rt 5 Se pees Spee eee tase te pene epee pooneee = r. ==> x = ane ee sess ssst sBeaese Sates bees + = ' Tees +f 3 = = 3 = = LE Sepeeorres se =) = ; ; : = SS =tiz = = ~ == =. ith epeeeees : Saree a a =: > aes Seriets ses treee % = : qtrertrorintrire Fede ea pore see seaiecrest Peseee a Seestessatse SSEHES — S ae = . = 3 : * i + > >= yess ~ 3 of Rees ze bs ripteit aes > Sree =e = = "3 F pep ersareee SSS sere; prot its se3es = < > : SReerareror bese -€-} s ceease wares Srergssearics Seesese pes > > 4 = aie 3 = = Ssberoteser ies : = : SS Sciistcapecsee spo S saesesrses ae ssepiss teas : - Risser ee Te $334 ererirarscy wiser ‘ = p< tekeereeaes = SSS sere: LL: COPYRIGHT DEPOSIT: ill Dr. S. M. BABCOCK, INVENTOR OF THE BABCOCK MILK TEST. / TESTING MILK AND ITS PRODUCTS \ A MANUAL FOR DAIRY STUDENTS, CREAMERY- AND CHEESE FACTORY OPERATORS, FOOD CHEMISTS, AND DAIRY FARMERS BY E. H. FARRINGTON and FF. Ws WOELL Professor in Charge of Dairy School Asst. Prof. of Agr’l Chemistry Of the University of Wisconsin 3%5 5°59 Be With pllusteations ee RU a ena THIRTEENTH REVISED AND ENLARGED EDITION MADISON, WIS. - MENDOTA BOOK COMPANY 1904 - ALL RIGHTS RESERVED THE LIBRARY OF CONGRESS. | One Copy Receiver MAY. 2 1904 Corvei@H#t ENTRY Man-3- 140% ASS\) X KXe. Na. Mi Grade ene COPY B. CoPpyYRIGHT, 1897, 1899, 1901 AND 1904, By E. H. FARRINGTON anp F. W. WOLL. £eoe € 68 € 9 8 ¢& e@@ @€¢F € @é ¢€ e e@ecg ¢& @ ee e*¢ DED ple © € e'5 > € @ Che J e® “62 2 Xe e CANTWELL PRINTING COMPANY MADISON, WIS. PREFACE TO FIRST EDITION. The present volume is intended for the use of dairy students, factory operators, dairymen, food chemists, and others inter- ested in the testing or analysis of milk and its products. The subject has been largely treated in a popular manner; accuracy and clearness of statement, and systematic arrangement of the subject matter have, however, been constantly kept in mind. The aim has been to make the presentation intelligible to students with no further training than a common-school educa- tion, but their work will naturally be greatly lightened by the aid of an able teacher. Complete directions for making tests of milk and other dairy products are given; difficulties which the beginner may meet with are considered in detail, and suggestions offered for avoid- ing them. It is expected that a factory operator or practical dairyman, by exercising common sense and ordinary care, can obtain sufficient knowledge of the subject through a study of the various chapters of this book to make tests of milk, cream, etc., even if he has had no previous experience in this line. For the benefit of advanced dairy students who are some- what familiar with chemistry and chemical operations, Chapter XIV has been added giving detailed instructions for the com- plete chemical analysis of milk and other dairy products. The detection of preservatives and of artificial butter or filled cheese has also been treated in this connection. As the subject of milk testing is intimately connected with the payment for the milk delivered at butter- and cheese fac- tories, and with factory dividends, a chapter has been devoted to a discussion of the various systems of factory book-keeping, and tables greatly facilitating the work of the factory secretary or bookkeeper have been prepared and are included in the Appendix. iv Testing Milk and Its Products.” Acknowledgment is due to the following parties for the use of electrotypes, viz.: Creamery Pkg. Mfg. Co., Chicago, IIl.; Vermont Farm Machine Co., Bellows Falls, Vt.; Elgin Mfg. Co., Elgin, Ill.; D. H. Burrell & Co., Little Falls, N. Y.; De Laval Separator Co., New York City; Henry Trémner, Phila- delphia, Pa.; Springer Torsion Balance Co., New York City; J. H. Monrad, Winnetka, Ill.; Borden & Selleck Co., Chicago, Ill.; Dairymen’s Supply Co., Philadelphia, Pa.; Bausch & Lomb Opt. Co., Rochester, N. Y.; John W. Decker, Columbus, Ohio; C. L. Fitch, Forth Atkinson, Wis., and the agricultural experiment stations at New Haven, Conn., and Madison, Wis. Madison, Wis., October 1, 1897. PREFACE TO THIRTEENTH EDITION. The first three editions of this book were sold in about a year and the twelfth edition was exhausted six years later. Every year that passes brings some valuable contributions to our knowledge of the subjects treated in the book and a fre- quent revision of it is therefore desirable. The present edition contains all the methods and 1 desea tions that have stood the test of actual use during the past few years; the new information which has appeared since the last revision of the book, has been carefully sifted, and what was deemed of sufficient importance has been incorporated in such detail as the scope of the book permitted; many changes and additions suggested by the experience of the authors have also been introduced. In brief, the book has been subjected to a renewed, critical examination and revision.. The general adoption of it as atext bookin American Dairy Schools, as well as the favorable reception which it has been accorded by users of Babcock testers, and the dairy public in general, is naturally a source of gratification to the authors. Madison, Wis., March 25, 1904. TABLE OF CONTENTS. PAGE. Introduction . . . caer : ; raster it Chap. I. faa earioTs OF MILK AND ITS PRODUCTS. . 11 Composition of milk: Water. Fat. Casein and albu- men. Milk sugar (lactose). Ash. Other components. Colostrum milk. Composition of milk products. Chap. Il. SAMPLING MILK .... “ 23 Sweet milk. Partially churned rh bite: milk. - Frozen milk. Chap. Ill. Tae BABCOCK TEST—MILK ...... 28 “A. Directions for making the test: Sampling. Adding acid. Mixing milk and acid. Whirling bottles. Adding water. Measuring the fat. Lutley dividers. B. Discussion of the details of the test : 1. Glassware. Test bottles. Pipettes. ‘‘ Fool pipettes.’’ | Acid measures. The Swedish acid bottle. Calibration of glassware. Calibration with mercury. Calibration with water. The Trowbridge method of calibration. 2. Centrifugal machines. Speed required for the com- plete separation of the fat. Ascertaining the necessary speed of testers. Hand testers.. Power testers. 3. Sulfuric acid. Testing the strength of the acid. The Swedish acid tester. The color of the fat column an index to the strength of the acid used. Influence of temperature on the separation of fat. 4. Water to be used in the Babcock test. Reservoir for water. 5. Modifications of the Babcock test. The Russian milk test. Bartlett’s modification. Siegfeld’s modification. - Bausch and Lomb centrifuge. ; Chap. IV. THE BABCOCK TEST— CREAM PE hat ete RP eters 74 Errors of measuring the cream. Weighing cream. Cream-test bottles. The bulb-necked cream bottle. The Winton cream bottle. Cream-weighing scales. Measur- ing cream for testing. Use of milk test bottle. Use of 5 ce pipette. Proper readings of cream tests. vi Testing Milk and Its Products. Chap. V. THE BABCOCK TEST—OTHER MILK PRO- DUCTS Skim milk, butter milk pad hes “The sdoublenceeet test bottle. The Wagner test bottle. The double-sized skim milk bottle. Cheese. Condensed milk. Chap Vil. THE LACTOMETER AND ITS APPLICATION The Quevenne lactometer. Influence of temperature. N. Y. Board of Health lactometer. Reading the lacto- meter. Time of taking lactometer readings. Influence of bi-chromate on lactometer reading. Calculation of milk solids. Adulteration of milk. Legal standards. The specific gravity of the milk solids. Calculation of extent of adulteration: Skimming. Watering. Watering and skimming. Chap Vii. TESTING THE ACIDITY OF MILK AND CREAM Cause of acidity in milk. Methods of testing acidity. Manns’ test. Devarda’s acidimeter. The alkaline-tablet test. Determination of acidity in sour cream. Spillman’s cylinder. Rapid estimation of the acidity of apparently sweet milk and cream. Detecting boracic-acid preserva- tivesin milk. ‘Alkaline Tabs.”’ Chap. Vill. TESTING THE PURITY OF MILK : The Wisconsin curd test. The fermentation test. The Monrad rennet test. The Marschall rennet test. Chap. IX. TESTING MILK ON THE FARM : Variations in milk of single cows. Number of Heh re- quired during a periodof lactation in testing cows. When ' to test a cow. Gurler’s method. Sampling milk ofsingle cows. Variations in herd milk. Influence of heavy grain feeding on the quality of milk. Influence of pasture on the quality of milk. Method of improving the quality of milk. Chap. X. COMPOSITE SAMPLES OF MILK it oak hoe Methods of taking composite samples. Use of tin dipper. Drip sample. Scovell sampling tube. The equity milk sampler. One-third sample pipette. Pre- servatives for composite samples. Care of composite samples. Fallacy of averaging percentages. A patron’s dilemma. PAGE. 85 93 108 125 131 148 ‘Table of Contents. 4 Chap. Xl. CREAM TESTING AT CREAMERIES . The space system. The oil-test churn. The Babcock test for cream. Sampling and weighing. Chap. Xll. CALCULATION OF BUTTER AND CHEESE YIELDS. A. Calculation of yield of butter: Butter fat test and yield of butter. Variations in composition of butter. Overrun of churn over test. Factors influencing the overrun. Calculation of overrun. Conversion factor for ‘butter fat. Butter yield from milk of different richness. Use of butter chart. Use of overrun table. B. Calculation of yield of cheese; From fat. From solids not fat and fat. From casein and fat. Chap. XIll. CALCULATING DIVIDENDS vii PAGE. 165 176 190 A. Calculating dividends at creameries: Proprietary - creameries. Co-operative creameries. JLlustrations of calculations of dividends. Paying for butter delivered. Milk and cream dividends. Relative-value tables. B. Calculating dividends at cheese factories: Proprie- tary factories. Co-operative factories. Chap. XIV. CHEMICAL ANALYSIS OF MILK AND ITS PRO- TRU! SUNS ae epee deni Sih Oi Ra pee Nk Mme ES Milk. Cream. Skim milk, butter milk, whey. Con- densed milk. Butter. A practical method of estimat- ing salt in butter. Detection of artificial butter. Reich- ert-Wollny method (Volatile acids). Tests for the detec- tion of oleomargarine and renovated butter. The boiling test. The Waterhouse test. Cheese. Detection of oleo- margarine cheese ( ‘‘Filled’’ cheese). Tests for adulteration of milk and cream. Detection of pasteurized milk or cream. Boiled milk. Detection of preservatives in dairy products. Boracic acid. Bi-car- bonate of soda. Fluorids. Salicylic acid. Formalde- hyde. Government food standards. Appendix SN Ta Seno Gp wos RR oe, a Table I. Composition of milk and its products. Table II, State and city standards for dairy-products. Table III. Quevenne lactometer degrees correspond- ing to the scaleof the N. Y. Board of Health lactometers. 204 233 Vill Testing Milk and Its Products. Table IV. Value of es for specific gravities from 1.019 to 1.0369. Table V. Correction table for specific gravity of milk. Table VI. Per cent. of solids not fat, corresponding to 0 to 6 per cent. of fat and lactometer readings of 26 to 36. Directions for the use of tables VII, VIII, IX and XI. Table VII. Pounds of fat in 1 to 10,000 pounds of milk testing 3 to 5.35 per cent. Table VIII. Pounds of fat in 1 to 1,000 lbs. of cream — testing 12.0 to 50.0 per cent. fat. Table IX. Amount due for butter fat, in dollars and cents, at 12 to 25 cents per pound. Table X. Relative-value tables. Table XI. Butter chart, showing calculated yield of butter, in pounds, from 1 to 10,000 pounds of milk testing 3.0 to 5.3 per cent. of fat. Table XII. Overrun table, showing pounds of butter from 100 pounds of milk. Table XIII. Yield of cheese, corresponding to 2.5 to 6 per cent. of fat, with lactometer readings of 26 to 36. | Table XIV. Comparisons of Fahrenheit and Centi- grade (Celcius) thermometer scales. Table XV. Comparison of metric and customary weights and measures. Suggestions regarding the organization of co-operative creameries and cheese factories. Constitution and by-laws for co-operative factory asso- ciations. Index PAGE, . 264 Testing Milk and its Products. INTRODUCTION. The need of a rapid, accurate and inexpensive method of determining the amount of butter fat in milk and other dairy products became more and more apparent, in this country and abroad, with the progress of the dairy in- ) dustry, and especially with the growth of the factory system of butter- and cheese making during the last few decades. So long as each farmer made his own butter and sold it to private customers or at the village grocery, it was not a matter of much importance to others whether the milk produced by his cows was rich or poor. But aS creameries and cheese factories multiplied, and farm- ers in the dairy sections of our country became to a large extent patrons of one or the other of these, a Sys- tem of equitable payment for the milk or cream BOS became a vital question. I. The creameries in existence in this Sonate. up to within fifteen years were nearly all conducted on the cream-gathering plan: the different patrons creamed their milk by the gravity process, and the cream was hauled to the creamery, usually twice or three times a week, where it was then ripened and churned. ‘The patrons were paid per inch of cream furnished; a creamery inch is a quantity of cream which fills a can twelve inches : | 2 Testing Milk and Its Products. in diameter, one inch high, or 113 cubic inches. This quantity of cream was supposed to make a pound of but- — ter, but cream from different sources, or even from the same sources at different times, varies greatly in butter- producing capacity, as will be shown under the subject of cream testing (2101). The system of paying for the number of creamery inches delivered could not therefore long give satisfaction. The proposition to take out a small portion, a pint or half a pint, of the cream furnished by each patron, and determine the amount of butter which these samples would make on being churned in so-called test churns, found but a very limited acceptance, on account of the labor involved and the difficulty of producing a first-class article from all the small batches of butter thus obtained. 2. The introduction of the so-called oil test churn in creameries which followed the creamery-inch system, marked a decided step in advance, and it soon came into general use in gathered-cream factories (203). In this test, glass tubes of about 2 inch internal diameter and nine inches long, are filled with cream to a depth of five inches, and the cream is churned; the tubes arethen placed in hot water, and the column of melted butter formed at the top is read off by means of a scale showing the num- ber of pounds of butter per creamery inch corresponding to different depths of melted butter. While the oil test is capable of showing the difference between good and poor cream, it can not make strictly accurate distinctions between different grades of good and of poor cream.? As 1 Refers to paragraph numbers. 2 Wisconsin experiment station, bulletin 12. Introduction. 3 a result, perfect justice cannot be done to different pat- rons of creameries where: payments for cream delivered are made on the basis of this test. 3. In cheese factories, and since the introduction of the centrifugal cream separator, in separator creameries, the problem of just payment for the milk furnished by differ- ent patrons was no less perplexing than in the case of gathered-cream factories. By the pooling system gener- ally adopted, each patron received payment in propor- tion to the number of pounds of milk delivered, irre- spective of its quality. Patrons delivering rich milk naturally will not be satisfied with this system when they find that their milk is richer than that of their neigh- bo.’s. The temptation to fraudulently increase the amount of milk delivered, by watering, or to lower its quality by skimming, will furthermore prove too strong for some patrons; the fact that it was difficult to prove any fraud committed, from lack of a reliable and practi- cal method of milk analysis, rendered this pooling system - still more objectionable. 4. As another instance in which the need of a simple _ test for determining the fat content of different kinds of milk was strongly felt, may be mentioned the case of pri- vate dairymen and breeders of dairy cattle who desired to ascertain the butter-producing capacities of the indi- vidual cows in their herds. The only manner in which this could be done, was by the cumbersome method of trial churnings: by saving the milk of the cow to be tested, for a day or a week, and churning separately the cream obtained. This requires a large amount of work when a number of cows are to be tested, and can not 4 Testing Milk and Its Products. therefore be done except in comparatively few cases, with cows of great excellence or by farmers having abun- dant hired help. 5. Introduction of milk tests. The first method which fulfilled all reasonable demands of.a practical and reli- able milk and cream test was the Babcock test, invented by Dr. 8. M: Babcock, chief chemist to the Wisconsin experi- ment station. A description of the test was first pub- lished in July, 1890, as bulletin No. 24 of Wisconsin ex- periment station, entitled: A new method for the estimation of fat in milk, especially adupted to creameries and cheese factories. This test, which is now known and adopted in all parts of the world where dairying is an important in- dustry, was not, however, the first method proposed for this purpose which could be successfully operated out- side of chemical laboratories. It was preceded by a number of different methods, the first one publisbed in this country being Short’s method, invented by Mr. F. G. Short and described in bulletin No. 16 of Wisconsin experiment station (July, 1888). 6. Short’s test. In this ingenious method, a certain quantity of milk (20 ce.!) was boiled with an alkali solu- tion and afterwards with a mixture of sulfuric and acetic acids; a layer of insoluble fatty acids separated on top of the liquid and was brought into the graduated neck of the test bottles by addition of hot water; the reading gave the per cent. of fat in the sample of milk tested. Short’s method did not find very wide application, both because it was rather lengthy and its manipulations somewhat difficult for non-chemists, and because several 1 See 48, footnote. - ss Introduction. 5 other methods were published shortly after it had been given to the public. 7. Other milk tests. Of these may be mentioned, be- sides the Babcock test already spoken of, the Failyer and Willard method, ! Parson’s method, ? Cochran’s test, 3 the Patrick or Iowa station test,* and the Beimling (Leff- mann and Beam) test.> Of foreign methods published at about the same time, or previously, the Lactocrite, ® Lie- bermann’s method, 7 the Schmid, * Thorner, ’ Nahm," and Rose-Gottlieb"! methods may be noted. 8. All these tests were similar in principle, the solids not fat of the milk being in all cases dissolved by the action of one or more chemicals, and the fat either meas- ured as such in a narrow graduated tube, or brought into solution with ether, gasoline, etc., and a portion thereof weighed on evaporation of the solvent. While this prin- ciple is an old one, having been employed in chemical laboratories for many years past, its adaptation to prac- tical conditions, and the details as to apparatus and chem- icals used were of course new and different in each case. The American tests given were adopted to a limited extent within the states in which they were originated 1 Kansas experiment station report, 1888, p. 149. 2N. H. experiment station report, 1888, p. 69. 3 Journal of Anal. Chem., III (1889), p. 381. 4 Ta. exp. sta., bull. No. 8, February, 1890; lowa Homestead, June 14, 1889. 5 Vermont exp. sta., bull. No. 21, September, 1890. For description of these and other volumetric methods of milk analysis, see Wiley, Agri- eultural Analysis, Vol. III, p. 490 et seq; Wing, Milk and its Products, p.33 et seq, and Snyder, Chemistry of Dairying, pp. 112-113. ; 6 Analyst, 1887, p. 6. 7 Fresenius’ Zeitschr., 22, 383. 8 Ibid., 27, 464. 9 Chem. Centralbl., 1892, 429. 10 Milchzeitung, 1894, No. 35; 1897, No. 50, 11 Landw. Vers. Stat., 40, 1. 6 Testing Milk and Its Products. and even outside of them, as in case of the Short, Pat- rick and Beimling methods. The Babcock test soon, however, nearly everywhere replaced the different meth- ods mentioned, and during the past ten years or more it has been in practically exclusive use in creameries and cheese factories in this country, where payments are made on the basis of the quality of the milk delivered, as well as in the routine work in experiment station laboratories, and among milk inspectors and private dairymen. 9. The Babcock Test. An examination of the causes of the present general adoption of the Babcock test will show the strong points of the test, and the requirements made of a practical milk test. The main causes why this test has replaced all competitors are doubtless to be sought in its simplicity and its cheapness. Its manipu- ations are few and readily learned, and it is cheap, both in first cost and as regards running expenses. The test is furthermore speedy, accurate,‘ and easily applied under practical conditions, and in the opinion of the writers it is the very best milk test at our disposal. The method is applicable, besides to whole milk, to cream, skim milk, butter milk, whey, condensed milk, and (if a small scale for weighing out the sample is avail- able) to cheese. With all its advantages, the Babcock milk test is not in every respect an ideal test. The handling of the very corrosive sulfuric acid requires constant care and atten- 1Forasummary of comparative analyses made by the Babcock test and gravimetric analysis up to 1892, see Hoard’s Dairyman, Oct. 7, 1892, p. 2560; also Schrott-Fiechtl, Milchzeitung, 1896, p. 183 et seq. Introduction. 7 tion; the speed of the tester, the strength of the acid, the temperature of the milk to be tested, and other points, always require watching, lest the results obtained be too low or otherwise unsatisfactory. In the hands of careful operators the test can, however, always be relied upon to give most satisfactory results. . 10. Foreign Methods. In European countries four practical milk and cream tests, besides the Babcock test, are in use at the present time, viz.: Gerber’s acid- butyrometer, the lactocrite, DeLaval’s butyrometer,and Fjord’ s certrifugal cream test. ! Of these the last test given has never, to our @ knowledge, been intro- duced into this country, and the first three only on a small scale. il. The Gerber method? (fig. 1) is essentially the old Beimling method (7), worked out independently by the Swiss chemist, Dr. N. Gerber. In this test sulfuric acid of the same strength is used as in the, Fi@.1. The Gerber acid- butyrometer, Babcock test, and a small quantity of amyl alcohol is added. The amyl alcohol facilitates the separation of the fat, but introduces 1 The Lister-Babcock milk test advertised in English papers and known as such in England, is the regular Babcock test, to which the English man- ufacturers have prefixed their names; the same applies to the Ahiborn- Babcock method and the Krugmann-Babcock method. 2Gerber, Die praktische Milchprtifung, 7th edition, 1900. Bore Testing Milk and Its Products. a source of error which may become serious, when the results obtained with a new lot of amyl alcohol can not | be checked against gravimetric analysis or against tests made with amyl alcohol known to give correct © results. This method is, however, extensively used in European countries, having there practically re- placed the Babcock test or been adopted in preference to it. 12. The Lactocrite was one of the earliest practical milk tests introduced. It was invented by De Laval in 1886. ‘The acids used in this test are lactic acid (origi- nally, acetic acid) with a mixture of hydrochloric and sulfuric acids. This test is now but rarely met with. 13. In the De Laval butyrometer (fig. 2) the same acid - is used as in the Babcock test, but the tubes employed and the manipulations of the method differ materially from Fig. 2. De Laval’s butyrometer. Introduction. ere this test; a smaller sample of milk is taken (only 2 ce. ) and a correspondingly small quantity of acid used. Where a large number of milk samples are tested every day, as is the case, for instance, in Huropean milk control sta- tions, the butyrometer may be preferable to the Babcock test; but it requires more skill of the operator and does not work satisfactorily in case of sour, loppered, or partially churned milk.. The machine placed on the market both by Dr. Gerber and the De Laval Company are more expensive than the Babcock testers sold in this country; the De Laval test requires a high speed, 5-6000 revolutions per minute; and therefore places greater de- _ mands for solidity in the machine than does the Babcock test. : 14. Fjord’s centrifugal cream tester! (fig. 3) is exten- sively used in Denmark and is mentioned in this connec- tion as it furnishes, as a rule, a reliable method for comparing the quality of different lots of milk. The method was published in 1878, by the late N.J. Fjord, director of the state experi- mentstation in Copenhagen, through whose exertions and on whose authority it was introduced into Danish creameries in the middle of the eighties. No chemicals are added in this test, the milk being simply placed in glass tubes, seven inches long and about two-thirds of an inch in diameter,and whirled FiG.3. Fjord’s centrifugal: cream tester. 1State Danish experiment station, Copenhagen, sixth and ninth re- ports, 1885-7, 10 Testing Milk and Its Products. for twenty minutes at a rate of 2000 revolutions per minute at 55° C.(131° F.). The reading of the cream layer thus obtained gives the per cent. of cream, and not of butter fat, in the sample tested. One hundred and nine-two samples of milk can be tested simultan- eously. Within the limits of normal Danish herd milk, the results obtained correspond to the percents of fat present in the samples, one per cent. of cream being equal to about 0.7 per cent. of fat; outside of these limits the test is, however, unreliable, especially in case of very rich milk and strippers’ milk. Only sweet milk can be tested by this method. The recent introduction of milk tests proper into Denmark, like the Gerber, Bab- cock and De Laval tests may, however, in time force the Fjord cream test out of Danish creameries, for similar reasons that relegated to obscurity the gravity cream tests. ! 1Among foreign milk tests in use abroad should also be mentioned the Woliny Refractometer,which, in the hands of atrained chemist, may prove better adapted for use where a very large number of samples are to be tested at a time, than any other milk test available. CHAPTER I. COMPOSITION OF MILK AND ITS PRODUCTS. Before taking up the discussion of the Babcock milk test, a brief description of the chemistry of milk and its products is given, so that the student may understand what are the components of dairy products, and the rela- tion of these to each other. Only such points as have a direct bearing on the subject of milk testing and the use of milk tests in butter and cheese factories or private dairies will be treated in this chapter, and the reader is referred to standard works on dairying for more detailed information in regard to the composition of dairy pro- ducts. 15. Composition of Milk. Milk is composed of the fol- lowing substances: water, fat, casein, albumen, milk sugar, and ash. A few other substances are present in small quantities, but they are hardly of any practical impor- tance and will not be considered here. The components of the milk less the water are known collectively as milk solids or total solids, and the total solids less the fat, 1. e., casein, albumen, milk sugar, and ash, are often spoken of as solids not fat or the non-fatiy milk solids. The milk serum includes all components of the milk less the fat; the serum solids are therefore another name for the solids not fat; when given, they are, however, generally calcu- lated to per cent. of milk serum, not of milk. If, e. g., a sample of milk contains nine per cent. of solids not fat, 12 Testing Milk and Its Products. and three per cent, of fat, the milk serum will make up 97 per cent. of the milk, and the serum solids, —°3°° = 9.28 per cent. of the milk serum. 16. Water. The amount of water contained in cows’ milk ranges from 82 to 90 per cent. Normal cows’ milk will not,as a rule,contain more than 88 per cent. of water, nor less than 84 per cent. In states where there are laws regulating the sale of milk, as is the case in eighteen states in the union (see Appendix, Table IT), the maximum limit for water in milk in all instances but one (South Carolina) is 88 per cent.; the state mentioned allows 88.5 per cent. of water in milk offered for sale within her borders. The effect of fraudulently increasing the water content of milk*by watering is considered under Adulteration of Milk (118). 17. Fat. The fat in milk is not in solution, but sus- pended as very minute globules, which form an emulsion with the milk serum; the globules are present in immense numbers, viz., on the average about one hundred millions in a single drop of milk; a quart of milk will contain about two thousand billions of fat globules, a number written with thirteen figures. The size of the globules in the milk from the same cows varies according to the stage of the period of lactation, the globules being largest at the beginning of the lactation period, and gradually decreasing in size with its progress. Different breeds of cows have fat globules of different average sizes; the Channel Island cows are thus noted for the relatively large fat globules of their milk, while the lowland breeds, the Ayrshire, and other breeds have uniformly smaller globules. The diameter of average sized fat Composition of Milk and Its Products. 13 globules in fresh milkers is about 0.004 millimeter, or one six-thousandth of an inch; that is, it takes about six thousand such globules placed side by side to cover one ineh in length. The globules in any sample of milk vary greatly in size; the largest globules are recovered in the cream when the milk is set or run through a cream separator, and the smallest ones remain in the skim milk; thoroughly skimmed separator skim milk contains only a relatively small number of very minute fat globules. Milk fat is composed of so-called glycerides of the fatty acids, i. e., compounds of the latter with glycerin; some of the fatty acids are insoluble in water, viz., palmitic, stearic, and oleic acids, while others are soluble and vol- atile, the chief ones among the latter being butyric, cap-_ rylic,and capronic acids. The glycerides of the insoluble fatty acids make up about 92 per cent. of the pure milk fat; about 8 per cent. of the glycerides of volatile fatty acids are therefore found in natural milk-(and butter- ) fat. The distinction between natural and artificial but- ter lies mainly in this point, since artificial butter (but- terine, oleomargarine) as well as other solid animal fats contain only a very small quantity of volatile fatty acids. The glycerides of the volatile fatty acids are unstable compounds, easily decomposed through the action of bacteria or light; the volatile fatty acids thus set free, _ principally butyric acid, are the cause of the unpleasant odor met with in rancid butter. . Cows’ milk generally contains between three and six per cent. of fat; in American milk we find, on the average, toward four per cent. of fat. The milk from single cows in perfect health will occasionally go below 14 Testing Milk and Its Products. or above the limits given, but the mixed milk from a whole herd rarely falls outside of these limits. The standard adopted by the U. 8. government for fat in milk is 3.25 per ct. The legal standard for fat in milk in most states of the Union is 3 per cent.; Rhode Island allows milk containing 2.5 per cent. of fat to be sold as pure, while Georgia and Minnesota require it to contain 3.5 per cent., and Massachussetts 3.7 per cent. (in the months of May and June; see Appendix, Table II). 1S. Casein and albumen. These belong to the so-called nitrogenous substances, distinguished from the other com-. ponents of the milk by the fact that they contain the element nitrogen. Another name is albuminoids or protein — compounds. Casein is precipitated by rennet in the presence of soluble calcium salts, and by dilute acids and certain chemicals; albumen is not acted upon by these agents, but is coagulated by heat, a temperature of 170° F. being sufficient to effect a perfect coagulation. The casein, with fat and water, form the main components of nearly all kinds of cheese. In the manufacture of ched- dar and most other solid cheeses, the casein is coagulated by rennet, and the curd thus formed holds fat and whey mechanically, the latter containing in solution small quantities of non-fatty milk solids. The albumen goes into the whey and is lost for cheese making; in some countries itis also made into cheese by evaporating the whey under constant stirring; whole milk of cows or goats is often ad- ded and incorporated into such cheese (primost, gjedost). Casein is present in milk partly in solution, in the same way as milk sugar, soluble ash-materials and albu- men, and partly in suspension, in an extremely fine col- loidal condition, mixed or combined with insoluble Composition of Milk and Its Products. 15 calcium phosphates. The casein and calcium phosphates in suspension in milk may be retained on a filter made of porous clay (so-called Chamberland jilters). About 80 per cent. of the nitrogenous compounds of normal cows’ milk are made up of casein; the rest is largely albumen. If the amount of casein in milk be determined by precipitation with rennet or dilute acids, and the albumen by boiling the filtrate from the casein precipitate, it will be found that the sum of these two compounds does not make up the total quantity of nitro- genous constituents in the milk. The small remaining portion (about five per cent. of the total nitrogenous constituents) has been called by various authors, globu- lin, albumose, hemi-albumose, nuclein, nucleon, proteose, etc. The nitrogenous constituents of milk are very un- stable compounds, and their study presents many and great difficulties; as a result we find that no two scien- tists who have made a special study of these compounds agree as to their properties, aside from those of casein and albumen, or their relation to the nitrogenous sub- stances found elsewhere in the animal body. For our purpose we may, however, consider the nitrogen com- . pounds of milk as made up of casein and albumen,. and the term casein and albumen, as used in this book, is meant to include the total nitrogenous constituents of milk, obtained by multiplying the total nitrogen content of the milk by 6.25.1 1 The factor 6.25 is generally used for obtaining the casein and albumen from the total nitrogen in the milk, although 6.37 would be more correct, Since these substances, according to our best authorities, contain on the average 15.7 per cent. of nitrogen Ge =6.37) 16. Testing Milk and Its Products. The quantity of casein in normal cows’ milk will vary from 2 to 4 percent., and of albumen, from .5 to .8 per cent. The total content of casein and albumen ranges between 2.5 and 4.6 per cent., the average being about 3.2 per cent. Milk with a low fat content will contain - more casein and albumen than fat, while the reverse is generally true in case of milk containing more than 3.5 per cent. of fat. 19. Milk sugar or lactose belongs to the group of organic compounds known as carbohydrates. It is a commercial product manufactured from whey and is obtained in this process as pale white crystals, of less sweet taste and less soluble in water than ordinary sugar (cane sugar, sucrose). About 70 per cent. of the solids in the whey, and 33 per cent. of the milk solids, -are composed of milk sugar. _ When milk is left standing for some time, viz., from one to several days, according to the temperature of the surrounding medium, it will turn sour and soon become thick and loppered. This change in the composition and the appearance of the milk is brought about through the action of acid-forming bacteria on the milk sugar. These are present in ordinary milk in immense numbers, and under favorable conditions of temperature multiply rapidly, feeding on the milk sugar as they grow, and decomposing it into lactic acid. When this change alone occurs, there is not necessarily a loss in the nutritive value of the milk, since milk sugar breaks up directly into lactic acid, as shown by the following chemical formula: C,,H,,0,,-H,O (lactose) = 4 C,H ,O, Cactie acid) 1 One molecule of milk sugar is composed of 12 atoms of carbon (€), 22 atoms of hydrogen (H), 11 atoms of oxygen (O), and one molecule of water (H5QO). In the same way, the lactic-acid molecule consists of three atoms of carbon, 6 atoms of hydrogen, and 3 atoms of oxygen. Composition of Milk and Its Products. 17 Ordinarily the souring of milk is, however, more com- plicated, and other organic bodies, like butyric acid, al- cohol, etc., and gases like carbonic acid are formed, re- sulting in a loss in the feeding value of the milk. While sour milk may therefore contain a somewhat smaller pro- portion of food elements than sweet milk, the feeding of it to farm animals, especially pigs, will generally pro- duce better results than is obtained in feeding similar milk in a sweet condition. The cause of this may lie in the stimulating effect of the lactic acid of sour milk on the appetites of the animals, or in its aiding digestion by increasing the acidity of the stomach juices. That the souring of milk is due to the activities of bacteria present therein is shown clearly by the fact that sterile milk, i. e., milk in which all germ life has been killed, will remain sweet for any length of time when kept free from infection. The amount of milk sugar found in normal cows’ milk varies from 3.5 to 6 per cent., the average content being about 5 per cent.; in sour milk this content is decreased to toward 4 per cent. . 20. Ash. The ash or mineral substances of milk are largely composed of chlorids and phosphates of sodium, potassium, magnesium and calcium; iron oxid and sul- furic and citric acids are also present in small quantities among the normal mineral milk constituents. The amounts of the different bases and acids found in milk ash have been determined by a number of chemists; the average figures obtained are given in the following table, calculated per 100 parts of milk (containing .75 per cent. of ash) and per 100 parts of milk ash. 2 18 Testing Milk and Its Products. Mineral Components of Milk. In per cent. of Milk. In per cent. of Ash. Potassium oxid (K,0O) ......... .19 per ct. 25.64 per ct. Sodium oxid (Na.Q) ............ .09 12.45 hme (CaQ) 224) :6:25- a Ree: 18 . 24.58 Magnesia (MeO he oss cS 02 3.09 Tron-oxid' (‘Wes Ov). ecsre ee .002 34 Phosphoric anhydrid (P,0;). .16 21.24 Chiorin (Ob). s. Site ee? A? . 16.34 . .762 per ct. 103.68 per ct. Less oxygen, corresponding to Pol I ay gE! Mee Re Pee oe ereem ee tors .012 3.68 75 100.00 The combinations in which the preceding bases and acids are contained in the milk are not known with cer- tainty. According to Soldner, 36 to 56 per cent. of the phosphoric acid found in milk, and from 53 to 72 per cent. of the lime, are present in suspension in the milk as di- and tri-calcium phosphates, and may be filtered out by means of Chamberland filters (18), or by long continued centrifuging (Babcock'). The rest of the ash constituents are dissolved in the milk: serum. The ash content of normal cows’ milk varies but little, aS a rule only between .6 and .9 per cent., with an aver- age of .7 per cent. Milk with a high fat content gen- erally contains about .8 per cent. of ash; strippers’ milk always has a high ash content, at times even exceeding one per cent. Ordinarily, the mineral constituents are, however, the components of milk least liable to variations. 21. Other Components. Besides the milk constituents enumerated and described in the preceding pages, nor- 1 Wis. experiment station, twelfth report, p. 93. Composition of Milk and Its Products. 19 mal milk contains a number of substances which are present in but small quantities and have only scientific interest, such as the milk gases (carbonic acid, oxygen, nitrogen), citric acid, lecithin, cholesterin, urea, hypo- xanthin, lactochrome, etc. 22. Average Composition. The average percentage composition of cows’ milk will be seen from table I in the Appendix. The following statement shows the limits within which the components of normal American cows’ milk are likely to come: Minimum. Maximum. Average. AES 1S es a 9 82.0 perct. 90.0 perct. 87.4 per ct. ERM Race eisai cacce-crhie weston 2.3 7.8 a Casein and albumen......... 2.5 4.6 oa PPA SURAT Sv sciisinans venues Gone ons 3.0 6.0 5.0 ASI Gnas Ck OOS ae 6 9 i 23. Colostrum Milk. The liquid secreted directly after parturition is known as colostrum milk or biestings. It is a thick, yellowish, viscous liquid; its high content of albumen and ash is characteristic, and also its low con- tent of milk sugar. Owing to the large quantity of albumen which colostrum contains, it will coagulate on being heated toward the boiling point. In the course of four to five days the secretion of the udder gradually changes from colostrum to normal milk; the milk is con- sidered fit for direct consumption or for the manufacture of cheese and butter, when it does not coagulate on boil- ing and is of normal appearance as regards color, taste, and other properties. For composition of colostrum milk, see Appendix, Table I. 24. Composition of milk products. In addition to its use for direct consumption, milk is the raw material from 20 Testing Milk and. Its Products. which cream, butter, cheese, and condensed milk are ob- tained. When milk is left standing for some time or subjected to centrifugal force, it will separate into two distinct parts, cream and_skim milk. The proportion of each part which is obtained and their chemical composition will de- pend on the method by which the separation is effected; in the so-called gravity process where the cream is separated on standing—either in shallow pans in the air, or in deep cans, submerged in cold water—a less complete separa- tion is reached, less skim milk being obtained and this being richer in fat than when the separation takes place through the action of centrifugal force. In modern creameries the milk is now generally skim- med by means of cream separators. Separator cream will contain from 15 to 50 per cent. of fat, according to the adjustment of the separator and of the milk supply; ordi- narily it contains about 25 per ct. of fat. Cream of aver- age quality, in addition to the fat content given, consists of about 66 per ct. of water, 3.8 per ct. casein and albu- men, 4.3 per ct. milk sugar, and .5 per ct. ash. The skim milk is made up of the milk serum (15) anda small amount of fat, viz., toward .4 per ct. when obtained by the gravity process, and less than .2 per ct. in the case of separator skim milk. Milk set in shallow pans in the air, or in deep cans in water above 60° F., will give skim milk containing one-half to over one per ct. of © fat. Skim milk is used as a food for young farm animals or aS human food, and in this country only in excep- tional cases, for the manufacture of cheese. 25. Cream is used for the manufacture of butter or for direct consumption. In the former case a certain amount Oomposition of Milk and Its Products. 21 of acidity is generally allowed to develop therein pre- vious to the churning process. This secures a more complete churning and produces peculiar flavors in the butter, without which it would seem insipid to the ma- jority of people in this country. Nearly all American butter is salted before being placed onthe market. Salt is a preservative and for a limited length of time pre- vents butter from spoiling. Unsalted butter made from sweet cream is a common food article in Southern and . Middle Europe, but only an insignificant amount is man- ufactured and consumed in America; salted butter made in Europe also contains considerably less salt than Amer- ican butter (see Appendix, Table I). Butter contains all the fat of the cream but a small portion which goes into the butter milk, and a small unavoidable mechanical loss incident to the handling of the products. Butter should contain at least 80 per ct. of fat and ordinarily contains about 83 per ct.; besides this amount of fat, butter is gen- erally composed of water, about 13 per ct., curd and milk sugar 1 per ct., and salt 3 per ct. Butter milk is similar to skim milk in composition, but varies much more than this product, according to the acidity, temperature, and thickness of the cream, and other churning factors. It contains about 9 per ct. of solids, viz., milk sugar (and lactic acid) 4 per ct., casein and albumen 4 per ct., fat .3 per ct., and ash .7 per ct. 26. The quantities of butter and by-products obtained in the manufacture of butter are .as follows: 1000 lbs of milk of average quality will give about 850 lbs. of skim milk and 145 lbs. of cream (separator slime and mechan- ical loss, 5 lbs.); this amount of cream will make about A2 lbs. of butter and 100 lbs. of butter milk (mechanical loss, 3 lbs. ). 22 Testing Milk and Its Products. 27. In the manufacture of American cheddar cheese, whole milk is heated to about 86° F.,and a small amount of rennet extract is added, which coagulates the casein; the albumen of the milk is not precipitated by rennet and remains in solution (18). ‘‘Green’’ cheese,as taken from the press, is made up, roughly speaking, of 37 per ct. of water, 34 per ct. of fat, 24 per ct. of albuminoids (nearly all casein), and about 5 per ct. of milk sugar, lactic acid,and ash (largely salt). In the curing of cheese there is some drying off, but the main changes occur in the breaking up of the firm curd into soluble and digest- ible nitrogenous compounds, peptons, amids, ete. Whey is the by-product obtained in the manufacture of cheese. It consists of water and less than 7 per ct. of solids; of the latter about 5 per ct. is milk sugar, .8 per ct. albumen, .6 per ct. ash, and .3 per ct. fat. Whey is generally used for feeding farm animals; it is the raw- product from which milk sugar and whey cheese are made. 28. Condensed Milk is manufactured from whole milk or from partially skimmed milk. In many brandsa large quantity of sugar (25 per ct. or more) is added to the condensed milk in the process of manufacture so as to secure perfect keeping quality in the product. Brands to which no sugar has been added are also on the market, and in case of such brands the relation between the var- ious solid constituents of the condensed milk will be es- sentially the same as that between the constituents of milk solids. Condensed milk should contain at least 10 per ct. of fat, and must be free from preservatives and all other foreign substances (except sugar). Tables are given in the Appendix showing the average composition of the various milk products. _ CHAPTER II. SAMPLING [MLK. 29. The butter fat in milk is not in solution, like sugar dissolved in water, but the minute fat globules or drops, in which form it occurs, are held in suspension in the milk serum (17). Being lighter than the serum, the fat . globules have a tendency to rise to the surface of the milk. If, therefore, a sample of milk is left standing for evena short time, the upper layer will contain more fat than the lower portion. This fact should always be borne in mind when milk is sampled. The rapidity with which fat rises in milk can be easily demonstrated by allowing a quantity of sweet milk to stand ina cylinder or a milk can for a few minutes, and testing separately the top, middle and bottom layer of this milk. The amount of mixing necessary to evenly distribute the constituents of milk throughout its mass may be as- certained by adding afew drops of cheese color to a quart of milk. The yellow streaks through the milk will be noticed until it has been poured several times from one vessel to another, when the milk will have a uniform pale yellow color. Stiring with a stick or a dipper will not produce an even mixture so quickly or so complete- ly as pouring the milk afew times from one vessel to another; in sampling milk for testing it should always be mixed by pouring, just before the milk is measured into the bottle; if several tests are made of a sample, the milk should be poured before each sampling. 24 Testing Milk and Its Products. 30. Partially churned milk. A second difficulty some- times met with in sampling whole milk arises from the fact that a part of the butter fat may be separated in the form of small butter granules, by too zealous mixing or by reckless shaking in preparing the sample for testing. This will happen most readily in case of milk from fresh Cows or with milk containing exceptionally large fat globules. When some of the butter granules are thus churned out, they quickly rise to the surface of the milk after pouring and cannot again be incorporated in the milk by simple mixing; it is, therefore, impossible to obtain a fair sample of such milk for testing without tak- ing special measures which will be explained in the fol- lowing. The granules of butter may be so small as to pass. into the pipette with the milk and the quantity ' measured thus contain a fair proportion of them, but they will be found sticking to the inside of the pipette when this is emptied, and thus fail to be carried into the test bottle with the milk. A similar partial churning of the milk will sometimes take place in the transportation cans. When such milk is received at the factory, the butter granules are caught by the strainer cloth through which the milk is poured, and are thus lost both to the factory and to the farmer. This separated fat cannot be put into the cream or added to the granular butter, without running the risk of mak- ing mottled butter, and it will not enter into the sample of milk taken for testing purposes. When milk samples are sent by mail or express in small bottles, or carried to the place of testing, they often arrive with lumps of butter floating in the milk or Sampling Milk. 25 sticking to the glass. This churning of the milk can be easily prevented by completely filling the bottle or the can. If there is no space left for the milk in which to splash around, the fat will not be churned out in transit. 31. Approximately accurate results may generally be obtained with a partially churned sample of milk, if a teaspoonful of ether be added to it. After adding the ether, cork the bottle and shake it until the lumps of butter are dissolved. This ether solution of the butter — ‘will mix with the milk, and from the mixture a fairly satisfactory sample may generally be taken. The dilution of milk by the ether introduces an error in the testing, and only the smallest quantity of ether necessary to dis- solve the lumps of butter should be used. If desired, a definite quantity of ether, say five per cent. of the vol- ume of the sample of milk to be tested, may be added; in such cases the result of the test must be increased by the per cent. of ether added. HXAMPLE.—To a 4-o0z. sample (120 ce.) of partially churned milk, 5 per cent., or 6 cc., of common ether are added; the mix- ture gives an average test of 4.2 per cent. The test must be in- creased by 5, x4.2=.21, and the original milk therefore con- tained 4.24+-.21=4.41 per cent. of fat. Milk containing ether must be mixed cautiously with acid so as to avoid loss of the contents of the bottle by the sudden boiling of the ether due to the heat evolved. Instead of adding ether to partially churned samples, the milk may be heated to about 110° F. for a few min- utes, so as to melt the butter granules; the sample is now shaken vigorously until a uniform mixture of milk and melted butter is obtained, and a pipetteful then quickly drawn from the sample. 26 Testing Milk and Its Products. 32. Sampling sour milk. When milk becomes sour, the casein is coagulated and the mechanical condition of the milk thereby changed so asto render difficult a correct sampling. The butter fat is not, however, changed in the process of souring; this has been shown by one of us, among others, in a series of tests which were measured from one sample of sweet milk into six test bottles. A test of the milk in one of these test bottles was made every month for six months, and approximately the same amount of fat was obtained in the tests throughout the series, as was found originally in the milk when tested in a sweet condition. If the milk is in condition to be sampled, its souring does not therefore interfere with its being tested by the Babcock test or with the accuracy of the results obtained. In order to facilitate the sampling of sour or loppered milk, some chemical may be added which will re- dissolve the coagulated casein and produce a uniform mixture that can be readily measured with a pipette. Any alkali (powdered potash or soda, or liquid ammonia) will pro- duce this effect. Only avery small quantity of powdered alkaliis necessary for this purpose. The complete action of the alkali on sour milk requires a little time, and the operator should not try to hasten the solution by adding too much alkali. An excess of alkali will often cause such a violent action of the sulfuric acid on the milk to which the acid is added (on account of the heat generated or the presence of carbonates in the alkali) that the mix- ture will be thrown out of the neck of the test bottle when 1See Hoard’s Dairyman, April 8, 1892. The same holds true for cream, as shown by Winton (U.S. Dept. Agr., Div. of Chemistry, bull. 43, p. 112). Sampling Milk. 27 this is shaken in mixing the milk and the acid (37). When powdered alkali is.added to the milk, it should be allowed to stand for a while, with frequent shaking, until the curd is all dissolved and an even translucent liquid is obtained. Such milk may become dark-colored by the action of the alkali, but this color does not interfere with the accuracy of the test. Instead of powdered soda or potash, these substances dissolved in water (soda or potash lye), or strong am- monia water, may be used for the purpose of dissolving the coagulated casein in a sample of sour milk. In this case, a definite proportion of alkali solution must, how- ever, be taken, 5 per cent. of the volume of milk being usually sufficient, and the results obtained are increased accordingly. (See example cited on p. 25.) 33. Sampling frozen milk. When milk freezes, it sep- arates into two distinct portions: Milk crystals, largely made up of water, with a small admixture of fat and other solids, and a liquid portion, containing nearly all the solids of the milk. In sampling frozen milk it is therefore essential that Doth the liquid and the frozen part be warmed and mixed thoroughly by pouring gently back and forth from one vessel into another; the sample is then taken and the test proceeded with in the ordinary manner (36). CHAPTER III. THE BABCOCK TEST. 34. The Babcock test is founded on the fact that strong sulfuric acid will dissolve all non-fatty solid constituents Fic. 4. The first Babcock tester made. of milk and _ other dairy products, and _ wiJl set free the fat. This will separate on standing, but to effect a speedy andcomplete — separation, the bottles holding the mixture of milk and acid are placed in a centrifugal, machine, a so-called tester, and whirled for four minutes; hot water is then added so as to bring the liquid fat into the graduated neck of the test bot- tles, and after a re- peated whirling, the length of the column of fat is read off, show- ing the per cent. of fat contained in the sample tested. The Babcock Test. 29 Sulfuric acid is preferable to other strong mineral acids for the purpose mentioned, onaccount of its affinity to water; when mixed with milk, the mixture heats greatly, thus keeping the fat liquid without the applica- tion of artificial heat and rendering possible a distinct reading of the column of fat brought into the neck of the test bottles. | So far as is known, any kind of milk can be tested by the Babcock test. Breed, period of lactation, quality or age of the milk is of no importance i in using this method, so long as a fair sample of the milk can be secured. In case of samples of milk or other dairy products rich in solids it requires a little more effort to obtain a thorough mixture with the acid than with dairy products low in solids, like skim milk or whey, which may be readily mixed with the acid. A.—DIRECTIONS FOR MAKING THE TEST. 35. The various steps in the manipulation of the Bab- cock test are discussed in the following pages; attention is drawn to the difficulties which the beginner and others may encounter in the use of the test, and the necessary precautions to be observed in order to obtain accurate and satisfactory results are explained in detail. The effort has been to treat the subject exhaustively and from a practical point of view, so that persons as yet unfamil- iar with the test may turn to the pages of this book for help in any difficulties which they may meet in their work in this line. 36. Sampling. The sample to be tested is first mixed by pouring the milk from one vessel to another two or 30 Testing Milk and Its Products. three times so that every portion thereof will contain a uniform amount of butter fat (29). The measuring pipette which has a capacity of 17.6 cubic centimeters (see fig. 6), is filled with the milk immediately after the mixing is com- pleted, by sucking the milk into it until this ‘rises a little above the mark around the stem of the pipette; the forefinger is then quickly placed over the end of the pipette before the milk runs down below the mark. By slightly releasing the pressure of the finger on the end of the pipette, the milk is now allowed to run down until it just reaches the mark on the stem; the quan- tity of milk contained in the pipette will then, if this is cor- rectly made, be exactly 17.6 cc. | The finger should be dry in }In6 measuring out the milk so that | jij the delivery of milk may be read- ily checked by gentle pressure on the upper end of the pipette. The point of the pipette is now placed in the neck of a Bab- cock test bottle (fig. 5), and the milk is allowed to flow slowly down the inside oftheneck. Care must be taken that none of the milk measured out is lost in this transfer. The portion of the milk remaining in the pointofthe pip- _‘F 14. 6. Fia. 5. : P ° 17.6 ce. pi- 1 test bottle, ette is blown into the test bottle. ““yette 0 Ly CO a Guo oo ooo on - The Babcock Test. 31 The best and safest manner of holding the bottle and the pipette in this transfer is shown in fig. 7. Fig. 8 shows a position which should be avoided, since by hold- ing the bottle in this way, there is danger that some of the milk may com- pletely fill the neck of the bottle, and as a result, flow over the top of the neck. Pipettes, the lower part of which slip readily into the necks of the test bottles, may be emptied by lowering the pipette into the neck of the bot- tle till it rests on its rim, when the milk is allowed to run into the _ test bottle. | 37. Adding Acid. The acid cylinder (fig. 9) holding 17.5 cce., is filled to the mark with sulfuric acid of a specific gravity = of 189-7 83." White =e rs \ amount of acid is care- mate . fully poured into the Fig.7. The right way ofemptying test bottle containing the pipette into test bottle. milk. In ad din g the acid, the test bottle is conveniently held at an angle (see fig. 7), so that the acid will follow the wall of the bottle and not run in a small stream into the center of the milk, the bottle being slowly turned around and the 32 Testing Milk and Its Products. neck thus cleared of adhering milk. ° By pouring the acid into the middle of the test bottle, there is also a danger of completely filling this with acid, in which ease the plug of acid formed will be pushed over the edge of the neck by the ex- = pansion of the air in the bot- | tle, and may be spilled onthe ¢<¢* SSS) hands of the operator. a= ~_ The milk and the acid in | 2, the test bottle should be in two distinct layers, without a black portion of partially mixed liquids between them. Such a dark layer is often fol- lowed by an indistinct separa- tion of the fat in the final reading. The cause of this may be that a partial mixture of acid and milk before the acid is diluted with the water of the milk may bring about too strong an action of the | acid on the milk, and the fat | } in this small por- hs tion may be slightly Zi ee charred by the 7 str ong acid. The Fig.8. The wrong way of emptying pipette appearance of into test botile. black floceulent matter in or below the column of fat which generally results, in either case renders a correct measurement of fat difficult and at times even impos- The Babcock Test. | 30 sible; if the black specks occur in the fat column itself, the readings are apt to be too high; if below it, the diffi- culty comes in deciding where the column of fat begins. 38. Mixing milk and acid. After adding the acid, this is carefully mixed with the milk by giving the test bottle a rotary motion. In doing this, care should be taken that none of the liquid is shaken into the neck of the test bottle. When once begun, the mixing should be continued until prupleted; a partial and interrupted mixing of the liquids will often cause more or less black material to separate with the fat when the test is finished. Clots of curd which separate at first by the action of the acid on the milk, must be entirely dissolved by continued and - careful shaking of the bottle. Beginners sometimes fail to mix thoroughly the milk and the acid in the test bottle. As the acid is much heavier than the milk, a thin layer of it is apt to be left unnoticed at the bot- TE ee, HOU of the bottle, unless this is vigorously acid cylinder. Shaken toward the end of the operation. The mixture becomes hot by the action of the acid on the water in the milk and turns dark colored, owing to the effect of the strong sulfuric acid on the nitrogenous constituents and the sugar of milk. Colostrum milk or milk from fresh cows will form a violet colored mixture with the acid, due to the action of the latter on the albumen present in such milk in con- siderable quantities (23). : When milk samples are preserved by means of potas- ium bichromate (188), and so much of this material has 3 34 Testing Milk and Its Products. been added that the milk has a dark yellow or reddish color, the mixture of milk and acid will turn greenish black, ‘and a complete solution is rendered extremely difficult on account of the toughening effect of the bichro- mate on the precipitated casein. This difficulty is still more pronounced with milk preserved with formalde- hyd. : } 39. Whirling bottles. After the milk and the acid have been completely mixed, the test bottle is at once placed in the centrifugal machine or tester and whirled for four or five minutes at a speed of 600 to 1200 revo- lutions per minute, the proper speed being determined by the diameter of the tester (66). It is not absolutely necessary to whirl the test bottles in the centrifuge as soon as the milk and the acid are mixed, although this method of procedure is much to be preferred; they may be left in this condition for any reasonable length of time (24 hours, if necessary) without the test being spoiled. If left until the mixture becomes cold, the bottles should, however, be placed in warm water (of about 160° F.) for about 15 minutes before whirling. Four minutes at full speed is sufficient for the first whirling of the test bottles in the centrifuge; this will bring all fat to the surface of the liquid in the bottle. 40. Adding water. Hot water is now added by means of a pipette or some special device (10 in fig. 58), until the bottles are filled to near the scale on the neck (80). The bottles are whirled again at full speed for one minute, and hot water added a second time, until the lower part The Babcock Test. 35 of the column of fat comes within the scale on the neck of the test bottle, preferably to the 1 or 2 per cent. mark, so as to allow for the sinking of the column of fat, due to the gradual cooling of the contents of the bottle. By dropping the water directly on the fat in the second filling, the column of fat will be washed free from light flocculent matter, which might otherwise be entangled therein and render the reading uncertain or even too high. A final whirling for one minute completes the separation of the fat. _ 41. Measuring the fat. The amount of fat in the neck of the bottle is measured by the scale or gradua- tions on the neck. Each division of the scale represents two-tenths of one per cent. of fat, and the space filled by the fat shows the per cent. of butter fat contained in the sam- ple tested. The fat is measured from the lower line of separation between Fira. 10. Measuring the the fat and the water, to the top of piazienpoule. | the fat column, at the point 5, shown in the figure 10, the reading being thus taken from a to b, and not to ¢ or to d. Comparative gravi- metric analyses have shown that the readings obtained in this manner give correct results. While the lower line of the fat column is nearly straight, the upper one is curved, and errors in the reading are therefore easily made, unless the preceding rule is observed. It ~ jt] a Ee it ake. Testing Milk and Its Products. The fat obtained should form a clear yellowish liquid distinctly separated from the acid solution beneath it. There should be no black or white sediment in or below the column of fat, and no bubbles or foam on its surface. The bottles must be kept warm until the readings are made, so that the column of fat will have a sharply de- fined upper and lower meniscus. The readings should be made when the fat has a tem- perature of about 140° F., although the results obtained will not be appreciably affected if the temperature falls below 120°. The fat separated in the Babcock test solid- ifies at about 100° F. No reading should be attempted if the fat is partly solidified, as it is impossible to get an accurate reading in this case.* 42. Readings of tests of milk made in steam turbine testers with tightly closed covers which prevent the free escape of exhaust steam (7 1) will come .2 to .3 per cent. too high if the temperature of the fat is allowed to rise to that of the exhaust steam during the process of whirling. In such eases the test bottles must be allowed to cool to about 140° (by placing them in water of this tempera- ture for afew minutes) before readings are taken.” 1 The effect of differences in the temperature of the fat on the readings obtained will be seen from the following: If 110 and 150° F. be taken as the extreme temperatures, at which readings are made, this difference of 40° F., (22.3° C.) would make a difference in the volume of the fat column ob- tained in case of 10 per cent. milk, of .00064 x 2 x 22.8=.028544 cc., or .14 per cent., .00064 being the expansion coefficient of pure butter fat per degree Centigrade between 50 and 100° C.( Zune, Analyse des Beurres, I, 87), and 2, the volume of the fat in cc. contained in 17.6 cc. of 10 per cent. milk. On 5 per cent. milk this extreme difference would therefore be about .07 per cent., or considerably less than one-tenth of One per cent. 2 See Wis. experiment station rep. X VII, p. 76. The Babcock Test. 37 A pair of dividers will be found convenient for meas- uring the fat, and the liability of error in reading is decreased by their use. The points of the dividers are placed at the upper and lower limits of the fat column (from a tod in fig. 10). The dividers are now lowered, one point being placed at the zero mark of the scale, and the mark at which the other point touches the scale will show the per cent. of fat in the sample tested. The dividers must be tight in the joint to be of use for this purpose. 42a. A simple device for measuring the fat column in the Babcock test has Fre. 11. been made by Mr. Fred Lutley of Winnipeg Dairy School ' (fig. 11). The instrument consists of two parts: a wooden piece, a, sliding inside ofb, which is made of tin and is open on one side, leaving the corrugated part of a accessible, so that this may be raised or lowered with the thumb. A steel pointer is attached to each part. The column of fat in a test bottle is read off with this instrument in the same way as with a pair of dividers. B. — DISCUSSION OF THE DETAILS OF THE Bascock TEST. 43. The main points to be observed as to apparatus and testing materials in order to obtain correct and satisfactory results by this test will now be considered, and such suggestions and help offered, as has been found desirable from an extensive experience with a great variety of samplesof milk, apparatus, and accessories. IN. Y. Produce Review, April 4, 1903. 38 Testing Milk and Its Products. 1.— GLASSWARE. 44. Test bottles. The test bottles should have a capacity of about 50 ce., or less than two ounces; they should be made of well-annealed glass that will stand sudden changes of temperature without breaking, and should be sufficiently heavy to withstand the maximum centrifugal force to which they are likely to be subjected in making tests. This force may, on the average, not be far from 30.65 lbs. (see 66), which is the pressure exerted in whirling the bottles filled with milk and acid in a — centrifugal machine of 18 inches diameter at a speed of 800 revolutions per minute. Special forms of test bottles used in testing cream and skim milk are described under the heads of cream, and skim milk testing (89, 90, 91, 99). _ When 17.6 cc., or 18 grams of milk (48) are measured into the Babeock test bottle, the scale on the neck of the bottles shows directly the per cent. of fat found in the milk. The scale is graduated from 0 to 10 per cent. 10 per cent. of 18 grams is 1.8 grams. As the specific gravity of pure butter fat (i. e. its weight compared with that of an equal quantity of pure water) at the temperature at which the readings are made (about 140° F.), is 0.9, then 1.8 grams of fat will occupy a volume of 1-2=2 cubic centimeters. The space between the 0 and 10 per cent. marks on the necks of the test bottles must therefore hold 2 cc., if correctly made. The scale is divided into. 10 equal parts, each part representing one per cent., and each of these is again sub-divided into five equal parts. Each one of the latter divisions there- The Babcock Test. 39 fore represents two-tenths of one per cent. of fat when 17.6 ce. of milk is measured out. The small divisions are sufficiently far apart in most Babcock test bottles to make possible the estimation of one-tenth of one per cent. of fat in the samples tested. As the necks of Babcock test bottles vary in diameter, each separate bottle must be calibrated by the manufac- turers; the length of the scale is not, for the reason given, apt to be the same in different bottles.’ If the figures and lines of the measuring scale become indistinct by use, the black color may be restored by rubbing a soft lead pencil over the scale, or by the use of ‘a piece of burnt cork after the scale has been rubbed with a little tallow. On wiping the neck with a cloth or a piece of paper the black color will show in the etchings of the glass, making these plainly visible. 45. Marking test bottles. Test bottles can now be bought with a.small band or portion of their neck or body ground, or ‘‘frosted,’’ for numbering the bottles with a lead pencil. Bottles without this ground label can be roughened at any convenient spot by using a wet fine file to roughen the smooth surface of the glass. There is this objection to the-latter method that unless carefully done, it is apt to weaken the bottles so that they will easily break, and to both methods, that the lead pencil marks made on such ground labels may be effaced dur- ing the test if the bottles are not carefully handled. 1 A fiat-bore lea bottle and one with a brass collar and screw used for opening and closing a small hole in the neck of the test bottle have been placed on the market by the Wagner Glass Works of New York. These have been tried by us, but no particular advantage over the round-neck bottles was discovered. 40 Testing Milk and Its Products. Small strips of tin or copper with a number stamped .thereon are sometimes attached as a collar around the necks of the bottles. They are, however, easily lost, especially when the top of the bottle is slightly broken, or at any rate, are soon corroded so that the numbers can only be seen with difficulty. The best and most permanent label for test bottles is made by scratching a number with a marking diamond on the glass di- rectly above the scale on the neck of the bottles or by grinding a number on the bottle itself. In ordering an out- fit, or test bot- tles alone, the =====j : operator may <== ————— ————n nd c i ————a ——— specify that the Fre. 12. Waste-acid jar. bottles are to be marked 1 to 24, or as many as are bought, and the dealer will then put the numbers on with a marking diamond. A careful record should be kept of the number of the bottle into which each particular sample of milk is meas- ured. Mistakes are often made when the operator trusts to his memory for locating the different bottles tested at the same time. 46. Cleaning test bottles. The fat in the neck of the test bottles must be liquid when these are cleaned. In emptying the acid the bottle should be shaken in order The Babcock Test. 41 to remove the white residue of sulfate of lime, etc., from the bottom; if the acid is allowed to drain out of the bottle without shaking it, this residue will be found to Fie. 13. Apparatus for cleaning test bottles. A, apparatus in position; the water flows from the reservoir through the iron pipe b into the in- verted test bottle d through the brass tube c, screwed into the iron pipe. B shows construction of the rubber support on which the tops of the test bottles rest; 7, draining sink. stick very tenaciously to the bottom of the bottle in the subsequent cleaning with water. A convenient method of emptying test bottles isshown in the illustration (fig. 12). After reading the fat col- 42 Testing Milk and Its Products. umn, the bottles are placed neck down, in the half-inch holes of the board cover of a five-gallon stoneware jar. An occasional shaking while the liquid is running from the bottles will rinse off the precipitate of sulfate of lime. A thorough rinsing with boiling hot water by means of an apparatus, devised by one of us! (see fig. 13), is generally sufficient to remove all grease and dirt, as well as acid solution .from the inside of the bottles. When the bottles have been rinsed, they are placed in an inverted position to drain, on a galvanized iron rack, as shown in fig. 14, where they are kept until needed. The outside of the bottles. should occa- sionally be wiped clean and dry. 47. The amount of unseen fat that clings to test bottles used for testing milk or cream, is generally not. sufficient to be noticed in testing whole milk, but it plays an im- portant part in testing samples of separator skim milk. It may be readily brought to light by making a blank test with clean water in bottles used for testing ordinary milk, which have been cleaned by simply draining the contents and rinsing once or twice with hot water; at the conclusion of the test the operator will generally find that a few drops of fat—sometimes enough to condemn a separator — will collect in the neck of the bottles. Boiling hot water will generally clean the grease from glassware for a time, but all test bottles should, in addi- Fig. 14. Draining-rack for test bottles. 1 Farrington. The Babcock Test. | 43 tion, be given an occasional bath in some weak alkali or other grease- dissolving solution. \ Persons doing con- \ siderable milk test- \ ing will find it of advantage to pro- \) vide themselves with a small cop- per tank, which can be filled with a weak alkali-solu- tion (figs. 15 and 16). After having = : been rinsed with Fig. 15. Tank for cleaning test bottles. hot water, the test bottles are placed in the hot solution in the tank, where they may be left completely covered with the liquid. If ——————— te) til : Fie@.16. Rack for holding test bottles in tank shown in fig. 15. 44° Testing Milk and Its Products. the tank is provided with a small faucet at the bottom, the liquid can be drawn off when the test bottles are wanted. A tablespoonful of some cleaning powder to about two gallons of water will make a very satisfactory cleaning solution; sal soda, Gold Dust, Lewis’ lye or Bab- bitt’?s potash are very efficient for this, purpose. The cleansing properties of solutions of any of these substances are increased by warming the liquid. The test bottles must be rinsed twice with hot water after they are taken from this bath. The black stains that sometimes stick to the inside of test bottles after prolonged use, can be removed with a little muriatic acid. An excellent cleaning solution may be made of one- half pound bichromate of potash to one gallon of sul- furic acid (Michels, Am. Cheesemaker, Jan. 1903). 