THE UNIVERSITY OF ILLNIOIS LIBRARY 1e NOTICE: Return or renew all Library Materialsl The Minimum Fee for each Lost Book Is $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN AUG 2 4 1390 MAR 0 1 2! 20 m L161— O-1096 Issued April 21, 1911. U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY.— Bulletin 134. A. D. MELVIN, Chief of Bureau. THE ESTIMATION OF TOTAL SOLIDS IN MILK BY THE USE OF FORMULAS. BY R. H. SHAW, Dairy Chemist^ Dairy Division, AND C. H. ECKLES, Professor of Dairy Husbandry, University of Missouri. WASHINGTON: GOVERNMENT PRINTING OFFICE, THE BUREAU OF ANIMAL INDUSTRY. Chief: A. D. Melvin. Assistant Chief: A. M. Farrington. Chief Clerk: Charles C. Carroll. Animal Husbandry Division: George M. Hommel, chief. Biochemic Division: M. Dorset, chief. Dairy Division: B. H. Rawl, chief. Inspection Division: Rice P. Steddom, chief; R. A. Ramsay, Morris Wooden, and Albert E. Behnke, associate chiefs. Pathological Division: John R. Mohler, chief. Quarantine Division: Richard W. Hickman, chief. Zoological Division: B. H. Ransom, chief. Experiment Station: E. C. Schroeder, superintendent. Editor: James M. Pickens. DAIRY DIVISION. B. H. Rawl, Chief Helmer Rabild, in charge of Dairy Farming Investigations. S. C. Thompson, in charge of Dairy Manufacturing Investigations. L. A. Rogers, in charge of Research Laboratories. George M. Whitaker, in charge of Market Milk Investigations. Robert McAdam, in charge of Renovated Butter Inspection. 2 LETTER OF TRANSMITTAL. U. S. Department of Agriculture, Bureau of Animal Industry, Washington, D. C, November 26, 1910. Sir: I have the honor to transmit herewith, and to recommend for publication in the bulletin series of this bureau, a manuscript entitled '^The Estimation of Total Solids in Milk by the Use of Formulas," by R. H. Shaw, of the Dairy Division of this bureau, and C. H. Eckles, of the Missouri Agricultural Experiment Station. The experimental work herein described forms a part of the investigations concerning milk which are being conducted at the Missouri station in cooper- ation with thi^ bureau. Owing to the necessity for some more rapid method of calculating the solids in milk than the usual laboratory procedure, the estimation of these constituents by means of formulas has been a common dairy practice for some years; and while a certain amount of error was known to exist in such calculations, it was assumed to be small enough to be negligible for most practical purposes. Inasmuch, how- ever, as a number of formulas are in use, each differing slightly in results from the others, it became a question of some importance to determine which of them was the most accurate. With the object of solving this problem the authors have made searching tests under exacting conditions of several of the best known formulas, and have in addition devised an improved lactometer which, with a table based upon the results of the work described in this bulletin, is believed to furnish a method which is more nearly accurate than any at present in use. Respectfully, A. D. Melvin, Chief of Bureau, Hon. James Wilson, Sea-etary of Agriculture. 3 CONTENTS. Page. Introduction 5 Synopsis of formulas in vogue 6 Experiments to compare the accuracy of existing formulas 7 Methods of calculation and terminology 8 Method of sampling 8 Method of determining specific gravity and total solids 9 Comparison of the formulas with gravimetrically determined results 9 The specific gravity of milk solids 11 Experiments to determine accuracy of lactometers 15 Tests of Babcock formula and new lactometer with individual milkings 17 Effect of temperature on specific gravity of milk 19 Recknagel 's phenomenon 20 How to use the modified lactometer and table 21 Method 21 Directions for using the table 22 Summary and conclusions 25 Appendix 26 ILLUSTRATION. Page. Fig. 1. Lactometer designed for use in experimental work 16 4 THE ESTIMATION OF TOTAL SOLIDS IN MILK BY THE USE OF FORMULAS. INTRODUgTION. Various formulas have been in use for a number of years as a means of determining the total solids in milk when the specific gravity and percentage of fat are known. This rapid estimation of the total soUds is a useful and convenient method for purposes where exactness is not required. Among the more common uses that have been made of this method is the preliminary examination of market milk by inspectors and the detection of adulterations at cheese factories. Recently certain organizations representing the dairy breeds of cattle have considered the advisability of reporting the percentage of total solids as well as of fat in makiag official tests of individual cows. It therefore became a question as to whether the determina- tion of the total solids by means of the formulas and the instruments in common use for finding the specific gravity was feasible and accu- rate enough. In view of this question Mr. Ed. H. Webster, then Chief of the Dairy Division of the Bureau of Animal Industry, requested the authors to take up the problem with the view of testing the accuracy of the estimation of total solids by the several formulas in common use and to suggest improvements looking toward greater accuracy in finding the specific gravity without making the determination impracticable for use by such men as usually have charge of official testing. For the present purpose milk may be regarded as composed of fat and milk plasma, the latter being made up of water and the various milk solids not fat, such as the proteins, sugar, ash, and other solids. Fat, having a specific gravity less than water, has the effect of lower- ing the specific gravity of milk, while the plasma solids, having a specific gravity greater than water, have the effect of raising it. It is clear, then, that a relation exists between the specific gravity of milk and its percentage of fat and solids not fat. The various for- mulas for calculating total solids or solids not fat, when the other two factors are given, are based upon