with the aid of a centrifugal\\nmachine. In this method the casein is dissolved with\\n3 cc. of a mixture of equal parts of amyl alcohol and\\nstrong hydrochloric acid, and sufficient concentrated\\nsulphuric acid to fill the bottle up to the neck.\\nProcess. 15 cc. of a well-mixed sample of milk are\\nplaced into the test-bottle, and then 3 cc. of amyl alcohol\\nand hydrochloric acid added and mixed then the con-\\ncentrated sulphuric acid is added and the liquids thor-\\noughly mixed. The neck of the bottle is now filled to\\nabout the zero-point with a freshly prepared mixture of\\nsulphuric acid and water. The bottle is placed in the\\ncentrifugal machine and whirled for one to two minutes\\nwhen the amount of fat is read off on the graduated neck\\nof the bottle.\\nCHAPTER II. BUTTER\\nComposition of Butter.\\nPer cent.\\nFat 87.0\\nWater. 11. 7\\nCasein 0.5\\nLactose lactic acid 0.5\\nMineral matter 0.3\\nAdulteration of Butter.\\na. By the addition of water and salt in excess.\\nb. By the addition of other fats, as beef, swine or", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0147.jp2"}, "146": {"fulltext": "134 PRACTICAL HYGIENE\\nvegetable fats, as cocoanut butter, cottonseed oil, etc.\\nFor the adulteration of butter these fats must first be\\nmixed with water so that they may resemble butter.\\nMargarine and butterine are examples of artificial butter.\\nWell-cleaned, melted beef-fat is allowed to solidify\\nat 35 C. and then pressed to remove the heavy melted\\nstearin; the oleomargarine is then treated with sour\\nmilk, coloring-matter, and oil to convert it into arti-\\nficial butter.\\nThe examination of butter includes the estimation\\nof water, mineral matter, and testing for foreign fats.\\na. Water\\nInto a platinum crucible are placed 5 grams of incin-\\nerated asbestos in threads, and a glass rod. This is\\ndried at ioo\u00c2\u00b0 C. and weighed. 10 grams of butter\\nare now weighed accurately and placed in the cruci-\\nble, melted on the water-bath the fat is well mixed\\nwith the asbestos, and dried at ioo\u00c2\u00b0 C. to constant\\nweight.\\nb. Mineral Matter\\n10 grams butter are placed in a porcelain crucible,\\nweighed and melted, and the larger part of the fat is\\nremoved by filtration by passing through a filter with-\\nout ash, washing with ether. The filter is then again\\nplaced in the crucible and the residue incinerated un-\\ntil it is white and then weighed again.\\nc. Fat, Casein, and Ash\\nThe dried residue from the water determination is\\ntreated with 76 benzine and stirred until the lumps", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0148.jp2"}, "147": {"fulltext": "ANALYSIS OF FOODS 1 35\\ndisappear. The contents of the dish are then trans-\\nferred to a weighed crucible with the aid of a wash-\\nbottle containing benzine, and weighed until free from\\nfat. The contents of the crucible are now dried at\\nioo\u00c2\u00b0 C. for two hours and weighed. This weight,\\nless the weight of the crucible, represents the weight\\nof the casein and ash. The w T eight of the fat is calcu-\\nlated from the data obtained.\\nThe contents of the crucible are then ignited, below\\na red heat, and then weighed again. The loss in\\nweight represents the casein, the remainder the min-\\neral matter, chiefly salt.\\nd. Foreign Fats\\nThe pure fat is prepared by melting butter, heat-\\ning to 60 C, and filtering off the clear fat from the\\nresidue.\\nMilk-fat consists of a variable quantity of triglyc-\\nerides of different fatty acids, of which the principal\\namount is the glyceride of stearic, palmitic, and oleic\\nacids (83 to 90 per cent.); the remainder consists of\\nglycerides of the so-called volatile fatty acids (butteric,\\ncapronic, caprylic, and caprinic).\\nIn all other animal or vegetable fats the glycerides\\nof the volatile fatty acids are present in quantities of\\n5 per cent., the milk-fat being characterized by the\\nhigh proportion of combined volatile acids.\\nConsequently the estimation of the volatile fatty\\nacids is the safest method to discover adulteration of\\nthe milk-fat. The Reichert-Meissl method is best\\nadapted for this purpose.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0149.jp2"}, "148": {"fulltext": "136 PRACTICAL HYGIENE\\n5 grams of clear, filtered fat are placed in a round-\\nbottomed flask of about 300 cc. capacity and carefully\\nweighed, and 2 cc. of the sodium hydroxid solution\\nand about 10 cc. of alcohol (96 per cent.) are added.\\nThe mixture is shaken and placed on a boiling watei-\\nbath for fifteen minutes, then the alcohol is distilled\\noff. 100 cc. distilled water are now placed in the\\nflask and it is again placed on the water-bath for fifteen\\nminutes so that the soap is fully dissolved. It is\\nessential to have the flask closed with a well-fitting\\ncork at all times so as to exclude the carbon\\ndioxid of the air. To the contents of the flask\\nare now added several granules of pumice stone\\nand 40 cc. dilute sulphuric acid of which 30 to\\n32 cc. 2 cc. of the sodium hydroxid solution, and\\nthe flask connected with a condenser. The flask\\nis heated with a small flame until the insoluble\\nfatty acids are melted to a transparent mass, during\\nwhich time (about half an hour) exactly no cc. have\\nbeen distilled over. The distillate is now well mixed\\nand 100 cc. filtered through a dry. filter into a beaker\\nholding 200 to 250 cc, 0.5 cc. phenolphthalein solu-\\ntion added, and titrated with 1/10 normal sodium hy-\\ndroxid solution until a red color is produced. The\\nnumber of cubic centimeters of sodium solution used\\nshould be increased by one-tenth. The Meissl degree\\nexpresses the number of cubic centimeters of 1/10\\nnormal solution of sodium hydroxid that are required\\nto neutralize no cc. of the distillate derived from 5 cc.\\nof fat. At its lowest this is 26. The Meissl degree\\nfor animal and vegetable fat is 0.6-1.0; of cocoa-fat,\\n7.0", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0150.jp2"}, "149": {"fulltext": "ANALYSIS OF FOODS 1 37\\nIf the Meissl degree is below 26, and the fat ap-\\npears otherwise normal, there is no doubt that it has\\nbeen adulterated with cheaper fats.