48. Pipette. The difference in the weights of various samples of normal milk generally falls within compara- tively narrow limits; if a given volume of water weighs . one pound, the same volume of the usual grades of nor- mal milk will weigh from 1.029 to 1.033 pounds, or on the average, 1.03 lbs. 18 grams of water measures 18 cc.'; 18 grams of milk will therefore take up a smaller volume than 18 ce., viz: 18 divided by 1.03, which is very nearly 17.5. This is the quantity of milk taken in the Babcock test. A certain amount of milk will ad- here to the walls of the pipette when it is emptied, and 1 Cubic centimeters (abbreviated: cc.) are the standard used for meas- uring volume in the metric system, similar to the quart or pint measure in our ordinary system of measures. One quart is equal toa little less than 1,000 cubic centimeters. In the same way, grams represent weight, like pounds and ounces. Onecc. of water at 4° Centigrade weighs 1 gram; 1,000 grams (=1 kilogram) are equal to 2.2 lbs. Avoirdupois. (See Appendix for Comparisons of metric and customary weights and measures.) The Babcock Test. 45 this thin film has been found to weigh about one-tenth of a gram; consequently 17.6 cc. has been adopted as the capacity of the pipette used for delivering 18 grams of milk. For convenience in measuring the ae the shape of the pipette is of importance. The mark on the stem should be two inches or more from the upper end of the pipette. The lower part should be small enough to fit Fra. 1 S Pip- loosely into the neck of the test bottle, and not A, propercon- contracted to a fine hole at the point; the truction; B, undesirable point should be large enough to allow a construction quick emptying of the pipette (fig. 17). 49. Fool Pipettes. Soon after the Babcock test began to be generally used at creameries as a method of paying for the milk, a creamery supply house put on the market a 20 cc. milk-meas- _- uring pipette, which was claimed to show the exact butter value of milk, instead ofits content of butter fat as is the case in using the ordinary 17.6 cc. pipette. A 20 cc. pipette will deliver 2.4 cc. more milk than a 17.6 cc. pipette, (or 13.6 per cent. more), and the results obtained by using these pipettes will, therefore, be about 13.6 per cent. too high. In consider- ing the subject of Overrun (214) itis noted that the excess of butter yield over the amount of fat contained in a certain quan- tity of milk will range from about 10 to 16 per cent., or on the average, about 12 per cent. -20 ce. pipettes may, therefore, give approximately the yield of butter obtained from a quantity of milk, but as will be seen, this yield is variable, according to the skill of the butter makerand according to conditions beyond his control; it cannot therefore be used as a standard in the same manner as the fat content of the milk. Similar 22 ce. pipettes were also sent out. These pipettes created a great deal of con- fusion during the short time they were on the market, and were popularly termed ‘fool pipettes.’’ It is not known that any of these pipettes have been sold of late years. 46 Testing Milk and Its Products. A recent Wisconsin law makes ita misdemeanor to use other pipettes than 17.6 cc. ones for measuring milk where thisis paid for by the Babcock test. 50. Acid measures. A 17.5 cc. glass cylinder (fig. 9) for measuring the acid is generally included in the outfit, when a Babcock tester is bought. This cylinder answers every purpose if only occasional tests are made; the acid is poured into the cylinder from the acid bottle as needed, ora quantity of acid sufficient for the number of test bottles to be whirled at a time,is poured into asmall glass beaker provided with a lip, or into a small porce- lain pitcher; these may be more easily handled than the heavy acid bottle, and the acid measure is then filled from such a vessel. Where a considerable number of tests are made regu- larly, the acid can be measured into the test bottles faster and with less danger of spilling, by using some one of the many devices proposed for this purpose. There is some objection to nearly all of these appliances, auto- matic pipettes, burettes, etc., although they will often give good satisfaction for a time while new. Sulfuric acid is very corrosive, and operators as a rule take but poor care of such apparatus, so that it is a very difficult matter to design a form which will remain in a good work- ing order for any length of time. Automatic pipettes attached to acid bottles or reservoirs, to prove satisfac- tory, must be made entirely of glass, and strong, of sim- ple construction, tightly closed and quickly operated. 51. The Swedish acid-bottle answers these requirements better than any other device known to the writers at the present time. Its use is easily understood (see fig. 18); it gives good satisfaction if the hole in the glass stop 1 Laws of 1903, chapter 43. | The Babcock Test. i 47 cock through which the acid passes has a diameter of at _ least one-eighth of an inch, as is generally the case. We have used or inspected some half a dozen other devices, which have been placed on the market by vari- ous dealers for delivering the acid, _ but cannot recommend them for ® use in factories or outside of chem- i ical laboratories. | 52. Instead of measuring out the acid, Bartlett’ suggested adding it directly to the milk in the test bot- . / tles, till the mixture rises to a mark 1 on the body of the bottle at the point where this will hold 37.5 cc., } i. e., the total volume of milk and ‘acid (89). This method of adding the acid is in the line of simplicity, but has not become generally adopted. If the method is used the marks should be put on by the manufacturers, as the operator in attempting to do so will be apt to weaken or break the bottles. Nh SWEDISH &= ACID BOTTLESS} = —4) sri, ——— Fic. 18. Swedish acid-bot- tle; the side tube is made to hold 17.5 ce. of acid. CALIBRATION OF GLASSWARE. Test Bottles. The Babcock milk test bottles are so constructed that the scale or graduation of the neck ‘Ineasures a volume of 2 cubic centimeters, between the zero and the 10 per cent. marks (44). The correctness of the graduation may be easily ascertained by one of the following methods: 53. (A.) Calibration with mercury. 27.18 grams of metallic mercury are weighed into the perfectly clean 1 Maine experiment station, bull. No. 31. 48 Testing Milk and Its Products. and dry test bottle. Since the specific gravity of mer- cury is 13.59, double this quantity will occupy a volume of exactly 2 cubic centimeters (48). The neck of the test bottle is then closed with a small, smooth and soft cork, or a wad of absorbent cotton, cut off square at one end, the stopper being pressed down to the first line of the graduation. The bottle is now inverted so that the mercury will run into its neck. If the total space in- cluded between the 0 and 10 marks is just filled with the two cubic centimeters of mercury, the graduation is cor- rect. Bottles, the whole length of the scale of which vary more than two-tenths of one per cent., are inaccu- rate and should not be used. : The mercury may be conveniently transferred from one _ test bottle to another, by means of a thin rubber tube which is slipped over the end of the necks of both bot- tles, and one weighing of mercury will thus suffice for a number of calibrations. In transferring the mercury, - care must be taken that none of it is lost, and that small drops of mercury are not left sticking to the walls of the bottle emptied. A sharp tap on the bottle with a lead pencil will help to remove minute drops of mercury from the inside. Unless the bottles to be calibrated are per- fectly clean and dry, it is impossible to transfer all the mercury from one bottle to another. After several calibrations have been made, the mercury should be weighed again in order to make certain that none has been lost by the various manipulations. The scales, figs. 34 and 35, shown in (91), are sufficiently delicate for making these weighings. . 54. Cleaning mercury. Even with the best of care, mercury used for calibration of glassware will gradually The Babcock Test. 49 become dirty, so that it will not flow freely over a clean surface of glass. It may be cleaned from mechanical impurities, dust, films of grease, water, etc., by filtration through heavy filter paper. This is folded the usual way, placed in an ordinary glass funnel and its point perforated with a couple of pin holes. The mercury will pass through in fine streams, leaving the impurities on the filter paper. Mercury may be freed from foreign metals, zine, lead, etc., sometimes noticed as a grayish, thin film on its surface, by leaving it in contact with common nitric acid for a number of hours; the mercury is best placed in a shallow porcelain or granite ware dish and the nitric acid poured over it, the dish being covered to keep out dust. The acid solution is then carefully poured off and the mercury washed with water; the latter is in turn poured off, and the last traces of water absorbed by means of clean, heavy filter paper. The mercury to be used for calibration of glassware Should be kept in a strong bottle, closed by an ordinary stopper. In handling mercury, care must be taken not to spill any portion of it; finger-rings should be removed when calibrations with mercury are to be made. Mercury forms the most satisfactory and accurate ma- terial for calibration of test bottles, on account of its heavy weight and the ease with which it may be manip- ulated. Equally correct results may, however, with proper care be obtained by using water for the calibration. (B.) Calibration with water. This may be done by means of a delicate pipette or burette, or by weighing in a somewhat similar manner, as explained in case of cali- bration with mercury. 4 50 Testing Milk and Its Products. 55. a, Measuring the Water. Fill the test bottle with water to the zero mark of the scale; remove any surplus water and dry the inside of the neck witha piece of filter paper or clean blotting paper; then measure into the bottle 2 cc. of water from an accurate pipette or burette, divided to 1, of a cubic centimeter. If the graduation is correct, 2 cc. will fill the neck exactly to the 10 per cent. mark of the scale. 56. b, Weighing the water. Fill the bottle with water to the zero mark of the scale and remove any surplus water in the neck, as before. Weigh the bottle with the water contained therein. Now fill the neck with water to the 10 per cent. mark, and weigh again. The differ- ence between these weights should be 2 grams. In all cases when calibrations are to be made, the test bottles, or other glassware to be calibrated, must be thoroughly cleaned beforehand with strong sulfuric acid or soda lye, and washed repeatedly with pure water, and dried. Glassware is not clean unless water will run freely over its surface, without leaving any ad- hering drops. 57. (C.) The Trowbridge method of calibration... An extremely simple and accurate method of calibrating test bottles has been proposed by Mr. O. A. Trowbridge of Columbus, Wis. He conceived the idea of measuring the capacity of the graduated portion of the neck of a milk test bottle with a piece of metal which is carefully filed to such a size that it will displace exactly two cubic centi- meters of water. He used a thirty-penny wire nail, cutting off the head of the nail and attaching to it a short piece 1 Hoard’s Dairyman, Mar. 8, 1901, by De Witt Goodrich. The Babcock Test. 51 of fine wire, either looped at one end, as shown in fig. 19 (A), or as one straight piece of about three inches long. The wire serves as a handle for lowering the measure into the neck of the test bottles. Ifthe wire is attached as Shown in fig. 19 (A), a string can be fastened to the loop for holding the measure in the proper place in the test bottle. When a test bottle is to be calibrated by this standard measure, it is filled with water to the zero mark on the neck of the bottle. The water adhering to the neck is carefully removed with a strip of blotting paper, and the measure (A) is then lowered into the test bottle, as Shown in (B), to the point where the wire loop is at- tached. _If the water rises from 0 to 10 on the neck when the point of the meas- ure is also at ten, the scale is correct. If greater varia- tions than .2 of one per cent. oceur, the bottle should be rejected. The figure (C), shows one Fig. 19. (A) Trowbridge cali. Of these calibrators made in (O) Natie modifivationateay, “8 two sections, so that the accu- racy of the 5 as well as the 10 mark on the scale may be ascertained. This modification was proposed by Louis F. Nafis & Co., Chicago. 52a u- Testing Milk and Its Products. 58. The standard measure. In the place of an iron nail a piece of copper or glass rod may be advanta- geously used asa standard measure. The standardization is most conveniently done by weighing. Since the specific gravities of iron, copper and glass are 7.8, 8.9, and about 2.7, respectively, pieces of these materials replacing 2 ce. of a liquid, will weigh 15.6, 17.8 and 5.4 grams, for iron, copper and glass in the order given. A measure of the right weight may be suspended by a very fine copper or platinum wire (melted into the glass rod if this material be chosen), and is used directly for calibrating test bottles as described above. Before a measure so made is used as a standard, its accuracy should be determined by weighing the amount of water at a temperature of 17.5° C, which it replaces. The specific gravity of glass especially, varies somewhat ac- cording to its composition, so that a standardization of a measure by- weight alone cannot be depended upon al- ways to give correct results. 59. In submerging the measure in the testi bottle to be calibrated, care must be taken that all air bubbles are removed before the position of the meniscus of the water is noted; if a metal standard measure is used, it must be kept free from rust or tarnish. 60. Intermediate divisions. The space between 0 and 10 on the scale of the Babcock test bottle is divided into 50 divisions, each five of which, as previously shown, representing 1 per cent. (44). Since these intermediate divisions are generally made with a dividing machine, they are as arule correct, but it may happen that the divisions have been inaccurately placed, although the The Babcock Test. 53 space between 0 the 10 is correct. The accuracy of the intermediate divisions can be ascertained by sliding along the scale a strip of paper upon which has been marked the space occupied by one per cent., and com- paring the space with those of each per cent. on the seale. 61. Calibration of skim milk test bottles. The value of each division on the skim milk bottles is one-twentieth of one per cent. (99); there are ten of these divisions or .1 cc. in the whole scale which shows .5 per cent. fat. It requires very careful work to calibrate this scale and it is best done by weighing the amount of mercury which will just fill the space between the first and the last divisions (53); the correct weight of this mercury 1s 1.359 grams. 62. Calibrating Cream test bottles. The cream bottles may be calibrated by any of the methods given for milk bottles. A cream test bottle neck that measures thirty per cent. fat will hold 6 ce., and 6 grams of water or 81.54 grams of mercury. - The Trowbridge method of calibrating sie test. bot- tles may also be found convenient for cream bottles and the same standard measure used. The part of the scale from 0 to 10 being calibrated first, then from 10 to 20, and from 20 to 30 per cent. in the same way. 63. Pipette and acid cylinder. The pipette and the acid cylinder used in the Babcock test may be calibrated by any of the methods already given. Sufficiently accurate results are obtained by weighing the quantity of water which each of these pieces of apparatus will hold, viz., 17.6 grams and 17.5 grams, respectively. The 54 , Testing Milk and Its Products. necessity of previous thorough cleaning of the glassware is evident from what has been said in the preceding. The pipette and the acid. measure may be weighed empty and then again when filled to the mark with pure water, or the measureful of water may be emptied into a small weighed vessel, and this weighed a second time. In either case the weight of the water contained in the pipette or acid measure 1s obtained by difference. ! Calibrations of the acid cylinder are generally not called for, except as a laboratory exercise, since small variations in the amount of acid measured out do not affect the accuracy of the test. 2.—CENTRIFUGAL MACHINES. 64. The capacity of the testing machine to be selected | should be governed by the number of tests which are likely to be made at one time. For factory purposes a twenty-four or a thirty-two bottle tester is large enough, and to be preferred for a larger tester, even if toward a hundred samples of milk are to be tested at atime. The operator can use his time more economically in running a machine of this size than one holding fifty or sixty bot- tles; the work of filling or cleaning the bottles and measuring the fat can be done while the tester is running if a double supply of bottles is at hand. Large testers require more power than smaller ones, and when sixty tests are made at a time, the fat column in many bottles 11 Cubic centimeter of distilled water weighs 1 gram, when weighed in a vacuum at the temperature of the maximum density of water (4° C); for the purpose of calibration of glassware used in the Babcock test, suf- ficiently accurate results are, however, obtained by weighing the water in the air and at a low room temperature (60° F.). The Babcock Test. 55 will get cold, before the operator has time to read them, unless special precautions are taken for keeping the bot- tles warm. 65. The tester should be securely fastened to a solid foundation and set so that the revolving wheel is level. The latter must be carefully balanced in order that the tester may run smoothly at full speed whenempty. A machine that trembles when in motion is neither sat- isfactory nor safe, and the results obtained are apt to be too low. High-standing machines are more apt to cause trouble in this respect than low machines, and should therefore be subjected to a severe test before they are accepted. If all the sockets are not filled with bottles’when a test is to be made, the bottles must be placed diametrically opposite one another so that the machine will be balanced when run. The bearings should be kept cleaned and oiled with as much care as the bearings of a cream separator. : : The cover of the machine should always be kept closed while the bottles are whirled, and should not be removed until the machine stops; it should be tight fitting and may be fastened with hooks soldered on the side of the machine; test bottles sometimes break while the machine is running at full speed, and every possible pre-. caution should be taken to protect the operator from any danger from spilled acid or broken glass. 66. Speed required for the complete separation of the fat. There is a definite relation between the diameter of the Babcock testers and the speed required for a perfect separation of the fat. In the preliminary work with the 56 Testing Milk and Its Products. Babcock test the inventor found that with the machine used, the wheel of which had a diameter of eighteen inches, it was necessary to turn the crank, so as to give the test bottles seven or eight hundred revolutions per minute, in order to affect 4 maximum separation of fat; later work has shown that this speed is ample. Taking therefore this as astandard, the centrifugal force to which the contents of the test bottles are subjected when sup- ported on an eighteen-inch wheel and turned 800 revolu-— tions per minute, can be calculated as follows: — The centrifugal force, F, acting on the bottles isexpressed by the formula ao WW BOO ht a a ee in which w = the weight of the bottle with contents, in pounds; v = the velocity, in feet per second, and r = the radius of the wheel in feet. . When the wheel is turned 800 times a minute, a bottle sup- ported on its rim will travel 27rx 89° = 23.1415 X #5 & 8h =62.83 feet per second. The weight ofa bottle, with milk and acid, is about 3 ounces, or ; of a pound. Substituting these values for v and w, gives 5 X 62.83" _ 59 65 Ibs. The bottles are therefore, under the conditions given, sub- jected to a pressure of about 30:65 pounds. In order to calculate the speed required for obtaining this force in case of machines of other diameters, the value of v in formula (I) is found from f B22 KOK Sa aT Substituting the values for F and w, f 32.2 ais T_| /52643 : 16 In this equation the values r = 5, 6, 7, 8, 9, 10, 11, 12 inches are substituted in each case (=3, 45) 75, - - - 44 feet), and the Y= (IT) Ve The Babcock Test. | ny velocity in feet per second then found at which the bottles are whirled when placed in wheels of diameters 10 to 24 inches, and subjected in each ease to a centrifugal force of 30.65lbs. As the number of revolutions per minute a v being as before the velocity in feet per seeond, and 7 the radius of the wheel, the speed at which the wheel must be turned, is found by sub- stituting for v the values obtained in the preceding calculations in case of wheels of different diameters. The results of these calculations are given in the following table: Diameter Velocity in feet Number af revolutions of wheel, D. per second, v: of wheel per minute. 10 46.84 1074 12 51.31 980 14 55.43 909 16 59.26 848 18 62.84 800 20 66.24 759 22 69.47 724 24 72.56 693 These figures show that a tester, for instance, 24 inches in diameter, requires less than 700 revolutions per minute for a perfect separation of the fat in Babcock bottles, while a ten- inch tester must have a speed of nearly 1100 revolutions, in order to obtain the same result. The speed at which testers of different diameters should be run to effect a complete separation has been calculated by Prof. C. L. Beach in the following manner.! The same standard as before is taken, viz., 800 revolutions for an 18-inch tester (radius 9inches); then if x designate the radius of the tester and y the speed required, we have : xy?=9 <800?, or /9 X 800? ta ze The figures obtained by the use of this formula are similar to those given in the preceding table. 1 Private communication. 58 Testing Milk and Its Products. 67. To find the number of turns of the handle corres- ponding to the number of revolutions made by the wheel, the handle is given one full turn, and the number of times which a certain point or part of the wheel revolves, is noted. If the wheel has a diameter of 20 inches, and revolves 12 times for one turn of the handle, the latter should be turned “5° —63 (see table), or about once every second, in order to effect a maximum separation of fat. By counting the number of revolutions, watch in hand, and consulting the preceding table, the operator will soon note the speed which must be maintained in case of his particular machine. It is vitally important that the required speed be always kept up; if through careless- ness, worn-out or dry bearings, low steam pressure, etc., the speed is slackened, the results obtained will be too low; it may be a few tenths, or even more than one per cent. Care as to this point is so much the more essen- tial, as the results obtained by too slow whirling may seem to be all right, a clear separation of fat being often obtained even when the fat is not completely separated. 68. Ascertaining the necessary speed of testers. In buying a tester the operator should first of all satisfy himself at what speed the machine must be run to give correct results: the preceding table will serve as a guide on this point. He should measure out a dozen tests of the same sample of milk, and whirl half the number at the speed required for machines of the diameter of his tester. Whirl the other half at a somewhat higher speed. If the averages of the two sets of determinations are the same, wi.hin the probable error of the test (say, less than one-tenth of one per cent.) the first whirling The Babcock Test. 59 was sufficient, as it is believed will generally be the case. If the second set of determinations come higher than the first set, the first whirling was too slow, and a new series of tests of the same sample of milk should be made to ascertain that the second whirling was ample. This method will test not only the speed required with the particular machine at hand, but will also serve to indicate the correctness of the calibration of the bottles. A large number of tests of the same sample of milk made as directed (pouring the milk once or twice previ- ous to taking out a pipetteful for each test) should not vary more than two-tenths of one per cent. at the outside, and in the hands of a skilled operator will generally come within one-tenth of one per cent. If greater dis- crepancies occur, the test bottles giving too high or too low results should be further examined, and calibrated according to the directions already given (53 et seq. ). 69. Hand testers. When only a few tests are made at a time, and at irregular intervals, as in case of dairymen who test single cows in their herds, a small hand tester answers every purpose. These may be had in sizes from two to twelve bottles. In selecting a particular make of tester the dairyman has the choice of a large number of different kinds of machines. It is asource of regret that most of the early machines placed on the market for this purpose were so cheaply and poorly constructed as to prove very unsatisfactory after having been in use for a time. The competition between manufacturers of dairy supplies and the clamor of dairymen for something cheap, fully accounted for this condition of affairs. This _applies especially to the many machines made with belts 60 Testing Milk and Its Products. or friction application of power. The main objection to such machines is the uncertainty of the speed obtained, when they have been in use for some time, and the belt or fric- tion appliance hall \ begins to slip. irate 7 me Hand testers | made with cog- ; geared wheels are more to be depended on for giving the nec- essary speed than belt or fric- tion machines; Fig. 21. Type of Babcock hand testers. the earlier machines of this kind were very noisy, but at the present time the best machines on the mar- ket are of this type. These are provided with spiral cog-gear- ing and ball bearings, are strongly made and will run smoothly and without noise (figs. 91 Fia. 22. Type of Babcock hand testers. and 22); in cog-geared machines the bottles are always whirled at the speed which the number of turns made by the crank would indicate. The Babcock Test. 61. 70. Power testers. For factory purposes, steam tur- bine machines (figs. 23-25) are most satisfactory when well made and well cared for. They should always be provided with a speed indicator and steam gauge, both for the pur- pose of knowing that suf- ‘ iy ae SU ST Fig. 23. Type of Babcock steam turbine testers. Fig. 24. Type of Babcock steam turbine testers. ficient speed is attained, and also to prevent what may be serious accidents from a general smash-up, if the tur- 62 Testing Milk and Its Products. bine ‘‘runs wild”’ by turning on too much steam. The revolving wheel of the tester should be made of wrought or malleable iron, or of wire, so that it will not be broken by the centrifugal force, thus avoiding serious accidents. = Theswinging pock- ets which hold the test bottles in some machines, should _ beso made that the bottles will not strike the center of the revolving frame when in a. = horizontal position. Tests have often been lost by the Fre. 25. Type of Babcock turbine testers. oo eee te : sues. end of the meet catching at the center, the bottles thus failing to take an upright position when the whirling stops. 71. The exhaust steam pipe of turbine testers should not have too many turns in it or be much reduced in size from that of the opening in the tester. A free escape of the exhaust steam is necessary to prevent the steam col- lecting in the test bottle chamber and overheating the test bottle when whirled (41). The cover of the tester should have an opening pro- vided with a sliding damper or some arrangement by which it can be closed when desired. If whole milk or cream is being tested, this hole should be open so that a draft of air may enter the test bottle chamber during whirling, and force the steam out of the bottle chamber The Babcock Test. 63 into the exhaust pipe. If skim milk is being tested, the opening in the cover should be closed. This shuts off the draft of air, and the exhaust steam heats the test bottles during whirling to 200° F. in some cases. This high temperature aids in separating the last traces of fat in skim milk and gives a most accurate test of samples containing less than one-tenth per cent. fat. Some of the most recent makes of turbine testers are provided with holes in the cover and dampers. A thermometer is also placed in the cover. 3.— SULFURIC ACID. 72. The sulfuric acid to be used in the Babcock test should have a specific gravity of 1.82-1.83.' The com- mercial oil of vitriol which can be bought for about 2 cents a pound in carboy lots, is commonly used. One pound of acid is sufficient for fifteen tests. The acid should be kept in stoppered glass bottles, preferably glass or rubber stoppered ones, since a cork stopper is Soon dissoived by the acid and rendered useless. If the bottle is left uncorked the acid will absorb moisture from the air and will after a time become too weak for use in this test. Lead is the only common metal which is not dissolved by strong sulfuric acid; where considerable milk testing is done, it is therefore desirable to provide a table covered with sheet lead on which the acid may be handled. 1A specific gravity of 1.82 means that a given volume of the acid weighs 1,82 times as much as the same volume of water at the same temperature _ (see also under Lactometer, 106) 64 / Testing Milk and Its Products. The acid dissolves iron, tin, wood and cloth, and burns the skin. If acid is accidently spilled, plenty of water should be used at once to wash it off. Ashes, potash, soda, and ammonia neutralize the action of the acid, and a weak solution of any one of these alkalies can be used after the acid has been washed off with water. The red color caused by the action of the acid on clothing can be removed by wetting the spot with weak ammonia water; the ammonia must, however, be applied while the stain is fresh, and is in its turn washed off with water. 73. Testing the strength of the acid. The strength of the acid can be easily tested by the use of such a balance as shown in fig. 34 (91). A dry test bottle is weighed, and then filled with acid exactly to the zero mark, or to any other particular line of the scale. It is then again weighed accurately; the difference between these two weights will give the weight of the acid in the bottle. Next empty the bottle and rinse it thoroughly with water (until the water has no longer an acid taste); fill the bottle with water to the same line as before and weigh; the difference between this weight and that of the empty bottle gives the weight of the same volume of water as that of the acid weighed. Divide the weight of the acid by the weight of the water; the quotient gives the spe- cific gravity of the acid. If this is between 1.82 and 1.83, the strength of the acid is correct. The outside of the test bottle should always be wiped dry before the liquids are weighed in it. Unless great care is taken in measuring out the acid and the water, and in weighing both these and the test bottle, the results obtained will not be trustworthy. The Babcock Test. 65. 74. Too strong acid can sometimes be successfully used by taking less than the required amount of each test, e. g., about15cce. Operators are warned against reducing the strength of the acid by adding water to it, as accidents are very apt to occur when this is done. A too strong acid can, if desired, be weakened by simply leaving the bottle uncorked for atime, or by pouring the acid into a bottle containing a small quantity of water. In the lat- ter case the first portions of acid should be added care- fully, a little at a time, shaking the bottle after each. addition, so as not to cause it to break from the great . heat evolved in mixing the acid and the water. Never dilute sulfuric acid by pouring water into it. 75. If the acid is too weak, correct results may some- times be obtained by using more than the specified quantity, say 20 cc. Ifa good test is not obtained with this quantity of acid, a new lot must be secured, as its specific gravity in such a case is below 1.82. The ob- serving operator will soon be able to judge’ of the strength of the acid by its action on milk in mixing the two liquids in thé Babcock test bottles; it is indeed re- markable what slight differences in the specifie gravity of the acid will make themselves apparent in working the test; as regards the rapidity with which both the curdled milk is dissolved and the mixture of acid -and milk turns black. 76. Strength of sulfuric acid. The relation between the strength of sulfuric acid and its specific gravity will be seen from the following table: 5 66 Testing Milk and Its Products. Strength of Sulfuric Acid (Lunge and Isler, 1890. ) Sulfuric Acid Specific Gravity HSO,). (15° C, water 4°C). 97 per cent. Sa mci Salsiewe-ae a cle tive cine ce neler dei ale OURS ese 1.841 Oats Mb ed bane he RUE RIE, a ORR Mera feat My i aS i 1.840 95 ME Sede ea wb ala dbeiteie 1s oso P Rta ae erat ea 2 oe ee 1.839 94 BE so 5 sei ieeeecbe ene souials cake Raareercrclckote Se ee ean ae 1.837 93 ari heats 3 afaik NG aoa «ads bmadines Accs setae ace eee ee 1.834 92 ik A PR APR ie gh Siege Bel Mn UB aedid doe ane eee 1.830 91 es «ince seth Soaecte acaeecls Ramet SO Se ee ee 1.825 90 ee RARER Diep ar pp cn nie Pree or GHAsga eae St eee 1.820 89 OF 29 a Ak FETs ee eae eee cies a a 1.815 88 arg ISM ae Perrdenatam site vont ene FM Te cs -- 1.808 It will be noticed that the sulfuric acid to be used in the Babcock test should contain 90 to 92 per cent. of acid (H,SO,); slightly weaker or stronger acid than this may, aS previously stated, be used by adjusting the quantity of acid taken for each test to the strength of the acid, but successful tests cannot be made with acid weaker than 89 per cent. or stronger than 95 per cent. 77. The Swedish acid tester is a small hydrometer, intended to show whether the acid to be used in the Babcock test is of the correct strength. We haveexamined a number of these testers, and have found them practically: useless for the purpose in- tended. The reason for this is that the instrument is not suffi- ciently sensitive; while the testersexamined were found to sink to the line marked Correct on the scale, when lowered into sul- furic acid of a specific gravity of 1.83, they would sink toa point much nearer the same mark, than to the lines marked Zoo strong or Too weak, respectively, when lowered into either too strong or too weak acid. 78. The color of the fat column an index to the strength of the acid used. The strength of the acid is indicated to a certain extent by the color of the fat which separates in the neck of the test bottle when milkistested. If the directions given for making the tests are carefully fol- lowed, the fat separated out will be of a golden yellow The: Babcock Test. 67 color. If the fat is light colored or whitish, it generally indicates that the acid is too weak, anda dark colored fat, with a layer of black material beneath it, shows that the acid is too strong, provided the temperature of both milk and acid is about 70°. [For influence of tempera- ture, see next paragraph. | i - The strength of the acid used in the test is notsuf- ficient at ordinary temperatures of testing to appreciably dissolve the fat, but a variation in the strength of the acid or in the temperature of the milk influences the intensity of the action of the acid on the fat, as shown in the color of the fat obtained. The following experiment shows the relation between the strength of the acid, the temperature of the milk, and the color of the fat: First:—From a sample of milk measure the usual quantity for testing into each of three bottles, A, Band C. Place A in ice water, and C in warm water, having bottle B at the ordi- nary temperature. After the bottles have been Jeftfor ten min- utes under these conditions, add the normal quantity of acid to each and proceed with the test in the ordinary manner. Second:—Measure some of the same milk into three other bottles, D, Eand F. Into test bottle D pour the usual amount of rather weak acid; add the same amount of acid of normal strength (1.82-1.83) to bottle E, and add 17.5 cc. of a still _stronger acid (concentrated sulfuric acid, sp. gr. 1.84), in test bottle F; complete these tests in the usual way. On the completion of the preceding six tests the operator will notice that the fat in the necks of test bottles A (cold milk) and D (weak acid) is much lighter colored than that in C (warm milk) and F (strong acid), and that the color of the fat in B (normal temperature) and E (normal acid) is somewhere be- tween that of these two series. 79. Influence of temperature on the separation of fat. ' The intensity of the action of the sulfuric acid on the 68 Testing Milk and Its Products. milk is influenced by the temperature of either liquid; the higher the temperature, the more intense will be the action of the acid on the solids of the milk. It may be noticed that acid from the same carboy willact differently on milk in summer than in winter time, if the acid and the milk are not brought to a temperature of about 70° before testing during both seasons. The temperature of the liquids may be as low as 40° F. in winter and as high as 80° F. in summer. This difference of forty degrees will often have considerable influence on the clearness of the fat separated, showing white curdy substances and a light colored fat in winter, or black flocculent specks, with a dark colored column of fatinsummer. Both these defects can be avoided when the acid is of the proper strength, by bringing the temperature of the milk and the acid to about 70° F. before the milk is tested. The operator should be particularly cautious against over-heating either milk or acid; so intense an action may be caused thereby as to force the hot acid out of the neck of the test bottle when it is added to the milk, thus spoiling the test and possibly causing an accident. 