this relation. It is not the purpose of this bulletin to bring out a new formula or to suggest modifications or revisions of those already in use. - The 5 6 ESTIMATION OF TOTAL SOLIDS IN MILK. main objects of the investigation herein reported were: (1) To com- pare the percentages of total soHds calculated by means of certain formulas in general use with those obtained gravimetrically in the laboratory; (2) to test under more exacting conditions the formula which yields results closest to gravimetrically determined total solids, and (3) to devise a new or modify an exis^ting lactometer with which the specific gravity may be more accurately determined. The authors desire to acknowledge their indebtedness to A. E. Perldns and G. C. Payne, of the Dairy Division and Missouri Agri- cultural Experiment Station, for assistance rendered in obtaining the data included in this bulletin. SYNOPSIS OF FORMULAS IN VOGUE. Behrend and Morgen ^ published in 1879 the first formula of which there is an}^ record which attempts the calculation of total solids from the specific gravity and the percentage of fat. They were closely followed in the same year by Clausnitzer and A. Mayer,^ who pub- lished another formula. These two formulas were, however, based on inaccurate data and have since been abandoned. Since that time numerous other formulas have been proposed, among them being one by Fleischmann and Morgen.^ In this formula the specific gravity of butter fat was assumed to be 0.94. This was changed to 0.93 by Fleischmann,^ and the formula thus revised is still in general use and is one of those compared in this investigation. Hehner's ^ formula appeared in 1882, that of Halenke and Moeslinger ^ in 1886. and that of Hehner and Richmond ' in 1888. The latter formula was revised in 1894 b}^ Richmond,^ and the revised form is known as Richmond's new formula. Babcock ^ published his formula in 1891, but changed it four years later. Comparisons of the various formulas with gravimetrically deter- mined total solids have appeared from time to time. Such compari- sons were made in 1889 by Woll," who worked with the Fleischmann and the Hehner and Richmond formulas. In his conclusions, which are in favor of the Fleischmann formula, he states that it may 1 Journal fiir Landwirtschaft, Band 27, p. 249. Berlin, 1879. 2 Forschunfjen auf dem Gebiete der Vieh-haltung und ihrer Erzeugnisse, p. 2G5. Bremen, 1879. 8 Journal fiir Landwirtschaft, Band 30, p. 293. Berlin, 1882. 4 Journal fiir Landwirtschaft, Band 33, p. 251. Berlin, 1885. 5 Analyst, Vol. VII, p. 129. London, 1882. fiChemiker-Zeitung, Jahrg. 10, semester 1, Chemisehes Repertorium, p. 8. Cothen, 1886. 7 Analyst, vol. 13, p. 26. London, 1888. 8 Proceedings of the Eleventh Aimual Convention of the Association of Official Agricultural Chemists, Washington, D. C, Aug. 23-25, 1894, United States Department of Agriculture, Bureau of Chemistry* Bulletin 43, p. 181. » Eighth Annual Report of Wisconsin Agiicultural Experiment Station, 1891, p. 292. Madison, 1892. 10 Twelfth Annual Report of Wisconsin Agricultural Experiment Station, 1895, p. 120. Madison, 1896. 11 Agricultuial Science, voL 3, p. 129. State College, Pa., 1889. EXPERIMENTS WITH EXISTING FORMULAS. 7 be used to advantage for calculation of total solids if the specific gravity of milk is taken at 15° C. In the early nineties the Association of Official Agricultural Chemists made some comparisons of the Fleischmann, the Hehner and Richmond, the Babcock (original), and the Richmond formulas. Their results are published in the proceedings of their tenth ^ and eleventh ^ annual conventions, and in commenting on the same they state that the Hehner and Richmond formula gave figures which compared best with those obtained gravimetrically. EXPERIMENTS TO COMPARE THE ACCURACY OF EXISTING FORMULAS. In a cooperative experiment between the Missouri Agricultural Experiment Station and the Dairy Division of the Bureau of Animal Industry, United States Department of Agriculture, a study was made of the changes in chemical composition which milk undergoes during the natural period of lactation. Among many other factors the specific gravity and the percentages of fat and total solids were determined under controlled conditions. These determinations were made on 12 animals through one entire lactation period, and on 2 of the animals through two entire lactation periods. Having these data at hand, it became purely a matter of substitution to apply the figures obtained for the specific gravities and the percentages of fat in some of the most frequently used formulas for determining total solids when these two factors are known, and comparing the figures so obtained with the corresponding percentages of total solids deter- mined gravimetrically. As stated in the introduction, several formulas have been published, but perhaps of these the four most used are those derived by Babcock (revised), Hehner and Richmond,^ Richmond, and Fleischmann. In the general lactation experiment above referred to the samples were taken from the very beginning of the lactation period to the very end of the period, but since the pur- pose of this investigation is to show the application of various formulas in determining total solids in normal milk, it was thought best to exclude the extremes from the comparisons, and so the figures, except when otherwise stated, refer to milk of normal composition. The 12 animals used in the investigation included 3 each of 4 breeds — Holstein-Friesian, Jersey, Ayrshire, and Shorthorn. Accord- ing to the general plan these animals were kept on a uniform ration 1 Proceedings of the Tenth Annual Convention of the Association of Official Agricultural Chemists, Chicago, Aug. 24-26, 1893. U. S. Department of Agriculture, Bureau of Chemistry, Bulletin 38, p. 107. 2 Proceedings of the Eleventh Annual Convention of the Association of Official Agricultui'al Chemists, Washington, D. C, Aug. 23-25, 1894. U. S. Department of Agriculture, Bureau of Chemistry, Bulletin 43, p. 182. 