\\nIf a the Meissl degree then the mixture of fat\\ncontains 3.J (a 0.6) per cent, milk-fat.\\nExample. 5 grams of fat were taken, and for 100 cc.\\nof distillate 15.2 cc. of tenth normal sodium hydroxid so-\\nlution were required, and the Meissl degree is 15.2\\n1.52 16.72.\\nThe fat was therefore not pure, but contained only\\n3.7 (16.72 0.6) or 59.6 per cent, of milk-fat, and\\n40.4 per cent, of foreign fat.\\ne. Melting-point\\nThe melting-point of fat can also be employed to\\ndetect adulteration.\\nThe melted fat is drawn into a capillary glass tube\\nwhich is then sealed at the lower end, the other end\\nbeing attached to the bulb of a mercurial thermometer\\nby means of a piece of rubber tubing, and then pla-\\ncing it into a wider cylinder containing glycerin. The\\nlatter is then warmed with a small gas flame, observ-\\ning when all the fat is entirely melted, and observing\\nthe thermometer. This indicates the melting-point\\nof the fat.\\nMelting-point of Fats\\nMilk-fat 33-37\u00c2\u00b0 C.\\nBeef-fat 4i~47\u00c2\u00b0 C.\\nBut since the addition of various oils may influence\\nthe melting-point of the mixture this is not a reliable\\nmethod.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0151.jp2"}, "150": {"fulltext": "138 PRACTICAL HYGIENE\\nf Solubility in Hot Alcohol\\nA more reliable method is the determination of the\\nsolubility of the fat in hot alcohol.\\nThe fat is melted on a boiling water-bath and\\nfiltered. 5 cc. are taken and placed in a round flask\\nof 60 cc. capacity, 20 cc. of absolute alcohol are added,\\nand the flask set in the water-bath and boiled for two\\nminutes. Pure butter-fat is wholly soluble in alcohol\\nand remains clear at the room temperature longer than\\n120 seconds, while other fats (as suet and lard) are not\\neasily dissolved to clear solution and become cloudy\\nwhen removed from the water-bath within 60 seconds.\\ng. Detection of Preservatives\\n1. Boric acid. 10 grams butter are saponified in a\\nplatinum crucible w T ith alcoholic caustic potash solu-\\ntion, evaporated to dryness, and incinerated. The ash\\nis treated with hydrochloric acid and tested with cur-\\ncuma paper which in the presence of boric acid, after\\ndrying at ioo\u00c2\u00b0 C, turns red, and when treated with a\\nsolution of sodium carbonate is turned blue.\\n2. Salicylic acid. 4 cc. of 20 per cent, alcohol are\\nplaced in a test-tube and two or three drops of dilute\\nferric chlorid are added. To this 2 cc. of butter-fat\\nare added and shaken. When salicylic acid is pres-\\nent the lower portion of the solution is colored violet.\\n3. Formaldehyde. 50 grams of butter are placed\\ninto a 250 cc. flask with 50 cc. water and melted, and\\nthen placed on a steam-bath, and 25 cc. distilled off.\\n10 cc. of the distillate are treated with two drops of", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0152.jp2"}, "151": {"fulltext": "ANALYSIS OF FOODS 1 39\\nammoniacal silver solution (i gram silver nitrate dis-\\nsolved in 30 cc. water and treated with ammonia until\\nthe precipitate is again dissolved, and then made up to\\n50 cc. with w T ater). If formaldehyde is present it\\ncauses a black clouding to appear after standing for\\nseveral hours in the dark.\\nCHAPTER III. MEAT AND MEAT PRODUCTS\\nMeat consists of the muscle fibers of the animal\\nbody which are held together by connective tissues\\nand surrounded or interposed by fat, sinews, and bone.\\nThe meat is of a quite variable composition, accord-\\ning to the portion of the body from which it is derived\\nand the mode of fattening, the age of the animal, and\\nother conditions. The pure muscle fiber is of less\\nvariable composition, but this does not reach the mar-\\nket as such.\\nThe chemical constituents of muscle meat are, on\\nan average,\\n75.0 per cent, water,\\n21.7 per cent, nitrogenous substances,\\n2.0 per cent, fat,\\n1.3 per cent, mineral matter.\\nThe nitrogenous substances are muscle fiber, con-\\nnective tissue, albumin, inosin, uric acid, and meat\\nbases (kreatin, kreatinin, karnin, xanthin).\\nThe chemical analysis of meat is made according\\nto the general methods.\\nSausage is generally preserved by the addition of\\nsaltpeter, boric acid, sodium borate, salicylic acid, or\\nso-called preserving salt (usually a mixture of sodium", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0153.jp2"}, "152": {"fulltext": "140 PRACTICAL HYGIENE\\nchlorid, saltpeter, and boric acid), or they are colored\\nwith anilin-red.\\nThe examination of sausage for these preserving\\nsalts is made by taking 10 grams and boiling with 100\\ncc. of water and filtering.\\nSeveral drops of the filtrate are added to 5 cc. sul-\\nphuric acid containing a few crystals of diphenylamin\\nin solution. If on shaking a blue color appears there\\nis saltpeter present (KNO\\nA portion of the filtrate is evaporated to dryness\\nafter adding a solution of sodium carbonate, the resi-\\ndue is incinerated, dissolved in hydrochloric acid, and\\nthis acid solution tested with strips of curcuma paper.\\nIf on drying the latter is colored red, boric acid is\\npresent.\\nThe remainder of the filtrate is shaken with ether,\\nthe latter is pipetted off, and the remainder is then\\nevaporated in a porcelain dish. The residue is dis-\\nsolved in a few drops of water and tested with ferric\\nchlorid. A violet color indicates the presence of\\nsalicylic acid.\\nAnimal Fats\\nBeef-fat is pretty hard, melting only above 45 C,\\nand has a specific gravity of 0.859 at ioo\u00c2\u00b0 C.\\nLard is of a consistence of a salve, melting between\\n42\u00c2\u00b0-45\u00c2\u00b0 C, and has a specific gravity of 0.860 at\\nioo\u00c2\u00b0 C.\\nIn the examination of fats they are melted to re-\\nmove foreign bodies (water, salts, etc.) and then filtered\\nand the melting-point determined.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0154.jp2"}, "153": {"fulltext": "ANALYSIS OF FOODS 141\\nThe estimation of the specific gravity is made at\\nioo\u00c2\u00b0 C. by means of a Westphal specific gravity bal-\\nance, or by means of an areometer of Koenig.