4.—WATER TO BE USED IN THE BABCOCK TEST. 80. Rain water, condensed steam, or soft water should be used for the purpose of bringing the fat into the neck of the test bottles. The surface of the fat column will then usually be clear and distinct. The foam or bubbles that sometimes obscure the upper line (meniscus) of the fat, making indistinct the point from which to measure it, is generally caused by the action of the acid on the carbonates in hard water. The carbonic acid gas liber- The Babcock Test. 69 ated from hard water by the sulfuric acid is more or less held by the viscid fat and produces a layer of foam on its surface. If clean soft water cannot be obtained for this purpose, hard water may be used by adding a few drops of sulfuric acid to the water before it is heated, thus causing the carbonic acid to be driven out of it. By simply boiling, many hard waters will be rendered soft and adapted to use in the Babcock test, as most of the carbonates which cause this foaming are thereby precipitated. If the test has been completed, and a layer of foam ap- pears over the fat, it may be destroyed by adding a drop or two of alcohol. If this is done, the fat column should be read at once after the alcohol is added, as the latter will soon unite with the fat and increase its volume. 81. Reservoir for water. When only a few tests are made at one time, the hot water can be added with the 17.6 ec. pipette. If many tests are made, the water is more conveniently and quickly filled into the test bottles by drawing it from a small copper reservoir or tin pail suspended over the testing machine.’ The flow of water through a rubber tube connected with the reser- voir, is regulated by. means of a pinch cock. The water must be hot when added to the test bottles so as to keep the fat in a melted condition until the readings are taken. Most turbine testers are now made with a very convenient water reservoir attached to the tester (figs. 23-25). 1 Ordinary tinware rusts very soon when water is left standing in it, and copper reservoirs are therefore more economical. 70 Testing Milk and Its Products. The use of zine or steel oilers, or perfection oil cans has been suggested, as a handy and rapid method of adding hot water to the test bottles. 5.—MoODIFICATIONS OF THE BABCOCK TEST. 82. The Russian milk test. The same chemical and mechanical principles applied in the regular Babcock AY, 4 Fig. 26. The Russian test. test, are used in the Russian milk test, except that in this case the machine in which the bottles are whirled, and the bottles them- selves, are so constructed that the latter can be filled with hot water while the machine is ‘ running at full speed, thus saving time and trouble incident to the stopping of the tester aa and filling the bottles by means of a pipette. weer iO The milk-measuring pipette (fig. 28) and the HUSetanteee acid measure used in the Russian test are one-half of the . ordinary size, and the test bottles are made in two pieces, with a detachable narrow graduated stem (see fig. 27). The machine is substantially made of cast iron; it is pro- New Yorn, The Babcock Test. 71 vided with a very satisfactory speed indicator which shows at any time the number of revolutions at which the bottles are being turned. The accompanying illus- trations show the apparatus used in the Rus- sian test. When the directions for operating the test are followed closely, the results ob- tained are accurate and very satisfactory. 83. Bartlett’s modification. Bartlett’ pro- posed a modification of the method of pro- cedure in the Babcock test, which aims to simplify the manipulations. 20 cc. of acid are added, instead of 17.5 cc., and the bottles filled with the milk-acid mixture are left standing for not Jess than five minutes and then filled with hot water to within the scale; the bottles are then whirled for five minutes | ; at the regular rate (52). % Fic. 93, . nthe experience of the authors the modi- Fipette used fication can not always be depended upon to sian test. —_ give satisfactory results. When published it was tried by each of the one hundred students in the Wisconsin Dairy School; while some of these operators obtained a clear separation of fat, and results that com- pared favorably with those made by the regular Babcock test, others failed to obtain correct results with the method as modified. It is not known that the modifica- tion has proved superior to or taken the place of the regular Babeock test to any extent.’ 1 Maine experiment station, Bull. No. 31 (S S.). 2The German dairy chemist Siegfeld in 1899 proposed a modification of the - Babcock test (Molkerei Ztg., Hildesheim, 1899, p.51) using 2 cc. of amyl alcohol with the sulfuric acid, and filling up with dilute sulfuricacid (1:1, sp. gr. 1.5) 72 Testing Milk and Its Products. 84. Bausch ‘and Lomb centrifuge. Fig. 29 shows a. form of hand centrifuge which may be used to advantage by physicians or in a pathological laboratories for the determination of fat in milk. The centrifuge is espe- cially designed for examination of urine, sputum, blood, etc., but has been adapted to milk analysis by the Leff- ta mann & Beam test, a special form of bottle (fig. 30) having been constructed for this pur- pose. The machine gives sat- isfactory results by the Bab- cock test as well, provided the acid used is 1.83-1.84, or if the bottles containing the acid-milk mixture be placed in hot water for five or ten minutes prior to the whirling. As the bottles are cali- brated for only 5 Fi4. 30. Test bottle for eg, of milk and the Fie. 29. Physician’s centrifuge physician’s that may be used formilk testing centrifuge. neck of the bottles, ip = f iss, | | & (BAUSCH @ LomBaptco, = i, ROCHESTER, N.Y. “| ayy 2 My with scale, is correspondingly fine, testing milk with this machine requires some nicety of manipulation not called for in case of testers constructed for the use of farmers and dairymen. in one filling, in place of waterafter the whirling. A clear separation of the fat is facilitated by both these changes, but when properly conducted there is no difficulty whatever in obtaining a clear fat column in the Babcock test as described in this book, and the modification will not therefore be likely to be introduced in American factories. It has become quite generally adopted in North German creameries where the Babcock test is.used. CHAPTER IV. CREAM TESTING. 85. Cream may be tested by the Babcock test in the same manner as milk, and the results obtained are accu- rate when the necessary care has been taken in sampling the cream and measuring the fat. The composition of cream varies greatly according to the process of cream- ing, temperature of milk during the creaming, quality Fira. 3. Students testing dairy products. = and composition of the milk to be creamed, ete.. The cream usually met with in separator creameries will con- tain from 25 to 50 per cent., or on the average about 35 per-cent. of fat. Cream from hand separatorsmay be as 74 Testing Milk and Its Products. rich as this, but as delivered to creameries it often con- tains only 20 per cent. of fat. An average grade of market cream as retailed contains about 25 per cent. of fat. If 18 grams of 25 per cent. cream is measured into an ordinary Babcock test bottle, there will be 18x.25=4.5 grams (or, since the specific gravity of butter fat is about .9, +°—5 ec.) of pure butter fat in the bottle. It isshown, however, (p. 38), that the space from 0 to 19 in the neck of these bottles holds exactly 2 ec. The neck of the milk test bottles will not be large enough to show the per cent. of fat in asample of cream if 18 grams are taken for test- ing, and it is therefore necessary to adopt special meas- ures when cream is to be tested. 86. Errors of measuring cream. Several factors tend to render inaccurate the measuring of cream for the Bab- cock test, and correct results can therefore only be ob- tained by weighing the cream. Ifa 17.6 ce. pipette is used for measuring the cream, it will not deliver 18 grams of cream, as it will of milk, for the following reasons: 1. The specific gravity of cream is lower than that of milk; if a certain quantity of milk weighs 1030 Ibs., the same quantity of cream will weigh from 1020 lbs. to be- low 1000 lbs., the weight being determined by the rich- ness of the cream; the more fat the cream contains, the less a certain quantity of it, e. g., a gallon will weigh.’ 2. Cream is thicker (more viscous) than milk at the same temperatures, and more of it will adhere to the sides of the measuring pipette than incase of milk. This is of Special importance in testing very rich or sour créam. 1 For specific gravity of cream of different richness, see table on p. 75, ‘ Cream Testing. 15 3. In case of separator cream, more or less air will become incorporated with the cream during the process of separation. In the ripening of cream, the fermenta- tion gases developed are held'in the cream in the same way as bread dough holds the gases generated by yeast. In either case the weight of a certain measure of cream is diminished. 87. As an illustration of the effect of the preceding factors on the amount of cream measured out by a Bab- cock 17.6 cc. pipette, the following weighings of separ- ator cream are given (column bd). The cream was in all cases fresh from the separator; it was weighed as de- livered by the pipette into a cream test bottle (91), and the test proceeded with at once; the specific gravity of the cream was determined by means of a picnometer, (247). The data given are in all cases averages of sev- -eral determinations; the samples of cream have been grouped according to their average fat contents. ' Weight of fresh separator cream delivered by a 17.6 cc. pipette. Per cent Weight of Cream deliv- of fat in Specific y Cay (17 5° ©.) ered, grams. cream. (b) 10 1.023 17.9 15 1012 WE 20 1.008 17.3 25 1.002 lee? 30 .996 17.0 35 .980 16.4 40 .966 16.3 45 .950 16.2 500 947 15.8 The figures in the table show plainly the variations in the specific gravity of cream of different richness and 1 For influence of condition of cream on the amount measured out with a 17.6 ce. pipette, see also Bartlett, Maine exp, sta., Bull. 31 (S.S.), 76 Testing Milk and Its Products. the error of making tests of cream by measuring it with a 17.6 cc. pipette, especially if the pipette is not rinsed and the washings added to the test bottle; if the cream to be sampled is fresh separator cream testing over 30 per cent., less than 17.0 grams of cream will be delivered into the test bottle, and the results of the reading will be at least one-eighteenth too low, or about 1.4 per cent. on a 25 per cent. cream. If the cream is sour, the error will of course be still greater. | It should be remembered that the specific gravities of the cream given in the table refer to fresh separator cream only. Considerable air is incorporated during the separation, and cream of this kind is therefore lighter than gravity cream of corresponding fat contents. 88. Weighing cream for testing. For the reasons stated in the preceding, accurate tests of cream can only be made by weighing the cream into the Babcock test bottles. This is recognized by a law passed by the Wisconsin leg- islature of 1903, which requires cream to be weighed for testing where it is sold on the basis of its fat content.' The simplest method is to weigh 9 or 18 grams of the sample on asmall cream weighing scale (see p. 79) into one of the special forms of cream-test bottles. Cream test bottles. Special forms of bottles have been devised for testing samples of cream by the Bab- cock test by Bartlett of Maine, Winton of Connecticut, and by various manufacturers. - 89. The bulb-necked cream bottles (fig. 32) allow the 1 Chapter 48, laws of 1903, An act to prescribe the standard measures for the use of the Babcock test in determining the per cent. of butter fat in milk or cream. Cream Testing. Mel testing of cream containing 23 or 25 per cent. of fat, when the usual quantity of cream (18 grams) is ee The neck is graduated from 0 to 23 per cent., and in some cases to 25 per cent., the i alten, tion extending both below and above the bulb. This is sometimes an inconvenience, as the water must be added carefully so that the lower end of the column of fat will always come below the bulb, in the graduated part of the neck, and not in the bulb itself. Hspec- ially in case of beginners, tests are often lost when this bottle is first used, for the reason given. It is recommended to fill these bottles with the first portion of hot water to just above the bulb, so that one can see how much water f[ | to add the second time in order to bring the |. fat within the scale. Hach division of the scale on these cream bottles represents two-tenths of one per cent. of —_ fat, as in case of the milk test bottles. This Wis Sanaa form of bottle is no longer used to any extent, pale as it has been largely replaced by the cream-bottle de- scribed in the following paragraph. 90. The Winton cream bottle. The cream test bottle devised by Winton,' (fig. 33), has a neck of the usual length, and of sufficient width to measure 30 per cent. of fat. 'The scale of the neck is divided into one-half per cents., but readings of a quarter of a per cent. can easily be estimated. Determinations of fat in cream accurate 1 Connecticut experiment station (New Haven), Bull. No. 117; meDOEE 1894, p. 224. 78 Testing Milk and Its Products. to a quarter of a per cent. are sufficiently exact for most ya ey eee en oe a es ae oi < Go Loon 9M A OD ae Nea a tee Fig. 33. The cream test bottle. commercial purposes, e. g., in creameries, and this form of cream bottle will be found very convenient . in making tests of composite sam- ples of cream. — Cream test bottles of a smaller bore, similar to that shown in fig. 33, are greatly to be preferred to those with wide necks, since they permit of accurate readings to a quarter ofa per cent. Other forms of cream-test bottles which will allow the testing of 50-55 per cent. cream have been placed on the market during late years by some manufacturers. These bot- tles have very long necks and re- quire especially constructed, large and deep (and therefore costly) testers (see fig. 25). It does not ap- pear that these machines or accom- pany ing bottles have met with gener- al favor among creamery operators. 91. Scales for weighing the cream. When a small, delicate balance is used, cream can be weighed rapidly into the bottles. Either of the scales shown inthe accompanying illustra- tions (fig. 34-35), will be found sufficiently accurate for this pur- pose; a small scale of this kind is also convenient and | - Cream Testing. ae helpful in testing cheese, butter and condensed milk, in determining the strength of sulfuric acid, and the accuracy of test bottles and pipettes (q. v.). In testing cream by weight, the test bottle is first weighed empty, and again when 9 or 18 grams of cream have been placed in it; the difference between the two weights gives the weight of cream taken for the test. If the cream contains less than 30 per cent. of fat, the regular milk test bottle can be used for testing the cream, if not much more than 5 grams are weighed out; SSE a) Fig. 34 and 35. Scales used for weighing cream, cheese, etc., in the Babcock test. if more cream is taken, or if this is richer than 30 per cent., it is advisable to use the cream bottle. The cream scale shown in fig. 35 permits the weighing of six samples of cream on each pan with only one taring of the bottles, which greatly facilitates the work of test- ing the cream. | The operator should be careful in weighing the cream not to spill it on the outside of the test bottle. If less than 18 grams of cream has been weighed into the bottle, sufficient water is added to the bottle to make the total volume about 18 cc. The usual quantity of acid (17.5 ce. ) is then added, and the test completed in the ordinary manner. The reading of the amount of fat in the neck of the test bottle will not show the correct per cent. of 80 Testing Milk and Its Products. fat in the cream, unless 18 grams were weighed out. If less than 18 grams were taken the per cent. of fat in the cream tested is obtained by multiplying the reading by 18, and dividing the product by the weight of the cream taken. EXAMPLE: Weight of cream tested, 5.2 grams; reading of col- umu of fat 19.8, 9.7, average 9.75; per cent. of fat in the cream G78 ae tig ga eS 70. om It is very convenient to weigh out 18 grams of cream (or a fraction thereof) so that the readings may be taken directly from the neck of the bottle. The smaller the quantity of cream taken for a sample, the greater is the error introduced by inaccurate weighings or read- ings. The reading is rendered more accurate and cer- tain if a number of tests of a sample are made, at least two or three, and the results averaged. 92. Measuring cream for testing. Where a special cream scale or a small balance is not available, fairly satisfactory results may be obtained with cream of low or average quality by measuring out the sam- ple with a 17.6 pipette and correcting the results as indicated below. One of the cream testbottles or a common milk test bottle may be used for this purpose. The table given on p. 75 shows that a 17.6 cc. pipette, in the case of cream containing less than 25 per cent. fat and fresh from the separator, will deliver only 17.2 grams of cream, that is, the results will be 4.2 or .44 per cent. toolow. In the same way in case of 40 per cent. cream only 16.3 grams of cream would be de- livered, and the results therefore .94 per cent. too Cream Testing. 81 low. When the cream has been ripened or is thick, less cream would be delivered than the amounts given, and the error introduced by measuring out the samples correspondingly increased. A table of correction for testing such cream by measuring the sam- ple has been prepared by Prof. Eckles of Iowa experi- ment station.’ Approximately correct results may be obtained in testing thin cream by using an 18 cc. measuring pipette; to avoid the expense and trouble of using two different pipettes, one for milk and one for cream, a pipette with two marks on the stem, at 17.6 cc. and 18 cc., has been placed on the market, the former mark being used when milk is tested, and the latter for cream.’ 93. Use of milk test bottles. Cream may be tested by emptying a 17.6 cc. pipetteful of the sample into two or more milk test bottles, dividing the amount about equally between the bottles and filling the pipette with water once or twice, which is then in turn divided about equally between the test bottles; the per cent. of fat in the cream is found by adding the readings obtained in each of the bottles. Milk and water must be mixed before the acid is added. . This method does away with the error incident to the adhesion of cream to the side of the pipette, but not that due to the low specific gravity of the cream, and the re- Sults obtained will therefore be too low. The dilution of 1 Press Bull. dated August, 1901. 2 Professor Spillman, in Bull. 32 of Washington experiment station, recommends the use of a 176 ce. pipette for testing cream, the results ob- tained being corrected by a certain per cent., as shown in a table given in the bulletin. The table is based on the figures given on p. 74 of this book, and is ee only applicable to fresh separator cream. 82 Testing Milk and Its Products. the cream with water in the test bottles not only makes it possible to bring into the bottle all the cream measured out, but also insures a clear test. If ordinary cream is mixed with the ordinary quantity of sulfuric acid used in the Babcock test, a dark-colored fat will generally be obtained, while the cream diluted with an equal or twice its volume of water, when mixed with the ordinary amount of acid, will givea light yellow, clear column of fat, which will allow of a very distinct and sharp reading. The number of bottles to be used for testing a sample of cream by this method must be regulated by the rich- ness of the cream. If the sample probably contains 20 per cent. .or more, a pipetteful should be divided nearly equally between three milk test bottles, and two-thirds of a pipetteful of water is added to each bottle. If the cream contaius less than 20 per cent. of fat, it will only be necessary to use two milk test bottles, dividing the pipetteful between these,and adding one-half of a pipette- ful of water to each bottle. By using cream test bottles (90), more accurate tests may be obtained in case of cream containing as much as 25 per cent. of fat, by dividing one pipetteful between two bottles, rinsing half a pipette of water into each one, than by adding all the cream to one bottle without rins- ing the pipette, for reasons apparent from what has been said in the preceding. 94. Use of a5 cc. pipette. When the cream isin good condition for sampling, satisfactory results can be ob- tained by the use of a 5 ce. pipette, provided great care is taken in mixing the cream before sampling; 5 ce. of cream are measured into a milk test bottle, and two Cream Testing. 83 pipettefuls of water are added. In this way all the cream in the pipette is easily rinsed into the test bottle. The readings multiplied by +5—3.6 will give the per cent. of fat in the cream. If the specific gravity of the cream tested varies appreciably from 1, corrections should be made accordingly; e. g., if the specific gravity is 1.02; the factor should read = =3.53; if .95, er a 9, ete. 95. Proper readings of cream tests. The accompanying illustration (fig. 36), shows the proper method of read- | ing the fat column in cream tests; read- ings are taken from a to J, not to d or to ec." No special precautions other than those required in testing milk have been found necessary in testing cream, ex- cept that it is sometimes advisable not to whirl the test bottles in the cen- trifuge at once after mixing, but to let the cream-acid mixture stand for a while, until it turns dark colored. At first, the mixture of cream and acid is much lighter colored than that of milk and acid, owing to the smaller amount of solids not fat contained in the cream. The liquid beneath the fat in a com- eas inthe neck of a pleted test ofcream i sometimesmilky = ing should be made the fat ee white and cloudy, making ortoc. an exact reading difficult. Such defects can usually be overcome by placing the test bottles in hot water for about ten minutes previous to the whirling, or 1 The size of the meniscus is magnified in the cut. 84 Testing Milk and Its Products. by allowing the fat to erystalize (which is done by cool- ing the bottles in cold water after the last whirling) and remelting it by placing the bottles in hot water. 96. The error due to the expansion of the fat in case of excessively hot turbine testers having no openings in the cover aS mentioned on p. 36, is especially noticeable in cream testing, where it may amount to one per cent. or more. In order to obtain correct results with such testers, the hot cream test bottles must be placed in water at about 140° F. for a few minutes before the results are read off. CHAPTER V. BABCOCK TEST FOR OTHER MILK PRODUCTS. 97. Skim milk. Each division on the scale of the neck of the regular Babcock test bottle represents two-tenths of one per cent. (44). Whena sample of skim milk or butter milk containing less than this per cent. of fat is tested, the estimated amount is expressed by different operators as one-tenth, - a trace, one-tenth trace, or one to five- hundredths of one per cent. Gravimetric chemical analyses of skim milk have shown that samples which give only a few small drops of fat floating on the water in the neck of the test bottle, or adhering to the side of the neck, generally contain one-tenth of one per cent. of fat, and often more. Samples of skim milk containing less than one-tenth of one per cent. of fat are very rare, and it is doubtful whether a sample of separator skim milk representing a full ran of, say 5,000 lbs. of milk, has ever shown less than five-hundredths of one per cent. of fat. Under ordinary factory conditions, few separators will deliver skim milk containing under one-tenth of one per cent. of fat, when the sample is taken from the whole day’srun.. This must be considered a most satisfactory Separation.* 98. The reason why the Babcock test fails to show all the fat present in skim milk must be sought in one or two causes: a trace of fat may be dissolved in the sulfuric acid, or owing to the minuteness of the fat globules of 1 For comparative analyses of separator skim milk by the gravimetric method and by the Babcock test, see Wis. exp. station bull. 52 and rep, XVII, p. 81; see also Woll, Testing skim milk by Babcock test, in Country Gentleman, April 26, 1902. 86 Testing Milk and Its Products. such milk they may not be brought together in the neck of the bottles at the speed used with the Babcock test. ° The latter cause is the more likely explanation. Ifa drop of the dark liquid obtained in a Babcock bottle from a test of whole milk, be placed ona slide under the micro- scope, it will be seen that a fair number of very minute fat globules are found in the liquid. These globules are not brought into the column of fat in the neck of the bottle by the centrifugal force exerted in the Babcock test, unless the bottles are whirled in a turbine tester in which they are heated to 200° F. or higher, (see 71); the loss of the fat contained in these fine globules is compensated for, in the testing of whole milk, by a liberal reading of the column of fat separated out, the reading being taken from the. lower meniscus of the fat to the top of the upper one (see p. 35); in some separator skim milk, on the other hand, not enough fat remainsto completely fill the neck, and the ap- parent result of the reading must therefore be increased by from five-hundredths to one-tenth of one per cent. It follows from what has been said that tests of skim milk showing no fat in the neck of the test bottles on completion of the test, generally indicate inefficient work of the centrifugal tester or of the operator, or of both. The test should be repeated in such cases, using more acid and whirling for full five minutes. Separator skim milk should be allowed to stand 10 to 15 minutes for the air to escape before the sample is taken. In order to bring as much fat as possible into the neck of the bottles in testing skim milk, it is advisable to add somewhat more acid than when whole milk is tested, viz., about 20 ec., and to whirl the bottles at full speed for at Babcock -Test for other Milk Products. 87 least five minutes, keeping the tester as hot as possible the whole time.! The readings must be taken as soon as the whirling is completed, as owing to the contraction of the liquid by cooling, the fat otherwise adheres to the inside of the neck of the test bottle as a film of grease which cannot be measured by the scale. 99. The double-necked test bottle, (fig. 37), suggested by one of us, * is made espe- cially for measuring small quantities of fat and gives most satisfactory results in testing skim milk and butter milk. Each division ie of the scale in these bottles represents five- f N\ hundredths of one per cent., and the marks i Ny are so far apart that the small fat column fijj// ffl can be easily estimated to single hundredths | of one per cent. In the first forms, now | out of use, the neck was graduated to hun- dredths of one per cent. The value of the divisions of the scale on the double-necked test bottles has been a rr. 37. Pie : : : : - double-necked subject of considerable discussion, and vari- skim milk bot- ous opinions have been. expressed whether called. the Ob a1. they show one-tenth or one-twentieth (.05) bott ey of one per cent. of fat. By calibration with mercury the © value of the divisions will be found to be .05 or one- twentieth of one per cent., but as shown above, the results obtained in using the bottles for thin separator skim milk often come at least .05 per cent. too low, so that, practically speaking, each division may be taken to 1 See Wis. exp. station, report X VII, p. 81. 2 Farrington, and first constructed by Mr.J.J. Nussbaumer, of Illinois 88 Testing Milk and Its Products. show one tenth of one per cent., if the fat fills only one division of the scale or less.* The double-necked bottle is very convenient for the testing of separator skim milk, thin butter milk and whey. The milk, acid and water are added to the bottle through the large side-tube; the mixing of milk and acid must be done with great care, so that none of the con- tents is forced into the fine measuring tube and lost; it is best to add half of the acid first and mix it with the milk, and then add the rest. When the fat is in the lower end of the measuring tube, it can be forced into the scale by pressing with the finger on the top of the side tube. In placing the double necked bottle in the tester they should be put with the filling tube toward the center so as to avoid any of the fat being caught be- | tween this tube and the side of the bot- | : tle when it resumes a vertical position. oul Bone) as test bottle is ae fragile and ex- Testing BoTm| §=—s Mensive than the ordinary Babcock bot- | i tles, and must be carefully handled; it has recently been made of heavier glass fetes Sue ese this form is to be highly recom- skim milk bottle. mended.” 100. The double-sized skim miik bottle is of no particular value. It is difficult to obtain a thorough mixture of 1 Wis. experiment station, bull. 52; Penna. experiment station, report 1896, p. 221. 2 A copper double-necked test bottle with a detachable graduated glass neck was designed and tried by one of us (F.) afew years ago, but no special advantages over the glass bottle was found for it. Babcock Test for other Milk Products. 89 the milk and the acid in these bottles, and the tests invariably come too low, more so than with the regular Babcock bottles or the double-necked skim milk bottles, for reasons that are readily seen. 101. Buttermilk and whey. The testing of buttermilk or whey by the Babcock test offers no special difficulties, and what has been said in regard to tests of separator skim milk is equally true in case of these by-products. Whey contains only a small quantity of solids not fat, viz., less than 7 per cent. (27), and the mixing with acid and the solution of the whey solids therein is therefore readily accomplished; the acid solution is of a light reddish color, turning black but very slowly. 102. Cheese. Cheese can be easily tested by the Bab- cock test if a small scale (fig. 34) is at hand for weighing the sample; the results obtained will furnish accurate information as to the amount of fat in the cheese, provided good judgment and exactness are used in sampling and weighing the cheese. The following method of sampling cheese is recommended: ' ‘“ W here the cheese can be cut, a narrow wedge reach- ing from the edge to the center of the cheese will more nearly represent the average composition of the cheese than any other sample. This may be cut quite fine, with care to avoid evaporation of water, and the portion for analysis taken from the mixed mass. When the sample is taken with a cheese trier, a plug. taken perpendicular to the surface, one-third of the distance from the edge to the center of the cheese, will more nearly represent the average composition than any other. The plug should © Pa ee Aerie eee WHE! Vivien, bull! No. 46) p. 37. 90 Testing Milk and Its Products. either reach entirely through or only half way through the cheese. ‘¢ For inspection purposes the rind may be rejected, but for investigations, where the absolute quantity of fat in the cheese is required, the rind should be included in the sample. Itis well, when admissible, to take two or three plugs on different sides of the cheese and after splitting them lengthwise with a sharp knife, take portions of each for the test.’’ 103. When asatisfactory sample of the cheese has been obtained, about 5 grams are weighed into a milk test bottle, or a larger quantity may be used with a cream test bottle. The test bottle is first weighed empty, and again after the pieces of cheese have been added. About 15 cc. of warm water is added to the cheese in the test bottle, and this is shaken occasionally until the cheese softens and forms a creamy emulsion with the water. A few cc. of acid will aid in this mixing and disintegra- tion, the process being hastened by placing the bottles | in tepid water. When all lumps of cheese have disap- peared in the liquid, the full amount of acid is added, and the test completed in the ordinary manner. The per cent. of fat in the cheese is obtained by multi- plying the reading of the fat column by 18 and dividing the product by the weight of cheese added to the test bottle. The weighing of the cheese and the reading of the fat must be done with great care, since any error introduced is more than trebled in calculating the per cent. of fat in the cheese. . 104. Condensed milk. The per cent. of fat in wn- sweetened condensed milk can be obtained by weighing | Babcock Test for other Milk Products. 91 8 grams into a test bottle and proceeding in exactly the same way aS given under testing of cheese. It is not necessary to warm the condensed milk in the test bottles, since the solution of this in water is readily effected. Enough water should be added to make the total volume of liquid in the bottles 15 to 18 ce. If a scale is not available for weighing the sample, fairly accurate results may be obtained by diluting the condensed milk with water (1:3), and completing the test in the ordinary manner. When this is done, the re- sults must be corrected for the dilution which the sample received. 105. Sweetened condensed milk. The testing of sweet- ened condensed milk presents peculiar difficulties, whether it is to be tested by the Babcock test or by chem- ical analysis. It may, however, be readily tested by the Babcock test by introducing certain changes in the manip- ulation of the test as worked out by one of us (F).’ A brief description of the manipulations adopted is here given. About sixty grams of condensed milk are weighed into a 200 cc. graduated flask, to this 100 ce. of water are added and the solution of the condensed milk effected. The flask is then filled to the mark with water and after mixing thoroughly, a 17.6 cc. pipette full | is measured into a Babcock test bottle. About three ce. of the sulfuric acid commonly used for testing milk are then added and the milk and acid mixed by shaking the bottle vigorously. The milk is curdled by the acid, and make this separation complete and to compact the curd "1 Wis. expt. station, report XVII, pp. 86-89. 92 Testing Milk and Its Products. the curd and whey separated somewhat. In order to into a firm lump, the test bottle is whirled for about six minutes at a rather high speed (1,000 pe in a steam- heated turbine centrifuge. . The chamber in which the bottles are whirled ought to be heated to about 200° F. This can be done either by the turbine exhaust steam which leaks into the test- bottle chamber of some machines, or by means of a valve and pipe which will allow steam to be turned directly into the test bottle chamber. After this first whirling the test bottles are taken from the centrifuge and by be- ing careful not to break the lump of curd nearly all the whey or sugar solution can be poured out of the neck. Ten cc. of water are then poured into the test bottle and the curd is shaken up with it so as to wash out more of the sugar. Three ce. of acid are now added as before and the test bottle whirled a second time in the centri- fuge. The whey is decanted again and this second wash- ing removes so much of the sugar that what remains will not interfere with testing in the usual way. The curd re- maining in the test bottle after the second washing is shaken up with ten cc. of water and to this water-emul- sion of the curd the usual amount, 17.5 ec., of sulfuric acid is added and the test completed in the same way as milk is tested. The amount of fat finally obtained in the neck of the test bottle is calculated to the weight of con- densed milk taken. CHAPTER VI. THE LACTOMETER AND ITS APPLICATION. 106. The Quevenne factometer. This instrument (see fig. 39, next page) consists of a hollow glass cylinder weighted by means of mercury or fine shot so that it will float in milk in an upright position, and provided with a narrow stem at its upper end, inside of which is found a graduated paper scale. In the better forms, like the Que- venne lactometer shown in the figure, a thermometer is melted into the cylinder, with its bulb atthe lower end of the lactometer and its stem rising above the lactometer Seale. The lactometer is used for the determination of the Specific gravity of milk. The term specific gravity means the weight of a certain volume of a solid or a liquid sub- _ stance compared with the weight of the same volume of water at 4° C. (39.2° Fahbr.); for gases the standard of comparison is air or hydrogen. If the milk which a can will hold weighs exactly 103.2 fbs., this can will hold a smaller weight of water, say 100 fbs., as milk is heavier than water; the specific gravity of this milk will then Nee, la. The specific gravity of normal cows’ milk will vary in different samples between 1.029 and 1.035 at 60° F., the average being about 1.032. | 107. The lactometer enables us to determine rapidly the relative weight of milk and water. Its application rests on well-known laws of physics: When a body floats in a liquid, the weight of the amount of liquid 94 Testing Milk and Its Products. which it replaces is equal to the weight of the body. It will sink further into a light liquid than into a heavy one, be- cause a larger volume of the former will be required to equal the weight of the body. A lactometer will therefore sink deeper into milk of a low specific grav- ity than into milk of a high specific gravity. The scale of the Quevenne lactometer is marked at 15 and 40, and divided into 25 equal parts, with figures at each five divisions of the scale. The single divis- ions are called degrees. The 15 degree mark is placed at the point to which the lactometer will sink when lowered into a liquid of a specific gravity of 1.015, and the 40 degree mark at the point to which it will sink when placed in a liquid of a specific gravity of 1.040. The specific gravity is changed to lacto- meter degrees by multiplying by 1000 and subtracting 1000 from the product. Example: Given, the specific gravity ofa sample of milk, 1.0345; corresponding lacto- meter degree, 1.0345 x 1000—1000=34.5. Conversely, if the lactometer degree | is known, the corresponding specific gravity is found by dividing by 1000 Fig. 39. Quevenne and adding 1 to the quotient (34.5-~1000 lactometer floating in milkina tin cyl- =.0345; .0345-+-1=1.0345). inder (112). The Lactometer and Its Application. 