3 The formula of Hehner and Richmond was compared in the same way as the others, but the results were so nearly identical with those of the Babcock formula that it was thought best to omit them from this bulletin. 8 ESTIMATION OF TOTAL SOLIDS IN MILK. throughout the entire milking period in order to eUminate possible changes in the composition of the milk due to feed. This ration con- sisted of alfalfa hay, three-fifths, the other two-fifths being made up of corn 8 parts, bran 1 part, and oats 1 part. The ratio between the hay and the grain was kept the same at all times. The cows were kept in the barn during the night and in an adjoining lot having no grass or other food during the day. The animals were fed and milked twice daily, at 5 a. m. and 4 p. m. The ration served to keep the animals in good condition, and the production of milk was about typical of the breeds, although not equal to that produced previously by the same animals when opportunity was given to vary the ration and adapt it to the needs of the individual. ; METHODS OF CALCULATION AND TERMINOLOGY. In preparing the mass of calculations involved in this bulletin free use was made of tables prepared by the several authors of the for- mulas. In calculating and averaging percentages the rule followed was to discard the third decimal figure when it was less than 5, and to increase the second by one when it was 5 or more. This will explain what may appear to be discrepancies in some of the tables. To be strictly accurate the average of a series of specific-gravity determinations must be made by first converting the result for each determination into terms of specific volume. These figures may then be averaged in the usual manner and the resulting average converted back into terms of specific gravity. The error introduced, however, by simply dividing the sum of the specific gravities by the number of determinations was so very small that the averages given in this bulle- tin were all made in this way. In order to avoid confusion, the term plasma" is employed to designate whole milk minus the fat; "plasma solids" to designate the solids in milk minus the fat; and " total solids" the solids including the fat. METHOD OF SAMPLING. The milk was weighed after milking and mixed by pouring it back and forth from one pail into another. A sample of about 1 quart was placed in a glass jar bearing the number of the cow and the num- ber of pounds for that particular milking, and delivered to the laboratory. A certain number of cubic centimeters per pound were then measured out and placed in a covered receptacle to make up a composite sample to represent a week's milk from that particular cow. Formaldehyde was added in the proportion of 1 part to 5,000 to preserve the sample. At the end of the week the composite sample was thoroughly mixed and a subsample taken for chemical analysis. GRAVIMETRICALLY DETEBMINED RESULTS. 9 METHOD OF DETERMINING SPECIFIC GRAVITY AND TOTAL SOLIDS. The specific gravity of the milk was determined at 15° C. by means of a Westphal balance. The determinations of fat and total solids were made by the Bab- cock asbestos method. A woolly asbestos was used in perforated copper cylinders, and the determinations were conducted according to the official method as described in Bulletin 107 (revised) of the Bureau of Chemistry, United States Department of Agriculture. COMPARISON OF THE FORMULAS WITH GRAVIMETRIC ALLY DETERMINED RESULTS.^ The main table showing the comparisons of the three formulas in the individual cases is found in the appendix. Tables 1, 2, and 3, imme- diately following, are made up of averages from figures in the main table. No explanation will be needed to show how the various figures are obtained. A study of the tables will show that in the case of every cow, regardless of breed or individuality, the Babcock for- mula yielded results closest to those obtained by gravimetric deter- mination of the total solids. A comparison of the results obtained by the Babcock formula with the gravimetric results shows that 256, or 59.53 per cent, of the 430 cases agree within 0.25 per cent, and that 389, or 90.46 per cent, agree within 0.5 per cent. Using Richmond's formula in the same way, 360, or 83.7 per cent, of the cases fall within the prescribed limit of 0.5 per cent. Likewise Fleischmann's formula shows 309 cases of agreement, or 71.85 per cent. With the Hehner and Richmond formula, the figures of which are omitted from this publication for reasons previously stated, there was a similar agree- ment in 387, or 89.99 per cent, of the cases, showing that this formula yields results practically identical with those derived from the Bab- cock formula. A study of Table 4 will reveal the fact that the calculated figures from the Babcock formula do not differ from the gravimetric figures in any uniform direction, but that the plus and minus differences nearly counterbalance. That they do nearly counterbalance is shown conclusively in Table 3, where it will be seen that the average figure for the calculated solids for the entire series of comparisons differs only 0.07 per cent from the corresponding average figure determined gr avime trically . 1 In some cases in this bulletin the specific gravities are given in terms of Quevenne degrees. These degrees, of course, refer to the arrar^gement of the scale on the style of the lactometer known as the Quevenne lactometer. Quevenne degrees are converted into specific gravity by dividing by 1,000 and then adding 1 to the quotient. For example, if the Quevenne reading is 32.5 the specific gravity is 1.0325. 76857°— Bull. 134—11 2 10 ESTIMATION OF TOTAL SOLIDS IN MILK. Table 1. — Number of instances where Jhe total solids calculated by the Babcock, Richmond, and Fleischmann formulas lie within stated limits of the gravimetrically determined total solids. [Number of cases.] Cow No. Between 0 and 0.24 per cent. Between 0.25 and 0.49 per cent. Between 0.50 and 0.74 per cent. Between 0.75 and 1 per cent. Over 1 per cent. Babcock. Richmond. Fleischmann. Babcock. Richmond. Fleischmann. Babcock. Richmond. Fleischmann. I Babcock. Richmond. Fleischmann. Babcock. Richmond. Fleischmann. 