\\nOf great value in determining the purity of fats is\\nthe estimation of the iodide degree.\\nLard is frequently adulterated with the stearates of\\ncottonseed oil. To determine this mode of adultera-\\ntion 10 cc. of the clear, melted fat are placed in a flask\\nand 20 cc. of absolute alcohol added. This is then\\nplaced on a boiling water-bath and 2 cc. of an alco-\\nholic-ether solution of silver nitrate added. (Beche s\\nreagent 1 gram silver nitrate dissolved in 200 cc. al-\\ncohol, and 40 grams ether added.)\\nIf cottonseed oil is present a reduction of the silver\\nnitrate takes place causing a brown color, or a precipi-\\ntation of the metal, while with pure fat it remains\\nunchanged.\\nCHAPTER IV. FLOUR\\nExamination for the Presence of Foreign Seeds\\nAbout 2 grams of the flour are placed into a test-\\ntube and 10 cc. of acid-alcohol added (70 cc. absolute\\nalcohol, 30 cc. water, and 5 cc. hydrochloric acid);\\nthis is slightly warmed, shaken, and the resulting\\ncolor observed.\\nPresence of secale cornutum (ergot) reddish to violet.\\nlolium temulentum (garlic) orange-red\\nagrostemma githago (cockle) to yellow.\\nrianthus, etc. greenish.\\nFlour is sometimes adulterated with white mineral\\nsubstances, gypsum, calcium carbonate, this form of", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0155.jp2"}, "154": {"fulltext": "142 PRACTICAL HYGIENE\\nadulteration being detected by estimating the amount\\nof ash in 10 grams of flour.\\nThe total ash of flour does not exceed 2 per cent.\\n(wheat flour 0.5 to 1 per cent.; rye flour 2 per cent.),\\nin all of which 0.2 per cent, of sand is included.\\nThe amount of sand is estimated by treating the\\nash of 10 grams of flour with 25 cc. of 10 per cent,\\nhydrochloric acid, and after standing one quarter of\\nan hour the insoluble part is filtered off, washed, dried,\\nand weighed.\\nTo test for coarser mineral adulteration a teaspoonf ul\\nof flour is placed in a test-tube and shaken with 20 cc.\\nof chloroform, and allowed to stand. Pure flour collects\\nin the upper portion of the liquid the mineral parti-\\ncles sink to the bottom.\\nCHAPTER V. VINEGAR\\nVinegar should not contain less than 4 per cent,\\nacetic acid, as experience has shown that when less is\\npresent it does not keep well. Besides acetic acid the\\nvinegar contains alcohol and extractives, according to\\nthe raw material from which it is made, besides other\\nconstituents.\\nThe estimation of acetic acid is made by titrating\\n10 cc. of vinegar with normal sodium hydroxid solu-\\ntion and phenolphthalein.\\n1 cc. normal sodium hydroxid 0.06 gram acetic\\nacid.\\nAdulteration of vinegar with free mineral acids is\\ndetected as follows 10 cc. of vinegar are placed in a", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0156.jp2"}, "155": {"fulltext": "ANALYSIS OF FOODS 1 43\\ntest-tube with 3 drops of an aqueous solution of methyl\\nviolet 1 1000). If mineral acids are present the\\ncolor changes to light blue or green.\\nThe nature of the acid is determined as follows\\n10 cc. of vinegar are treated with\\n1 Barium chlorid and hydrochloric acid. A heavy\\nwhite precipitate indicates the presence of sulphuric\\nacid.\\n2. Silver nitrate and nitric acid. If this turns dark\\nit indicates the presence of hydrochloric acid.\\n3. Calcium chloride. A white precipitate indicates\\nthe presence of oxalic acid.\\nIt is to be remembered that a faint reaction is no\\nindication of the presence of free acids as this may be\\nbrought about by salts in solution.\\n4. Nearly fill a test-tube with vineger and sulphuric\\nacid, one and one, being careful to pour the sulphuric\\nacid on the vinegar, and not the vinegar on the acid\\ncool the mixture and add, cautiously, along the side of\\nthe test-tube, a few drops of ferrous sulphate solution, so\\nthat the liquids will come in contact, but not mix if\\nnitric acid is present, the stratum of contact will show\\na purple or reddish color, which changes to brown. If\\nthe liquids are then mixed, a clear brownish purple\\nliquid will be obtained.\\nThe Brucine Test, To a few cubic centimeters of\\nvinegar in a test-tube add four or five drops of brucine\\nand then a few drops of concentrated sulphuric acid,\\nand if nitric acid is present, a red color will be de-\\nveloped.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0157.jp2"}, "156": {"fulltext": "144 PRACTICAL HYGIENE\\nTo distinguish cider vinegar from spirit vinegar.\\nPlace a weighed quantity of the sample to be tested\\nin a porcelain dish, and evaporate it at a temperature\\nof ioo\u00c2\u00b0 C.j until constant; the residuum should be,\\nfor cider vinegar, not less than 2 per cent., and should\\nbe from a clear, light brown to a dark brown color,\\nsoft, viscid, and hygroscopic; and, when burned,\\nshould give off the odor of burned apples. A lead\\nacetate solution will cause an immediate light yellow-\\nish brown precipitate in cider vinegar, the precipitate\\nsettling, usually in flakes, in less than five minutes.\\nCHAPTER VI. FOOD MATERIALS CONTAINING ALKALOIDS\\na. Coffee\\nBy the term coffee we understand bean-like seeds\\nof the fruit of the coffee-tree. The quality varies with\\nthe country in which it grows.\\nThe unroasted beans have a yellowish green color.\\nThese are often imitated by artificial preparations, but\\nthe latter are commonly colored with ochre which is\\nharmless.\\nBefore using the beans are roasted, whereby their\\nconstituents are changed and the beans take on a\\nbrownish color. In the preparation of coffee as a\\nbeverage the beans are ground and an infusion made\\nwith hot water, when about 26 per cent, is dissolved.\\nThe constituents of coffee are the alkaloid caffein,\\n(C 8 H io N 2 acid, an ethereal oil, and the product of\\nroasting, besides which it contains fat, albumen, min-\\neral matter, and cellulose.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0158.jp2"}, "157": {"fulltext": "ANALYSIS OF FOODS 1 45\\nCoffee is not unfrequently adulterated by the addi-\\ntion of sugar-beats, chicory, yellow beets, figs, pears,\\ncereals, malt, acorns, leguminosae, and coffee berries.\\nEstimation of caffein content. 