95 108. Influence of temperature. Like most liquids, milk will expand on being warmed, and the same volume will, therefore, weigh less when warm than before; that is, its specific gravity will be decreased. It follows then that a lactometer is only correct for the temperature at which it is standardized. If a lactometer sinks to the 32-mark in a sample of milk of a temperature of 60° F., it will only sink to, say 33, if the temperature of the milk is 50° F., and will sink farther down, e. g., to 31, if the temperature is 70° F. Lactometers on the market at present are generally standardized at 60° F. and to show the correct specific gravity the milk to be tested should first be warmed (or cooled, as the case may be) to exactly 60° F. Asthis is a somewhat slow process, tables have been constructed for correcting the results for errors due to differences in temperature (see Appen- dix, Table V). 109. As the fat content of a sample of milk has a marked influence on its specific gravity at different tem- peratures, the co-efficient of expansion of fat differing greatly from that of the milk serum, the table cannot give absolutely accurate corrections for all kinds of milk, whether rich or poor. But the errors introduced by the use of one table for any kind of whole milk within a comparatively small range of temperature, like ten de- grees above or below 60°, are too small to have any im- portance outside of exact scientific work, and in such, the specific gravity is always determined by means of a picnometer or specific gravity bottle, at the temperature at which this has been calibrated. In taking the spe- cific gravity of a sample of milk by means of a lacto- 96 Testing Milk and Its Products. meter, the milk is always warmed or cooled so that its temperature does not vary ten degrees either way from 60° F. 110. The temperature correction table for whole milk, given in the Appendix shows that if, e. g., the specific gravity of a sample of milk taken at 68° F. was found to be 1.034, its specific gravity would be 1.0352 if the milk was cooled down to 60°. If the specific gravity given was found at a temperature of 51°, the corrected specific gravity of the milk would be 1.0329. In practical work in factories or at the farm, sufficiently accurate temperature corrections may generally be made by adding .1 to the lactometer reading for each degree above 60° F., and by subtracting .1 for each degree be- low 60°; e. g., if the reading at 64° is 29.5, it will be about 29.5+.4=29.9 at 60° F.; and 34.0 at 52° F. will be about 34.0 —.8=33.2 at 60° F. The table in the Appen- dix gives 33.0 as the corrected figure in both cases. The scale of the thermometer in the lactometer should be placed above the lactometer scale so that the tempera- ture may be read without taking the lactometer out of the milk; this will give more correct results, will facil- itate the reading and save time. ll. N. Y. Board of Health lactometer. In the East, and among city milk inspectors generally, the so called New York Board of Health lactometer is often used. ‘This does not give the specific gravity of the milk directly, as is the case with the Quevenne lactometer; but the scale is divided into 120 equal parts, known as Board of Health degrees, the mark 100 being placed at the point to which the lactometer sinks when lowered into milk of a specific Cream Testing. 97 gravity of 1.029 (at 60° F.); this is considered the lowest limit for the specific gravity of normal cows’ milk. The zero mark on the scale shows the point to which the lac- tometer will sink in water; the distance between these two marks is divided into 100 equal parts, and the scale is continued below the 100 mark to 120. As100° on the Board of Health lactometer corresponds to 29° on the Quevenne lactometer, the zero mark showing in either case a Specific gravity of 1, the degrees on the former lactometer may easily be changed into Quevenne lacto- meter degrees by multiplying by .29. To further aid in this transposition, table III is given in the Appendiz, showing the readings of the two scales between 60° and 120° on the Board of Health lactometer. 112. Reading the lactometer. For determining the spe- cific gravity of milk in factories or private dairies, tin cylinders, 14 inches in diameter and 10 inches high, with a base about four inches in diame- ter, are recommended (see fig. 39); another form of specific-gravity cylinders, in use in chemical laboratories, is shown in fig. 40. The cylinder is filled with milk of a tempera- ture ranging between 50° and 70° F., to within an inch of the top, and the lactometer is Slowly lowered therein until it floats; it is left in the milk for about half a minute before lactometer and thermometer readings are == taken, both to allow the escape of air which cifte gravy bas been mixed with the milk in pouring it _ cylinder. preparatory to the specific gravity determina- tion, and to allow the thermometer to adjust itself to the 7 98 - Testing Milk and Its Products. temperature of the milk. The lactometer should not be left in the milk more than a minute before the reading is taken, as cream will very soon begin to rise on the milk, and the reading, if taken later, will be too high, as the bulb of the lactometer will be floating in partially skimmed milk (23). In reading the lac- tometer degree, the mark on the scale plainly visible through the upper portion of the meniscus of the milk should be noted. Owing to surface tension the milk in immediate contact with the lactometer stem will rise above the level of the surface in the cylinder, and this must be taken into consideration in reading the degrees. _ There is no need of reading closer than one-half of a lac- tometer degree in the practical work of a factory ora dairy. 113. Time of taking lactometer readings. The specific gravity of milk should not be determined until an hour or two after the milk has been drawn from the udder, as too low results are otherwise obtained (Recknagel’s. phenomenon).' The cause of this phenomenon is not definitely understood; it may come from the escape of gases in the milk, or from changes occurring in the me- chanical condition of the nitrogenous components of the milk. The results obtained after a couple of hours will as a rule come about one degree higher than when the milk is cooled down directly after milking and its specific gravity then determined. 114. Influence of bi-chromate on lactometer readings. When potassium bi-chromate is added to milk samples to preserve them from souring (188), the specific gravity 1 Milchzeitung 1883, 419; Bulletin No. 43, Chem. Div., U. S. Department of Agriculture, p. 191; Analyst 1894, p. 76. The Lactometer and Its Application. 99 of the milk is thereby increased; with the quantity usu- ally added (4 gram to a pint of milk) the increase amounts to about 1 lactometer degree, and this correction of lacto- meter readings should be made with milk samples pre- served inthismanner. Toavoid thiserror, Dr. Hichloff* recommends using a solution of bi-chromate in water (43 grams to 1 liter), the specife gravity of which is 1.032, or similar to that of average milk; 5 ce. of this so- lution is required for a pint of milk. No correction is necessary for the dilution with this small amount of liquid preservative. 115. Cleaning of lactometer. The lactometer should be cleaned directly after using, by rinsing with cold water; it is then wiped dry with a clean cloth and placed in the case. CALCULATION OF MILK SOLIDS. 116. A number of chemists have prepared formulas for the calculation of milk solids when the fat content and the specific gravity (lactometer reading) of the milk are known. By careful work with milk tester and lacto- meter it is possible by means of these formulas to deter- _ mmine the composition of samples of milk with consider- able accuracy outside of, as well as in chemical laborator- ies. As the complete formulas given by various chemists (Behrend and Morgen, Clausnitzer and Mayer, Fleisch- mannn, Hehner and Richmond, Richmond, Babcock )* are very involved, and require rather lengthy calculations, tables facilitating the figuring have been prepared. The | formulas in use at the present time, in this country and - 1Technik der Milchpritifung, p. 98. 2 Agricultural Science, vol. III, p. 189. ae 100 Testing Milk and Its Products. abroad, are those proposed by Fleischmann, Hehner and Richmond, and Babcock. Babcock’s formula is the one generally taught in American dairy schools and is there- . fore given here; it forms the foundation of table VI for solids not fat in the Appendix. By the use of these tables the percents of solids not fat may be found, corresponding to lactometer readings from 26 to 36, and to fat contents from 0 to 6 per cent. The formula, as amended in 1895," is as follows, S being the specific gravity and f the per cent. of fat in the milk. ‘ 100 S—Sf Solids not fat= (00-073 s¢—1) (00) 2.5 The derivation of this formula is explained in the re- port referred to. 117. Short formulas. The tables made up from this formula, giving the percentages of solids not fat corres- ponding to certain per cents. of fat and lactometer read- ings, are given in the Appendix. 2 1 56.2x100_, 73 49.8100 _ 4 99. 1187 Air a 1187 Composite Samples of Milk. 161 ' 195. The figures given in the table show that when the different lots of milk vary in test and weight, as in the first case, the correct average test of the 1187 tbs. of milk is not found by dividing the sum of these tests by five, which would give 4.14 per cent.; but the percentage ‘which 56.2 (the total amount of fat in the mixed milk) is of 1187 (the total amount of milk), is 4.73, and this is the correct average. test of the mixed milk made up of the five different lots. In the second case, the variations in both the weights of the different lots of milk and their tests, are compara- tively small, and both methods of calculation give there- fore practically the same average test; but also in this case, the correct average test is found by dividing the total amount of fat by the total quantity of milk, making 4,22 per cent., instead of 4.20 per cent., which is the arithmetical mean of the five tests. The quantities of milk in the various lots do not enter into the calculation of the latter.’ 196. The second example represents more nearly than the first one the actual conditions met with at creameries and cheese factories. Asa rule the mixed milk from a herd of cows does not vary more in total weight or tests, within a short period of timelike one to two weeks, than the figures given in this example. On account of this fact, samples taken, for instance, with a small dipper may give perfectly satisfactory results to all parties concerned. If the different lots of milk varied in weight and test from 1 In the experiment given on p. 187, the arithmetical mean of the tests given is 5.15 per cent., while the true average fat content of the milk is 4.85 per cent. 11 162 Testing Milk and Its Products. day to day, as shown in the first case, it would be neces- sary to use a ‘‘ milk thief’’ or one of the sampling tubes for taking the composite samples; the size of each of the _ samples taken would then represent an exact aliquot por- tion of the various lots of milk (180). 197. A patron’s dilemma. The following incident will further explain the difficulties met within calculating the average tests of different lots of milk. The weekly composite sample of the milk supplied by a creamery patron from his herd of 21 cows tested 4.0 per cent. fat. One day the farmer brought to the creamery a sample of the morning’s milk from each of his cows, and had them tested; after adding the tests together and dividing the sum by 21, he obtained an average figure of 5.1 percent. of fat. From this he concluded that the average test.of the milk from his cows ought to be 5.1, instead of 4.0, and naturally asked for an explanation. 198. The first thing done was to show him that while5d.1 was the correct average of the figures representing the tests of his twenty-one cows, it was not a correct average test of the mixed milk of all his cows, as he had not considered, in calculating this average, the quantities of milk yielded by each cow; the following illustration was used: . Cow No. 1, yield 25 ibs. of milk, test 3.6 per cent.=0.9 ibs. of butter fat. Cow No. 2, yield 6 ibs. of milk, test 5.0 per cent.=0.3 ibs. of butter fat. — Notalees.. 381 ibs. 2)8.6 1.2 ibs. 4.3 per cent. The two cows gave 31 tbs. of milk containing 1.2 ibs. of fat; the test of the mixed milk would therefore not be 4.3 per cent. —7 but e387 percent. If the fat in the mixed milk was calculated by the average figure 4.3 per cent., 1.33 Ibs. of fat would be obtained, i.e., 0.13 fds. more than the cows produced. In order to further demonstrate the actual composition of the mixed milk of the twenty-one cows, the milk of each cow was weighed and tested at each of the two milkings of one day. The weights and tests showed that the cows produced the fol- lowing total number of pounds of milk and of fat: Composite Samples of Milk. 163 Morning milking, 113.3 tbs. of milk, containing 5.17 tbs. of fat. Night milking, 130.9 tbs. of milk, containing 4.98 tbs. of fat. 5.17 x 100 113.3 =3.80 per cent. of fat. The morning milk therefore contained 4.98 x 100 130.9 The sum of the morning and night milkings gave: milk, 244.2 tbs., fat 10.15 tbs. The mixed morning and night milk, ae per cent. of fat. This is the true average test of the morning and night milkings of these twenty-one cows, as found by weighing and testing separately the milk of each cow at both milkings. 199. The total milk was strained into a large can at the farm, both in the morning and in the evening. A sample of the mixed milk was in each case taken with a long-handled dipper as soon as the milkings were finished. When the cans of milk were delivered at the creamery, a sample of each was taken with a Scovell sampling tube. The tests of these four samples are given below, together with the results from the individual tests: = 4.56 per cent. of fat, and the night milk therefore, contained Morning Milk.| Night Milk. Sample taken at the farm, with RRUAISEE Sceennra yaanensae cin ctqntecdnpuneossiacs 4.4perct. | 3.8perct. Sample taken at creamery with Sco- BMP PRMD cece cnac ovsa news swipscnnis «cus tna 4.5‘ 2 ey ea Calculated from weights and tests of milk from each COW............cceeee0 4.5 ao st The figures given show that practically uniform tests were obtained by the different methods of sampling. The sum of the weights of the milk from the different cows was as follows: Morning Mitk.| Night Milk. Daily Milk. . Total milk produced........ 113.3 tbs. 130.9 tbs. 244.2 tbs. Milk in samples............... 12.3 tbs, 8.9 tbs. 21.2 tbs. Milk for family use......... AN | ia | 2.5 Tbs. Milk taken tocreamery| 98.5 tbs. 122.0 ibs. 220.5 tbs. 164 Testing Milk and Its Products. It hasalready been shown from the weights and tests of each cow’s milkthat the herd milk contained 4.1 per cent. of fat. Multiplying the total milk delivered at the creamery, 220.5 ibs., by .041 gives 9.04 tbs. of fat. The morning and night milkings, which were weighed and tested separately, contained the fol- lowing quantities of butter fat: Morning: Malk: 220.4 cece 98.5 tbs. x .045=—4.438 tbs. of butter fat JOSE EA DU soned pose cenocconce 122.0 Ibs. x.038=4.63 Ibs. of butter fat Motalie sc: sensescetescrse: 220.5 tbs. 9.06 tbs. By weighing, sampling and testing separately the morning and night milkings of twenty-one cows, deducting the weight of milk in the samples and what was taken out for family use, it was found that 9.04 ibs. of butter fat was sent to the creamery. The weights and tests of this same milk when delivered at the creamery, gave 9.06 ibs. of butter fat. ; 200. This example furnishes an excellent illustration of the accuracy of the Babcock test and of the closeness of results which may be obtained at creameries when proper care is taken in weighing, sampling and testing the milk. Similardemonstra- tions may be made by any factory operator, and with equally satisfactory results, provided the work is carefully done. CHAPTER XI. CREAM TESTING AT CREAIMERIES. 201. The cream delivered at gathered-cream factories is now in many localities tested by the Babcock test, and this has been adopted as a basis of paying for the cream in the same manner as milk is paid for at separator creameries. It has been found to be more satisfactory to both cream buyer and seller, than either the oil-test churn or the space (or gauge) systems which have been used for this purpose in the past. “The details of the application of the Babcock test to the practical work at cream-gathering creameries have been carefully investigated by Winton and Ogden in Connecticut,’ Bartlett in Maine,” and Lindsey in Massa- chusetts,? and we also owe to the labors of these chemists much information concerning the present workings of other systems of paying for the cream delivered at creameries. rig, a 202. The space system. Numerous tests have shown that one space or gauge of cream does not contain a defi- nite, uniform amount of fat. In over 100 comparisons made by Winton it was found that one space of cream ‘ 1 Conn. experiment Sues (New Haven), bull. No. 108 and 119; report 1894, pp. 214-241. 2 Maine experiment station, bull. 3 and 4 (S.S.). 3 Hatch experiment station, report 1894, pp. 92-108 ; 1895, pp. 67-70. 4 'The space is the volume of a cylinder, 84% inches in diameter and 32 of an inch high. The number of spaces in each can of milk is read off before skimming by means of a scale marked on a strip of tae in the side of the can (Conn. exp. sta., bull. No 119). 166 Testing Milk and Its Products. contained from .072 to .170 tbs. of butter fat, or on the average .13.fb., and the number of spaces required to make one pound of butter varied from 5.01 to 11.72. It is also claimed that in the winter season when the cream is gathered at long intervals, like once a week, it is neces- sary for the buyer to accept the seller’s statement of the record of the number of cream spaces which he furnishes, te B Fra. 56. The oil-test churn. since the cream cannot be left in the creaming cans for solong atime. These objections to the space system apply only to the method of paying for the cream, and not to the manner in which the cream is obtained. 203. The oil-test churn. As stated in the introduction, the oil-test churn (fig. 56) has been used quite extensively among gathered-cream factories; this system is based on Cream Testing at Creameries. © 167 the number of creamery inches of cream which the various patrons deliver to the factory; one inch of cream contains 113 cubic inches.’ The driver pours the patron’s cream into his 12-inch gathering pail, measures it with his rule and records the depth of the cream in the can, in inches and tenths of an inch. The cream is then stirred thoroughly with a ladle or a stout dipper, and a sample is taken by filling a test tube from the sample case, to the graduation mark by means of a small conical dipper pro- vided with a lip. A driver’s case contains either two or three ‘‘cards,’’ holding fifteen test tubes each (see fig. 57). The tubes as filled are anne placed in the case and (etttiit tt | ria the corresponding num- Hedin | ber is in each instance ; 7 Sees cil recorded in front of the patron’s name together with the number of inches of cream _ fur- nished by him. On the arrival at the ; ; ; ‘ Fig.357. Cream-gatherer’s creamery the tin cards sample:case. holding the tubes are placed in a vessel filled with water of the temperature wanted for. churning (say, 60° in summer and 65° to 70° in winter). When ready for churning they are placed in the oil-test churn, the cover of the churn put on, and the samples of cream churned to butter. On the completion of the churning, the cards are transferred to water of 175-190° Fahr., 1].e.,a layer of cream one inch deep in a 12-inch pail; two inches in an 8-inch pail contains 10).531 cubic inches, two inches in an 834-inch pail 110.18 cubic inches, and two inches in an 84-inch pail 118 49 cubic inches. 168 ’ Testing Milk and Its Products. where they are left for at least ten minutes to melt the butter and ‘‘cook the butter milk into a curd.’’ The oil will now be seen mixed all through the mass. The. test tubes are then warmed to churning temperature and churned again, by which process the curd is broken into fine particles, which, when the butter is re-melted, will settle to the bottom. The butter is melted after the second churning by placing the tubes in water at. 150-175° F., allowing them to remain therein for at least twenty minutes. Some samples must be churned three or four times before a good separation of oil is obtained. A clear separation of oil is often facilitated by adding a little sulfuric acid to the tubes. The length of the column of liquid butter fat is de- termined by means of a special rule for measuring the butter oil; this rule shows the number of pounds and tenths of a pound of butter which an inch of cream will make; the first tenth of a pound on the rule is divided into five equal parts, so that measurements may be made to two-hundredths of a pound. The melted fat is meas- ured with the rule, by raising the tin card holding the bottles, to about the height of the eye; the reading is recorded on the driver’s tablet under Test per inch, oppo- site the number of the particular patron. The test per inch multiplied by the inches and tenths of an inch of cream supplied will give the butter yield in pounds, with which the patron will be credited on the books of the creamery. 204. The objection to this system of ascertaining the quality of cream delivered by different patrons lies in the fact that it determines the churnable fat, and not the Cream Testing at Creameries. 169 total fat of the cream; the amount of the former obtained depends on many conditions beyond the control of the patron, viz., the consistency, acidity and temperature of the cream, the size of the churn or churning vessel, ete. The same reasons which caused the churn to be replaced by methods of determining the total fat of the milk, in the testing of cows among dairymen and breeders, have gradually brought about the abandonment of the oil test. in creameries and the adoption of the Babcock test in its place. | af 205. The Babcock test for cream. Both the space system and the oil-test churn used for estimating the quality of cream at creameries have now largely been replaced by the Babcock test in the more progressive creameries in this country, and composite samples of cream are collected and tested in a similar manner as is done with milk at separator creameries and cheese factories. A very satisfactory method of arrangements for work- ing the Babcock test, in use‘in many eastern creameries, is described by Winton and, Ogden in the Connecticut report previously referred to. The cream gatherer who collects the cream in large cream cans is supplied with a spring balance (1; see fig. 58), pail for sampling and weighing the cream (2), sampling tube (3), and collect- ing bottles (5). At each patron’s farm he takes from his wagon the sampling pail and tube, the scales, and one small collecting bottle. He should find in the dairy of the patron the cans of perfectly sweet cream, kept at a temperature of 40° to 50° F., and protected from dirt and bad odors. Hither sour or frozen cream must be rejected. 170 Testing Milk and Its Products. Fig. 58. Outfit for cream testing by the Babcock test at gathered- cream factories. The patron’s number should be painted in some conspic- uous place near the cream cans in his dairy house. The gatherer hangs the scale on a hook near the cream to be collected; the scale should be so made that the hand of the dial will stand at zero when the empty pail is hung Testing Cream at Creameries. : 171 on it. The cream is then poured at least twice from one can to another in order to mix it thoroughly.? 206. When properly mixed, the cream is poured into the weighing pail and is weighed and sampled. The authors give the following description of the cream sam- pling tube used, and directions for sampling and weigh- ing the cream. ‘“Sampling Tube.—This tube, devised by Mr. Ogden, is of stout brass, about ,; of an inch thick, and a few inches longer than the weighing pail which is used with it. On the upper end, a small brass stop-cock of the same bore is fastened. It should be nickel plated inside and out, to keep the metal smooth and free from corrosion. These tubes may be obtained from less than ; to over }inch bore. The greater the diameter of the weighing pail, the wider should be the bore of the tube. For use with pails 8 inches in diameter, a 3, inch bore sampling tube will serve the purpose, but when fii pail has a diameter of 9 or more inches, a tube with a bore of } inch or more should be used. It must be borne in mind that doubling the diameter of the pail, or of the sampling tube, increases its capacity fourfold. ‘The tube when not in use ca be kept in an upright position to permit draining. ‘* Sampling and Weighing.—Lower the sampling tube, cock end up, with the cock open, to the bottom of the weighing pail which holds the mixed cream. When it is filled raise it out of the liquid and allow it to drain for a few seconds. By this means the tube is rinsed with the cream to be sampled and any 1 The necesstty of care in mixing the cream is shown by the following illustration given by the authors referred to. Per cent of fat in cream which stood for 24 hours. Sample drawn Surface. Bottom. with sampling tube. _ Not mixed.................... 28.00 5.00 19.25 Poured ONCE........... ss... 23.75 22.00 22.50 IROUTCOU TWICE cecoc cies cee rer es aoe. 22.25 172 Testing Milk and Its Products. traces of cream adhering to the tube from previous use are removed. With the cock still open, slowly lower the sampling tube to the bottom of thecream pail. Afterallowing a moment for the cream to rise in the tube to the same height as in the pail, close the cock and raise the sampler carefully out of the cream. As long as the cock is closed, the cream in the tube will not flow out, unless the tube is strongly jarred. Allow the cream adhering to the outside of the tube to drain off for a few seconds, then put the lower end into the 1 to 15 oz. wide-mouth glass collecting bottle which hears the patron’s number on its cork, and open the cork. The cream will then flow out of the sampler into the bottle, which is afterwards securely corked and put into the cream gatherer’s case. Immediately weigh the cream in the cream pail to the quarter or half pound, as may _be judged expedient, and record the weight. ‘‘Tf the patron has more than one pailful, repeat with each pailful the operation of sampling and weighing, putting all the samples in one and the same bottle. Weigh all cream collected in one and the same sampling pail and draw a sample from each separate portion weighed.”’ 207. After sampling and weighing each patron’s cream it is poured into the driver’s large can, and the sample bottles are carried in a case to the creamery where the contents of each bottle is poured into the composite sample jar of the particular patron. The samples of cream in the smail bottles, besides furnishing the means - of testing the richness of the cream, give the creamery owner or manager an opportunity to inspect the flavor of each lot of cream, and the condition in which it has been kept by the various patrons. Potassium bi-chro- mate is placed in the composite sample jars, and these are cared for and tested in the same manner as composite samples of milk (192). 208. The collecting bottles should be cleaned with cold, and afterwards with hot water, as soon as they are Testing Oream at Creameries. 173 emptied, and before a film of cream dries on them. When washed and dried, these bottles are placed in the cases, ready for the next collecting trip. There can ‘be no confusion of bottles since the corks and not the bottles are marked with the numbers of the respective patrons. ) : 209. When this system of testing composite sam- ples is adopted, the patrons are paid for the number of pounds of butter fat contained in their cream, in ex- actly the same way as milk is paid for at separator ‘ereameries. It makes no difference how thick or how thin the cream may be, or how much skim milk is left in the cream when brought to the factory. Highty pounds of cream containing 15 per cent. of fat is worth no more or less than 48 pounds of cream testing 25 per cent.; in either case 12 pounds of pure butter fat is delivered. This will make the same amount of butter in either case, viz., toward 14 lbs., and both patrons should therefore receive the same amount of money. There is a small difference in the value of the two lots of cream to the creamery owner or the butter maker, in favor of the richer cream, both because its smaller bulk makes the transportation and handling expenses lighter, and because slightly less butter fat will be lost in the butter milk, a smaller quantity of this being obtained from the richer cream. But it is doubtful if the dif- ferences thus occurring are of sufficient importance to be noticed under ordinary creamery conditions; the example selected presents an extreme case of variation _ in the fat content of cream. A trial of this system at five Connecticut creameries, supplied mostly with Cooley 174 Testing Milk and Its Products. cream, by over 175 patrons, showed that the average composition of the cream from the different patrons varied only from 16.9 to 19.8 per cent. fat. The cream of some patrons on certain days contained only 9.5 per cent. of fat, and other patrons at times had as high a test as 30 per cent., but these great differences largely disappeared when the average quality of the cream delivered during a period of time, like a month or more, was considered. | ; 210. Smaller differences in the composition of cream will, however, always occur, even if the same system of setting the milk, like the cold deep-setting process, is used and the water is kept at the same temperature at all times. This is due to differences in the composition of the milk and its creamiug quality; whether largely from fresh cows or from late milkers; whether kept standing for a time before being set or submerged in the creamer immediately after milking and straining; diameter of creaming cans, etc. Bartlett states' that the percentage of fat in the cream from the same cows may be increased ten per cent. or more by keeping the water at 70° instead of at 40° F. The higher temperature will give the richer cream, but the separation will not be so complete, since a richer skim milk is obtained from the milk set at this temperature. Separator cream is not materially influenced by the conditions mentioned, as the separator can be regulated to deliver cream of nearly uniform richness from all kinds of sweet milk. 211. At creameries where both milk and cream are de- livered, somewhat of an injustice is done to patrons de- 1 Maine experiment station, bulletin No. 3 (S.8.). Testing Cream at Creameries. 175 livering cream, by paying for the amounts of butter fat furnished by the different patrons. By multiplying the cream fat by 1.03 (or by 1.044"), the value of his pro- ducts to the creamery is taken into proper account, and _ justice is done to all parties concerned’ (238). 1See Spillman, Dairy and Creamery, Chicago, April 1, 1899. 2 This subject is discussed in detail in the 17th annual report of Wis. experiment station, pp. 40-92; see also the 20th report of this Station, pp. 130-31. CHAPTER XII. CALCULATION OF BUTTER AND CHEESE YIELD. A.—CALCULATION OF YIELD OF BUTTER. 212. Butter-fat test and yield of butter. The Babcock test shows the amount of pure butter fat contained in a sample of milk or other dairy products. The butter ob- tained by churning cream or milk contains, in addition to pure butter fat, a certain amount of water, salt-and eurd. While an accurate milk test gives the total quan- tity of butter fat found in the sample of milk or cream tested, the churn cannot be depended upon either to leave the same amount of butter fat in the butter milk or to include the same amount of water, salt and curd in the butter at each churning. If a quantity of milk, say 3,000 fbs., be dicnoreee mixed in a vat, and then divided into half a dozen equal portions, a Babcock test of the different lots will show the same percentage of butter fat in each portion. If, on the other hand, each of these lots be skimmed, and the cream ripened in different vats and churned separately, the same weight of butter from each lot of 500 tbs. of milk will not be obtained, even by the most expert but- ter maker, or if all the operations of skimming, cream ripening, churning, salting and butter-working were made as nearly uniform as possible. Careful operators Calculation of Butter- and Cheese Yield. 177 can handle the milk and cream so that very nearly the same proportion of the fat contained in the milk is re- covered in the butter in different churnings, but since the water and salt in butter are held mechanically and are not chemically combined with it, the amounts retained by the butter are quite variable in different churnings, especially since the laws governing the retention of water in butter are but imperfectly understood. 213. Variations in the composition of butter. As an illustration of the variability of butter in its composition, the analyses made in the breed tests at the World’s Fair in 1893 may here be cited; the butter was in all cases made by as nearly identical methods and under as uni- form conditions as could possibly be obtained by the skilled operators having this work in charge: the aver- age composition of 350 samples of this butter, with upper and lower limits, was as shown in the following table: Composition of samples of butter, World’s Fair, 1898. a3] ae Sum of alt and es e’rd, Water. Fat. Curd. ash. salt = s Per cent. | Per cent. | Per cent. | Per cent. | Per cent. Average of 350 analyses ............ 11.57 |. 81.70 95 2.78 15,30 Lower and Eber limits . ...-| 8.63-15 00 | 76.53-88.26 .00-2,14 TOUS YO8 "ete aeacoceee. Analyses of fifty samples of creamery butter taken in 1896, from the tubs ready for market at as many Wiscon- sin creameries, showed that no two of them were ex- actly alike in composition, but varied within the limits given below: * 1 Wisconsin experiment station, bull. 56. 12 178 Testing Milk and Its Products. Summary of analyses of Wisconsin creamery butter. ees A ou a Salt and |water, curd, Water. Fat. Curd. ash salt and ash. . Per cent. | Per cent. | Per cent. | Per cent. Per cent Eighesti 2c: 17.03 87.50 2.45 4.73 22.95 ow CStssix- eee 9.18 77.07 36 1.30 12.50 MAVICNAE Cesc ccc.ences: 12.77 83.08 1.28 2.87 16.92 The preceding analyses show the composition of butter 3 made at one place where every possible effort was taken to produce a uniform product, and of butter made at fifty different creameries, where there was more or less variation in the different operations of manufacture and in the appliances and machinery used. The majority of the samples of butter analyzed, in either case, were very near the average composition given, but since there are such wide variations in the composition of the butter made by the uniform methods adopted in the World’s Fair breed tests, butter of a more uniform composition cannot be expected from the thousands of different cream- eries and private dairies which supply the general market with butter. The analyses of the fifty samples of creamery butter, given above, show that the content of the butter fat varied from 77 to over 87.5 per cent., and according to the average of the analyses, 83 pounds of butter fat was contained in, or made, 100 tbs. of butter. There was, therefore, in this case produced 20.5 per cent. more butter than there was butter fat, since 83; .100.:: 100: x; therefore 100 x 100 __ X=— gg = 120.5. Calculation of Butter- and Cheese Yield. 179 214. ‘Overrun’? of churn over test. The yield of butter is not, however, as a rule compared with the amount of butter fat contained in the butter, but with the total butter fat of the whole milk from which it was made. This ‘‘increase of the churn over the test’’ is what is generally called overrun in creameries. The overrun obtained in different creameries, or even in the same creameries at different times, will be found to vary considerably. When the milk is accurately tested and the butter well worked, this overrun will vary from 10 to 16 per cent. ; that is, if a quantity of milk contains exactly 100 ths. of butter fat, as found by the Babcock test or any other accurate method of milk test- ing, from 110 to 116 tbs. of butter ready for market may be made from it. 215. Factors influencing the overrun. Even under the very best of care and attention to details, variations will occur in the speed of the separator, in the conduct of the ripening and churning processes, and in the condition of the butter when the churn is stopped; hence absolutely uniform losses of fat in skim milk and butter milk, or the same water- and salt contents of the butter, cannot be expected. : : | The overrun is influenced by two factors: the losses of butter fat sustained in separating the milk and churning the cream, and the gain due to the admixture of water, salt, ete., in the manufacture of butter. Considering first the losses of fat in skim milk and butter milk. the separator will usually, when run at normal speed and capacity, leave the same per cent. of fat in skim milk, — whether rich or poor milk is skimmed. An exception 180 Testing Milk and Its Products. to this may be found in separating rich milk having large fat globules or milk from fresh milkers, in either of which cases the large size of the fat globules occasions a more complete separation of fat by the centrifugal force. But generally speaking, the statement holds good that the total loss of fat in separator skim milk is a factor of the quantity of milk run through the separator, rather than of its quality. It follows from this, however, that the relative losses of fat in skim milk will vary to some extent according to the quality of the milk separated. Selecting two extremes in the quality of milk, 2.5 and 6.0 per cent. of fat, there will be found, say .2 per cent. of fat in the skim milk from either lot, provided the sep- arator is not unduly crowded, and the separation is con- ducted under normal conditions in each case. But .2 per cent. fat makes 8 per cent. of the total fat in the poor milk ( io milk. It takes 4000 ibs. of the 2.5 per cent. milk to furnish 100 ibs. of fat, and only 1666 tbs. of the 6 per cent. milk; in skimming the poor milk, a loss of .2 per cent. of fat is sustained in the skim milk from 4000 Ibs. of milk, while in the rich milk a similar loss is sustained in the skim milk from only 1666 ths. of milk. The example gives an extreme case, and one not likely to be met with in practice. The range in the richness of the milk delivered by different patrons at the factory is usually within one-half or one per cent of fat. In such cases the proportion of fat lostin skimming does not vary much, e. g., in case of milk containing 3.5 and 4.0 per cent. of fat, and variations in the overrun occurring when the proper care in skimming, ripening and churning is —8), and only 3 per cent. of that in the rich Calculation of Butter- and Cheese Yield. 