4 20 15 15 15 14 18 10 10 14 4 16 16 6 9 11 9 7 11 1 6 2 4 12 4 4 11 8 2 9 99 2 Total for breed 50 30 20 30 47 26 17 26 34 16 16 23 36 12 15 6 26 1 27 9 3 5 9 20 6 7 6 23 10 7 2 1 "i" 2 1 1 3 11 2 5 7 205 206 13 15 10 17 12 13 1 1 2 209 Total for breed 300 1 1 80 69 55 33 38 42 17 19 19 2 5 14 1 2 3 12 14 17 23 9 15 14 14 22 8 15 8 11 16 4 11 9 5 12 2 9 7 9 11 2 5 9 8 12 6 3 1 3 1 1 1 3 2 3 1 5 6 4 7 1 1 1 1 2 1 1 301 301 302 1 .... 1 Total for breed 400 75 73 54 39 38 40 9 10 23 1 2 6 1 1 23 21 7 21 17 3 14 11 3 11 7 7 10 10 8 14 10 5 1 1 3 2 3 5 7 6 1 2 1 402 403 Total for breed 51 41 28 25 28 29 2 8 18 1 3 Total cases 256 230 171 133 130 138 37 57 83 3 10 34 1 3 4 Table 2. — Data of Table 1 expressed in percentages. [Per cent of cases.] Cow No. Between 0 and 0.24 per cent. Between 0.25 and 0.49 per cent. Between 0.50 and 0.74 per cent. Between 0.75 and 1.00 per cent. Over 1 per cent. M o 8 m fl O 1 d 1 o '53 o ,o & pq 1 d g 1 o yi '53 8 % pq g 1 5 d d 1 o in 'S o « M 13 Cl o 1 d 9 1 o 8 24. 32 M o o o « ■ g s o s d 1 S 4 80 40.54 45. 45 60 37.84 54. 55 40 27.03 42.42 16 43.24 48.49 24 24.32 33.34 36 18.92 33.34 4 16.22 6.06 16 32.43 12.12 16 29. 73 24. 24 99 5.41 118 Percent for breed. 205 52. 64 49.48 35.80 37. 89 27.. 37 28.41 9.47 21.05 24.21 2.10 U..58 1 63. 83 50 65.21 55.33 42.50 56.52 34.04 40 50 2^.M 27.66 36.16, 6.38 30 12.50 28.2619.56 12.76 17.50 13.05 21.27 17.50 4.35 2. 13 2.' 17 2.13 2.50 6.52 4.26 12. 50 15.22 2. 13 2.13 4.26 206 37. 50 13.04 37.50 21.74 209 2.17 2.17 Percent for breed. 300 300 60. 15 51.87 41.35 24.80 28.57 31.51 12.77 19.2311.53 37.501 4.17 14.29 14.29 1.50 3.67 10.52 .75 1.50 2.26 46. 15 58.33 68 62. 16 57.69 58.34 56 59.46 m fis 57. 69 33.33 44 43.24 33.34 42.32 37.50 20 32.44 16.66 34.61 29.17 36 3. 85 12.50 8 8.11 8.33 19.23 25 16 18.92 8.33 3.85 3.85 4.17 8 2. 70 8.33 4.84 301 32 12 2.70 8.34 301 302 29.73:32.44 16.66.50 2.70 "8."33 2.70 2.70 Per cent for breed. 400 60.49 65. 70 72.41 50 59.68 43. 55 31.46 30.65 32. 26 7.26 8.07 18.'55 .81 .81 .81 .81 60 .58.02 21.43 40 .37. 93 21.43 31.44 24.14 50 28. 57 34.48 57.14 40 34.48 35. 72 2.86 3.45 8. 57 6. 90 21 . 43 14.29 24.14 42.85 2.86 ^771 3.45 402 403 Percent for breed. Total percent 65.39 51.29 34. 61 32.05 37.18 37. 18 32.09 2.56 10.26 24.36 1.28 3.85 59.53 53.48 39.76 30.93 30.23 8.60 13.25 19.30 .70 2.32 7.90| .23 .70 .93 SPECIFIC GRAVITY OF MILK SOLIDS. 11 Table 3. — Average specific gravity, nitrogen, sugar, fat, and total solids for each cow, each breed, and the total average. Cow No. Specific gravity of milk. Total nitro- gen. Sugar. IT of Solids not fat. Total solids- gravi- metric. Total solids— Bab- cock. Total solids- Rich- mond. Total solids— Fleisch- mann. 4 99 118 Average for breed 205 206 209 Average for breed 300 300 301 301 302 Average for breed 400 402 403 Average for breed Total average Degrees. 33. 4 32.9 34.2 P. ct. 0.61 .53 .65 P. ct. 4. 79 4. 99 4. 87 P. Ct. 4.88 4.70 5.39 P. ct. 9. 23 8.95 9. 66 P. ct. 14. 19 13.65 15.05 P. ct. 14.21 13.87 15.02 P. ct. 14.35 14.02 15.16 P. ct. 14.47 14. 13 15.28 33.5 :60 4.88 4.99 9. 28 14.30 1 14.37 14.51 14.63 32.9 29.8 31.4 .47 .44 .52 5.09 4. 25 4. 29 3.23 2.96 3.09 8. 78 7.98 8.45 11.99 i 12.10 10.94 11 11.51 1 11.54 12. 24 11.16 11.70 12. .37 11.26 11.80 31.4 .48 4. 54 3.09 8. 40 11.48 11.55 11.70 11.81 3.3.3 31.8 .33. 1 32.6 31.7 .60 .48 .54 .51 .55 4. 86 4. 84 5.02 5 4. 78 4. 20 3.49 4. 28 3.84 4.49 9.23 8. 56 9.11 8. 85 8. 77 13.43 12.05 13.39 12.72 13. 24 13.38 12. 12 13.41 12.77 13.32 13.52 12.28 13. 54 12.93 13.48 13. 64 12. .39 13. 67 13.04 13. 58 32.5 .54 4. 90 4. 06 8. 90 12.96 ! 13 13. 15 13.26 33.9 33.8 33.2 .53 .54 .49 5.09 4. 97 5.23 3.86 4.04 3.34 9. 22 9. 16 8. 79 13.08 13.20 12. 12 13. 12 13.28 12.31 13.24 13.41 12. 49 13.38 13.55 12. 50 33.6 .52 5. 10 3.75 9.06 12.80 1 12.90 13.05 13.14 32.8 .54 4.86 3. 97 8.91 12.89 12.96 13.10 13.21 THE SPECIFIC GRAVITY OF MILK SOLIDS. Assuming that milk is a mixture of milk plasma and fat, it will be seen at once that if the specific gravities of the fat and of the plasma solids were constant quantities the relation of the specific gravity of the milk, the percentage of fat, and the percentage of plasma solids could be expressed mathematically. From such a mathematical relation it would be but a step to derive a formula for finding any one of these factors when the other two were given. The specific gravity of butter fat is about 0.93 at 15° C, the varia- tion from this figure in different samples being so slight as to be negligible for all practical purposes. It may then be considered as a constant, and is so treated in the formulas compared in the previous part of this bulletin. The specific gravity of the plasma solids is not a constant, but varies in different samples of milk. This variation is, however, not a large one, being generally within comparatively narrow limits in normal milk. It is because of these narrow limits that formulas are admissible. Richmond,^ working in England, found from the analyses of over 200 samples of milk the average specific gravity of the plasma solids to be 1.616. Fleischmann ^ obtained the figure 1.6007 from the aver- age of a large number of samples from cows in North Germany. The 1 Richmond's Dairy Chemistry, p. 6. London, 1899. 2 Fleischmann's Book of the Dairy, p. 33. London, 1896. 