5 grams coffee are\\nfinely pulverized and extracted with hot water, the\\ninfusion precipitated with neutral lead acetate solu-\\ntion, filtered, and the filtrate treated with hydrogen\\nsulphid, mixed with magnesia and sand, and evapo-\\nrated to dryness, the residue thoroughly extracted with\\nchloroform. This is then evaporated to dryness,\\nboiled with water, filtered, the filtrate evaporated in\\nvacuo and in the drying oven. The resulting caffein\\nis then also examined microscopically to determine\\nwhether it is pure or not.\\nEstimation of extractives. 10 grams of dry coffee\\nare placed in a beaker with 25 cc. water. This is\\nweighed to 0.1 gram and then warmed, boiling for\\nfifteen minutes, preventing the loss of foam at the be-\\nginning of the boiling. After cooling, water is again\\nadded to the original weight, mixed, filtered, and the\\nspecific gravity of the filtrate determined at 15 C. by\\nmeans of a Westphal balance, or a pycnometer.\\nBy consulting Schultze s extract table, the extractive\\ncontent of the solution is read off in per cent, by w r eight,\\n.r, and calculate (a) the extract content, and its wa-\\nter content (c) according- to the formula a x\\nv 7 100 x\\nPer cent.\\nTrillich found the average for chicorv to be 70.7\\nfig coffee 73.5\\nbarley coffee 65.0\\ncoffee husks only 20.0\\nand for true coffee about 25.0", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0159.jp2"}, "158": {"fulltext": "146 PRACTICAL HYGIKNK\\nb. Tea\\nThe thein content of tea varies from one to three\\nper cent.\\n1. Estimation of Thein. Five grams of finely pow-\\ndered tea are extracted three times, for one hour, each\\ntime with 300 cc. of water, the three extracts are mixed\\nand concentrated to one-fourth the volume, and while\\nhot freshly precipitated lead hydroxid is added and\\ncoarse, washed sand mixed with it. The mixture is\\nevaporated to dryness on a water-bath and the residue\\nis extracted with chloroform for three hours in a\\nSoxhlet extraction apparatus. The residue which re-\\nmains is dissolved in water, the filtrate placed in a\\nporcelain dish, and evaporated on a water-bath, the\\nresidue dried at ioo\u00c2\u00b0 C. and weighed.\\n2. Determination of ash. The ash determination\\nis of greater importance than the estimation of the\\nthein content in determining adulteration. It should\\nnot be less than 3 per cent, nor more than 7 per cent.\\nOf the ash only 2.5 to 4 per cent, should be soluble\\nin water, and not more than 1 per cent, soluble in\\nacid.\\nEXAMINATION OF FOOD MATERIALS FOR CHEM-\\nICAL PRESERVATIVES\\nThe chemical preservatives most frequently em-\\nployed to preserve food materials are boric, sulphur-\\nous, benzoic, and salicylic acids, and formaldehyde,\\neither alone or in various combinations.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0160.jp2"}, "159": {"fulltext": "ANALYSIS OF FOODS 1 47\\nBoric acid and borates\\nQualitative test. The substance to be tested is ren-\\ndered alkaline with milk of lime, evaporated to dry-\\nness, and incinerated. The ash is dissolved in the\\nsmallest possible quantity of concentrated hydrochloric\\nacid, filtered, and the filtrate evaporated to dryness on\\nthe water-bath. No great loss of boric acid need be\\nfeared in this operation. The residue is moistened\\nwith a little dilute hydrochloric acid, and curcuma\\ntincture added, and again evaporated to dryness. The\\npresence of the least trace of boric acid is shown by\\nthe cinnabar or cherry-red color of the residue. This\\nreaction is extremely delicate, 0.5 to 1.0 milligram of\\nboric acid in the residue, or, for instance, 0.001 to\\n0.002 per cent, in milk is shown with the greatest cer-\\ntainty in this manner.\\nConcentrated hydrochloric acid also gives with cur-\\ncuma tincture a red color which, however, disappears\\nupon the addition of water, and on drying changes to\\nbrown, while the boric acid color appears only on dry-\\ning and disappears only on the addition of much wa-\\nter, or boiling water. The red color adheres very te-\\nnaciously to the vessels but is easily removed with\\nalcohol.\\nThe ash, after treatment w T ith curcuma tincture, can\\nbe used for the flame reaction by moistening it with\\nhvdrochloric acid and transferring it to the gas flame.\\nThe flame shows a green border.\\nQuantitative estimation. The quantitative estima-\\ntion of boric acid is quite difficult, and in the presence\\nof sodium salts can only be carried out by expert", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0161.jp2"}, "160": {"fulltext": "148 PRACTICAL HYGIENE\\nchemists. Traces of boric acid are widely distributed\\nin nature, and are also contained in glass vessels and\\ngreat care must be exercised in giving an opinion on\\nthis account.\\nSulphurous Acids and Sulphides\\nQualitative test. The intense and characteristic\\nodor of sulphurous acid is noticeable only on the very\\ncopious application of this agent for purposes of the\\npreservation of food materials. If only small quanti-\\nties are present the following preliminary tests are\\nmade The material to be tested is treated with hy-\\ndrochloric acid and zinc and a strip of filter-paper\\nmoistened with lead acetate is laid over the mouth of\\nthe flask containing the mixture. If a brown or black\\ncolor is produced on the strip of paper one must de-\\ntermine whether sulphur dioxid w T as really present.\\nIf the paper is not colored no sulphurous acid was\\npresent. From recent observations we know that sul-\\nphurous acid results from the fermentation of differ-\\nent substances, from the reduction of sulphates or\\nfrom albuminous substances, and the simple qualita-\\ntive determination of the presence of sulphurous acid\\nor its salts does not show that it was added as a pre-\\nservative.\\nQuantitative estimation. For this purpose 200 cc.