181 taken, are due, therefore, primarily to differences in the water- and salt contents of the butter made (205). 216. The losses from very poor, very rich and average milk, as received at creameries and cheese factories, can be traced from the following statement; this gives the quantities of fat lost in handling milk of four grades, viz: 2.5, 3.5, 4.0 and 6.0 per cent., in case of each grade calculated to a standard of 100 tbs. of fat in the milk. To supply 100 ths. of fat would require the following amounts of the different grades of milk: 4000 tbs. of milk testing 2.5 per cent. will contain 100 tbs. of fat. 9857 as a sc 3.5 ce 4c a 100 (¢ (6 9500 sé a tt 4.0 ce ce dé 100 a ¢e 1666 a5 a te 6.0 be ce 5 100 a ce Assuming that the skim milk contains .2 per cent. of fat and makes up 85 per cent. of the whole milk, that the butter milk test .3 per cent., and forms 10 per cent. of the whole milk, the butter-fat record of the quantities of different grades of milk containing 100 Ibs. of fat will appear as follows: Fat available for butter in different grades of milk. Fat ‘ Whole ‘ ‘ Butter Total | availa Grade of milk. milk Skim milk. milk. loss. | ble for- butter. 2.5 per cent........... 4000 tb. 3400 tb. 400 tb. Ibs. |Per cent. 2.5 per ct. .2 per ct. .3 per ct. anv evotandeccees 100 ib. 6.8 tb. 1.2 tb. 8.0 92.0 3.5 per cent......... eal Ro MOOT. UO 2429 tb. 286 tb. 3.5 per ct. .2 per ct. .3 per ct. 1 ER Raaieee ree 100 ib. 4.9 tb. 9 ib. 5.8 94.2 4.0 per cent........... 2500 ib. 2125 ib. 250 ib. 4 per ct. .2 per ct. .3 per ct. Ha brseeck Soecdets 100 ib. 4.3 ib. 7 ib 5.0 93.0 6.0 per cent........... 166624 tb. 1417 ib. 167 tb. 6 per ct. .2 per ct. .3 per ct. PA Geccosesennnes: 100 ib. 2.8 ib, 5 ib. 3.3 96.7 182 Testing Milk and Its Products. The table shows that with 2.5 per cent.-milk, there is a loss of 6.8 fbs. of fat in the skim milk and 1.2 ibs. of fat in the butter milk for every 100 Ibs. of fat in the whole milk, ora total loss of 8.0 fbs. from these sources. In case of 6 per cent. milk these losses are 2.8 tbs. and .5 Ibs. for skim milk and butter milk, respectively; a total loss of 3.3 Ibs., or 4.7 tbs. less than the losses with the very poor milk. This difference in the losses shrinks to only .8 pound of fat in case of 3.5 and 4.0 per ct. -milk, when a quantity containing 100 tbs. of fat is handled in both cases. The overrun from each of the four grades of milk can be calculated for butter containing a certain per cent. of fat. Assuming the fat content of butter to be 83 per cent., on the average (213), the quantity of butter obtained from the 100 tbs. of fat, or rather from the portion thereof which is available for butter, in each case will be as follows: Butter cont. Availablefat. 83 pr. ct. fat. 100 tbs. of fat from 4000 tbs. of 2.5 pr. et. milk, 92.0 tbs.= 110.8 ibs. LOO et MOOT Pega hae) we 6 O42. ieee LOOK SN ee phamara 5) i] Roman bye S| ates ‘90.0. *. =a 1 Co Mapa gt 1666 GO) cet! ats, 96.7. 5 == Ge res The overrun in each ease will be: For 2.5 per cent. milk=110.8—100=10.8 per cent. pee iene) * iM = 113.5—100=48.5 “ eS) Se) ~ ¢ ==114 5-100 149°" G20 ces “ =1165—100=16.5 Z, All butter makers should obtain more butter from a certain quantity of milk than the Babcock test shows it to contain butter fat, but it is impossible to know exactly, except by chemical analysis, how much butter fat is lost Calculation of Butter- and Cheese Yield. 183 in the skim milk and the butter milk, and how much water, salt and curd the butter will contain. | 217. Calculation of overrun. The overrunis calculated by subtracting the amount of butter fat contained in a certain quantity of milk, from the amount of butter made from it, and finding the per cent. which this difference is of the amount of butter fat in the milk. Example: 8000 tbs. of milk is received at the creamery ona certain day; the average test of the milk is3.8 per cent.; 340 ibs. of butter was made from this milk, as shown by the weights of the packed tubs. By asimple multiplication we find that the milk contained 8000 .038=304 tbs. of butter fat. The difference between the weight of butter and butter fat is, therefore, 36 tbs.; -_ 36 X 100 36 is 301 the milk; that is, the overrun for the day considered was 11.8 per cent. =11.8 per cent. of the quantity of butter fat in The formula for the overrun is as follows: x= ie 100 b and f designating the quantities of butter and butter fat, respectively, made from or contained in a certain quantity of milk. In the preceding example, the calcu- (340—804) x 100 304 In gathered-cream factories the overrun will naturally come higher than in separator creameries, since no loss of butter fat in the skim milk occurs in the former. The overrun based on the amount of fat in the cream will not under average creamery conditions be likely to vary much from 18 per cent. 218. Conversion factor for butter fat. A committee of _ the Association of American Agricultural Colleges and Experiment Stations at the ninth annual convention of lation would be as follows: =11.8 per cent. 184 Testing Milk and Its Products. the Association reported that ‘‘ in the ninety-day Colum- bian Dairy Test, 96.67 per cent. of the fat in the whole milk was recovered in the butter. This butter on the average contained 82.37 per cent. butter fat; in other words, 117.3 pounds of butter were made from each 100 pounds of butter fat in the whole milk.* The exact con- version factor would be 1.173. As this is an awkward number to use, and as ii is so nearly thesame . . . it has seemed best to recommend that the latter be used as the conversion factor.’’ A resolution was adopied by this association recom- mending that the approximate equivalent of butter be computed by multiplying the amount of butter fat by 14. These figures are the result of more than ordinary care in skimming, churning and testing, and probably repre- sent the minimum losses of fat in the manufacturing pro- cesses. The increase of churn over test represented by one-sixth, or 16 per cent., may therefore be taken as a maximum ‘‘overrun’’ under ordinary factory conditions. Butter makers who report overruns of 16-20 per cent. do not show their expertness in butter making by such high figures, but their lack of accuracy in testing, or careless- ness in working the butter; a large overrun may be ob- tained both by reading the test too low, and by leaving an excess of water in the butter, through insufficient working or other causes. 219. Butter yield from milk of different richness. a. Use of butter chart. The approximate yield of butter from milk of different richness is shown in table XI in the 1 When 82.37 ibs. of butter fat will make 100 ibs. of butter, how much butter will 96.67 ibs. of butter fat make? 82.37 : 96.67: :100: x, x=117.3. wa Culculation of Butter- and Cheese Yield. 185 Appendix. This table is founded on ordinary creamery experience and will be found to come near to actual every-day conditions of creameries where modern meth- ods are followed in the handling of the milk and its pro- ducts. The table has been prepared in the following manner: It is assumed that the average loss of fat in the skim milk is .20 per cent., and that 85 tbs. of skim milk is obtained from each 100 lbs. of whole milk; to this loss of fat is added that from the butter milk; about 10 lbs. of butter milk is obtained per 100 tbs. of whole milk, testing on the average .30 per cent. If f designate the fat in 100 tbs. of milk, then the fat recov- ered in the butter from 100 tbs. of milk will be f— (7a X -20-+- a0, X.30) =f—.20 There is, on the other hand, an increase in weigth in the butter made, owing to the admixture of non-fatty components therein, principally water and salt. Butter packed and ready for the market will contain in the neighborhood of 84 per cent. of fat (213), so that the fat recovered in the butter must be in- creased by 19°=1.19. If B therefore designate the yield of but- ter from 100 ibs. of milk, the following formula will express the relation between yield and fat content, provided there are no other factors entering into the problem, viz.: B=(f—.20) 1.19 Certain mechanical losses are, however, unavoidable in the creamery, as in all other factory operations, viz., milk and cream remaining in vats and separators, butter sticking to the walls of the churn, etc. These losses have been found to aver- age about 8 per cent. of the total fat inthe milk handled, under normal conditions and under good management (218); we therefore deduct this amount from the preceding value for B, and have: ee B=(f—.20) 1.16 220. Table XI in the Appendix, founded on this form- ula, may be used to determine the number of pounds of 186, Testing Milk and Its Products. butter which milk containing 3 to 5.3 per cent. fat will be likely to make. It presupposes good and careful work at the separator, churn and butter worker, and under such conditions will generally show yields of butter varying but little from those actually obtained. It may be conveniently used by the butter maker or the manager to check the work in the creamery; the average test of the milk received during a certain period is found by dividing the total butter fat received, by the total milk, and multiplying the quotient by 100; the amount of butter which the total milk of this average fat content will make, according to the table, is then compared with the actual churn yield. Example: A creamery receives 200,000 tbs. of milk during a month; the milk of each patron is tested and the fat con- tained therein calculated. The sum of these amounts of fat may be 7583 ibs.; the average test of the milk is then 3.79 per cent. According to table XI, 10,000 tbs. of milk, testing 3.8, will make 418 ibs. of butter, and 200,000 tbs., therefore, 8360 tbs. of butter. The total quantity of butter made during the month will not vary appreciably from this figure if the work in the creamery has been properly done. 221. b. Use of overrun table. The table referred to above gives a definite calculated butter yield for each grade of milk, according to average creamery conditions. As it may be found that this table will give uniformly either too low or too high results, table XII in the Appendia is included, by means of which the butter yield cor- responding to overruns from 10-20 per cent. may be ascertained in a similar way as above described. The total yield of butter is divided by the total num- ber of pounds of fat delivered; the quotient will give the Calculation of Butter- and Cheese Yield. 187 amount of butter made from one pound of fat, and this - figure multiplied by the fat delivered by each patron shows the pounds of butter to be credited to each patron. To use the table, find in the upper horizontal line the number corresponding most nearly to the number of pounds of butter from one pound of fat. The vertical column in which this falls gives the pounds of butter from 100 fbs. of milk containing the per cents. of fat given in the outside columns (Babeock’). B.—CALCULATION UF YIELD OF CHEESE. 222. a. From fat. ‘The approximate yield of green Cheddar cheese from 100 ibs. of milk may be found by multiplying the per cent. of fat in the milk by 2.7; if f designate the per cent. of fat in the milk, the formula will, therefore, be: Yield eenee eo ET a Dane eee ee = sels) The factor 2.7 will only hold good as the average of a large number of cases. In extensive investigations dur- ing three consecutive years, Van Slyke? found that the number of pounds of green cheese obtained for each pound of fat in the milk varied from 2.51 to 3.06, the average figures for the three years 189294, inel., being 2.73, 2.71, and 2.72 tbs. respectively. The richer kinds of milk will produce cheese richer in fat, and will yield a relatively larger quantity of cheese, pound for pound, than poor milk, for the reason that an in- crease in the fat content of milk is accompanied by an 1 Woll, Handbook for Farmers and Dairymen, p. 307. 2N, Y. experiment station (Geneva), bulletins No. 65 and 82. 188 Testing Milk and Its Products. increase in the other cheese-producing solids of the milk.* The preceding formula would not, therefore, be correct for small lots of either rich or poor milk, but only for milk of average composition, and for large quantities of normal factory milk. For cured cheese the factor will be somewhat lower, viz., about 2.6, on the average. 223. b. From solids not fat and fat. Ifthe percentages of solids not fat and of fat in the milk are known, the following formula by Babcock will give close results: Yield of green cheese=1.58(2+.91f) . . (I) s being the per cent. of solids not fat in the milk, and f the per cent. of fat.” The solids not fat can be readily ascertained from the lactometer reading and the per cent. of fat, as shown on p. 100, by means of table VI in the Appendiz. Table XIII in the Appendix gives the yield of cheese from 100 tbs. of milk containing from 2.5 to 6.0 per cent. fat, the lactometer readings of which range between 26 and 36. By means of this table cheese makers can cal- culate very closely the yields of cheese which certain quantities of milk will make; as it takes into considera- tion the non-fatty solids as well as the fat of the milk, the results obtained by the use of this formula will be more correct than those found by means of formula (1). The uncertain element in the formula lies in the factor 1 Investigation as to the relation between the quality of the milk and the yieid of cheese have been conducted by a number of experiment sta- tions; the following references give the main contributions published on this point; N. Y. (Geneva) exp. station, reports 10-13, incl.; Wis. exp. sta., reports 1l and 12; Ont. Agr. College, reports 189496, incl; Minn. exp. sta., b. 19, reports 1892-’94, incl.; lowa exp. sta., bull. 21; Hoards Dairyman, 1892, p. 2400. Z 2 For derivation of this formula, see Wisconsin experiment. station, twelfth report, p. 105. Calculation of Butter- and Cheese Yield. 189 1.58, which, as shown above, is based on an average water content of 37 per cent. in the green cheese. This may, however, be changed to suit any particular case,.e. g., 35 per cent (4,°°—1.54), 40 per cent. (1,°°=1.67), ete. The average percentages of water in green cheese found by Van Slyke in his investigations referred to above, were for the years 189294, respectively, 36.41, 37.05 and 36.70 per cent. 224. c. From casein and fat. If the percentages of casein and fat in the milk are known, the yield of cheese may be calculated by the following formula, also pre- pared by Dr. Babcock: Yield of cheese=1.1f+2.5 casein . . . (III). This formula will give fairly correct results, but no more so than formula (II); it is wholly empirical. CHAPTER XIII. — _ CALCULATING DIVIDENDS. AG —CALCULATING DIVIDENDS AT CREAMERIES. 225. The simplest method of calculating dividends at creameries is to find the number of pounds of butter fat delivered to the creamery by each patron for a certain length of time, and then multiply this number by the price per pound of fat. Farmers are usually paid once a month for their milk at the factory. Each lot of milk is weighed when delivered at the creamery, and a small quantity thereof is saved for the composite sample, as previously explained under Composite tests (176). Some creameries test these samples at the end of each week, and others after collecting them for ten days or two weeks. If the four weekly composite samples of a patron’s milk tested 3.8, 4.0, 3.9, 4.1 per cent., these four tests are added together, and the sum divided by 4; the result, 3.95 per cent., is used as the average test of this milk. By multiplying the total number of pounds of milk delivered by this patron, by his average test, the total weight in pounds of butter fat delivered to the fac- tory during the month is obtained. This weight of fat is then multiplied by the price to be paid by the creamery per pound of butter fat; the product shows the amount of money due this patron for the milk delivered during the time samples were taken. 226. Price per pound of butter fat. The method of ob- taining the price to be paid for one pound of butter fat Calculating Dividends. 191 | varies somewhat in different creameries, on account of the different ways of paying for the cost of manufacturing the butter. The method to be followed is generally deter- mined by agreement between the manufacturer and the milk producers, in case of proprietary creameries, or be- tween the shareholders, in co-operative creameries. The following methods of paying for the cost of manufacture are at the present time met with in American creameries. 227. I. Proprietary creameries. First. — When the creamery is owned by some one person or company, the owner or owners agree to make the butter for about 3 cents a pound; the difference between the total receipts of the factory and the amount due the owner is then divided between the different patrons, according to the amount of butter fat contained in the milk which they delivered. In the majority of cases, the price charged for making butter is now 3 cents a pound; 2? and 24 cents are some- times charged. The larger the amount of milk received at a factory, the lower will naturally be the cost of man- ufacturing the butter.’ Second.—The proprietor of the creamery sometimes agrees to pay a certain price for 100 tbs. of milk deliv- ered, according to its fat content, the price of milk con- taining 4 per cent. of butter fat being the standard. This price may change during the different seasons of the year by mutual agreement. Third.—A creamery owner may offer to pay 1 to 2 cents, usually 14 cents below the average market price of butter, for each pound of butter fat received in the milk. 228. II. Co-operative creameries. In this case, where the creamery is owned by the patrons, one of the stock- 1 Wisconsin experiment station, bull. 56, p. 26. 192 Testing Milk and Its Products. holders who is elected secretary attends to the details of running the factory and selling the product. His ac- counts show the amount of money received each: month for the butter and other products sold, and the expenses of running the factory during this time. The expenses are subtracted from the receipts, and the balance is divided among the patrons, each one receiving his pro- portionate share according to the amounts of butter fat delivered in each case (as shown by the total weight and the average test of milk delivered during this time). In nearly all cases, the farmers receive about eighty pounds of skim milk for each hundred pounds of whole milk they deliver to the factory, in addition to the amount received for the milk, calculated according to one or the other of the preceding methods. 229. Iflustrations of calculations of dividends. In order to illustrate the details of calculating dividends, or the amount to be paid each patron for the milk supplied each month, when payments are made by each of the four systems given, it will be assumed that a creamery receives 5000 pounds of milk daily for thirty days, and makes 6650 tbs. of butter from the 150,000 ibs. of milk received during this time. The average test of this milk may be found by multiplying the total weight of milk delivered by each patron by his average test, and divid- ing the sum of these products by the total weight of milk received at the creamery (in the example given, by 150,- 000), the quotient being multiplied by 100. Such caleu- lations may show that, e. g., 5700 tbs. of butter fat have been received in all in the milk delivered by the differ- ent patrons; this multiplied by 100 and divided by Calculating Dividends. 193 150,000 gives 3.8 as the average test, or the average amount of butter fat in each 100 tbs. of milk received during the month. So far the method of calculation is common for all dif- ferent systems of payment given above; the manner of procedure now differs according to the agreement made between owner and patrons, or between the shareholders, . in case of co-operative creameries. 230. I. First.—If the net returns for the 6650 Ibs. of butter sold during the month were $1197, and the cream- ery is to receive 4 cents per pound of butter as the cost of manufacture, etc., the amount due the creamery is 6650 x .04=$266, and the patrons would receive $1197— $266=$931. This sum, $931, is to be paid tothe patrons for the 5700 tbs. of butter fat, which, as shown above, was the weight of fat contained in the 150,000 tbs. of milk delivered during the month. The price of one pound of butter fat is then easily found: $931+5700= 164 cents. This price is paid to all patrons for each pound of butter fat delivered in their milk during the month. The monthly milk record of three patrons may, e. g., be given in the following table: First week||Second week||Third week Fourth week 2 4s Total|| ~ & Patrons See Ra ao eS Milk|| $9 Milk | Test || Milk | Test ||Milk | Test || Milk| Test || tbs. || $5 Tbs. |pr.ct.'| tbs. |perct.!| tbs. |prct.|! tbs. |perct. ; = | # INO: | 3000) | 3.6 38000 | 3.5 3600 | 3.65 3450 | 3.45 |/18,550|| 3 a2, 700 | 3.8 665 | 3.8 720 | 3.6 750 | 3.7 2,825|| 3.73 “ 3.....| 2480 | 4.2 || 2000] 38.8 || 1850 | 4.0 1500 | 3.6 || 7,830 Multiplying each patron’s total milk by his average test gives the number of pounds of butter fat in his milk, 13 194 Testing Milk and Its Products. and this figure multiplied by .16} shows the money due for his milk, as given below: Patron. Fetaly an Average test Butter fat,| Price of fat | Amounts per cent. tbs. per ib., cents. due. INGOs be titisn: 13,550 3.00 481.0 1614 $78. 56 INOge2 es ees 2,825 3.7 104.5 1614 17.06 INO: (BRAY okeces 7,830 3.9 305. 4 16% 48.96 231. Second.—When the proprietor of a creamery | agrees to pay a certain price for 100 tbs. of 4 per cent. milk, the receipts for butter sold and the price per pound ~ of butter do not enter into the calculation of the amount due each patron for his milk; but the weight and the test of each patron’s milk are just as important as before. If it is agreed to pay 66 cents per 100 Ibs. of 4 per cent. - milk (i. e., milk containing 4 per cent. of butter fat), the price of one pound of butter fat will be 66+4=164 cents, and the amount due each patron is found by multi- plying the total weight of butter fat in his milk by this price. To facilitate this calculation, so-called Relative- Value Tables have been constructed, the use of which is . explained below (237). 232. Third.—Ifacreamery agrees to pay for butter fat, say 14 cents per pound below the average market price of butter each month, the price of one pound of butter fat is found by averaging the market quotations and sub- tracting 14 cents therefrom. If the four weekly market prices were 173, 17, 165 and 19 cents, the average of these would be 174 cents, and this less 14 gives 16 cents as the price per seta of fat to be nel to the patrons; this price is then used in calculating the dividends as in case of first method (230). Calculating Dividends. 195 Patron. Total aut Average test|Butter fat,) Price of fat, | Amounts per cent. Ss. per lb. , cents. due. INP LESS Rast e ~ 13,550 3.55 481.0 16 $76. 96 UNO} Dice gcse ss<2 2 "325 3.7 104.5 16 16.72 Norstar... ite: "830 3.9 305. 4 16 48. 86 233. II. If the creamery is owned by the farmers, the running expenses for a month are subtracted from the gross returns received for the butter, and the price to be paid per pound of butter fat is found by dividing the amount left, by the total number of pounds of butter fat delivered during the month. This price is used for pay- ing each patron for his milk according to the amount of fat contained therein, as already explained under Pro- prietary Creameries (230). The monthly running expenses of a co-operative cream- ery generally include such items as the wages of the butter maker (and manager or secretary, if these officers are salaried ), labor (hauling, helper, ete. ), cost of butter packages, coal or wood, salt and other supplies, freight and commission on the butter sold, repairs and insurance on buildings, etc. A certain amount is also paid into a sinking fund (say 5 cents per 100 tbs. of milk), which represents the depreciation of the property, wear and tear of building and machinery, bad debts, ete. These items are added together, and their sum subtracted from the gross receipts for the butter sold during the month. 234. Assuming the receipts for the butter during the month to be $1197, and the running expenses of the fac- tory $285, the amount to be divided among the patrons is $912; the quantity of butter fat received was 5700 ibs., 196 Testing Milk and Its Products. and the price per pound of butter fat will therefore be 16 cents. The account will then stand as given in (232). 235. Other systems of payment. Besides these four systems of payment, there are various other agreements made between manufacturer and producer, but with them all the one important computation is the price to be paid per pound of butter fat; this forms the basis of calculating the factory dividends, when milk is paid for by the Babcock test. 236. Paying for butter delivered. In some instances patrons desire to receive pay for the quantity of butter which the milk delivered by them will make. This can be ascertained quite accurately from the total receipts — and the total weights of both butter fat and butter. The total money to be paid for butter (the net receipts) are divided by the number of pounds of butter sold, to get the price to be paid per pound of butter; the total yield of butter divided by the total amount of butter fat de- livered in the milk, gives the amount of butter corre- sponding to one pound of butter fat, and the pounds of fat delivered by each patron is then multiplied by this figure. This method requires more figuring than those given in the preceding, and the dividends are no more accurate, in fact less so, than when calculations are based on the price per pound of fat. 237. Relative value tables. These tables give many of the multiplications used in computing the amount due for various weights of milk testing from 3 to 6 per cent. of fat. They can be easily constructed by any one as soon as the price of one pound of fat is determined in each case. If the price to be paid per pound of fat ig ; Calculating Dividends. 197 say 15 cents, the value of each 100 fbs. of milk of differ- ent quality is found by multiplying its test by 15. If the average tests of the different patrons’ milk vary from 3 to 5 per cent., the relative-value table would be as follows: 3.0 15=45e. per 100 lbs. 3.6 15=54e. per 100 Ibs. 3.1 15=46.5e. As 3.7 X 15=55.5e. KS 3.2 15=48¢ os 3.8 X 15=67e. ri 3.3 X 15=49.5e. = 3.9 15=58.5e. a 3.4xX15=5le. . i 4.0 15=60e. 3k 3.5 X 15=62.5¢. 7 ete. By continuing this multiplication, or adding the mul- tiplier each time for each tenth of a per cent. up to 5 per cent. of fat, a table is made that can be used for calcu- lating the amount due per 100 ibs. of milk, at this price per pound, and the weight of milk delivered by each patron is multipHed by the price per 100 ibs. of milk shown in the table opposite the figure representing his test. Example: alkali = —}: a ce. = acid-solution; the ammonia dis- tilled over Hehe ae neutralized 5.00—.51=4.49 ec. acid. By blank trials it was found that the reagents used furnished an equivalent of .02 cc. acid in the distillate; this quantity sub- tracted from the acid-equivalent of the nitrogen of the milk leaves 4.47 ce. 1 ce. semi-normal HCl-solution corresponds to ae % : 4 N 7 milligrams or .007 grams of nitrogen; 4.47cc. = HCl therefore 1 Sutton, Volumetric Analysis, 4th edition, p. 31. 2 The factor 6.30 or 6.37 is more correct for the albuminvoids of milk, bak has not yet been generally adopted (p. 15, foot note). Ohemical Analysis of Milk and Its Products. 211 represents .03129 gram of nitrogen. This quantity of nitrogen was obtained from the 5.1465 grams of milk measyred out; the .03129 100 __ aes Sc =.608 per cent of nitrogen, and .0608 x 6.25=3.80 per cent. of casein and albumen. milk therefore contains 254. Casein and albumen may be determined separately by Van Slyke’s method;' 10 grams of milk are weighed out and diluted with about 90 cc. of water at 40°-42° C. 1.5 ec. of a 10 per cent. acetic-acid solution are then added; the mixture is well stirred with a glass rod and the precipitate allowed to settle for 3-5 minutes. The whey is decanted through a filter and the precipitate washed two or three times with cold water. The nitro- gen is determined in the filter paper and its contents by the Kjeldahl method; blank determinations with the regular quantities of chemicals and the filter paper used are made, and the nitrogen found therein deducted. The per cent. of nitrogen obtained multiplied by 6.25 gives the per cent. of casein in the milk. 255. Albumen is determined in the filtrate from the casein-precipitate; the filtrate is placed on a water bath and heated to boiling temperature of water for ten to fifteen minutes. The washed precipitate is then treated by the Kjeldahl method for the determination of nitro- gen; the amount of nitrogen multiplied by 6.25 gives the amount of albumenin the milk. The difference between the total nitrogenous components found by the Kjeldahl method, and the sum of the casein and the albumen, as given above, is due to the presence in milk of a third class of nitrogen compounds (18). 1 Bulletin No. 46, p. 189, Chemical Division, U.S. Dept. of Agriculture. 212 - ‘Testing Milk and Its Products. 256. e. Milk sugar is generally determined by differ- ence, the sum of fat, casein and albumen (total N <6.25), and ash, being subtracted from the total solids. It may be determined directly by means of a polariscope, or gravimetrically by Fehling’s solution; only the former method, as worked out by Wiley,' will be given here. The specific gravity of the milk is accurately deter- mined, and the following quantities of milk are measured : out by means of a 100 ce. pipette graduated to .2 cc. (or a 64 cc. pipette made especially for this purpose, with marks on the stem between 63.7 and 64.3 cc. ), according to the specific gravities given: 1.026, 64.3 ec.; 1.028, 64.15 cec.; 1.030, 64.0 ce.; 1.032, 63.9 ce.; 1.034, 63.8 ec. ; 1.036, 63.7 ce. These quantities refer to the Schmidt- Haensch half-shadow polariscopes, standardized for a normal weight of 26.048 grams of sugar. The milk is measured into a small flask graduated at 100 ce. and 102.6 c¢.; 30 ce. of mercuric-iodid solution (prepared from 33.2 grams potassium iodid, 13.5 grams mercuric chlorid, 20 cc. glacial acetic acid and 640 cc. water) are added; the flask is filled to 102.6 ce. mark with distilled water, the contents mixed, filtered through a dry filter, and when the filtrate is perfectly clear, the solution is polarized in a 200 millimeter tube. The reading of the scale divided by 2, shows the per cent. of lactose (milk sugar) in the milk. Take five readings of two different portions of the filtrate, and average the results. 257. f. Ash. About 20 cc. of milk are measured into a flat-bottom porcelain dish and weighed; about one-half of a ce. of 50 per cent.-acetic acid is added, and the milk 1 Agricultural Analysjs, ili, p. 275; Am. Chem, Jour., 6, p. 289 et seq. Chemical Analysis of Milk and Its Products. 213 first dried on water bath and then ignited in a muffle oven at a low red heat. Direct heat should not be applied in determining the ash of milk, since alkali chlorids are likely to be lost at the temperature to which milk solids have to be heated to ignite all organie carbon. Example: Weight of porcelain dish-+milk.....49.0907 grams. ' Weight. of porcelain dish............... 28.3538 grams. Weight of milk.................20.7369 grams. Weight ofdish-+milk, afterignition 28.5037 grams. Write OP IGM Won tu gv uoce kassenteeeens 28.3538 grams. Weight of milk ash........... .1499 gram. Per cent. of ash= aie per cent. The residue from the determination of solids (251) may also be used for the ash determination. 258. Acidity of milk. The acidity of milk is conven- iently determined by ‘means of Farrington’s alkaline tablets (see p. 120), or by one-tenth normal soda solu- tion. In the latter case 20 cc. of milk are measured into a porcelain casserole; a few drops of an alcoholic phe- nolphtalein solution are added, and soda solution is drop- ped in slowly from a burette until the color of the milk remains uniformly pinkish on agitation. 1 cc. of - alkali corresponds to .009 grams lactic acid, or to .045 per cent. when 20 ce. of milk are taken (see p. 112). B. —CREAM, SKIM MILK, BUTTER MILK, WHEY, CoN- DENSED MILK. 259. The analysis of these products is conducted in the same manner as in case of whole milk, and the same constituents are determined, when a complete analysis is wanted. Skim milk, butter milk, and whey generally 214 Testing Milk and Its Products. contain only small quantities of solids, and especially of fat, and it is, therefore, well to weigh out a larger quan- tity than in case of whole milk; if possible, toward 10 grams. The acidity of sour milk and butter milk must. be neutralized with sodium carbonate previous to the dry- ing and extraction, as lactic acid is soluble in ether and would thus tend to increase the ether-extract (fat), if not combined with an alkali previous to the extraction. 260. Specific gravity of butter milk. The specific grav- ity of butter milk (as well as of sour or loppered milk) is determined by Weibull’s method; a known volume of the milk is mixed with a certain amount (say 10 per cent.) of ammonia of a definite specific gravity, and the specific gravity of the liquid determined after thorough mixing and subsequent standing for an hour. If A desig- nate the volume of butter milk taken, B that of ammo- nia, and C that of the mixture; and if furthermoreS de- signate the specific gravity of the butter milk, s, that of the ammonia, and s, that of the mixture, we have ga C82 Bai A Klein’ has modified this method by weighing the liquids, thus securing greater accuracy; 22 to 24 per cent.-ammonia is used, one-tenth as much being taken as the amount of milk weighed out. The results come uni- formly .0005 too high, and this correction should always be made. The following formula will give the specific gravity of the milk, which in case of careful work will be accurate to one-half lactometer degree; if the letters given above designate weights (instead of volumes as_ before) and specific gravities of the liquids, respectively, we have A S B S2 Ss; 1 Milchzeitung, 1896, p. 656; see also De Koningh, Analyst, 1899, p. 142. S= Chemical Analysis of Milk and Its Products. 215 261. Condensed milk. The same methods are, in gen- eral, followed in the analysis of condensed milk as with whole milk. Condensed milk is preferably diluted with five times its weight of water prior to the analysis, both because such a solution can be more easily handled than the undiluted thick condensed milk, and the errors of analysis are thereby reduced, and because the fat is not readily extracted except when the milk has been diluted. The same constituents are determined as in ‘case of whole milk, viz., solids, fat, casein and albumen, . ash, milk sugar, and cane sugar (if any has been added to the milk). The cane sugar is determined by the dif- ference between the solids not fat and the sum of the casein, albumen, milk sugar and ash; if the student has a knowledge of the manipulation of the polariscope and has had experience in gravimetric sugar analysis, the milk sugar is determined gravimetrically, and the cane sugar by the difference between the polariscope reading after inversion and the milk sugar present. The specific gravity of condensed milk may be determined by a method similar to that of McGill.t 50 gr. of the thoroughly mixed sample are weighed into a tared beaker and washed with warm water into a 250 ce. flask, cooled to 60°, filled to the mark and carefully mixed. The specific gravity of this solution (@) is then taken and the original density is calculated by means of the following formula: Concentration. The extent of concentration of con- densed milk may be determined approximately by the formula devised by McGill (loc. cit. ): 1 Bulletin 54, Laboratory Inland Rev. Dept., Ottawa, Canada. Sp. gr. of condensed milk = 216 Testing Milk and Its Products. as Concentration (¢) =—— where a and s designate the solids not fat and specific gravity, respectively, of the condensed milk, and a, and s, the corresponding data for the milk used. Ifs, =1.030 as 9.27 and «a, =9 per cent., then c= —— gives the concentration. C.— BUTTER. 262. Sampling. A four- to eight-ounce sample of but- ter is melted in a tightly-closed pint fruit jar, shaken vigorously and cooled until the butter is hardened, the jar being shaken vigorously at short intervals during the cooling so as to keep the water of the butter evenly dis- tributed in the mass. 263. a. Determination of water. Small pieces of but- ter (about 2 grams in all) are taken from the sample by means of a steel spatula and placed in glass tubes, seven- eighths of an inch in diameter and two and a half inches long, closed at the bottom by a layer. of stringy asbestos, and filled two-thirds full of asbestos prepared as for milk analysis (250). Thetubes are dried at 100° C. in a water oven, until no further loss in weight takes place, and are then cooled and weighed. The loss in weight shows the per cent. of water present. 