12 ESTIMATION OF TOTAL SOLIDS IN MILK. latter investigator has published a formula for calculating the specific gravity of the plasma solids when the specific gravity of the milk, the percentage of fat, and the percentage of total solids are known, thus: sXo(t-f) ^~100Xo-sXo(100-0-s/ The values for the specific gravity of plasma solids, the specific gravity of milk, the percentage of total solids, the percentage of fat, and the specific gravity of the fat in this formula are denoted, respectively, b}'' the letters n, s, t,f, and o. Applying this formula to the average of the 430 determinations given in Tables 1, 2, and 3 it is found that 1.638 is the average specific gravity of the plasma solids. It has already been noted that the Fleischmann formula gave figures higher than the Richmond, which in turn gave figures higher than the Babcock. Since the average of the total solids determined by the latter agreed very closely with our gravimetrically determined total solids, it may be inferred that if Babcock had given a figure for the specific gravity of plasma solids to correspond with his revised formula, it would have been very close to our figure. It may be seen that the difference between these three formulas is largely due to the difference in the specific gravity of the plasma solids of the milk chosen by the respective investigators to represent the normal. As previously noted, Babcock's original formula appeared in 1891 and its corrected form in 1895. As it originally stood it was: Plasma -lid. = (j^^|4^- l)x (100-/) 2.6 In the above, S represents the specific gravity and/ the percentage of fat. Subsequent to its publication Babcock found the constant, 2.6, too high and changed it to 2.5, so that the formula as it now stands is: Plasma solids = ( ^„,^^"^^-g^^ - l)x (100 -/) 2.5 This revised form is the one used in the former part of this bulletin.* In deriving this formula Babcock assumes that the difference between the specific gravity of water and that of milk plasma is nearly in direct proportion to the solids which the plasma contains,^ and that if this difference be divided by a constant factor which 1 With the exception of the introduction of a few intermediate steps and the substitution of the term plasma for serum, the subject-matter showing the derivation of the Babcoclc formula was taken almost verbatim from his original article, to which reference has already been made. When the revised formula was published no figures for the values of x and a were given. Rather than use his original figures, which are now obsolete, it was thought advisable to use our own figures for the purposes of illustration; hence the factor 2.47 will be found in the resulting formula instead of 2.5. '' Dr. Babcock calls attention to the fact that this assumption is not quite correct (see Twelfth Annual Report, Wisconsin Agricultural Experiment Station, p. 121), since if the plasma solids were always of the same composition the specific gravity of the plasma solids and the plasma would change at different rates. This error, he states, is a very small one and is counterbalanced by the variation in the composition of the plasma solids in normal milk. SPECIFIC GRAVITY OP MILK SOLIDS. 13 represents the increase in specific gravity caused by 1 per cent of plasma solids the result will be the percentage of solids in the plasma. If the percentage of solids in the plasma found in this way be multi- plied by the percentage of plasma in the milk and the product divided by 100, the result will be the percentage of plasma solids in the milk Let /= percentage of fat in any milk. 100 —/= percentage of plasma in any milk. ;S' = specific gravity of milk at 60° F. 0.93 = specific gravity of butterfat at 60° F. 0? = specific gravity of plasma at 60° F. a = increase in the specific gravity of the plasma caused by 1 per cent of plasma solids. Then, I.— Percentage of plasma solids in any milk = X = volume in c. c. of 100 grams of milk. "^^^ ^ = volume in c. c. of plasma in 100 grams milk. f or 1.0753/= volume in c. c. of fat in 100 grams milk. Since the volume of the milk equals the sum of the volumes of fat and plasma, then o X Clearing of fractions and reducing 100a; = lOOS - Sf+ 1.07 bSSfx Transposing and combining x(100 - 1.0753;S/) = lOOSf-Sf ^ lOOS-Sf ^^^^100-1.0753>S/ II. By first getting a value for x from a large number of analyses a is found. Subtract 1 from x and divide the remainder by the per- centage of solids which the plasma contains. The percentage of solids in the plasma is found by dividing the percentage of plasma solids in the milk by the percentage of plasma (100—/) and multi- plying by 100. The value of a in our work is 0.004044. Substituting the value of x and a in I. lOOS-Sf 100-1.0753/S/ 100-/ .004044 ^ 100 then C lOQ^f 0753^/ ~ 0^ ^100 ~/) X 2.4703 = percentage of plasma solids in the milk. 14 ESTIMATION OF TOTAL SOLIDS IN MILK. The percentage of total solids is found by adding the percentage of fat to the percentage of plasma solids. It will readily be seen that Babcock's value of representing the increase in specific gravity of the plasma caused by 1 per cent of the plasma solids depends directly upon the specific gravity of the plasma solids. This is a common point of weakness in all formulas derived for the same purpose. Since the plasma solids are composed of several solids, chief of which are milk sugar, proteins, and ash, the specific gravity of the plasma solids must depend upon the specific gravity of the various components taken individually. Richmond ^ states that the specific gravity of milk sugar is 1.666, that of the proteins 1.346, and that of the ash 4.12. A change in the ratio of the milk sugar and the pro- teins will affect the specific gravity of the plasma solids and conse- quently the value of a. With a milk containing an abnormally high percentage of sugar the total solids calculated by the formulas would be theoretically too high. They would be too low under the reverse condition. This is very well shown in the table below, the results in which are obtained from milk of a cow of the Shorthorn breed at the parturition period. As is well known, the milk taken at this time is abnormally high in proteins, while the milk sugar is abnormally low. The cow freshened on the morning of October 23. Table 4. — Showing application of the Bahcock formula to colostrum milk. Date. Total nitrogen. Fat. Sugar. Total Gravi- metric. solids. Babcock formula. Per cent. Per cent. Per cent. Per cent. Per cent. Oct. 23— a. m 2. 