\\nof beer or wine, for instance, are treated with 5 cc. of\\nphosphoric acid, placed in a retort or distillation flask\\nattached to a Liebig s condenser, and 100 cc. are dis-\\ntilled off. The condensation tube must be conducted\\ninto 20 cc. of tenth normal iodin solution. It is rec-", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0162.jp2"}, "161": {"fulltext": "ANALYSIS OF FOODS 1 49\\nominended to carry out the procedure by conducting\\na continuous stream of carbon dioxid gas washed in\\nwater, through the distillation flask one prevents in\\nthis manner the return of the distillate on cooling off\\nthe distillation flask. The iodin solution should not\\nbe entirely decolorized. The iodin converts the sul-\\nphurous acid into sulphuric acid (S0 2 2H 2 2l\\nH 2 S0 2 HI), which, after acidulation with hydro-\\nchloric acid, can be precipitated with barium chlorid\\nand weighed as barium sulphate. 1 milligram barium\\n-sulphate represents 0.2748 milligram sulphur dioxid.\\nSalicylic Acid and Salicylates\\nQualitative test. If salicylic acid is plentifully\\npresent it is easily detected 50 cc. of the liquid, beer\\nor wine for instance, are acidulated with sulphuric\\nacid, shaken with 50 cc. of equal parts of ether and\\npetroleum ether and the clear ether extract filtered.\\nThe ether and petroleum ether in the filtrate are fully\\nremoved and to the remaining liquid a few drops of\\nhighly diluted neutral ferric chlorid solution are added.\\nA violet color indicates the presence of salicylic acid\\nthe intensity of the color is indicative of the quantity\\npresent.\\nDetection of salicylic acid in milk and butter. 100\\ncc. of milk are diluted with 100 cc. of distilled water\\nof 6o\u00c2\u00b0 C, and precipitated with 8 drops of acetic acid\\nand 8 drops of a solution of mercuric oxid in nitric\\nacid, shaken and filtered. The filtrate is shaken with\\n50 cc. of ether which takes up the salicylic acid. But-\\nter is first treated with sodium carbonate by making a", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0163.jp2"}, "162": {"fulltext": "150 PRACTICAL HYGIENE\\nhomogeneous mixture, and then proceeding as in\\ntesting wine or beer.\\nBenzoic Acid and Benzoates\\nQuantitative test of Meissl. The substance to be\\nexamined is mixed with barium hydroxid and evap-\\norated to dryness on a water-bath (milk is first mixed\\nwith clean sand). The residue is then acidulated with\\nsulphuric acid and shaken three to four times with\\ncold 50 per cent, alcohol. For the removal of milk-\\nsugar and salts it is necessary to treat with barium\\nhydroxid, evaporate to dryness, acidulate with sul-\\nphuric acid, and then extract the benzoic acid with\\nether. The ether is evaporated under 6o\u00c2\u00b0 C, when\\nthe benzoic acid crystallizes out. Dissolved in water,\\nbenzoic acid gives a beautiful reddish yellow color\\nwith dilute, neutral ferric chlorid solution.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0164.jp2"}, "163": {"fulltext": "PART V\\nVENTILATION AND HEATING\\nCHAPTER I. VENTILATION\\na. Natural ventilation. The study of the inter-\\nchange between the inside and outside air in the ven-\\ntilation of rooms and buildings may be made in sev-\\neral different ways. The most common method is\\nthat devised by Pettenkofer. This method consists in\\ngenerating carbon dioxid in a closed room, by burning\\ncandles, or by the action of acids on carbonates, mix-\\ning it thoroughly with the room air, and then deter-\\nmining the rate at which the carbon dioxid in the air\\ndiminishes through the interchange between the in-\\nside and outside air. The proportion of carbon dioxid\\nin the room air and in the outside air is first deter-\\nmined, then, after generating the carbon dioxid, ex-\\naminations of the air are made, at intervals of fifteen\\nminutes, during one or several hours. The quantity\\nof the incoming air, or the amount of ventilation, is\\nthen calculated by means of Seidell formula\\np. a\\nx 2.303 X m X log cubic meters\\nPi a\\nwhere m the cubic content of the room in cubic\\nmeters,\\np x carbon dioxid in room air at beginning of\\nobservation,\\nfl 2 carbon dioxid in room air at end of ob-\\nservation,", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0165.jp2"}, "164": {"fulltext": "152 PRACTICAL HYGIENE\\na carbon dioxid in outside air,\\nx quantity of incoming air.\\nb. Artificial ventilation. To determine the inter-\\nchange brought about between the room air and the\\noutside air through artificial ventilation we measure\\nthe velocity of the current of the incoming air as it\\nissues from the ventilator openings, or as it passes out\\nthrough the exit openings. This is done by means\\nof an anemometer.\\nAnemometers are of two kinds: (1) dynamic ane-\\nmometers, in which the air current sets in motion a\\nsmall wheel whose motion is communicated by means\\nof clock-work to a set of dials on which the velocity\\nof the air current is recorded in meters; and (2) static\\nanemometers, in which the air current is measured by\\nthe pressure which it exerts on a thin sheet of metal\\nwhich is connected with a scale on which the degree\\nof deflection from the zero-point denotes the rate of\\nmovement.\\nEach anemometer should be tested first as to the\\ndegree of its efficiency. It requires a definite velocity\\nof current to start the wheel of a dynamic anemome-\\nter, and this factor is different for each instrument.\\nUsually the necessary calculations for the correction\\nof these instruments have been determined by the\\nmaker therefore it is not necessary to go into the\\ndetails of the operation.\\nProcess. A reading of the dials of the anemometer\\nis made when it is placed in the ventilator opening for\\none minute and another reading taken. The difference\\nbetween the two readings will indicate the velocity of the", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0166.jp2"}, "165": {"fulltext": "VENTILATION AND HEATING 1 53\\nair current in sixty seconds, or divided by sixty, will in-\\ndicate the velocity of the current per second. The\\nresult is expressed in meters per second.\\nIt is not sufficient to make a single observation at\\nthe center of the ventilator opening as the velocity of\\nthe air current there is greater than at any other point.\\nUsually an observation is made at the center and at\\neach of the four corners of a rectangular opening, or at\\nleast two of the opposite corners besides the center,\\nand then taking the mean of all the observations.