264. b. Fat. The tubes are placed in Caldwell ex- tractors and extracted for four hours with anhydrous ether; the ether is then distilled off, and the flasks dried in the steam bath and weighed, the increase in weight giving the fat in the samples of butter weighed out. 265. c. Casein. 10 grams of butter are weighed into a small beaker provided with a lip, and treated twice with about 50 ec. of gasoline each time; the solution is Chemical Analysis of Milk and Its Products. 217 filtered off, and the residue transferred to a filter and dried; its nitrogen content is then determined by the Kjeldahl method (253). The nitrogen in the filter and the chemicals used is determined by blank trials and de- ducted. The nitrogen multiplied by 6.25 gives the casein in the butter. 266. d. Ash. (1) 10 grams of butter are weighed into a porcelain dish and treated twice with gasoline, as in the preceding determination; the solution is filtered through an ash-free (quantitative) filter, and the filter when dry is transferred to the dish. The dish is heated in an air- bath for half an hour and then placed in a muffle oven, where the contents are burnt to a light greyish ash; the dish is now cooled in a desiccator and weighed. The difference between this weight and that of the empty dish gives the amount of ash in the butter weighed out. 267. (2) About two grams of butter are weighed intoa Small porcelain dish, half filled with stringy asbestos; the dish is dried for an hour in the water oven, and the fat then set fire to with a match, the asbestos fibre serving aS a wick. When the flame has gone ouf, the dish is placed in a muffle oven, and the residue burnt toa grey- ish ash. After cooling, the dish is weighed, and the per cent. of ash in the butter calculated as under method 1. 268. Complete analysis of butter in the same sample. About 2 grams of the butter are weighed into a platinum gooch half filled with striugy asbestos, and dried in a water oven at 100° C. to constant weight, cooled and weighed. The difference gives water in the sample. The gooch is then treated repeatedly with small portions of gasoline, suction being applied, and again dried in the water‘oven, 218 Testing Milk and Its Products. cooled, and weighed; the fat in the sample is obtained from the difference between this and the preceding weight. The gooch is then carefully heated over direct flame until a light greyish ash is obtained;’this operation is preferably done in a muffle oven to avoid a loss of alkali chlorids. The loss in weight gives the casein in the sample weighed out, and the increase in the weight of the gooch over that of the empty gooch with asbestos, gives the ash (mainly salt) of the butter. The salt in the ash may be dissolved out by hot water, and the chlorin content of the solution determined by means of a stand- ard silver-nitrate solution, using potassium chromate as an indicator. 269. A practical method of estimating the salt content of butter. A method of estimating the salt content of butter, which is applicable also outside of chemical laboratories, has been worked out jointly by Messrs. Alfred Vivian and C. L- Fitch.:. The salt of the butter is dissolved in hot water, and a certain portion of the solution when cool is pipetted off and titrated with a silver-nitrate solution prepared by dissolving one silver-nitrate tablet in 50 cc. water, potassium chromate being used as anindicator. The silver nitrate tablets are sold for 60 cents per 100, which number is sufficient to make 100-150 tests. The method has been advertised in the dairy press under the name of ‘‘ Fitch’s Salt Analysis.’”’ Directions for making tests by this method are furnished with the apparatus when this is bought. The price of a complete outfit is $4.50. DETECTION OF ARTIFICIAL BUTTER. 270. Determination of the specific gravity of the fil- tered butter fat serves as a good preliminary test. A number of practical methods for the detection of artifi- cial butter have been proposed, but they are either worth- 1 Wis. Experiment Station, X VII Report, pp. 98-J01; Hoard’s Dairy- man, February 15, 1901, ‘‘ Uniform Salting of Butter.” Ohemical Analysis of Milk and Its Products. 219 less, in case of samples containing a considerable propor- tion of natural butter, or give satisfactory results only in the hands of experts. The Reichert-Wollny method given in detail below is the standard method the world over, and the results obtained by it are accepted in the courts. 271. Filtering the butter fat. The butter to be exam- ined is placed in a small narrow beaker and kept at 60° C. for about two hours. The clear supernatant fat is then filtered through absorbent cotton into a 200 ce. Erlen- meyer flask, taking care that none of the milky lower portion of the contents of the beaker be poured on the filter. In sampling the butter fat, it is poured back and forth repeatedly from a small warm beaker into the flask, and the quantity wanted is then drawn off with a warm pipette. 272. Specific gravity. This is generally determined at 100° C. The method of procedure is similar to that de- seribed under milk (248). The picnometer (capacity _ about 25 ec.) is filled with dry filtered butter fat, free from air bubbles; the fat is heated for 30 minutes in a beaker, the water in which is kept boiling. On cooling, the weight of picnometer and fat is obtained, and by cal- culation as usual, the specific gravity of the fat. The specific gravity of pure natural butter fat at 100° C. ranges between .8650 and .8685, while artificial butter fat (i. e., fat from other sources than cows’ milk) has a spe- cific gravity at 100° C. of below .8610, and generally about .85. 273. Reichert-Wollny method ( Volatile Acids). 5.75 ce. of fat are measured into a strong 250 ce. weighed saponi- fication flask, by means of a pipette marked to deliver 220 Testing Milk and Its Products. this amount, and the flask when cool is weighed again. 10 ec. of 95 per cent.-alcohol and 2 ce. of a concentrated soda solution (1:1) are then added to the flask which is securely stoppered with a cork stopper tied down with a piece of twine. The flask is heated for an hour on the water bath, being gently rotated from time to time in order to facilitate the saponification. The flask is then uncorked, the alcohol evaporated slowly and the heating continued until the last traces of alcohol are gone. 100 ce. of recently boiled distilled water are now added, and the flask heated on the water bath until the soap formed is completely dissolved. When cooled to about 70° C., 40 ee. of dilute sulfuric acid (25 ec. cone. H,50, per liter) are added to the soap solution to decompose the soap into free fatty acids and glycerol. The flask is restoppered and heated until the insoluble fatty acids separated out form a clear oily layer on the surface of the acid solution in the flask. After cooling to room temperature, a few pieces of pumice stone (prepared by throwing the pieces at a white heat into distilled water and keeping them under water until used) are added, the flask connected with a glass condenser, heated siowly till boiling begins, and the contents then distilled at such a rate as will bring 110 cc. of the distillate over in as nearly thirty minutes as possible. The distillate is mixed thoroughly and filtered through adry filter; 100 ce. of the filtrate are poured into a 250 ce. beaker and titrated with a deci-normal barium-hydrate solution, half a cubie centimeter of pheno]phtalein solu- tion being used as an indicator. Sy “Te oe je Fe. *-w Ae 239° Appendix. of solids not fat (Continued). Per cent. Table VI. ‘WEIIO | |STAN H WOMDR CHNMH MOMNDR SHAHN WoOKWaA oO "4u00 19g FeeeGeeo aa COOD ODED OD HAHAH HHH iisisisgin isisisicoi SS ae COO Ol rere Oo DnODOaA Qeaas SScoon Boned a co) PABRBAD MBMAWRD AQABRR AQRAGDS SoScoSO Soccs gc Ce pe a a a er ee ean SE as ae eres : COMI MB=O1d LANTOS NDONHS Donte Doastos wo Ne COCO HASH OSHHIDINID I9HOSS SEKRRKKR KRGHHODD BSHASE BF BPRRWRWD BRAWM®W HARABD AAGaana aasnas aacadcad « : SHOIDNDS AHOHOS AHoDO CHS AHOOmM MMe aa pe xt Sanna AANNS Hoeooet HASLS ASSVSS SSSSx K 2 DRBARWD BRWPD AWARD AAGaAGD aoanaan caadcac a4 a CMHONH GOHONH SHHMD LPOnMm KOrne Hondo wD 4 | 8 | 28RAR GRSSS SSRER AAAKA ARRRR SSITS | 68 ADWMNHD WDNDBM® AVBAVWD ABAGan aaaaao aaoaacaic S rm 0D 10 P= o> m4 oD 10 P= mo 10 OS Ato OO AH co OO A119 I OD oF 7, a coco S Ferre ONONS GHaaS SSSog Seaan & A WMOWNHDH DHNNHNHN HWHHNHH WHNHDHHD QDaaAaa aasaaac «a < COON CNHSA+H SDHONH DOHONH COHOMD KROwHo oo a A 8 co SH SH HHI9I9Ls INGSOSOS SSCRRK KRRDOOH HBDOdOS BF Ce DWHWHNW DONWNN OOWNH HDWOWHHW HDHHHH HHnKD Ow 2 SMM B BHORD HMA HMMM S Wonk oO AKoODO TA ca 2 Sass ANNANN ott toto bb Ss SSSBE QN 5 DWOHNNOD WOONMH NMKDHO WHE HDH BDHOWHHD HDHonHD oO st Dr BAANH SGHONH DHONH DDONH GOHONH SOMONE a Ra DNHNHRD ARSSS SSaae BAAN ANRHD SSAA F By I~>OErh FE DOOD WWMDHDEHD HDOHDHDH DHOWDHD BDOoHDOD Ow < © NA =H 25 OD rs 0 LO I SD ro 09 10 T= OD rm oO 10 P= oO rm 30 10 P= o> m4 cd 10 hy © NI es oO |. Saar MERE DHDDHH BHSGS SSSGSS BHAA A N eee ee. eee ee - kee I~ ly by ~~ colle oe eke ole.e) 18) (5'e) (6) (eo) F9) (0) RIE QBHONK SCHSANH SGHSNH SHONH SHON © is Bou TiDiID WINSSS SSORRK KRKOOOD DHOSRS = Dt Dll el Da Dd [std to Bd SS TS Dt Sell Del Bd Bad De Ba a a I~ - Ye ere I- ee ee bt SN+5O ONHSDH ONHODO 1D oD S sank o mw Je) | Ress NNANN ood 0000 OD Sat) 1929191919 CHOC S | Oe Sl Sl St Baad iy tk kX Ii~ rPrerehr ry ~~ & bX ree i- be ~eeerere tt ‘BJ JO poate IDOI~NDA OMAAMH NON DA CHNMH NORDOR Oo “‘quoo Jod | CD OD CD CN 9D CN MN OD 0D SH SH SH SH eH PHS ts 1919191919 1919101919 © 240 Testing Milk and Its Products. Directions for Use of Tables VII, VIII, IX, and XI. TABLES Vi, and Vill. Find the test of the milk in table VII or of cream in table VIII; the first or last horizontal row of fig- ures, the amounts of fat in ten thousand, thousands, hundreds, tens, and units of pounds of milk are then given in this verti- cal column. By adding the corresponding figures for any given quantity of milk or of cream, the total quantity of butter fat contained therein is obtained. Example: How many pounds of fat is contained in 8925 Ibs. of milk testing 3.65 per cent.? On p. 242, second column the test 3.65 is found, ana by going downward in this column we have: SOQORD Sia ee Pens weaas 292. Ibs. QO0 MDS 8 care Aeeecoaeseos toeeo OS, OD) Vill Os Bane ee saser CCD nOCCOD -7 Ibs 5 WDS..2.- eeeeeseseeeteeneeeee .2 lbs 8925 lbs. of milk. 825.8 lbs. of fat. 8925 lbs. of milk testing 8.65 per cent., therefore, contains 325.8 Ibs. of butter fat. TABLE IX. The price per pound is given in the outside vertical columns, and the weight of butter fat in the upper and lower horizontal row of figures. The corresponding tens of pounds are found by moving the decimal point one place to the left, the units, by moving it two, and the tenths of a pound, by moving it three places to the left. The use of the table is, otherwise, as explained above. Example: How much money is due for 325.8 lbs. of butter fat at 1544 cents per pound? In the horizontal row of figures beginning with 1544 on p. 247, we find; 30). ¢ SOS stec seeks wcestecteccuseecs $46 .50 90) ves een se setae tee terest 8.10 Dtesl DStyaeescows aerate vee cecass 77 eG Sersasrencesveceventmerans 12 825.8 Ibs. «$50.49 825.8 Ibs. of butter fat at 1544 cents per pound, therefore, is worth $50.49. TABLE XI. Find the test of milk in the upper or lower hori- zontal row of figures. The amounts of butter likely to be made from ten thousand, thousands, hundreds, tens, and units of pounds of milk are then given in this vertical column. The use of the table is, otherwise, as explained above in case of table VIT. Example: How much butter will 5845 lbs. of milk testing 3.8 per cent. oe apt iso eee under good creamery conditions? In the column headed 8, we find: BOOO MD See a sesescecassnesncsbeser= 209.0 lbs SOOM OS sececerese ce esansien seer 33.4 lbs CADW o ye Sasa acooasco occa. aot 1.7 lbs Del Siicest.cecscescetostcencrse .2 lbs 5845 lbs. 244.3 Ibs. 5845 lbs. of milk testing 3.8 per cent. of fat will make about 244.3 lbs. a: butter, under conditions similar to those explained on pp. 184-188. Appendix. 241 Table Vil. Pouads of fat in 1 to 10,000 Ibs. of milk, testing 3.0 4 to 5.35 percent. (Sce directions for use, p. 240. ) # |I3.0013.05)3. 10/3. 15/3. 20/3. 25||3.30 3.30 208 3 .50|3.55]} 306] 311] 315} 320/| 9,000 4,000|| 120} 122} 124} 126] 128] 130|| 132] 134] 136] 138] 140! 142]! 4000 3,000||90.0|91.5/93.0|94.5/96.0/97.5||99.0] 101} 102) 104} 105] 107/|| 3,000 2,000}/60 .0|61 .0|62. 0/63 . 0/64. 0|65.. 0/166 ..0/67 .0/68. 0/69.0|70.0/71.0|] 2,000 1,000//30. 0/30.5/31.0/31.5/82.0/32.5||38..0/33..5134. 0/34.5]35. 0135 -5|| 1,000 900]|27 .0|27.5|27.9/28. 4|28.8/29.3]|29.7/30.2/30.6/31.1131.5]32.0l] 900 800||24.0/24. 4/24. 8195. 2125 .7/26.0]/26. 4/26. 8127. 2127 .6|28.0/28.4]| - 800 700||21..0|21 4/21 .7|22.1/22.4/22.8]/28 1/23 .5|23.8]24 9/24 5/24.9]| 700 600||18 0118. 3/18. 6{18 919. 2/19.5]/19 8/20. 1/20.4]20.7/21 .0/21.3]| 600 500||15 .0/15.3/15.5]15.8|16.0/16.3]/16.5/16.8|17.0|17.3]17.5/17.8]| 500 400||12.0/12.2/12. 4/12. 6/12..8|13.0]}13. 2/13. 4|13.6|13.8|14.0/14.2|| 400 300|| 9.0] 9.2] 9.3] 9.5] 9.6] 9.8|| 9.9110.1]10.2/10.4110.5110.7/| 300 200|| 6.0] 6.1) 6.2] 6.8] 6.4] 6.5|| 6.6] 6.7] 6.8] 6.9] 7.0] 7.1] 200 100|| 3.0] 8.1) 3.1] 3.2} 3.2] 3.3]| 3.3] 3.4] 3.4] 3.5] 3.5] 3-6l1 100 90|| 2.7] 2.8] 2.8] 2.8] 2.9] 2.9/1 8.0] 8.0] 8.1] 8.1] 3.2] 3.2] 90 80|| 2.4] 2.4] 2.5] 2.5] 2.6] 2.6] 2.6] 2.7] 2.7] 2.8] 2.8] 2-si| 80 70|| 2.1) 2.1] 2.9] 2.2) 2.9] 2.3]] 2.3] 2.3] 2.4] 2.4] 2/5] 2-5I1 — 70 60|| 1.8} 1.8| 1.9] 1.9] 1.9] 2.0] 2.0} 2.0] 2.0] 2.1) 2.1) 2-111 — 60 50] 1.5] 1.5] 1.6] 1.6] 1.6] 1.6] 1.7| 1.7] 1.7] 1.7] 1.8] 1.8]| 50 40|] 1.2} 1.2] 1.2] 1.3] 1.3] 1.3] 1.3] 1.8] 1.4] 1.4} 1.4) 1.4/1 40 30]/ 9} .9] .9] .9] 1.0] 1.0]] 1.0] 1.0] 1.0] 1.0] 1.1, 1.1] 30 Gl ah ee) cel eT lah al 7] all 20 HN eBh eae gk ek Bl 3k gl igi isk. z4) al 10 Bees e8 ak 38h 2B Sl Bl - 28k 3l 8) ay. 9 Bere 221g) 8) 28F sil 8p Bla] 1al 8] 23H: > 8 GE TB] Re iat en) a) ei ee | ae 2 eo 9) Sap 2 8) ok 2) 9) all. 6 ee 2 9), Si oi Bt ol 2). 8) alk ee ea a et ah > a ce 8 el eee ee a ew ctl ail Tl a) a 8 a) A) ad} AP a) aa) Aa) a) a at ———— | | —— | —_——————— | <<< _— | ——— | ————_ | — | fF | EE | SS 3.00)3 05/3 .10)3. 15/3. 20/3. 25]/3 .30|3 35/3. 40/3 . 45/3 50/3 .55 | . Test. ‘qsor, | 16 242 Testing Milk and Its Products. Table Vii. Pounds of fat in | to 10,000 Ibs. of milk ( Continued). £ 3.60/3.65/3. 70/3. 75/3. 80/3 .85|/38 .90/3.95/4.00/4.05/4.10/4.15 o Milk Milk Tbs. -lbs. 10,000)| 360} 365) 370) 375} 380) 385|| 390} 395) 400) 405 410} 415}/10, 000 9,000|| 324] 329} 333]. 338) 342] 347|| 351} 356] 360] 3865] 369} 374|| 9,000 8,000/| 288] 292] 296] 300] 304] 308]| 312] 316) 320) 324] 328] 332|| 8,000 7.000|| 252} 256] 259] 263) 266] 270|| 273] 277| 280] 284] 287] 291]! 7,000 6,000/|| 216| 219] 222] 225] 228) 231|| 234] 237] 240] 248] 246] 249|| 6,000 5, 000|| 180} 183] 185] 188} 190) 193|| 195} 198} 200] 203] 205} 208|| 5,000 4,000), 144| 146} 148! 150) 152) 154|| 156) 158) 160} 162) 164) 166) 4,000 3,000|| 108} 110] 111} 113} 114) 116|| 117} 119] 120) 122] 123} 125|) 3,000 2° 000||72.0/73. 0174. 0/75 .0|76. 0/77 .0||78.. 0/79 . 0180. 0/81 . 0|82.0/83.0]| 2,000 1, 000) |36 . 0/86 .5|/37 0/87 .5/38 . 0/38 .5|/39. 0/39 .5/40.0/40 .5/41.0/41.5)} 1,000 -900)/32.4!32 .9/33.3/83 .8/84. 2134. 7/1385 .11385 . 6/36 . 0/386 .5/36. 9137.4 900 8001/28 . 8129 . 2/29 .6'30. 0/30. 4/30. 8]/31. 2/31. 6/32 .0)382. 4/32 . 8/33 .2 800 700||25 . 2125 . 6125. 9126. 3126. 6/27 . 0|/27.3/27.7/28.0|28.4/28.7/29.1]| 700 6001/21 .6/21 .9|22. 2/22 5/22. 8/23. 1|/23.4/23.7/24.0/24.3/24.6/24.9]) 600 500||18.0118.3/18.5/18. 8/19. 0/19.31/19.5/19.8!20.0/20.3/20.5/20.8!| 500 400}/14.4/14.6]14.8]15.0)15.2|15.4)|15.6)15.8/16.0/16.2/16.4/16.6 400 3001/10. 8/11.0/11 .1/11.3/11 4/11. 6]/17.7/11.9/12.0/12.2112.3]12.5]] 300 900!) 7.2)-7.3) 7.4 7.51) 7.67.7) 7.8) 7.91 8. 0F 8.1) 8.2833 200 1002S -6)-Sotl25- & 3-8) 3.8 om 3.9} 4.0} 4.0} 4.1) 4.1] 4.2 100 90|| 3.2] 3.3] 3.3] 3.4! 3.41 3.5/| 3.5] 3.6] 3.6] 3.7] 3.7] 3.7 90 80|| 2.9] 2.9] 3.0 3.0 30] 3.1] 3.1] 3.2] 3.2] 3.21 3.3] 3.3]| 80 70 2.5.9: Gl 2.6) 2.6 2. 7) 2. TS. To. 82S 282 70 60H 2.2) 2.2] 2.2! 2.3] 2.3] 2.31) 2.3] 2.4] 2.4] 2.4] 2.5] 2.5 60 50l| 1.8] 1.8] 1.91 1.9] 1.9] 1.9]| 2.0] 2.0] 2.0) 2.0} 2.1] 2.1 50 40|| 1.4] 1.5] 1.5] 1.5] 1.5} 1.5/| 1.6] 1.6] 1.6] 1.6] 1.6] 1.7 40 S01 1.1) 1-1] 1.1) ¥.1) £.11-1-2)) 1.2) 1.2} 1 2} 1.9) 1.2) 1-2 30 20] (7 27] 7 8 ‘gi isi isl isl cs} csi .s| csi 20° TONS. 24s oer a ea Ae SA Arcee 4 10 9). .3) .3] .3 sl Be: piece: | ay. eee” | ey. | | 4 Sb 3lo Bl Bl cSl eS Sik sia Sees 3 Meas Sie Ble SP i aaa Bee Bia es 3 Be sO Ol OP Ob abel. oleae S28 BH Dh > Oi Ole 9 20) soe eo Oe ce 2 A A a He Ae OF Db ios oleae ico go 2 | Bice Regma eae, Pai |) Pik eee | ES 9 | Bt | a : Ad Seo TIS oe ea O aaa te, ele ean Ok ae ~_ © = 3.60/3.65 3.7013.75|3.80/3.85||3.90|3.95/4.00/4.05/4.1014.15|| al mt hS OS # OID I 00 © Appendia. Pounds of fat in I to 10,000 Ibs. of milk (Continued). Table VII. SSS SSS SS Saas eae Ss SSscs QS Sra ye cs SS. S1S SS S SS SSS) oOo DL Il~ O10 Test, = 3 SSeSeSeSeeesle o SD P= € 19 SH OD AN FS ‘ Test 2 SOHN oman : ie MNOMIDDSHOM DOMMDOMNDES ao oD GG HOW +t it BG 0102) 00 G8 Soi st Ce han MS OAR cece is MeN ered ect ce PY SON gi ot| Tait iy eee arena aloe eta’e Nt A Ouas wee Ce Repa ae 5 re . HHOONNRRMH Dre NOMOMOHKHR = HOONN HAH : =H 2 Gosh st 30 CON CT sr + (S) OMODON1IDDA OS OD SS DATO Oe + re ON OD CO =H OD =H OD = PIG PES GIO (CO sCO) Shiga as Reg ney renin seen Mea Mees Giseede ah en sabe eres ye keene ee MO SESH CO C0 NIG irr = . SAO ONN RA tr Oo PUN OPEV OP sah cele HOO NANAS . Ve) 18 GF NO D0 OOO 1 DAOSMOOME QU 0 © So SH ODD Wa COMNNANRe : Vea) (le) CO re Ph AN L~'CD CO HH ° ee Tie Ge pw Lied sien eet e ay lon Pasay (0) tng at Wel cee oan Bi Aer S UR iw) kovbiS. ei fiat gS Je} 0 HHOONANAH OO mot i= A Pb oD OH OD SH HOO CD ONY re eS . o> ) PSNDBHOOASCS ONDAHOON DO AH Cw Fs CSCNOMAOH HHOHOANGse : << Homo OoONnN ka Se pee sre as a tsa RS eee Tie tees AP ie ts Naa ie PRIS eas Crete teste at ed ee . TH GD 09 69 II 4 4 00 xt Ord O ON bh 6) OH WHO N A so . =H ie.2) OD OD OD NIEQ or : Dal 1 I 18 A OHO 1D NOOR Ot ees D1 CO ON P~ OD Op ) D199 = ON DO SH CD OD OAT A St . =H OH MAANANS A : < S Sere eea\(oys) So Saas aiea SS MESSRS) SoS SD I- Oo Hod Sl ps SSSSSEESESS8S See (SSNS (SV=) BD P= Ord HOON oe BY qe] =Z SOSSSSSSSS SOHESHAAAS "489, A- ocanrontonn e 244 Test. nse te ht kt DS DD CO CO RPrRPNmNNWWWE POR ORO RCO DODO Co Hy fh : MEDD WWE TNOMOTOPROR OONOAUhwNwoH oO HED WOR NOTMOROROR CNOPWHOWN Testing Milk and Its Products. 4.80/4.85)/4.90/4.95/5.00/5.05)/5.10)5.15]5 . 20/5. 25/5 .30)5.35 4 96 .0/97 .0)98.0|99.0 9. ee ee ee 4.80)4:85)/4.90/4.95/5.00/5 .05)/5. 10/5. 15/5. 20/5. 25/5. 30)5 35 102} 103} 104) 105) 106} 107 .0/51.5)/52 .0/52 5/53 .0/53..5 = for) i = (or) CO = ~] (su) oN ~] ~] = GO bS Ret et DO DD GO CD miethNwww er PEDO DOCG RE MOMOMONON HHENDNWwWABRE Sayer GN GRCURCU Te Retr bobo coo Re OO OLS OLS OS 1 MED DO WIPRO MOMNORHOHS HmwhOIONHON ho bd G2 co RPemNmwwOREe OOO oh Nb Hemme wP RIN NHOHUDNwWO BYE ROO! ete bob coto > Re DoWmawi Pe COOLS Or oH HERON WO RRO MORBHERHOANN NWROADONKOD Se bho to te Pot Ft bo bo C9 CO He OS OF SF Sd bo PHEW RRO THOHOANWNNN wWwowmowanwoe Ee ho hd co Oo “et ret DODO COCO RR OLS OU Sort 1 bo ho hd GG PH eEDOHOC OPO MH AHN WooDmnoep —> HE DONWWWRREN MOMOMSMON SSSOSSSSOSO ERO CC PAO MOMHRHRAHS WwUIDowooEeD ee ay Table VII. Pounds of fat in | to 10,000 Ibs. of milk ( Continued). 5351110, 000 4 9,000 8,000 7,000 6, 000 5, 000 4,000 - 3,000 2000 1,000 beh DD CO HR OU C3 I OO CO- “480, Appendix. 245 Table Vill. Pounds of fat in I to 1000 Ibs. of cream testing 12.0 to 50.0 per cent. fat. > (See directions for use, p. 240,) 2 Ei 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25] 26.| 27 | 28 | 29 | 30 a «3 2 Ef | 1000|} 120] 180] 140] 150! 160} 170] 180] 190} 200] 210) 220] 230] 240] 250] 260| 270] 280! 290! 300 Y00|| 108] 117] 126} 135] 144] 153] 162] 171] 180] 189] 198] 207| 216] 225] 234] 243] 252] 261] 270 96] 104] 112] 120] 128] 136] 144] 152} 160] 168| 176] 184] 192] 200] 208] 216] 224] 239| 240 700|| 84] 91}. 98] 105] 112) 119] 126] 133) 140] 147| 154] 161] 168| 175] 182] 189| 196] 203] 210 600]| 72] 78| 84] 90] 96) 102/ 108] 114] 120] 126] 132| 138] 144] 150] 156] 162) 168] 174] 180 500] 60] 65] 70} 75] 80} 85! 90/ 95]: 100] 105] 110] 115] 120) 125} 130] 135] 140} 145] 150 400]} 48] 62! 56] 60) 64] 68] 72) 76] 80} 84/ 88] 92] 96) 100} 104] 108] 112] 116] 120 300|] 36] 39} 42] 45] 48] 51! 54] 57| 60! 63] 66] 69] 72| 75! 78| 8i| 84] 87| 90 200]/ 24] 26] 28] 30) 32] 34) 36) 38] 40] 42] 44] 46] 48] 50] 52] 54] 56] 58] 60 100}} 12} 13] 14] 15] 16) 17] 18] 19) 20] 21! 22) 23] 24) 25] 261 27| 28] 291 30 901!10.8!11.7/12.6113.5114.4115.3116.2}17.1/18.0!18.9119.8!20.7/21 .6122.5128.4/24.3125.2/26.1127.0 80|| 9.6/10.4|11.2|12.0/12.8|13.6|14.4/15.2|16.0|16.8|17.6|18.4|19.2|20.0|20.8|21 .6|22.4|23 .2/24.0 70|| 8.4| 9.1] 9.8/10.5/11.2/11.912.6/13.3]14.0)14.7/15.4|16.1/16.8|17.5|18.2|18.9|19.6|20.3/21.0 60|| 7.2) 7.8] 8.4] 9.0] 9.6]10.2/10.8]11.4/12.0]12.6/13.2113.8]14.4|15.0|15.6|16.2/16.8|17.4118.0 50|| 6.0] 6.5] 7.0] 7.5] 8.0] 8.5| 9.0] 9.5/10.0/10.5|11 .0|11.5/12.0/12.5]13.0|13.5/14.0]14.5|15.0 40|| 4.8] 5.2) 5.6] 6.0] 6.4] 6.8] 7.2| 7.6] 8.0] 8.4] 8.8] 9.2) 9.6/10.0]10.4/10.8|11.2/11.6|12.0 30|| 3.6] 3.9] 4.2) 4.5] 4.8] 5.1] 5.4] 5.7] 6.0] 6.3] 6.6] 6.9] 7.2] 7.5] 7.8| 8.1| 8.4] 8.7] 9.0 20|| 2.4] 2.6] 2.8] 3.0] 3.2| 8.4] 3.6] 3.8] 4.0] 4.2] 4.4] 4.6] 4.8] 5.0] 5.2/5.4] 5.6] 5.8] 6.0 10|| 1.2] 1.3] 1.4] 1.5] 1.6] 1.7] 1.8] 1.9] 2.0] 2.1] 2.2] 2:3] 2.4] 2.5] 2:6] 2:7] 2:8] 2:9] 3:0 9]/1.08]1.171.26]1.35/1.44]1.58]1.62|1.71/1.80/1.89]1.98]2.07|2.16|2.25/2.34/1 .4312.52/2.61|2.70 8|| .96]1.04]1.12|1.20|1.28]1.36/1.44|1.52/1.60]1 .68/1.76|1.84)1 .92/2.00/2.08|2.16|2.24|2.32)2.40 7|| 84)" .91} .98/1.05/1.12]1.19]1.26|1.83/1.40]1.47/1.54]1.61/1.68|.75|1.82)1.89]1.96|2.03|2.10 6|| .72|:.78] .84| .90] .96/1.02/1.08/1.14|1.20]1 .26/1.32|1.38]1.44|1.50|1.56)1.62|1 .68|1.74/1 .80 5|| .60] .65| .70] .75| .80| .85| .90] .95/1.00/1.05/1.10]1.15|1.20|1.25]1.30]1 .35/1.40|1.45/1.50 4|| 48] .52| .56| .60] .64] 68] .72|'.76] .80] .84| .88] 92] .96|1.00|1.04]1.08]1.12|1.16/1.20 3]| .86] .39) .42] .45] .48) .51) .54] .57| .60| .63| .66] .69] .72] .75| .78| .81| .84| .87| .90 2|| .24| .26] .28] .80] .82| .24) .86] .38) .40] .42| .44] .46] .48] .50/ .52| 154] 156] .58] .60 1}| .12} .13] 14] .15] .16] .17| .18| .19| .20| .21| .22] 23] .24| 125] .26| .27| 128] .29] .30 -_— ~ Testing Milk and Its Products. ~~ _ Table Vill. Pounds of fat in | to 1000 lbs. of cream (continued). 246 “980,L | mates QOS eo eee @ @ @ > =H o> CH OD ON eh Gln eSReSSe9 9 48). 4 seaectses CD) SO CS CY A) OO et SH I GIB 01 00 93 00 HD xi scone HOO CIS © WOO CIO BeARRSSe* ID SA OID O19 © 9 90} 92) 94) 96 46) 47 45 88 44 asses GD 6D CDN eee ieaietor dbx 63 06 Hi 86 43 St SG ey SO CON EN et et OO HONS 010 HA 84 42 294) 301] 308) 315} 322] 329 3361 8 252} 258) 264] 270} 276) 282) 288 210} 215} 220) 225) 280} 235) 240: BeEAdaaa Od 00 b= 6 UD Sh OO OI St | | | | | | | | | | | | | | | | | | | 31 | 32 | 33 | 34 | 35 | 86 | 87 | 88 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 “Bq wei) 1000 SSSSssess SH SH 6D 69 ON CO et veces id ASH 83 0 69 80 RSS HS «ee wee & © 6 tH 1 00 19 NI OD TOW AYN COD MAMOOC HAI e e« © © © © © @ @ So (eo) | et i = (or) StB = inp) oS oS LYen) ive) = ine) oS (>| UBe S = (Se) — = inn) Stes —s wo (om) (oo) nN a a N 2) CO AI CO COMICON © © © « © «© @ © © by BA eS test OD OD OU OT OI i S RSIS An lad acacia herisd a patel ite cs oa eee SARIN oonaaede fom) Seas LB ra NI GD HD CO b= CO CD ret CNT GYD eH LO SO Ph 00 O> P= ea for} Bm& © +« © © «© © © Ow LO rt P= 6) Od LO rH be CD Seen se RASSENS sebcleieicl oS =H CO S ives} ON co 6 oO SON BIG 4 OU OT PE CEOs SSSRESTLS SU SNe Seu Bae NSS Se eae RRO ONOR aD BOANeeIt SSSRSAINSE 60 GO RGU Od ROVERS GUO Stet ES OD es a ss ae (Jeo) LD =| OO Gly. howe sreltia id) he elwerice A rs GO SN © Pr ur ROI EU NC BRAN aac oS Sagi s SP} IDS 19 Oi O19 S10 Wee RIL oS aS Yes) (o"a) ~ moO «© e e e @ @ « @ = OO oo | sta Macht BARSSNAS cintciii SSESSESSS SRLSSISRG FOROewaan e xe e e e e e e e ie,2) 5 act le NN ete ed Se Hs Ha Ua ES eT See NO oper Boel =) [x s) SANK a ‘ SSaR Ss On SO &1 00 =H [aryl ) I C2 GO st rt o> m1 © dee ease nLUFse es eS eae pe NS Oro Gra GNUCNIGN seit oe eG 19 NORSSRE a4 ae LD CON OY ive) ee 8 ee ‘ aR ie I MN eA A eS GN NG cere el Gly) CUCM reir Table IX. Tr Price pound, cents. Appendix. 12 to 25 cents per pound. (See directions for use, page 240.) Pounds of butter fat. 700 | 600 | 500 | 400 | 300 | 200 | 100 247 - Amount due for butter fat, in dollars and cents, at *sjus0 ‘punod dod ed,1g ce fe ff | fl | | | | | | } eee 130.50 ew 101.50) 87.00)72.50/58. 147 .50}132.75)118 .00)103.25) 88.50/73 .75/59.0 0 0 0 150 . 001135 .00|120 .00|105 .00] 90.00|75.00/60.00 0 0 162 .50)187 .25]122.00)106.75| 91.50/76 .25|61.0 £11155 .00|189.50}124 00/108 .50) 93.00|77.50|62 .00)4 157 .50|141 . 75/126 .00|110.25] 94.50/78.75/63 .00/4 96 .00/80 .00/64 .00/48 .00/32.00/16 .00 97.50/81 . 25/65 .00)48 . 75|/32.50/16 . 25 99 .00/82 50/66. 00/49 .50/33 .00|16.50 }{167. 50 150. 75/134. 00/117 .25/100.50183 .75|67 .00|50 . 25|33 50/16. 75 - 170 -00 153.00 136.00 119.00]102.00/85 .00/68..00|51 .00/34.00|17.00 172 .50/155 .25]138 .00}120. 75|103 .50)86. 25|69.00)51 . 75)34..50/17 .25 175.00/157 .50}140 .00)122 50/105 .00|87 .50/70 00/52 .50/35 .00)17.50 177 .50|159 . 75]142.00|124 . 25/106 .50/87 . 75|71 .00|53 . 25|35 .50)17.75 180 .00}162.00}144 .00|126 .00/108 . 00/90. 00/72. 00/54. 00/36 .00/18. 00 182 .50/164.25)146 .00/127 .75}109 50/91 . 25/73 00/54. 75|36 .50)18 . 25 185 .00]166 .50)148 .00)129 .50}111.00)92.50)74 00/55 .50/37 .00/18 .50 187 50/168. 75]150.00)131 . 25/112. 50/98, 75/75 .00|56. 25/37 50/18. 75)/183 = $ $ $ | $ | $ 84.00} 72.00/60.00/48 .00 85.75} 73.50/61 .25/49 .0 87.50} 75.00/62 .50/50.0 89.25) 76.50/63. 75/51 .0 0 0 0 91.00} 78.00/65 .00/52 .00 92.75} 79.50/66. 25/53 .00 94.50) 81.00/67. 50)|54 .00 96.25} 82.50/68 . 75/55 .00 98.00} 84.00|70.00|56 .00 99.75) 85.50/71 .25|/57.0 0 6. hss =(3150 15.75 700 | 600 | 500 | 400 | 300 |.200 | 100 12 12} 124 123 13 13} 134 13% 14 14} 14} ee 15 15} 154 153 16 16} 164. 163 you 17h} 174 173 18 18} 183 248 Testing Milk and Its Products. lable IX. Amount due for butter fat (Continucd). ae Pounds of butter fet. a5 i) | 3 Az 1,000) 900 | 800 | 700 | 600 | 500 | ior = 243 247 50/222 .75/198 .00)173. 25/148. 25, 250 .00/225.00/200 . 00/175 .00)150. 00)125 .00 100.0 190 .00}171 .00)152.00)133.00)114. 00). 95.00 192 .50)175. 25/154.00/154.75)115 .50) 96.25 195 00/175 .&9)156 .00/136.50/117.00) 97.50 197 .50)177 .75)158 .00}138 . 25/118 .50) 98.75 200.00}180. 00/160 .00/140 00/120 .00)100 .00 202 .50}182. 25/162 .00)141 . 75/121 .50)101.25 205 .06}184.50)164. 00/143 .50/125 .00)102 .50 207 .50)186 . 75/166 . 00/145 . 25)124 .50)103.75 210 .00/189 .00)168 . 00/147 . 00/126 .00|105 .00 212 .50/191 . 25/170 .00)148 . 75|127 .50/106 . 25! 215 .00)193 .50/172 .00)150 .50/129 .00/107 .50 217 .50|195 .. 75/174 00/152. 25/130 .50)108. 75 220 .00|198 . 00/176 .00)154 .00)152.00)110 . 00 222 .50/200. 25/178 .00/155 . 75/133 .50)111. 25 225 .00|202 .50/180. 00/157 .50)135 .00)112 .50 227 .50/204. 75/182 . 00/159 . 25/136 .50)113.75 230.00)/207 .00)184. 00/161 . 00/138 .00/115 . 00 252 .50)209 . 25/186 .00)162 .75)139 .50)116 . 25 235 .00|211.50/188 .00/164.50)141 .00)117 .50 237 .50/213..75)190 . 00/166 . 25)142 .50/118 .75 240 .00/216 .00}192 . 00/168 .00)144 .00!120 .00 242 .50)/218 .25}194 . 00/169 .75)145 .50)121 . 25 31245 .00/220.50/196 . 00/171 .50)147 . 00/122 .50 50)123 .75 400 | 800 | 200 | 100 76.00/57 .00)58 .00)19.00 77.00/57 .75|38 50/19. 25 78.00/58 .50/39 00/19 .50 79 .00)59 . 25/39 50/19. 75 80.00/60 . 00/40 .00/20 .00 81.00/60 . 75/40 50/20 . 25 82.00/61 .50)/41 00/20 .50 83.00/62 .25)41.50)/20.75 00/42.00|21.00 . 75|42.50}21 . 25}/213 50/45 .00)21 .50/|213 25/43 .50/21 .75|/213 .00/44.00)22 .00)|22° 75/44 .50|22 . 25)|224 84.00/63. 85 .00|63 86.00/64. 87.00|65. 88.00/66 89.00/66. | *s7 ued ‘punod Iod 90L.1ig 19 19} 195 193 20 204 204 203 21 90 .00)67 .50)45 00/22 .50)/223 91.00/68 92.00/69. 93 .00)69 94.00)70. 95.00/71 25/45 .50}22 . 75}|/22¢ 00/46 .00|23 .00}|23 . 75|46 50123 . 25}/232 50/47 .00]23 .50/|233 .25)47 .50)/23.. 75}|232 _—_———— | | | | | |] 96.00/72. 00/48 .00/24 .00}|24 97.00/72 . 75|48 .50/24. 25]/|242 98 .00/73 .50/49 . 00/24. 50}/24> 99.00/74. 25/49 .50/24.75]/243 0/75 .00/50 . 0025 .00}/25 400 | 300 | 200 | 100 Per cent. fat. Onanan annan PRPARR KERB 0 09 09 9 69 99 ©9 69 Co 09 CODARDT BPWDNDHO OMARDT PHONDHO BODADTN PWNHHO Appendix. : Table X. Relative-value tab‘es. (See directions for use, pp. 196-198. Price of milk per 100 pounds, in dollars and cents. 249 250 ‘Testing Milk and Its Products. Table X. Relative-value tables (Continued a: =| 3 Price of milk per 100 pounds, in dollars and cents. a 3.0 46| .48} .49| .51| 52] .54} .55] <57] .58 3.1 48; .50| .51) .53| .54| .56] .57] .59 60 3.2 50| .51] .53] .54|] .56| .58] .59] .61] .62 3.3 51] .538|] .54] .56] .58] .59| .61] .63] .64 3.4 53| .54| .56] .58| .59| .61] .638] .65] .66 3.5 54] .56] .58] .59| .61] .63 65| .66] .68 3.6 56] .58] .59| .61| .63] .65] .67| .68] .70 3.7 57; .59| .61] .63| .65] .67| .68] .70]} .72 3.8 59} .61;) .638| .65! .66] .68;) .70| .72| .74 3.9 60} .62| .64| .66] .68] .70| .72| .74 .76 4.0 62] .64| .66] .68| .70| .72|-.74| .76| .78 4.1 64} .66] .68| .70| .72] .74] .76) .78| .80 4.2 65| .67} .69| .71|-.78]| .761 .781 .80|. .82 4.3 OF). 2.69) SFL 78 154d PT 801 82 Sent 4.4 68| .70] .73| .75| .77| .79] .81 84); .86 4.5 70 | .72| .74] .76] .79]|-.81]-.83] :85] .88 4.6 71} .74| .76| .78| .80] .88] .85] .87] .90 4.7 73| .75| .78| .80} .82| .85] .87] .89] .92 4.8 74| .77) .79| .82| .84) .86] .89] .91] .94 4.9 76| .78}| .81 83} .86] .88| .91] .938] .96 5.0 77} .80] .82| .85| .87] .90| .92] .95]| .97 5.1 79} .82| .84| .87] .89] .92] .94] .97] .99 5.2 81} .838] .86| .88] .91] .94] .96; .99/1.01 5.3 || .83] .85) .87] .90] .93] .95] .9811.01 | 1.03 5.4 84} .86] .89] .92| .94] .97) 1.00} 1.03 | 1.05 5.5 85; .88}] .91| .93] .96} .99] 1.02 | 1.04 | 1.07 BG 87} .90| .92| .95] .98] 1.01 | 1.04 | 1.06 | 1.09 5.7 88| .91| .94] .97|1.00] 1.03 | 1.05 | 1.08 | 1.11 5.8 90} .93| .96] .99] 1.01 | 1:04 | 1.07 | 1.10 | 1.138 5.9 91 94} .97| 1.00 | 1.03 | 1.06 | 1.09 | 1.12 | 1.15 6.0 93} .96] .99] 1.02 | 1.05 | 1.08 | 1.11 | 1.14 | 1.17 AE Eee ire fom SaanbS SRans Appendix. — 951 Table X. Relative-value tables ( Continued). Price of milk per 100 pounds, in dollars and cents. Per cent. fat. | S> Or Or On Or Cn 3.0 61 63 64 66.) 567-1969 70 72 73 (6) 3.1 64 65 67 Sree eer Oa Renee el | 73 74 76 78 3.2 66 67 69 COO Te (Ae 75 77 78 80 3.3 68 69 71 doe} te Vo) oh 78 79 81 83 3.4 70 71 73 TGs AON 80 82 83 85 3.5 || .72 73 75 77 79 | .80 82 84 86 88 3.6 74 76 77 (o-|>° 81 83 85 86 88 90 out 76 78 80 81 x00, | 1208 87 89 91 93 3.8 78 80 82 84} .85 87 89 91 93 95 3.9 80 82 84 86 | .88 90 92 94 96 98 4.0 }} .82 84; .86| .88]| .90 92 1 7.94). ..96 | 298. | 1.00 4.1 84 86). .88-) 9001.92 Sag cob P08 3-100: [51.03 4.2 86 Ser 200 A. 92a) Ok Pe cud ook LOE tT .08.F 1.05 4.3 88 SO ee | wo} SOR BO AOL 1 08-1-F. 05 1.08 4.4 90 92 |. .95 97 99 | 1.01 | 1.08 ; 1.06 | 1.08 | 1.10 4.5 02,1 04.) «.97-| {99 4 1.01 | 1.03 | 1.06 | 1.08 |1.10 | 1.13 Bee 04. 97 4, -99 | 1 OL | 2.08 [°b206 | 1.08 (1.10 14 43°) 1.15 oe i) roe 1907) 01 >). 1.03. ¢ 1.06] 2.08 | 1.10 V 1.13 1.415) 1 18 feo .oo jt .Ob | 1203 + F064 °1.08.| 2.10 }1213-) 1.15 | 1.18") 1,20 £:9\| F-00 ) 1203:)1.05 | 1.08 | 1.10 | 1.13:} 145 41.18.) 1.20 | 1,23 5.0: |} 1.02 | 1.05 | 1.07 | 1.10 | 1.12 | 1.15 | 1.18 | 1.20 | 1.28 } 1.25 Gale) £00 4°1.07-) 1:10 | 1.12) P15 } P17 |-4 220) 1222 1.25 | 1.27 O.2)) £.07 | 1.09;} 2.12 | 0.14} 217) 1.20 41.22 | 1.25 |.1.27-1. 1.30 Boom 0O Tat B14 P17 bt P19) F622") 1.95) 127 | 1.80 |- 1.82 Pedeit Bok 8513.) 116) 2.19 |-2.21 1124 | 1-27. | F380 | 1.82 |. 1.35 : etd. bedocp tS pb 2h) 124 126 +129 1-182 | 1.85 |: 1: eS ho PETS yt. 20 | 1.23") 1.26 |, 1.29 | 1.32 |:1.34 | 1.87 | 1.40 ede |) de 20 2s | 1.25 P28 1-181 | 1.841.137 |: 1.389. |:1.48 Or htop 22 do 28180 | 1.33) 4 1.36-|.1.389 11.421 1, se da2h jd 24) 127% | 1.30 1-88 | 1.386) 139 | 1.42 | 1.45 |-1.48 0 |} 1.23 | 1.26 | 1.29 | 1.382 | 1.85 | 1.38 | 1.41 | 1.44 | 1.47 | 1.50 Testing Milk and Its Products. ' 252 Table X. Relative-value tables (Continued). Price of milk per 100 pounds, in dollars and cents. : “q10y "JU99 10, OMmMOoOanN Oat SaonranN wore CAN WHORHrO BD AO 8 Sy ea ANNAOD COCOA SH 1919190100 SGoOr~rerewO Lm | be Be es | bee ce | ees ere retest rst rs re wee e eee — Osat- OS MOANID ODHHtro moan rOnmnoem Nwnonte DRAROS COSHH AANA 0 of G8 Sh oh H191919190 OOO Ee EOMNOD FHHtHreOomMm omMNnM OMDOD Oat ONMDOGH- DRARD COORR AANA & 8 od od at Is iD OOSO~ I~ toe ee oe oe ee Sees eS Sees ee eeeeS 19 OO ml st be S2M190nM Hreomn ontro Oy 19 00 wa ~ONM OK DABD COSOSCSM FAAANN Acoso Higin wmOooor Seseqrere eee ee oe ee Be ce | SSeS ee wees ee _ tHe OND ODSPMHOD ANWDOM OBNHArR ONDHDH HRONIDA DDAPAD HBOSCSO BHAANN NANO AstHHin wWinoods eee Ss eee ee Bh ee Be | ba FD ro ee | Sewer | oe I oe Oe i oe Be | AW OH OD SM190H Homndto ronmnnowm Waranio WODADS Qa ~~ (3) See aA OI IN 65 68 CM) SH SH xt SH LD LD 1D 1D CO CO Soe Sees os Men fe ee oe Se ee oe | See Leal MOOR ON | HH Il © 09210 Mr oD c Od mate om Nee Onan ain ile) Doe tHtrean (0 Oe Oe OMe Olen) DODO Onn N eS OI ON GI od 63 CD OD SH SH =H HD 19 19 19 See eee Meee Looe Men pee Bn | Sees D A106 bk © OD 1 CO rt OO CO OD re sH I~ ON10 ky © OQ 10 hy 2 oO CO CO ro st CO OD I~ ODDO OOD ODDO O Coons r mAIN NI oO OD OD OO =H sf st sr 19 10 19 10 mre See en pen ee Sn Mn Maen Ph oe Soon eee ane Mee ee Sal en ee ee ee | Om ~~ OO wet HH COS St TH I~ Co QI HH I~ O N10 I~ © 69 10 1 © OD CO OO HOD CO I~ DD DO DO (oper Kener en) SS onr mA AC] OD CD) CO CO =H SH SH SH 10 10 10 re Cee oen en he ee Seneee Ss a pe Pee Be Ss oe A Bee oe | CO OD GI =H bP o> NA st bh Od N10 ON Dron Pr © 19 CO (<>) (ae) CO MD OD I~ l&§ OW DO BD SO) o> Cc. Sd ooonre SIA Gy GI OD OD OD OD —t st bs alll Von Von) — Appeudix. ; 253 Table XI. Butter chart, showing calculated yield of butter (in los.) from 1 to 10,000 {bs. of milk, testing 3.0 to 5.3 per cent. (See directions for use, p. 240.) Milk, Milk, bs. lbs. 10,000}| 325) 336) 348} 360) 371) 383]| 394) 406) 418) 429) 441) 452/110,000 9,000}} 293) 302) 313) 3824) 3834] 345]| 355) 365) 376] 386] 397] 407 9, 000 8,000} 260} 269) 278} 288) 297) 306)| 315) 325} 334) 3438] 353] 362 8, 000 7,000}| 228) 235} 244) 252) 260) 268]| 276) 284) 293] 300] 309] 316 7,000 6,000}} 195) 202) 209) 216) 223) 230)| 236] 244) 251] 257| 265] 271)] 6,000 3,000/|97.5] 101] 104] 108] 111] 115|| 118] 122] 125] 129| 132] 136]! 3,000 2,000|i65 .0|67..2/69.6/72.0|74.2176.6||78. 8|81..2|83.6|85.8I88.2190.4l| 2:000 1,000|/32.5/33..6/34..8/36.0/37.1/38.3//39.4/40.6/41.8/43.9144. 1/4521! 1,000 900||29.3)30. 2/31 .3|32. 4/33 .4184..5]|35.5/36.5|87.6/38.6|39.7|40.7]] 900 800|/26 .0126.9|27.8/28.8/29..7|30..6||31.5)/32.5/33.4/34.3135.3)86.2]] 800 700||22..8|23.5|24. 4/25 2/26 .0|26.8||27. 6|28. 4129 .3/30.0130.9|31.6]] 700 600||19 .5|20. 2/20 .9]21..6|22.3/23..01|23.6|24.4/25.1125.7|26.5|27.1|| 600 500|/16.3|16.8/17. 4/18 ..0/18.6|19..2||19.7/20.3120.9/21.5/22.1|22 6] 500 400|/18.0|13.4|13.9|14.4}14.8|15.3)|15.8|16.2116.7/17.2117.6|18.1]] 400 300|| 9.7]10.1/10.4/10.8/11.1]11.5||11.8/12.2/12-5/12.9|13.2113.6]| 300 200|| 6.5] 6.7| 6.9] 7.2] 7.4] 7.6|| 7.9] 8.1] 8.3] 8.6] 8.8] 9.0]/ 200 100] 3.2] 3.4] 3.5] 3.6) 3.7] 3.8|| 3.9] 4.1] 4.2] 4:3] 4.4] 4/5l1 100 90]/ 2.9] 3.0] 8.1) 3.2} 3.3] 3.4] 3.5] 8.6] 3.7] 3.8) 3.91 4.1] 90 80|] 2.6] 2.7). 2.8] 2.91 3.0] 3.1] 8.2] 3.3] 8.4] 3.4] 3.5] 3.6l| 80 70|] 2.3] 2.3] 2.4] 2.5] 2.6] 2.7] 2.8] 2.8] 2.9] 3.0] 3.11 3.2l1 70 60) 1.9] 2.0] 2.1] 2.2} 2.2) 2.31] 2.4] 2.4) 2.5] 2.6] 2:71 2.711 — 60 50} 1.6] 1.7] 1.7] 1.8] 1.9] 1.9] 2.0] 2.0] 2.1] 2.9) 2:91 2'3]] 50 40|] 1.3] 1.3) 1.4] 1.4] 1.5] 1.5] 1.6] 1.6] 1.7] 1.7| 1.81 1.8|| 40 30] 1.0] 1.0] 1-0] 1.1] 1.1) 1.2]] 1.2] 1.9] 1.3] 1.8] 1.3) 1-4|| 30 A et Toa). {sl} 28) 8) 4.81.58) 29 .9l| >. 20 10] 8} 8} .41 .4) 14) call ca} ca) cal 4) lat c5il 10 Gi Sie) | cals 3) Si A) db Lal cd aE A Be Sid) 8| 3). .3|b 8) 28 al ial o.4| ll 8 Alege 2) 8h Sh 8B Blt 3t al ail. Gh 928) 2p 2) 22) DIE oho) 8) ah cal all Blea cep 89 2) 2 a op a) a) fol cl fall A A ed eh Oh OB oi |. 91 ole ab als a Nae Ae aah heal a) a 8 a) a} tf a) a ay a) a) a a] ay 2 | sf | | |} | |] | — | —— | | — _ E 3.00/3. 10/3. 20/3 .30/3. 40/3. 50)/3 . 60/3 .70/3. 80/3 .90)4.00/4. 10 g 254 & 4 ,20/4.30)4.40/4.50/4.60/4.70|/4.80/4.90/5.00 Milk lbs. 10,000|| 464) 476) 487} 499) 510) 522 9,000|} 418) 428} 438) 449} 459) 470 8,000]; 871) 3881} 390} 399} 408) 418 7,000)| 825) 333] 341) 349] 357) 365 6,000}| 278) 286} 292} 299) 306) 313 5, 000|} 232) 238) 244) 250} 255) 261 4,000], 186) 190) 195) 200} 204) 209 3,000|} 189} 143) 146) 150) 153} 157 Q 000}/92.8/95.2/97.4/99.8] 102} 104 1, 000/46 .4/47.6/48. 7/49 .9/51.0/52.2 900/|41.8142.8/43.8]44.9145.9/47.0 800]/387 .1/38.1/39.0)89.9/40.8/41.8 700}/82 .5/33 .8)34.1184.9/35.7/36.5 600)|27 .8|28. 6/29. 2/29 .9130.6/31.3 500||28. 2/23. 8/24. 4/25 .0/25 .5)26.1 400||18 .6)19 .0/19 .5/20.0/20.4/20.9 300)|18.9)14.3)14.6]15.0/15.3)15.7 200)| 9.3) 9.5) 9.7/10.0/10.2,10.4 100}| 4.6} 4.8} 4.9) 5.0) 5.1) 5.2 90|| 4.2) 4.3] 4.4] 4.5) 4.6) 4.7 80}| 8.7| 3.8] 3.9} 4.0) 4.1) 4.2 70}| 3.3] 3.3] 3.4) 3.5) 3.6) 3.7 GOP 22 Sino 92-9 S Ol Sloe 50|| 2.3) 2.4) 2.4) 2:5) 2.6) 2.6 40|} 1.9} 1.9] 2.0} 2.0} 2.0} 2.1 30) 1-4) 1-4). 1.5) 1.5) 1251156 20) 29) 1.0% £204.01 1.0) 10 SLOWS. ols 25 e 2s eats eons Qe 4 a A Be Bl. 8]| .41 .41 ..4) .4[ .41 .4 Te 28 sole sole heee eas oA Glia aas|) wool soles el eels veo Bilty aalvoodl s saloevelcs cel = ce Alive seater alms al) 5 solvate ee Saif ods SAE sien aves ONG ey | ame A eats) sel (A ed 1 a Ih ae a pene! Ciera iacaetn cg era | s f g Testing Milk and Its Products. Table XI. Butter chart (Continued). 214 160 107 109 111 5.10'5.2015.30 S _— | ———_ | ———— 522 464 406 | 848 290 @| 232 174 114; 116 533 474 53 .4/54.5/55. 7/56. 8/58. 0/59. 