26 1.30 2.65 22.22 12. 86 Oct. 24— a. m 1.24 3.26 3.81 15.78 12.55 Oct. 24— p. m 1.09 4.57 4. 41 10. 53 14.06 Oct. 25— a. m .98 5. 42 4. 89 17. 19 15. 04 Oct. 25— p. m .93 5.08 4.63 16.34 14.67 Oct. 26— a. m .87 6. 23 4.79 17.04 16. 01 Oct. 26— p. m .82 5.35 5.40 16. 06 14.88 Oct. 27— a. m .79 5.87 5. 53 16. 85 15.53 Oct. 27— p. m .73 5.60 4. 96 15. 26 15.18 Table 5 was prepared from averages given in Table 3. The specific gravity of the plasma and the increase in specific gravity of the plasma caused by 1 per cent of plasma solids (Babcock's value a) were calculated by means of the Babcock formula. The specific gravity of the plasma solids was calculated by the formula of Fleisch- mann, to which reference has already been made. The last column of figures shows the factor which would result in each case were our figures for the value of a substituted for Babcock's in his formula. > Richmond's Dairy Chemistry, p. 65. ACCURACY OF LACTOMETERS. 15 Table 5. — Average data for each breed of cows. Breed. Num- ber of anal- yses. Average specific gravity of milk. Average fat content. Average total solids. Average specific gravity of plasma. Average specific gravity of plasma solids. Average value for a. Factor. Jersey Holstein Ayrshire Shorthorn All breeds 95 133 124 78 430 1.0335 1.0314 1.0325 1.0336 1.0328 Per cent. 4. 99 3.09 4.06 3. 75 3.97 Per cent. 14.30 11.48 12.97 12. 80 12. 89 1.03958 1.03500 1.03734 1.03811 1.03752 1.648 1.624 1.637 1.650 1.638 0. 004052 . 004038 .004025 . 004049 . 004044 2. 468 2. 477 2.485 2.469 2.470 It will be noted that there is no great variation in the figures in the last three columns, and also that the factor is but slightly different from Babcock's 2.5. This would, of course, follow from the close agreement between the grand average figures for the gravimetric total solids and that calculated by the Babcock formula. EXPERIMENTS TO DETERMINE ACCURACY OF LACTOMETERS. Having found which formula was best adapted for the purpose, the next question which naturally suggests itself is w^hether the ordi- nary lactometer when used to determine the specific gravity of milk is sufficiently accurate. Thirteen lactometers were available for comparison; 11 of these were Quevenne lactometers and 2 were of the type known as the New York Board of Health lactometer. These were thought to represent fairly well the ordinary lactometers on the market. They were com- pared with the Westphal balance on three different samples of milk, with the following results: Table 6. — Showing comparisons of various lactometers with Westphal balance. Instniment. Specific gravity of milk samples. Instrument. Specific gravity of milk samples. Skim milk. Hol- stein. Hol- stein fresh. Skim milk. Hol- stein. Hol- stein fresh. Quevenne lactometer 1 . . . 1.0345 1.0315 1.0325 Quevenne lactometer 9. . . 1.0350 1.0320 1.0330 Quevenne lactometer 2. . . 1.0340 1.0310 1.0320 Quevenne lactometer 10. . 1.0335 1.0310 1.0318 Quevenne lactometer 3. . . 1.0340 1.0315 1.0325 Quevenne lactometer 11. . 1.0350 1.0320 1.0330 Quevenne lactometer 4. . . 1.0335 1.0300 1.0320 New York Board of Quevenne lactometer 5. . . 1.0330 1.0300 1.0315 Health lactometer 1 1.0328 1.0307 1.0319 Quevenne lactometer 6 . . . 1.0340 1.0310 1.0325 New York Board of Quevenne lactometer 7... 1.0360 1.0330 1.0340 Health lactometer 2 1.0299 1.0281 1.0290 Quevenne lactometer 8 . . . 1.0370 1.0335 1.0350 Westphal balance 1. 0345 1.0313 1.0325 A glance at the foregoing figures will show discrepancies which are sufficient in some cases to account for as much as 1 per cent of total solids calculated from the Babcock formula. Of course, much of the discrepancy is due to the fault of the manufacturer in not 16 ESTIMATION OF TOTAL SOLIDS IN MILK. properly calibrating the instruments. However, in none of the lactometers tested was the scale divided into less than whole Quevenne degrees. Fractions of degrees could be read only by interpolation, and then the divisions were generally so narrow that a closer inter- polation than one-half of a degree was impossible; in fact, in some cases it was hardly possible to read closer than whole degrees. One Quevenne degree with a Bab- cock formula will account for 0.25 per cent of total solids. It is therefore obvious that the ordinary lactometer is unsuited for other than very gross results. The sensitiveness of the hydrometer, or lactom- eter, as it is termed when made for the special pur- pose of determining the specific gravity of milk, depends upon the ratio of the size of the bulb to the diameter of the stem. The larger the bulb is in pro- portion to the diameter of the stem, the more sensi- tive will be the lactometer, or, in other words, the longer will be the spaces representing units on the scale. A lactometer, then, may be made more sen- sitive by either diminishing the size of the stem or by enlarging the bulb. But the smaller the stem the more fragile is the instrument, and the larger the bulb, the more cumbersome. In designing a lactometer for our work several points were taken into account: (1) That it should accommodate the usual ranges of normal milk; (2) that it should have scale divisions representing tenths of Quevenne degrees; and (3) that it must be neither too fragile nor too cumbersome for prac- tical use outside of a chemical laboratory. After considerable experimenting in the labora- tory the dimensions of an instrument were decided upon and several were made to order from our specifications. (See fig. 1.) In order to test these lactometers against the Westphal balance, salt solutions were used, and the following results were obtained : Fig. 1.— Lactometer designed for use in experimental work. Table 7. — Comparison of new lactometers with Westphal balance, using salt solutions. Solution. West- phal. Lactom- eter I. Lactom- eter 11. 