\\nSimilar observations must be made at all the ventila-\\ntor openings in a room if more than one exists, to as-\\ncertain the total amount of the incoming air. The\\namount of ventilation may also be determined by ma-\\nking similar observations on the exit openings of the\\nventilators as to the amount of air leaving the room.\\nIn order to determine the amount of natural venti-\\nlation we find the cubic content of the room the\\ncubic space by multiplying the length, width, and\\nheight of the room in meters, together. We also de-\\ntermine the area of the ventilator openings.\\nExample. A room measuring 5 meters long, 3 meters\\nwide, and 4 meters high 60 cubic meters the cubic\\ncontent. (Ordinarily it is not necessary to make any de-\\nduction from the cubic content of a room on account of\\nthe furniture nor any additions for the recesses of win-\\ndows and doors, since the corrections would make very\\nlittle change in the result.) The ventilator opening is\\ncircular in shape and 48 cm. in diameter, or 24 cm. ra-\\ndius\u00e2\u0080\u0094 then it is 24 X 24 X 3.14 1808.64 sq. cm.\\n0.180864 sq. m. in area.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0167.jp2"}, "166": {"fulltext": "154 PRACTICAL HYGIENE\\nThe velocity of the incoming air current is as follows\\nIn one minute Meter.\\nAt the center of the circle 0.7386\\nlower margin 0.6700\\nupper 0.7200\\nright =0.7480\\nleft 0.7500\\nor 3.6266 -r- 5 0.7253 meter per second. The volume\\nof air entering each second is found by multiplying the\\narea of the opening by the velocity of the current\\n0.1808 X 0.7253 o. 131 134 cubic meter per second, or\\n472.08 cubic meters per hour. The dimensions of the\\nroom are 5X4X3 meters 60 cubic meters, the cubic\\ncontent, and it requires, therefore, 60 -r- 7.868 (the veloc-\\nity per minute) =7.62 minutes to change the air of the\\nroom, or the air is changed nearly eight times each hour.\\nCHAPTER II. HEATING\\nThe investigation of the warming of a building\\nshould include the following\\na. The extent of the combustion.\\nb. The heating effect produced in different parts\\nof the building.\\nc. The possibility of any detrimental effect on\\nhealth.\\n1. The study of the extent of the combustion com-\\nprises\\na. The chemical analysis of the combustion ma-\\nterials in order to estimate the theoretical\\namount of heat it can yield.\\nb. The estimation by means of a calorimeter of\\nthe amount of heat passing off as water, ex-\\npressed in calories.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0168.jp2"}, "167": {"fulltext": "VENTILATION AND HEATING 1 55\\nBy calorie is meant the amount of heat necessary\\nto raise the temperature of a liter of water i C.\\nc. The estimation by means of a pyrometer, of\\nthe temperature of the air entering and leav-\\ning the heater.\\nd. The estimation of the volume, the tempera-\\nture, and the chemical composition of the\\nsmoke. The volume of smoke is estimated by\\nmeasuring the size of the chimney and the ra_\\npidity of current of smoke passing out of it.\\nThe temperature is measured by means of a\\npyrometer or air-thermometer.\\nThe determination of the chemical composition of\\nthe smoke is made through gas analysis though it\\nusually consists of carbon dioxid, nitrogen, and oxygen,\\nwith the addition of carbon, watery vapor, though\\ncarbon monoxid is also frequently present, and is de-\\ntected by means of palladium chlorid solution. In\\nthe absence of carbon monoxid the estimation of the\\ncarbon dioxid and oxygen usually suffices.\\n2. The estimation of the heating effect on the dif-\\nferent rooms requires the determination of\\na. The temperature.\\nb. The humidity, especially the deficiency of sat-\\nuration.\\nc. The cubic contents of the rooms.\\nd. The amount of natural ventilation.\\n3. The determination of the possibility of any det-\\nrimental effect upon the health of the occupants is", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0169.jp2"}, "168": {"fulltext": "156 PRACTICAL HYGIENE\\nnot very readily determined. We may determine the\\npresence or absence of carbon monoxid, the tempera-\\nture of the room, the humidity of the atmosphere, and\\nin this manner derive some information as to the\\nhealthfulness of the room.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0170.jp2"}, "169": {"fulltext": "INDEX.\\nAcid, boric, in butter 137\\nhydrochloric 60\\nnitric 68\\nnitrous 68\\nphosphoric 68, 106\\nsalicylic, in butter 138\\nsilicic 67\\nsulphurous 60, 68\\nAir, atmospheric 6\\nchemical analysis of 41\\nPettenkof er flask method 45\\ntube method 53\\ncollection of samples of 49\\nimpurities in 41\\ngaseous 41\\nsolid 41\\nmoisture in 23\\nmovements, qualitative estimation of 34\\nquantitative estimation of 35\\nphysical examination of 7\\nsoil 123\\nvolume, reduction of 53\\nwater capacity of 28\\nAitken s dust counter 59\\nAlkalies in water 101\\nAlkaloids, food material containing 143\\nAluminum method for nitrates 93\\nAmmonia in air 61\\nqualitative test 61\\nquantitative test 61\\ngravimetric method 61\\nvolumetric method 62\\nAmmonia in water 70\\nfree and albuminoid 74\\nAmmonia-free water, collection of 75\\nAnalysis of air, chemical 41\\nfoods, sanitary 125\\nmilk, chemical 128\\nphysical 125\\nsoil, mechanical 114\\nwater, sanitary 64\\nAnemometer 37, 151\\nAnimal fats, examination of 140\\nAqueous vapor, estimation of, in air 23, 30, 54\\ntension of 22, 26", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0171.jp2"}, "170": {"fulltext": "158 INDEX\\nAsh in butter 134\\nmilk 129\\ntea 145\\nAtmometer, Pische s 32\\nAtmospheric air 6\\npressure 15\\nBabcock s method 131\\nBarometer 17, 49\\naneroid 22\\nmanner and place of hanging 19\\nmercurial 17\\ncistern 17\\ndifferential 21\\nstationary 21\\nscale 18\\nBarometric pressure, correction for 8, 20, 28\\nBellows, hand r 42\\nBenzoic acid and benzoates in food 146\\nBeaufort s scale of air movements 36\\nBoiling-point of water 7\\nRegnault s table 10\\nBoric acid in butter 137\\nand borates in food 146\\nBottles, glass-stoppered 49\\nBrucine