2 PEeNmpwerp se EHD Wwht NORE ANN 6 PDL we PRON TH OENNDNWO WNORNOBR YE pel seal SO OCS STS rte bobo COCO ee SUD Sd FA NID GO G9 SO Eh DHOwWNwWHDRO TOROWNINOH Ee hob 2 CoB Ot PED DWURO AHANASSKRS FAutobo COD RIN DENN AwWHNO AHNWOROaH pet Ft DD DD WO CO ON HH we Ro AHNWwWOROTH NROURHE ORE : ket Ft DD DOD CO He HE OF Rete pobocRROt Ot NICo ORO Oh DOLCE ROO DNONWONHAN BWDOPRNWOdAADN He hpw sk o Bees bene oe DOOPRORHND OHONSOB BOD |_| | | | |_| _ | | |] 4, 20/4. 30|/4.40/4.50)/4. 60/4. 70||4. 80/4. a0. C0|5.10|5.20|5.30 i 580} 592)|10,.000 thd C9 OIG S100 259 Appendix. Table Xl. Overrun table, showing pounds of butter from one hundred Ibs. of milk. (See directions for use, fat. Ora os 1d SS I> CO OD | 28.06 e900 09 6 68 68 68 5 SAH cS 2 Co f- ODO ford? We. fee te: Le OM OO CO Cf) SH I~ ©0160 10 1 SO CO O> © of CO OD OO SH Ho DDH 1d OIl- DS Cie Ce ae Tee | OO OO CD OD SH ra cO HO OD BSN DO S AI st cS NUS cau ee) HHH HH ~oao Ns rt AI tH 19 HHH CO 10 I> DW © rmaN oO =f ce St st SH SH = CHO me nt eerie} i ia i A I li nl i ali pI Vout Von) Vou) Ven i Con EE Von) You Von Ven Ven tos Sato OAH oO NRHOAN eS ee ak ce Hd co r= € SASH OO ONto OS SOmnN co st OMmreCAaON CMU CVe ir Feat eben (ej fase et Tee PL Yo eemt a nd AC Uae CEM ar aan } Oe ener 6a ie) oe WD CO CH & | ml | = (ae) 4 = N be | re i! — aa Lae = DO S =| re 5 —_— jon ; eee sh ree ae fat. OD SH id c OOM Ao OD SH uD CO P= of) 6) 6D OD OD OnmAN oO = ODOonmaA 1D © I> DW Od HO © If © Hid © l~ © Sage gre pele ie: Om Ao) OD SH 1D 6 DOOnN W1DO CO on on e060 OD. CO COO SH SH SH OSH SH SH SH H Dae Wher wow onary LD UD 19 1 1D SS P= OO Op ra NI OD SH 1D LD CO P= OO Op rat AY Of) St LD Oh. (een iery sO me ss eer eer cena hee 26) ie 1D WD 19 19 1D —$O O O OHOO Omron coc of) Hl 1) CO B= CO Od @ SSuANe BONDS OnN costo: LICOEA Via CY ani. SoM ht) Ceeee Tumi ea Sur AC ao Weer HID 19 1D 1D 11919 19 1D OD OH CHC CO _ Onno sd DO I DW OnA co 1 CO I~ CO OD OnAN co} ) (2) (> (>) (5) (=) PIO WOOMMOOUDMOODBDDOAOOAII NN e fon S - oj 4 OMOmooonoMOMmeDmoc KC ~1~I~I ~I CC Op So mommowomrerommx none nonr-I~ ~!l = Oc WMOmomoDononmnDmnmonan~ CO ES LIS ae ta OILS ale — de 73/1186] 11. 11.76|11.89 12.02|12. 11.91]/12.04/12.17|12. 12.33/12. 12. 48|12. 12.38/12.51]12. 64] 12. 12.53'12.66.12. 79112. \Bini 1282)12 918, J io) ~] uy Orme mowowoMmMmMmMmo xt On! 10, 10. — So 10. 10. 10. Pt: Tl? Lt; 11. le ie 185}. B23 As 12: 12. 1? ie iS. ke WODODDODOOMDNHMOMOM~I 96 . 92110 Oa} le .23)10. o9}10. .O4} 10. ~70}10. .85|10 .OO}11 .16}11 .81{11 A7I11 62/11 7811 .93}12 .09}12. 2.24/12. .40}12 .050| 12 Fall. .87|13. .02)13. .18}13. Soll. .49}13. i=) Ss Cc CO CO CO CL CO CO WD CO CH CH .90}10.03/10.17}10.380 .45}10.19}10.32}10.46 .21)10.34/10.48)10.61 .99}11.12}11.25}11.39 ~14/11.27}11.41}11.55 .29)11.42)11.56)11.70 .45}11.58}i11.71}11.85 .60)11.73111.87)12.0: .76}11.89]12.02)12.16 -91}12.04}12.18)12.32 .07|12.20]12.34)12.48)): .03}/12,67)12.71/12.85 .69]}12.83}12.97) 13.01 20; 4-24 | 28 Ne eo | 30 | 31 | 382 | 383 | 34 | 35 | 36 20) 8.33] 8.47| 8.60 35| 8.49] 8.62] 8.76 51| 8.64| 8.77| 8.91 67} 8.80] 8.91] 9.07 $2] 8.95] 9.09] 9.22 97| 9.11] 9.24] 9.37 13] 9.26] 9.39] 9.58 28] 9.42) 9.55| 9.68 44| 9.57| 9.70] 9.84 .59| 9.73] 9.86] 9.99 75] 9.88|10.01|10.15 36] 10.50}10.64)10.77 53|10.66)10.79}10.93 68}10.81/10.94)11.08 84}10.97)11.10)11.24 23)12.36/12.49)12.63 38}12.52)12.66}12.80 85}12.99!13.12)13.25 00/13.14|13.28]13.41]|5. 16/13.30}13.44}13.87 31/13 .45}13.59)13.72)/5. 47|13.60}13.74]13.87 62/13.75]13.89}14.02 er cent. of fat. | P OS Orr =| GUO OV OV OU OU OU HH ree HH HH Hee C0 G9 Go Ge wn GY WG Gt SODNMBMNALWNWHOODMIANIPWNWHODOONDOP WH HOO MIG I Appendix. | 257 Table XIV. Comparisons of Fahrenheit and Centigrade (Celsius) thermometer scales. Fahren- Centi- Fahren- Centi- Fahren- Centi- heit. grade. heit. grade. . heit. grade. Se. S00) |) -ba76~ - | 80 +140 60 211 99-44 175 79.44 139 59.44 210 98.89 174 78.89 138 58 .89 209 - 98.33 178 78.33 137 58.33 208 97.78 172 COIS 136 07.78 207 97 .22 171 77.22 135 57.22 206 96 .67 170 76.67 134 56.67 205 96.11 169 76.11 133 06.11 204 — 95.55 168 75.55 132 50.00 203 95 167 75 131 533) 202 94.44. 166 74,44 130 54.44 201 93.89 165 73.89 129 50.89 200 93.33 164 72.33 128 03.33 199 92.78 163 72.78 127 52.78 198 92.22 162 71.22 126 52.22 197 91.67 161 71.67 125 51.67 196 91.11 160 fh gals 124 51.11 195 90.55 159 70.50 123 50.55 194 90 158 70 122 50 193 . 89.44 157 69.44 121 49.44 192 88.89 156 68.89 120 48 .89 191 88.33 155 68 .33 119 48 .33 190 87.78 154 67.78 118 47.78 189 87.22 153 67.22 117 47 22 188 86.67 152 66 .67 116 46 .67 187 86.11 151 66.11 115 46.11 186 85.55 150 65.55 114 45.55 185 85 149 65 113 45 184 84.44 148 64,44 112 44 44 183 83.89 147 63.89 111 43 .89 182 83.33 146 63.33 110 43.33 181 82.78 145 62.78 109 42.78 180 82.22 144 62.22 108 42.22 179 81.67 143 61.67 107 41.67 178 81.11 142 61.11 106 41.11 177 80.55 141 , 60.55 105 40.55 258 Testing Milk and Its Products. Table XIV. Comparisons of thermometer scales (Continued. ) Fahren- Centi- Fahren- Centi- Fahren- Centi- heit. grade. heit. grade. heit. grade. +104 +40 +68 +20 +32 +0 103 39.44 67 19.44 31 —).55 102 38.89 66 18.89 30 1.11 101 38.383 65 18.33 29 1.67 100 37.78 64 17.78 28 2.22 99 37.22 63 17.22 PA 2.78 98 36.67 62 16.67 26 3.39 97 36.11 61 Grell 25 3.89 96 35.55 60 15.55 24 4.44 95 35 59 15 23 5 94 34.44 58 14.44 22, 5.55 93 39.89 57 13.89 21 6.11 92 33.39 56 13.33 20 6.67 91 32.78 5D 12.78 19 C22 90 32 22 54 12.22 18 7.78 89 31.67 53 11.67 17 8.33 88 31.11 52 et 16 8.89 87 30.55 51 10.55 15 9.44 86 30 50 10 14 10 85 29.44 49 9.44 13 10.55 84 28.89 48 8.89 12 pH 83 28.33 47 8.33 11 11.67 82 27.78 46 1.78 10 12.22 81 27.22 45 1.22 9 12.78 80 26.67 44 6.67 8 13.33 79 26.11 43 6.11 7 13.89 78 25.55 42 5.55 6 14.44 17 25 41 5 5 15.00 76 24.44 40 4.44 4 15.55 75 23.89 39 3.89 3 16.11 74 23.30 38 3.33 2 16.67 73 22.78 30 2.18 ik 17.22 72 22.22 36 2.22 0 17.78 fil PANS. OG 35 Ge —1 18.33 70 2 Ad: 34 PAu: 2 18.89 69 20.55 33 0.55 3 19.44 To convert deg. Fahrenheit to corresponding deg. Centigrade: Subtract 32, multiply difference by 5, and divide by 9. Example: Which degree Centigrade corresponds to110°F.? 110—32= 78; 78 X 5 = 890; 390 + 9 = 43.33, To convert deg. Centigrade to corresponding deg. Fahrenheit: Multiply by 9, divide product by 5, and add 82 to quotient. Example: Which degree Fahrenheit corresponds to 95.5° C.2 95.6 Xx 9= 859.5; 859.5 + 5= 171.9; 171.9 + 32 = 203.6. Appendix. - 259 Table XV. Comparison of metric and customary weights and measures. Cie aia Equivalents in phapEte welettts Equivalents in MicaSUTEs, metric system. measures. customary system. Pamehns: 03.2 ..--| 2.54 centimeters. 1 meter............ 39.37 inches. PTOOU:cacsne oases .0048 meter. Teme Gere. . 225.68 1.0936 yards. le coal (eae 1.6094 kilometers. 1 kilometer....... .6214 mile. 1 square inch..| 6.452 sq. centimeters.|| 1 sq. centimeter| .155 sq. inch. 1 square foot ..| 9.29 sq. decimeters. 1 square meter..|10.764 sq. feet. 1 square yard.| .836 sq. meter. 1 square meter..| 1.196 sq. yards. ISLC a ee ea .4047 hectare. 1 hectare ......... 2.471 acres. 1 cubic inch...|16.387 ee. LMC Sas Noe .061 cubic inch. 1 cubic foot....} .0288 cub. meter. 1 cub. decimeter|61.028 cubic inches. 1 cubic yard...| .765 cub. meter. 1 cub. meter...../35.314 cub. feet. i bushel...)c54.. .8002 hectoliter. 1 hectoliter...... 2.8377 bushels. 1 fluid ounce ../29.57 ce. EGG) ares eke a's .0338 fluid ounce. WM GUMATC.. oor. .9464 liter, APIGE TES. osesencsces 1.0567 quarts. Peallome sence: 3.7854 liters. 1 decaliter........) 2.6417 quarts. JAE 0 aga ee Bree 64.8 milligrams. 1h fe Lae are 15.43 grains. 1 ounce (av. )../28.35 grams. {1 COTA Ls, oaeees .035274 ounce. 1 pound (av.)| .4536 kilogram. | 1 kilogram....... 2.2046 pounds (av. ) 260 Testing Milk and Its Products. SUGGESTIONS regarding the organization of co-operative creameries and cheese factories. ie When the farmers of a neighborhood are considering the establishment of a creamery or cheese factory, they should first of all make an accurate canvas of the locality to ascertain the > nuniber of cows that can “be depended on to supply the factory with milk. The area which may be drawn from will vary according to the kind of factory which it is desired to operate. A successful separator creamery will need at least 400 cows within a radius of four to five miles from the proposed factory.! Small cheese factories can be operated with less milk, and gathered-cream and butter factories generally cover a much larger territory than that mentioned. In all cases, however, the question of the number of cows contributing to the enter- prise must be fully settled before further steps are taken, since - this isa point upon which success will largely depend. Methods of organization. The farmers should form their own organization, and not accept articles of agreement proposed by traveling agents. An agreement to supply milk from a stated number of cows should be signed by all expecting to join the association. When a sufficient number of cows has been pledged toinsure the successful operation of a factory, the farm- ers agreeing to supply milk should meet and form an organi- zation. This may -be done according to either of the following plans which have been known to give good satisfaction. Raising money for building and equipment. First.—Each member will sign an agreement to pay on or before a given date for a certain number of shares in the com- pany at......2.. dollars per share; or, Second.—An elected board of directors may be authorized to borrow a sum of money not exceeding......... thousand dollars on their individual responsibility, and the sum of......... cents, (usually five cents) per hundred pounds of milk received at the factory shall be reserved for the pwyment of this borrowed money. 1 Bull. 56, Wisconsin experiment station. Appendix. 261 Constitution and by-laws of a co-operative association are drawn up and signed by the prospective members of the association when it has been determined to form such an association. It is impossible to include in an illustration all the articles and rules that may be found useful in each particular instance; the following suggestions in regard to some of the points to be in- cluded in the documents are given as a guide only. It may be found advisable to modify them in various ways to meet the needs of the organization to be formed. After the constitution and by-laws have been drawn up and made plain to all the members of the association, they should be printed and copies distributed to all parties interested. CONSTITUTION OR ARTICLES OF AGREEMENT OF THE...........008- ASSOCIATION.! 1. The undersigned, residents within the Counties of......... : State of............ , hereby agree to become members of the........... Co-operative Association, which is formed for the purpose of manufacturing butter or cheese from whole milk. 2. The regular meetings of the association shall be held an- nually on the............ day of the month, Of%.......2:..+.0+0 Special meetings may be called by the president, or on written request of one-third of the members of the association, provided three day’s notice of such meeting is sent to all members. Meetings of the board of directors may be called in the same way, either by the president or by any two members of the board of directors. 3. Ten members of the association, or three of the board of directors, shall constitute a quorum for the transaction of busi- ness. 4. The officers of the association shall include president, sec- retary, treasurer, one of whom is also elected manager, and these officers together with three other members of the associa- 1The following publications have been freely used in preparing this constitution and by-laws: Woll, Handbook f. Farmers and Dairymen; Minn. experiment station, bull. No. 35; Ontario Agriculture College, spec: ial bulletin, May 1897. 8 SOF 262 Testing Milk and Its Products. tion shall constitute the board of directors. Each of these six officers shall be elected at the annual meeting and hold office for one year, or until their successors have been elected and © qualified. Any vacancies in the board of directors may be filled by the directors until the next annual meeting of the association. 5. The duties of the president shall be to preside at all meet- ings of the association, and perform the usual duties of such presiding officers. He shall sign all drafts and documents of any kind relating to the business of the association, and pay all money which comes into his possession by virtue of his office, to the treasurer, taking his receipt therefor. He shall call special meetings of the association when deemed necessary. In the absence of the president, one of the board of directors shall temporarily fill the position. - 6. Thesecretary shall attend all business meetings of the ~ association and of the board of directors and shall keep a care- ful record of the minutes of the meetings. He shall also give notices of all meetings and all appointments on committees, etc. Heshall sign all papers issued, conduct the correspond- ence and general business of the association, and keep a correct financial account between the association anditsmembers. He shall have charge of all property of the association not other- wise disposed of, give bonds for the faithful performance of his duties, and receive such compensation for his services as the board of directors may determine. ; 7, The treasurer shall receive and give receipt for all money belonging to the assuciation, and pay out the same upon orders signed by the president and the secretary. He shall give such bonds as the board of directors may require. 8. The board of directors shall audit the accounts of the association, invest its funds, appoint agents, and determine all compensations. They shall prescribe and enforce the rulesand regulations of the factory. They shall cause to be kept a rec- ord of the weights and tests of the milk or cream received from each patron, the products sold, the running expenses, etc., and sl all divide among the patrons the money due them each month. They shall also make some provision for the with- Appendix. 233 drawal of any member from the association, and make a report in detail to the association at the annual meeting. Such report shall include the gross amount of milk handled during the — year, the receipts from products sold, and all other receipts, the amounts paid for milk and for running expenses, and a com- plete statement of all other matters pertaining to the business of the association. 9. Among the rules and regulations to be eieceon by the board of directors may be included some or all of the following: a. Patrons shall furnish all the milk from all the cows prom- ised at organization of the association. b. Only sweet and pure milk will be accepted at the factory, and any tainted or sour milk shall be refused. ce. The milk of each patron shall be tested at least three times a month. | d. Any patron proved to be guilty of watering, skimming or otherwise adulterating the milk sent to the factory, or by tak- ing more than 80 pounds of skim milk or whey for every 100 pounds of whole milk delivered to the factory, shall be fined as agreed by the association. e. A partron’s premises may be inspected at any time by the board of directors, or their authorized agent, for the purpose of suggesting improvements in the methods of caring for the milk or the cows, in drainage and general cleanliness; or to secure samples of the milk of his cows for examination when it is deemed necessary. 10. Any changes or onan to the by-laws or constitu- tion of the association must be made in writing by the parties proposing the same, and posted prominently in a conspicuous place at the creamery, at least two weeks previous to their being acted upon. Such changes to be in force must be adopted by a two-thirds vote of the stockholders. 11. In voting at any annual or special meeting of the asso- ciation, the members shall be entitled to one vote for each cow supplying milk to the factory, or for each share of the stock owned by them, as agreed upon. INDEX. The figures refer to pages in the book. Acid measures, 33, 46, 53. Acid tester, Swedish, 66. Acidity of cream, 118; estima- LOMO olaose Acidity of milk, cause of, 108; determination of, 109, 2138; methods of testing, 120. Accuracy of alkaline tablets, 117. i Adulteration of milk, 101, 106, 224; calculation of, 106. Adulterated butter, 219; cheese, 223% Albumen, 15; determination of, in milk,209, 211. Albuminoids, 15. Albumose, 16. Alkaline tablet test, 113: stand- -ard solution of, 116; accu- racy, 117. Alkaline tabs, 124. American cheddar cheese, 22. Amphoteric reaction of milk, 108. Analysis, chemical, of butter, [216.9 2t0s butter, mink= 9213: _cheese, 222; condensed milk, 215; cream, 213; milk, 204; skim milk, 213; whey, 2138. Appendix, 233. i Artificial butter, detection of, DO Ss ene : Ash, determination of, in but- ter, 217, 218; in cheese, 223; in milder, Dao. Babcock test, the, 6, 28; Bart- lett’s modification of, 71; direction for, 29; discussion of details, 37; for butter milk, 89; for cheese, 89; for con- densed milk, 90; for cream, 74, 169; for skim milk, 85; for whey, 89; glassware used in, =345)= modifications of, 70; scales for weighing cream, cheese, etc., 82; water to be used in, 69. Bartlett’s modification of Bab- cock test, 71. Bausch and Lomb centrifuge, {ie Beimling test, 5. Bi-carbonate of soda, detection of, in milk, 229. ; Bi-chromate of potash, 98, 156; solution of, 99. Board of health degrees, 97, 236. Boiled milk, detection of, 227. Boiling test, the, 221. Boracie acid, in dairy products, 124, 228. Borax in dairy products, 228. B.&W. bottle, 87. Butter, artificial, 13; of, 2449: Butter chart, 253; use of, 185. Butter, 20; chemical analysis of, 216; complete analysis in same sample, 217; com- position of, 21, 233; defini- tion, 232; determination of ash, 217; casein, 216; fat, 216; water, 216; renovated, 222; sampling for analysis, 216; standard, 232; variations in composition, 177; yield, cal- culation of, 176. Butter fat, conversion factor for, 183; definition, 232; de- termination of specific grav- ity, 220; volatile fatty acids, 220; expansion co-efficient, 36; price per pound, 190; specific gravity, 38; standard, 231; table showing amounts due for, at 12 to 25 cents per pound, 247; test and yield of butter, 176. Butter making, quantities of products obtained in, 21. Butter milk, 21; Babcock test for, 89; chemical analysis of, 213; composition of, 233; spe- cific gravity of, 214. detection Index. Calculation of adulteration, 106; of concentration of condensed milk, 215; of milk solids, 99, 100; of over-run, 183; of sp. gr. of milk solids, 103; of yield of butter, 176, 182, 184; of cheese, 187; of dividends at creameries, 190; at cheese factories, 1¥¥; of percentages, 159. Calibration of glassware, 47. Carbohydrates, 16. Casein, 14; determination of, in butter, 216; in cheese, 223; in - milk, 209, 211. Centrifugal machines, 54. Chamberland filters, 15. Cheddar cheese, American, 22; composition, 233. Cheese, 22; Babcock test for, 89; calculating yield of, from casein and fat, 189; from fat, 187; from solids not fat and fat, 188; composition, 233; chemical analysis of, 222; definitions, 232; determina- tion of ash, 445; casein, 223; fat, 222; water, 222; ‘‘filled,’’ detection of, 223; quality of, from milk of different rich- ness, 200; sampling, 89; standard, 232; yield, calcula- tion of, 187; yield of, and quality of milk, relation be- tween, 188. Cheese factories, calculating dividends at, 199; co-opera- tive, 202; proprietary, 202. Cholesterin in milk, 19. | Citric acid in milk, 19. Cleaning solutions for test bot- tles, 44. Cleaning test bottles, 40; ap- paratus for, 41. = Cochran’s test, 5. Coloring matter in milk, for- eign, -detection of, 226. Colostrum milk, 19; composi- tion of, 233. 18 265 Composite samples, 148; care of, 158; case for holding, 154; methods of taking, 148; pre- servatives for, 155. Composite sampling, accuracy of, 155; use of drip sample, 150; one-third sample pip- ette, 153; Scovell sampling tube, 151; tin dipper, 148; equity milk sampler, 153. Composition of butter, 233; but- ter milk, 233; cheese, 233; colostrum milk, 233; con- densed milk, 233; cream, 233; milk, 19, 233; milk ash, 18; skim milk, 233; whey, 233. Condensed milk, 22; analysis of, 215; composition of, 233; determination of concentra- Lion, 216) "or sp. gr., of, (215; testing of, 90, 91. Control sample of milk, 101. Conversion factor for butter fat, 183. Conversion tables for thermo- meter scales, 257; for weights and measures, 258. Cows, number of tests required in testing, 136; when to test, 138. Cows’ milk, composition of, 19, 2333) Cream, 20; acidity of, 120; Bab- cock test for, 73, 169; bottles, the bulb-necked, 76; the Win- ton, 77; care in sampling, ne- necessity of 171; definition, 232; determination of “acidity of, 114, 123; errors of mea- suring in testing. 74; evapo- rated, 232; gelatin in, detec- tion of, 227; pasteurized, de- tection of, 226: scales, 78; separator, 20; separation of, influence of temperature, 174; spaces, 165; specific gravity, 75; standard, 232; starch in, 228: testing, 73; testing outfit, 170; testing at creameries, 165; use of 5 ec. pipette in, 266 82; use of milk test bottles in, 81; test bottles, 76; weight of, delivered by a 17.6 cc. pipette, 75. Creameries, calculating divi- dends at, 190, 192; co-opera- tive, 191; cream testing at, 165; proprietary, 191. Creamery inch, 1, 167. Curd test, the Wisconsin im- proved, 125. Definitions of milk and its products, 231. DeLaval’s butyrometer, 8. Devarda’s acidimeter, 113. Diameter of tester and speed required, relation between, 57. Dividends, calculating, at cheese factories, 199; at creameries, 190; of both milk and cream at the same factory, 198. Dividers, Lutley, 37. Double-necked test bottles, 87; value of divisions of, 87. Draining rack for test bot- tles, 43. Equity milk sampler, 153. Expansion coefficient for butter Henne eins Failyer and Willard’s test, 5. Farrington’s alkaline tablet test, 113. Fat, 12; color of, an index to strengtn of acid used, 66; content, causes of variation in, 135; determination of, in butter, 216; in cheese, 222; in milk, 208; globules, 12; in- fluence of separation of, 67; measuring of, in cream testing, 83; in milk testing, 35; pounds in 1-10,000 lbs. of milk, testing 3 to 5.35 per cent., 241; speed required for complete sepa- ration of, 56. Fermentation test, the, 128. Filled cheese, detection of, 223. temperature on - Testing Milk and Its Products. “Fitch’s Salt Analysis,’ 218. Fjord’s centrifugal cream test, 9. Fluorids, detection of, in nilk, 230. ’ Food, influence of, on quality of milk, 143, 145. Food 231. Fool pipettes, 45. Formaldehyd, detection of, in milk, 230. Frozen milk, sampling of, 27. standards, Government, . Gauges of cream, 165. Gelatine in cream, detection of, mete Gerber’s acid-butyrometer, 7; fermentation test, 128. Glassware used in the Babcock test, 38; calibration of, 47. Globulin, 15. Glycerides of fatty acids, 13. Goat cheese, 14. Government food _ standards, 231. Grain-feeding, heavy, influence of, on quality of milk, 143. Gurler’s method of _ testing cows, 138. Hand testers, 59. Hemi-albumose, 15. Herd milk, variations in, 142; ranges in variation of, 148. Hypoxanthin 19. Introduction, 1. Iowa station test, 5. Kumiss, 231. Lactic acid in milk, 16. Lactocrite, 5, 8. Lactose, 16. Lactochrome, 19. Lactometer, the, and its appli- cation, 93; bi-chromate, in- fluence on, 98; cleaning of, 99; degrees, 94; N. Y. board of health, 96, 236; Quevenne, 93; reading the, 97; time of tak- ing readings, 98. Index. Lecithin in milk, 19. Leffmann and Beam test, 5. Legal standards for milk, 102, 235. Liebermann’s method, 5. Lutley dividers, 37. Manns’ test, 110. Marschall rennet test, 130. Measuring fat column in test- ing cream, 83; in testing milk, 3D. Mercury, calibration with, 47; cleaning, 48. Metric and customary systems of weights and measures, comparison of, 259. Milk, acidity of, 108; adultera- tion of, 101; amphoteric re- action of, 108; ash, composi- tion of, 19; boiled, detection of, 227; chemical analysis of, 204; cholesterin in, 19; citric acid in, 19;. colostrum, 19; composition of, Tale table showing composition of, 233; composite sampling of, 148; condensed, 22, 90, 233; correc- tion tapie for specific grav- ity, 237; definitions, 231; de- tection of preservatives in, 124, 228; determination of aeidity. 120; 2185. of ash; 212) of casein and albumen. 209, 211; of fat, 208; of milk sugar, 212; of specific gravity, 204; of water, 207, 208; fat avail- able for butter in different grades of, «82; from cows in heat, 102; from sick cows, 102; from single cows,- sam- pling of, 139; variations in, 131; frozen, sampling of, 27; gases, 19; hypoxanthin, 19; lactochrome,' 19; lecithni, 19; legal standards, 102, 234; mi- ecroscopic impurities, 228; mineral components, 18; par- tially churned, sampling of, 24; quality of, influence of food, 145; of heavy grain 267 feeding, 143; of pasture, 145; method of improving, 146; sampling, 26; scales, 139; serum, 11; skimming, 156; solids, 11; calculation of, 99; specific gravity of, 103; sour- ing of, 16; sour, sampling of, 25; standards, 102, 2381, 234; sugar, 16; testing purity of, 125; urea, 19; water, 12; watering of, 106; watering and skimming, 106. Milk test, a practical, need of, 1; requirements of, 6; bottle, use of, in testing cream, 81; Russian, 70. Milk tests, Beimling (Leff- . Mann and Beam) 5;°Cochran, 5; DeLaval butyrometer, 8; Failyer and Willard, 5; Fjord, 9; foreign, 7; Gerber acid- butyrometer, 7; introduction of, 4; lactocrite, 5, 8; Lieber- mann, 5; Nahm, 5; Parson, 5; Patrick (Iowa station test), 5; retractometer, 10; Rdse- Gottlieb, 5; Schmied, 5; Short, 4; Thorner, 5. Milk products, composition of, 19, 233. Monrad rennet test, the, 129. Milk testing, 29; on the farm, 131. N.. Y. board of health lacto- meter, 96;degrees correspond- ing to Quevenne lactometer degrees, 236. Nafis modification of test bot- tle calibrator, 52. Nitrie acid test for adulteration of milk, 224. Non-fatty milk solids, 11. Normal solutions, 110. Nuclein, 15. Oil-test churn, 2, 166. Ohlsson test bottle, 87.. Oleomargarine, detection of, 219; cheese, detection of, 223. - 268 One-third sampling pipette, use OL, tbs: Organization of co-operative creameries and cheese fac- tories, suggestions concern- ing, 260. Overrun, 179; calculation of, 183; factors influencing, 179; table, 186, 255. Parson’s test, 5. Pasteurized milk or cream, de- tection of, 226. Pasture, influence of, on quality of milk, 145. Patrick’s test, 5. Patron’s dilemma, a, 162. Percentages, average, methods of calculation, 160; fallacy of averaging, 159. Phenolphtalein, 111. Physician’s centrifuge, use of, in milk testing, 73. Pipettes, 44, 53; proper con- struction of points, 45; pro- per method of emptying, 31; calibration, 53. Potassium bi-chromate, ‘156. Power testers, 61. Preservaline, 124, 220; detec- tion of, in milk, 124. Preservatives, for composite samples, 156; in milk, detec- tion of, 124, 220. Primost, 14. Process butter, detection of, 22m. Proteose, 15. Quevenne lactometer, the, 93; degrees corresponding to scale of N. Y. board of health lactometer, 96, 236. Recknagel’s phenomenon, 98. Refractometer, 10. Reichert number, 221. Reichert-Wollny method, 220. Relative-value tables, 196, 249. Rennet tests, 129. Testing Milk and Its Products. Renovated butter tests, for de- tection of, 221; boiling test, 221; Waterhouse test, 221. Reservoir for water in Babcock test, 71. R6se-Gottlieb method, 5. Russian milk test, the, 70.. Salicylic acid, tion of, 230. Sait, estimation in butter, 218. Sampling cheese, 89; milk, 23, 29; milk from single cows, 139. Sampling tube, for cream, 171; Scovell, 151; equity, 153. Scales for weighing cream, 78; milk, 139. Schmied method, the, 5. Scovell sampling tube, 151. Serum solids, 11. Short’s test, 4. Siegfeld’s modification of Bab- cock’s test, 73. Sinking fund, 195. Separator cream, 20. Skimming of milk, detection of, 106. Skim milk, 20; Babcock test for, 85; chemical analysis of, 213; composition of, 233; test bottles, 87, 88. Solids not fat, 11; formulas for calculating, 100; tables show- ing, corresponding to 0-6 per cent. fat and 26-36 lactometer degrees, 238. Sour milk, sampling of, 26. Space system, the, 165. Specific gravity, 93: cylinders, 94, 97; influence of tempera- ture, 95; of butter fat, deter- mination of, 220; of butter milk, 214; of condensed milk, 215; of milk, 204, 206; of milk solids, 103; of sour milk, 214; temperature correction table, 231» Speed required for separation of fat, 55. in milk, detec- complete Index. Spillman’s cylinder, 120. Standard measure for calibrat- ing test bottles, 52. Standards of purity, Govern- ment, for milk and its prod- ucts, 231. Starch in cream, 228. Steam turbine testers, 61, 62. Sulfuric acid, 63; table showing strength of, 65; testing strength of, 64. Sweetened condensed milk, 91. Swedish acid bottle, 46. Swedish acid tester, 66. Tank for cleaning test bottles, 43. Temperature of turbine testers, 62; of fat when tests are read, 36. Test bottles, 31, 38; apparatus for cleaning, 42: bulb-necked cream, 78; calibration, 53; cleaning, 40; cream, 78; ’ double-necked, 87; draining- rack for, 41; marking, 39; for cream testing, 78; for skim milk testing, 87; rack for use in creameries and cheese fac- tories, 154; tank for cleaning, 43, Winton cream, 79. Testers, 54; ascertaining speed of, 58; hand, 59; power, 61. Testing cows, number of tests required during a period of lactation, 136. Testing milk and its products, 1; on the farm, 131. Test sample, size of, 142. Thermometer scales, compari- son of, 257. Thermometer in frame of tur- bine testers, 63. Thoérner’s method, 5. Total solids in milk, 11; deter- mination of, 208. Trowbridge method of calibra- tion, 50. Turbine testers, 61, 62. Variation in butter, 177. composition of 269 Variation in quality of milk, 131, 143; causes of, 135; lati- tude of, 102; ranges in, 143. Volatile acids, 220. Wagner skim milk bottle, 88. Waste acid jar, 41. Water, calibration with, 49; de- termination of, in butter, 216; in cheese, 244; in milk, 207, 208; oil-stove for heating, 34; reservoir for, 69; to be used in tne Babcock test, 68. Waterhouse test, 221. Watering of milk, detection of, 106. Watering and skimming of milk, detection of, 106. Weights and measures, compar- ison of metric and customary, 257. Westphal balance, 206. Whey, 22; Babcock test for, 89; chemical analysis of, 213; composition of, 233; defini- tion, 232. Winton cream bottle, the, 79. Wisconsin creamery butter, summary of analyses, 178. Wisconsin curd test, the im- proved, 125. Wollny’s refractometer, 10. World’s Fair breed tests, com- position of butter from, 177; variation in quality of milk, 142. Yield of butter, calculation of, 176; and butter fat test, 176; trom milk of different rich- ‘ness, 182; table showing, from 1 to 10,000 lbs. of milk, testing 3 to 5.35 per cent., 253. Yield of cheese, calculation of, 187; relation between, and quality of milk, 187; table showing, corresponding to 2.5 to 6 per cent. of fat, with lactometer readings of 26 to 36, 256. Gesees SOS SSS SSS SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSOSSOSSSSSOSOSOOOO SAVED _A Billion Dollars to the Dairy Farmers and Buttermakers OF THE WORLD. That’s what the DE LAVAL CREAM SEP- ARATORS are estimated to have done since their invention twenty-five years ago. From creamery to farm their use has spread all over the world, until now more than 500,000 ma- chines are in use. No other invention ever did nearly so much for dairying. Have you had your share of this great sav- ing? If not there could be no better time to get in line for it. Don’t let any more of it go to waste. Send for a catalogue and name of nearest local agent. The De Laval Separator Co. RANDOLPH & CANAL STS. 121 YOUVILLE SQUARE, CHICAGO. General Offices: MONTREAL. 1213 FILBERT STREET, 75 & 77 YORK STREET, PHILADELPHIA. 74 CORTLANDT ST,, TORONTO. 9 & 11 Drumm St., NEW YORK. 248 McDERmoOT AVeE., SAN FRANCISCO WINNIPEG. SOSSSSSSSSSSSSSSSSSSSSSSSSSSSSS5999 9999S 9999S SSSSSSSSSSSSSSSSSSSSSSSSSSS50 Cososesosssosoooosossosososooosooscososoooosososoososeosesoososososossso THE “FACILE” lron Frame Babcock Milk Testers FACILE HAND TESTERS Sizes 6, 8, 10 and 12 Bottle » } ye Th FACILE STEAM TURBINE TESTER. 24 Bottle FACILE JR. TESTER] 2 Bottle FACILE STEAM TURBINE TESTER FACILE JR. TESTER 36 Bottle 4 Bottle D. H. BURRELL & CO., LITTLE FALLS, N. Y. Creamery, Cheese Factory and Dairy Apparatus and Supplies SEND FOR CATALOGUE VAUUUUUUURUUU0000000000000000000000000000000000000000 SaSAAAAAARAARAALALRAAAAALAALAARAAAAAABAABAAARAAARAA Accurate Creamery Glassware = q ¢ é ‘ I like to make glassware for the man who : dares me to please him with accuracy, q - quality, prompt services and low prices. , Anyone can make it for. the man that does 4 not care what he gets for his money just as } long as the bottles, etc., ‘‘look all right.”’ : Each and every piece of graduated glass- ‘ ware is thoroughly retested before shipping ‘ and when in need of a new supply and you : want such goods as I furnish to Dairy ‘ Commissioners and Dairy Schools in the ‘ United States and Canada, send me your orders. € q d 4 ‘ & Illustrated and Descriptive Catatogue Free upon Request | LOUIS F. NAFIS Bs EXPERT SPECIALIST, MILK TESTING APPARATUS 120-122 Randolph St. CHICAGO FECES EE EE SE Eee eee EE Ee aE EE EEE SS wat GERARD Suh toal teh Z A a Ge age ae ae ae a Fe ee a ee ae @oQqe @]OoOB 8 O2OB3B8B28 288883 B2832029 Chr. Hansen’s Lactic Ferment ee improves the flavor, uniformity and ‘CHR. HANSEN Ty keeping quality of butter and cheese tactic FERMENT) tp ce THE MARSCHALL RENNET TEST fon @) is indispensible for testing the milk —— in the Cheese Vat . me We are the manufacturers of Chr. Hansen’s Danish Rennet Extract, Cheese Color, Rennet Tablets and Cheese Color Tablets, Danish Butter Color and Columbian Butter Color. Write us for Descrip- tive Circulars oa Ree, Chr. Hansen’s =I es Laboratory Box 1031 LITTLE FALLS, N. Y. BWVVSV*V*SVSISI™IS*SVA*SBVS*SSES 4@0 2 © 2228282828200 2002 22 | t : | | | ! | TWO LEADERS The U. S. Separator and Agos Babcock Tester. The U. S. Separa- tor has always ex- celled in clean skim- ming and durability, and the 1904 Model “Low Can” places it farther in advance than ever before. Write for catalogue telling all about the latest improvements. If you don’t buy a U. S., you don’t get the best. As to the Superiority of the Agos Tester, we need but to call your attention to the following letter : Wisconsin Agrl. Exp. Station, Madison, Wis. The Turbine and Hand Agos Milk Testers, which you make, have been used in our Dairy School for several years. We have been well pleased with them, as they run smoothly and wear well. Iam glad to recommend them to anyone wanting a Babcock Tester. EK. H. FARRINGTON, (Prof. Dairy Husbd’y. ) IF INTERESTED, WRITE FOR CATALOGS. We have the following Western transfer points: La Crosse, Minneapolis, Chicago, Omaha, Sioux City, and Kansas City. Address all Letters to VERMONT FARM MACHINE COMPANY BELLOWS FALLS, VERMONT RUCUURCRURURUT00000000000080000000000000000000000000000 G9 9999999999 GS S9SSSSSSSSSSSSSSSS55S9S9599550 : WE MANUFACTURE EVERY } Apparatus and Instrument PERTAINING TO THE TESTING OF MILK AND ITS PRODUCTS SSSSSSSS5S9 Soe Se {= = mu We are the Sole Manufacturers of the following Q © 8 Wagner’s Patent Double-bore Skimmilk Test Bottle @ Wagner’s Patent Perfection Milk Test Bottle 8 Ghisson’s Patent Double-neck Skimmilk Test Bottle Russian Patent Pipette 8 Russian Patent Test Bottle and Reading Tubes Our glassware is handled by every reliable Dairy Supply House throughout the United States, Canada, England and Australasia. Ask your Supply House for the Wagner Goods and avail yourself of Absolutely Accurate Instruments. Our prices are right and our instruments are manufactured 8 ‘ in accordance with the Laws and are guaranteed to stand the test of the Agricultural Experiment Stations. Illustrated Price List Mailed upon Application THE WAGNER GLASS WORKS rs) 965-967 East 132d St., New York, N. Y. 0 COSSSSSSSSSSSSOSSOSSSSSSHSSOSSS SOSSSSSSSS 0CSSSSSSS55SS9S5S9S5S9555SS699 sooessosessoossosoososessossssssssossssoss SSSSSSSSSSS595SS EMIL GREINER NEW YORK CITY First Manufacturer of Babcock Test-bottles Guaranteed accurate goods for the Testing of MILK, CREAM, BUTTER, CHEESE, ETC. B99 9 9 99 9999 99S 999999999 SSS SSSSSSSSSS 0 0 0 5 © ] Farrington’s Alkaline Tablets For testing the acidity of milk and cream...... Bi-Chromate Tablets Blue Pill Tablets... For preserving composite samples of milk...... Wisconsin Viscogen For restoring the thickness” of pasteurized cream..... MANUFACTURED BY The Chas. S. Baker Co. Station R, Chicago, Ill. “\ SSFSSSSSSSSSESSSSSSSSSSSSESSLSESESSSESSS Try a Tubular Learn to Laugh Learn to laugh. Laugh at the other fellow when he gives you a chance—and makea chance to laugh by making your work easy and your profits good. If the other fellow buys a queer old bucket bowl separator, with a bowl full of suds making pieces—laugh. If you want a reason to Laugh Always Buy a Tubular Cream Separ- ator. You can’t buy the wrong Tubular — for there’s only one. You’ll find you’ve got a bucket bowl if you buy any other—for all others have bucket bowls. Here’s something simple — just a light Tubular Bowl — with only one plain little piece inside. The piece comes out—the bowl is washed —the piece is put back — all in three minutes. A Here’s something more —a low supply can — hardly waist high. A child can see into it — fill it — easily. Here’s another thing— entirely enclosed gears, run- ning in a mist of oil. No accidents, no oil cups to fill, no oil holes to dig out with a pin. Guess you see the difference between Tubulars and the bucket bowl kind. Our handsome catalog tells all about it—it is free for the asking. May we send you one? SH RE The Sharples Co., P. M. Sharples, Chicago, Ill. West Chester, Pa. ( ‘ SSFSFHSSESSSSSSSSSFSSSSSSSE SSS SSS SSSSSS SS SHSSSSSSSFSSSSSHSESSSHLHRELSS PDRELKKLKEKKKKELKKKKKKKKLKEKKLAKKKKKKKKLKKLKKLKKKLKKEKLKKLKKKLKLKKKKKKKLKKKKKKKKKKKK * KBE L EER LERREEREARERERERERHERELEREERERER ee BOOKS The following books on dairying and related topics will be sent, postage prepaid, upon re- ceipt of the price given. Woll, Handbook for Farmers and Dairymen. Third ed., INlew MOrie L003 FASS qo Wie esecnensessanenrekad os eplacewSconsokaesseeserccmvane $1 50 Grotenfelt-Woll, Principles of Modern Dairy Practice. Mhird ed, New York, 1899) 286) (Ds. nc...sc0sstec-cevonsvenscseocecooe 52 00 Wing, Milk andits Products. Sixth ed., New York, 1903, EULA eee een eeeeee ns lee wheedac SPO Se 8 ee ae 4 | UO008954b04 i : : : : AIDA