1.0245 1.0283 1.0315 1.0352 1.0248 1.0287 1.0318 1.0351 1.0248 1.0287 1.0319 1.0352 TESTS OF BABCOCK FORMULA AND NEW LACTOMETER. 17 Little comment is required on the above figures, as it is seen that the results obtained with the lactometers are practically identical with those of the Westphal balance. TESTS OF BABCOCK FORMULA AND NEW LACTOMETER WITH INDIVIDUAL MILKINGS. Since the figures given in the first part of this bulletin were all based on results obtained on composite samples from individual cows, it was deemed desirable at this point to test the Babcock formula on milk from individual milkings and at the same time to compare the figures obtained by the new lactometers and the Westphal bal- ance on the same milk. The only change in the laboratory procedure was that the percentage of fat was obtained by the Babcock test instead of by the extraction method. Four cows were selected with which to make the tests under con- ditions comparable with those found in making official tests of dairy cattle. For this purpose pure-bred cows were used, representing four breeds. These cows were milked and fed three times daily — at 5 a. m., 1 p. m., and 8 p. m. The animals remained in the barn the greater part of the time. They were allowed the freedom of a lot from two to four hours in the forenoon and from one to two hours in the afternoon. Each animal was fed according to her individual capacity and characteristics. The cows were on ofiicial test at the time these samples were secured and were receiving such treatment as, in the judgment of the herdsman, would give the best results for this purpose. The rations consisted of corn, silage, alfalfa hay, corn meal, bran, oats, and oil meal in somewhat varying proportions. Table 8 gives more specific data regarding the four cows used. The duration of the test was seven days, the average yields of milk and of butter fat for this period being as follows: Table 8. — Milking records of cows used in tests. No. of Cow. Breed. Days in milk. Average yield of milk per day. Average yield of fat per day. 16 .. . Jersey 367 119 20 258 Pounds. 10.9 16.7 13.7 10.5 Pounds. 0.57 .57 .53 .43 204 Holstein 300, Ayrshire 401. . , Snorthorn..: 18 ESTIMATION OF TOTAL SOLIDS IN MILK. The results of the work on the individual milkings from the cows described in the above table are found in Tables 9, 10, 11, and 12, next following. Table 9. — Lactometer results on individual milkings from Holstein-Friesian cow No. 204. Sample No. Specific gravity— Fat. Percentage of total solids— Westphal balance. i^actom- eter I. Lactom- eter II. Gravi- W^est- phal. i-^actom- eter I. Liactom- eter II Per cent. Per cent. Per cent. Per cent. Per cent. T 1 1 0310 1.0321 1 0320 2 9 11.59 11.23 11.52 11.49 L9 1 0320 1.0326 1 0324 3 2 12.26 11.85 12 11.95 L3 1 0315 1. 0315 1 0312 4 3 12. 93 13. 05 13. 05 12 97 L4 1 0308 L0312 1 0310 3 5 1L91 11^91 12! 01 1L96 L5 1 0317 1.0.319 1 0317 2 9 11.57 11.41 11.46 11.41 L6 1 0316 1.0320 1 0318 3 8 12. 72 12 Al 12. 57 12. 52 L7 1 0336 1.0335 1 0336 3 4 12. 70 12. 49 12. 47 12. 49 L8 1 0321 1.0323 1 0324 3 3 12. 23 12 12.05 12.07 L9 1 0299 1.0300 1 0301 3 5 12. 32 11.69 11.71 11.74 LIO 1 0320 1.0325 1 0322 3 5 12.26 12. 21 12. 34 12.26 Lll 1 0341 1.0337 1 0335 2 93 11.95 12.08 11.98 11.93 L12 1 0318 1. 0316 1 0314 4 12.62 12. 76 12.71 12. 66 L13 1 0318 1.0320 1 0320 3 3 12. 07 11.92 11.97 11.97 LU 1 0327 1.0322 1 0322 2 75 11.39 11.49 11.36 11.36 L15 1 0303 1.0298 1 0298 4 2 12.84 12.63 12.50 12.50 L16 1 0304 1.0312 1 0308 4 23 13.17 12. 71 12.91 12. 81 L17 1 0327 1.0324 1 0322 2 8 11.59 11. 55 11.47 11.42 L18 1 0312 1.0312 1 0309 3 95 12.60 12.55 12.55 12.48 L19 1 0313 1.0320 1 0317 3 70 12. 61 12.28 12. 45 12. 38 L20 1 0313 1.0321 1 0319 3 35 12.07 11.86 12.08 •12.01 L21 1 0310 1.0317 1 0317 3 78 12,44 12. 32 12.50 12.50 Table 10. — Lactometer results on individual milkings from Jersey cow No. 16. Sample No. Specific gravity— Fat. Percentage of total solids- West- phal balance. Lactom- eter I. Lactom- eter II. Gravi- metric. West- phal. Lactom- eter I. Lactom- eter II. Per cent. Per cent. Per cent. Per cent. Per cent. L22 1.0325 1.0329 1.0327 5.2 14.92 14.39 14.49 14.44 L23 1.0346 1.0348 1.0348 5.1 14.97 14.79 14.84 14.84 L24 1.0325 1.0330 1.0329 5.6 15.45 14.88 15 14.98 L25 1.0342 1.0347 1.0347 4.88 14.65 14. 45 14. 58 14.58 L26 1.0346 1.0350 1.0348 4.6 14.38 14.19 14.30 14.24 L27 1.0333 1.0335 1.0333 5.18 14.89 14.59 14.64 14.59 L28 1.0340 1.0351 1.0349 5.25 15.25 14.82 15.11 15.05 L29 1.0332 1.0338 1.0336 5.20 14.56 14.56 14. 71 14.66 L30 ; 1.0327 1.0333 1.0333 5. 68 15.33 15.05 15. 20 15. 20 L31 1.0345 1.0348 1.0349 5.40 15. 28 15.14 15. 21 15. 24 L32 1.0355 1.0357 1 . 0355 5 14. 85 14.91 14. 96 14.91 1.0344 1.0348 1.0346 5 14.87 14. 62 14. 72 14. 67 L34 1.0340 1.0342 1.0341 5.23 14.86 14.82 14. 87 14. 85 L35 1.0350 1.0350 1.0348 4.93 14.62 14. 72 14. 72 14.66 L36 1.0330 1.0333 1.0330 5. 75 15. 50 15.18 15. 26 15.18 L37 1.0351 1.0354 1.0354 5.15 14.93 14.99 15.06 15.06 L38 1. 0343 1.0347 1.0346 5.25 15.09 14.90 15 14.97 L39 1.0332 1.0333 1.0335 5.55 15.20 14.99 15.02 15.07 L40 1. 0351 1.0345 1.0344 5. 20 15. 19 15.05 14.89 14.86 L41 1.0354 1.0347 l.a346 5. 25 15.26 15.18 15 14.97 L42 1.0333 1.0333 1.0.333 5.30 15. 59 14. 71 14. 71 14.71 EFFECT OF TEMPERATURE ON SPECIFIC GRAVITY. 19 Table 11. — Lactometer results on individual milTcings from Shorthorn cow No. 401. Sample No. Specific gravity— Fat. Percentage of total solids — West- phal balance. Lactom- eter I. Lactom- eter II. Gravi- metric. West- phal. Lactom- eter I. Lactom- eter II. Per cent. Per cent. Per cent. Per cent. Per cent. L43 1.0340 1. 0342 1.0342 3. 8 13.44 13.08 13.13 13.13 L44 1.0344 1.0345 1.0344 3.65 13.22 13 13.03 13 L45 1.0340 1.0342 1.0342 4. 5 14. 43 13.92 13.97 13.97 L46 1.0350 1.0352 1.0351 3.9 13.80 13.45 13.50 13.48 L47 1.0352 1.0354 1.0353 3 12. t6 12. 41 12. 46 12. 44 L48 1.0340 1.0343 1.0342 4.4 14.29 13.80 13.88 13.85 L49 1.0344 1.0348 1.0347 4 13.54 13.42 13.52 13.50 L50 1.0357 1.0363 1.0363 3. 