test in vinegar 143\\nBurette, Bunte gas 42\\nMohr s 49\\nreading of 51\\nButter, adulteration of 133\\ncasein in 134\\ncomposition of 133\\ndetection of preservatives in 137\\nmelting-point of 136\\nmineral matter in 134\\nsolubility of, in hot alcohol 137\\nCaffein, estimation of, in coffee 144\\nCalcium 69\\nCarbon dioxid 44, 67, 97, 98, 100, 101\\nqualitative estimation of, in air 44\\nquantitative estimation of in air 45\\nmonoxid, qualitative tests 56\\nchemical tests 57\\nspectroscopic method 56\\nCasein in butter 134\\nCasserole, cleansing of 78\\nCentigrade scale 14\\nChemical analysis of air 41\\nmilk 128\\npreservatives in food 146\\nwater 67", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0172.jp2"}, "171": {"fulltext": "INDEX 159\\nChlorin 66, 68, 71\\nCleansing the casserole 78\\nClearness of water 65\\nClouds, designation of amount of 39\\nestimation of amount of 38\\nCoffee 143\\nCollection of sample of air 49\\nsoil 114\\nwater 64\\nColor of water 66\\nCopper in water 70\\nCorrections of barometric readings 8, 20, 53\\nCremometer 128\\nData on the label 65\\nDeficiency of saturation 23\\nDegrees of hardness, Clark s scale 82\\nMetric scale 82\\nDew-point 22\\nDrinking-water, approximate composition of 1 13\\nDust counter, Aitken s 59\\nDust in air, estimation of, by weight 58\\nDust particles 59\\nElutriation of soil 115\\nEstimation of moisture in air 23, 30\\nthein in tea 145\\nEvaporimeter 31\\nExtractives, estimation of, in coffee 144\\nFahrenheit scale 14\\nFat in butter 134\\nmilk, estimation of 127, 129\\nBabcock method 131\\nby means of lactobutyrometer 129\\nextraction method 129\\nLeff man-Beam method 133\\nFats, animal 140\\nforeign, in butter 135\\nFlorence flask 49\\nFlour 140\\nFog 38\\nFood materials containing alkaloids 143\\nFoods, sanitary analysis of 125\\nForeign fats in butter 135\\nFormaldehyde in butter 138\\nGaseous impurities in air 41\\nHail 33\\nHand bellows 48\\nHardness of water 80\\npermanent 85\\ntemporary 85", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0173.jp2"}, "172": {"fulltext": "160 INDEX\\nHeating, testing efficiency of 153\\nHehner s method for hardness of water 84\\nHumidity of the atmosphere 23\\nabsolute 22\\nrelative 22\\ncalculation of 30\\nHydrochloric acid, qualitative test 60\\nquantitative test 60\\nHydrogen sulphid 54, 67\\nHygrometers 24\\ndirect 24\\nDaniell s 24\\nDines s 24\\nRegnault s 24\\nindirect 25\\nhair 25\\nwet- and dry-bulb thermometer 25\\nHygroscope 31\\nHypsometer 7\\nImpurities in air, gaseous 41\\nsolid 41\\nammonium thiocyanate 73, 75\\nwater, limits of 1 r3\\nIndicators, lacmoid 86\\nphenolphthalein 48\\npotassium chromate 72\\nrosolic acid 47\\nIndigo solution 77\\nInterpretation of results in water analyses 109\\nIron in water 69\\nquantitative estimation of 102, 103\\nKnopp s elutriator 116\\nLactobutyrometer 129\\ntable 130\\nLactoscope 127\\nLead, in water, detection of 69, 96\\ncolorimetric method 96\\nLefTman-Beam method 133\\nLime, estimation of 69, 87\\nLimits of impurity in water 113\\nMagnesia, estimation of 69, 87\\nManometer, dynamic 34\\nMarx-Tromsdorf method for nitrates 87\\nMaterials, food, containing alkaloids 143\\nMaximum of saturation 23\\nMeat and meat products 138\\nMechanical analysis of soil 114\\nMelting-point of butter 136\\nMetals, heavy, in water 69", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0174.jp2"}, "173": {"fulltext": "INDEX l6l\\nMeteorology 7\\nMilk, chemical analysis of 128\\nash 129\\nfat 129\\ntotal solids 128\\nestimation of fat in 127\\nlactoscope 127\\ncremometer 128\\nexamination of 125\\nnature and composition of 125\\nphysical examination of 125\\nspecific gravity of 126\\nMineral matter in butter 134\\nMoisture, in air, estimation of 23\\nby chemical methods 30\\nevaporation of, from the earth s surface 31\\nprecipitation of 32\\nin soil, estimation of 121\\nNitric acid 68\\nNitrogen as nitrates, determination of 87\\naluminum method 93\\nMarx-Tromsdorf method 87\\nmethod of Grandval and Lajoux 89\\nSchultze-Tiemann method 90\\nnitrites, determination for 94\\nSchuyten s method 1 95\\nWarrington s modification of Griess method 94\\nNitrous acid 68\\nObservation of temperature 7\\nOdor of water 66\\nOrganic matter 58\\ndetermination of, Remsen s method 58\\nnitrogenous 58\\noxidizable 58, 78\\nOxygen 42, 104\\nPhosphoric acid 68, 106\\nPipettes 49\\nPotassium 69, 101\\nPrecipitation of moisture 32\\nPreservatives, detection of, in butter 138\\nPressure, atmospheric 15\\nPsychrometer 25\\nsling 26\\nPyrometer 11\\nRadiation, solar, measurement of 13\\nterrestrial 13\\nRain 32\\nRain-gauge 32", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0175.jp2"}, "174": {"fulltext": "1 62 INDEX\\nRain-gauge, position of 33\\nReaction of water 66\\nReading of barometer 17\\nReaumur scale 14\\nRecording results in water analyses 108\\nResidue, incineration of 71\\nResults, calculation of 53, 83\\ninterpretation of 109\\nrepresentation of 39\\nSalicylic acid in butter 138\\nfood 149\\nSalts in solution in water 67\\nSanitary analysis of food 125\\nwater 64\\nSaturation, deficiency of 23\\nmaximum of 23\\nScales, thermometer 14\\nSchultze-Tiemann method, for nitrates 90\\nSilicic acid 67\\nSleet 33\\nSnow 33\\nSoap solution, standard 81\\nSodium 69, 101\\nSoil air, estimation of carbon dioxid in 123\\nmechanical analysis of 114\\nelutriation of 115\\nsieving of 115\\nphysical analysis of 116\\ndrainage capacity of 1 20\\nestimation of level of ground-water in 121\\nmoisture in 121\\nporosity of 116, 117\\nPettenkof er s method 118\\nwater capacity of 118, 119\\nPettenkof er s apparatus 120\\nSolar radiation 13\\nSolid impurities in air 41\\nSolids, total, in water 70\\nSolubility, in hot alcohol, of butter 138\\nSolutions, standard\\nalkaline potassium iodid 105\\npermanganate 75\\nammonium chlorid 75\\nammoniof erric alum 73\\nammonium thiocyanate 102\\nantipyrin 95\\nbarium hydroxid 46\\nhydrochloric acid 102, 105\\niodin 55\\nmanganous chlorid 104", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0176.jp2"}, "175": {"fulltext": "INDEX 163\\nSolutions, standard\\nNessler s reagent 75\\nnitric acid 72\\noxalic acid 45, 73\\noxid of iron 108\\npotassium nitrate 88\\npermanganate 78\\nsilver nitrate 71, 74\\nsoap 81\\nsodium chlorid 72, 74\\nhydroxid 94\\nphosphate 107\\nthiosulphate 55, 105\\nstarch...... 55, 105\\nsulphuric acid 78\\nstandardizing of 79\\ntitration of 51\\nSulphurous acid, qualitative test 60, 68, 148\\nquantitative test 60, 148\\nTaste of water 66\\nTea 146\\nTemperature, observation of 7\\nat barometer 19\\nof soil 124\\nThein in tea, estimation of 146\\nThermograph 1 r\\nThermometers 7, 48\\nfor high temperatures 10\\nmaximum-minimum 11\\nmercurial 7\\nscale 14\\nspecial 10\\nspirit 10\\nVapor, aqueous 23 30, 54\\ntension of 22, 26\\nVentilation, testing efficiency of 151\\nartificial 152\\nnatural 151\\nVernier 18\\nVinegar, cider 144\\nspirit 144\\nWater, 63\\nammonia-free 75\\nchemical analysis of 67\\nqualitative 67\\nquantitative 70\\ncomposition of 65\\nclearness of 63", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0177.jp2"}, "176": {"fulltext": "164 INDEX\\nWater, collection of sample of 64\\ncolor of 66\\ndrinking-, approximate composition of 113\\nground-, course of 1 23\\nheight of 121\\nhardness of 80\\nClark s method 82\\nHehner s method 84\\ngravimetric determination of 86\\nnature and composition of 63\\nnitrate-free 93\\nodor of 66\\nphysical examination of 65\\nproperties of 63\\nreaction of 66\\nsanitary analysis of 64\\ntaste of 66\\nWeather prognostication 39\\nWind, force, rapidity, and direction of 34\\nWind vane 34, 37\\nZero-point, control of 7\\nZinc in water, detection of 70, 97\\nERRATA.\\nOn pape 16, 3d line from bottom, for higher read lower.\\nOn page 17, 2nd line from top, for lower read higher.\\nOn page 17, 3d line from top, for falling read rising.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0178.jp2"}, "177": {"fulltext": "Partial List of\\nOUR PUBLICA1 IONS.\\nBILTZ.\\nPractical Methods for Determining Molecular Weights.\u00e2\u0080\u0094 By\\nHenry Bii/tz, Privatdocent at the University in Greifswald.\\nTranslated (with the author s sanction) by Harry C. Jones,\\nAssociate in Physical Chemistry in Johns Hopkins University,\\nand Stephen h King, Harvard University. Cloth $2.00\\nHART. Third Edition.\\nChemistry for Beginners. By Edward Hart, Professor of\\nChemistry in Lafayette College. Third Edition, Revised and\\nGreatly Enlarged $1.50\\nJONES.\\nThe Freezing-point, Boiling-point, and Conductivity Methods.\\nBy Harry C. Jones, Associate in Physical Chemistry in Johns\\nHopkins University. Cloth $0.75\\nLANGENBECK.\\nThe Chemistry of Pottery. By Karl Langenbeck, Superin-\\ntendent of the Mosaic Tile Company, Zanesville, O., formerly\\nSuperintendent of Rookwood Pottery, Chemistry of the Amer-\\nican Encaustic Tiling Company, etc. Cloth. Illustrated. $2.00\\nLORD.\\nNotes on Metallurgical Analysis. By N. W. Lord, E.M., Pro-\\nfessor of Mining and Metallurgy in Ohio State University, $1.25\\nMASON.\\nNotes on Qualitative Analysis. By W. P. Mason, Professor\\nof Chemistry in Rensselaer Polytechnic Institute .80\\nNO YES.\\nOrganic Chemistry for the Laboratory. By W. A. Noyes,\\nPh.D., Professor of Chemistry in Rose Polytechnic Institute,\\nTerre Haute, Ind. $1.50\\nNOYES AND MULLIKEN.\\nLaboratory Experiments on the Class Reactions and Identifica-\\ntion of Organic Substances. By Arthur A. Noyes, Ph.D.,\\nAssociate Professor of Organic Chemistry in the Massachusetts\\nInstitute of Technology, and Samuee P. Mueeiken, Ph.D.,\\nInstructor in Organic Chemistry in the Massachusetts Institute\\nof Technology. Second, Thoroughly Revised Edition .50\\nSNYDER.\\nThe Chemistry of Soils and Fertilizers. By Harry Snyder,\\nB.S., Professor of Agricultural Chemistry in the University of\\nMinnesota $1.50\\nSNYDER.\\nThe Chemistry of Dairying. By Harry Snyder, B.S., Pro-\\nfessor of Chemistry in the University of Minnesota $1.50", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0179.jp2"}, "178": {"fulltext": "STILLMAN.\\nEngineering Chemistry. By Thomas B. Stiixman, Professor\\nof Analytical Chemistry in the Stevens Institute of Technology.\\nA Manual of Quantitative Chemical Analysis for the use of\\nStudents, Chemists, and Engineers $4.50\\n8vo. Cloth. 154 Illustrations.\\nVENABLE.\\nThe Development of the Periodic Law. By F. P. Venable,\\nProfessor of Chemistry in the University of North Carolina.\\ni2mo. Cloth. Well Illustrated $2.50\\nVENABLE AND HOWE.\\nInorganic Chemistry According to the Periodic Law. By F. P.\\nVenabi e, University of North Carolina, and Jas. Lewis\\nHowe, Washington and Lee University $1.50\\nCloth. 35 Illustrations.\\nWILEY.\\nPrinciples and Practice of Agricultural Chemical Analysis. \u00e2\u0080\u0094By\\nHarvey W. Wiley, Chemist of the U. S. Department of Ag-\\nriculture. Complete Work, Bound in Cloth, $9.50; Bound in\\nHalf Morocco $12.50\\nVol I.\u00e2\u0080\u0094 Soils $3.75\\n607 f p. 93 Illustrations, including 31 Plates.\\nVol II. Fertilizers $2.00\\n332 pp. 17 Illustrations.\\nVol III. Agricultural Products $3-75\\n665 pp. 125 Illustrations including Plates.\\nMethods for the Analysis of Ores, Pig Iron, and Steel, in use at the\\nLaboratories of Iron and Steel Works in the Region about\\nPittsburg, Pa. together with an Appendix containing various\\nSpecial Methods of Analysis of Ores and Furnace Products.\\nContributed by the Chemists in charge, and Edited by a Com-\\nmittee of the Chemical Section, Engineers Society of Western\\nPennsylvania Paper, .75 cloth, $1.00\\nSpecimen pages of any of the above books free upon application.\\nThe Chemical Publishing Company,\\nEASTON, PENNA.", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0180.jp2"}, "179": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0181.jp2"}, "180": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0182.jp2"}, "181": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0183.jp2"}, "182": {"fulltext": "NOV 17 1899", "height": "4821", "width": "3377", "jp2-path": "handbookofpracti00berg_0184.jp2"}, "183": {"fulltext": "", "height": "4461", "width": "2877", "jp2-path": "handbookofpracti00berg_0185.jp2"}, "184": {"fulltext": "", "height": "4924", "width": "3384", "jp2-path": "handbookofpracti00berg_0186.jp2"}}