7 13.82 13.39 13.54 13.54 L51 1.0335 1.0337 1.0336 4. 8 14.31 14. 16 14. 21 14.18 L52 1.0308 ].0316 1.0317 3. 55 11.92 11.97 12.17 12. 20 L53 1.0355 1 . 0360 1 . 03G0 2.95 12. 67 12. 43 12. 55 12. 55 L54 1.0344 1.0351 1.0349 4. 45 13. .59 13.96 14.15 14.09 L55 1.0347 1.0348 1.0345 4.50 14.14 14. 10 14.12 14.05 L56 1.0349 1.0352 1.0350 4. 45 13.92 14.09 14.17 14.12 L57 1.0337 1.0339 1.0338 5" 14.48 14.46 14.49 14. 47 L58 1.0335 1.0339 1.0338 4.65 14. 23 13.98 14. 07 14.05 L59 1 . 0350 1.03.55 1.0354 3.60 12. 73 13.09 13.22 13.19 L60 1.0362 1.0360 1.0359 4.60 14.56 14.60 14. 55 14.52 L61 1.0355 1.0359 1.0360 4. 40 14.37 14.19 14.28 14.31 L62 1 . 0358 1.0363 1.0364 4.15 14.04 13.96 14.09 14.11 L63 1.0344 1.0351 1.0349 4.30 14. 13.78 13.97 13.91 Table 12. — Lactometer results on individual millings from Ayrshire cow No. 300. Sample No. Specific gravity— Fat. Percentage of total solids — West- phal balance. Lactom- eter I. Lactom- eter II. Gravi- metric. West- pbal. Lactom- eter I. Lactom- eter II. Per cent. Per cent. Per cent. Per cent. Per cent. L64 1.0320 1.0327 1.0325 3 11.52 11.61 11.79 11.74 L65 1.0300 1.0303 1.0301 5.10 13.38 13.63 13.71 13.66 L66 1.0322 1.0323 1.0321 2. 50 10.79 11.05 11.08 11.03 L67 1.0325 1.0327 1.0327 4.05 12.99 13 13.06 13.06 L68 1.0326 1.0331 1.0328 2. 65 11.21 11.33 11.47 11.38 L69 1.0304 1.0310 1.0308 4. 25 12.40 12. 71 12.86 12. 75 L70 1.0315 1.0315 1.0313 2. 75 11.01 11.18 11.18 11.13 L71 1.0317 1.0323 1.0322 3.10 11.72 11.66 11.81 11.78 L72 1.0313 1.0309 1.0305 3.15 11.45 11.62 11.61 11.42 L73 1.0295 1.0294 1.0294 5 13.42 13.39 13.36 13.36 L74 1.0.308 1.0310 1.0308 3.25 11.53 11.61 11.66 11.61 L75 1.0320 1.0322 1.0319 4. 25 13.41 13.12 13.17 13.09 L76 1.0315 1.0317 1.0316 4.90 13.61 13.77 13.82 13.79 L77 1.0327 1.0327 1.0327 3.80 12.49 12. 75 12. 75 12. 75 L78 1.0320 1.0322 1.0320 4.90 13.67 13.90 13.95 13.90 L79.. 1.0322 1.0324 1.0322 4.50 13. 54 13.47 13.52 13.47 L80 1.0326 1.0329 1.0326 3.75 12.06 12. 66 12. 74 12.66 L81 1.0295 1.0290 1.0287 4. 75 12.48 13.09 12.96 12.89 L82 1.0330 1.0328 1.0328 3.30 12. 12.22 12.17 12.17 L83 1.0296 1.0298 1.0297 4.25 12. 51 12. 51 12. 56 12.54 L84 1.0278 1.0280 1.0278 5.40 13.15 13.44 13.49 13.44 EFFECT OF TEMPERATURE ON SPECIFIC GRAVITY OF MILK. An increase in temperature is accompanied by a lowering of the specific gravity as determined by the lactometer. To show the importance of maintaining the proper temperature when using the lactometer and at the same time to determine the size of the error introduced by the difference of a few degrees in temperature, specific gravity determinations were made at different temperatures on 20 ESTIMATION OF TOTAL SOLIDS IN MILK. several samples of milk. Only ordinary precautions were taken in this experiment, and the results are about such as would be obtained were the lactometers in practical use. Samples of milk were taken from representatives of the four breeds of cows previously used. Table 13. — Effect of temperature on specific gravity of milk when determined with new lactometer. Temperatures. Jersey milk. Shorthorn milk. Ayrshire milk. Holstein-Friesian milk. Specific gravity. Differ- ence. Specific gravity. Differ- ence. Specific gravity. Differ- ence. Specific gravity. Differ- ence. 9°C 1. 0364 1. 0360 1. 0356 1. 0351 1. 0345 1. 0338 1. 0331 1. 0365 1. 0361 1.0357 1. 0352 1. 0347 1. 0341 1. 0335 1. 0330 1. 0327 1.0323 1. 0318 1. 0313 1.0308 1. 0302 1. 0291 1. 0287 1. 0283 1. 0279 1. 0275 1. 0270 1.0265 11° C 13° C 15° C 17° C 19° C 21° C Average 0. 0004 .0004 .0005 .0006 .0007 .0007 0. 0004 .0004 .0005 .0005 .0006 .0006 0. 0003 .0004 .0005 .0005 .0005 .0006 0. 0004 .0004 .0004 .0004 .0005 .0005 .0006 .0005 .0005 .0004 Table 14. — Showing composition of milk used in Table 13. Milk. Fat. Total solids. Per cent. 6.2 4 3.7 2.7 Per cent. 15.21 13. 78 12. 28 10. 02 Shorthorn Holstein-Friesian It will at once be seen that the variation is different in different samples and also at different temperatures with the same sample. The greatest variation is in the Jersey, milk where the percentage of total solids is highest, and least in the Holstein-Friesian milk, where the percentage of total solids is lowest. As the temperature rises the variation for each degree increases. The average variation per centigrade degree counting all four breeds, is 0.00025, which would account for an error of about 0.08 per cent total solids if calculated with the Babcock formula. Reduced to Fahrenheit degrees the error would be five-ninths of 0.08, or about 0.044 per cent for each degree. recknagel's phenomenon. Milk when freshly drawn contains numerous bubbles of gas, and it is not until these have disappeared that the specific gravity can be determined. It has been demonstrated by Recknagel ^ and con- » Milchzeitung, Band 12, p. 419, Bremen, 1883. USE OF MODIFIED LACTOMETER. 21 firmed by other investigators that the specific gravity of milk changes on standing. On taking the specific gravity of milk after the air bubbles had escaped and again several hours later he found an increase. This peculiarity is called the Recknagel phenomenon. He ascribes the increase to a change in the volume of the proteins. The increase begins two or three hours after milking, and if the milk is held at about 15° C. continues with decreasing rapidity for two days. The amount of the increase is between 0.0008 and 0.0015, depending on the richness of the milk. This change is accelerated by lower temperatures, and the normal specific gravity, or the point where no further change takes place, may be obtained by keeping the milk at 5° C. or lower for six hours. HOW TO USE THE MODIFIED LACTOMETER AND TABLE. This section is designed to assist those who may desire to make use of the modified lactometer described in the preceding section and who are not accustomed to using delicate lactometers. Materials required: 1. The lactometer. 2. A pan of warm water. 3. An accurate dairy thermometer. 4. A suitable cylinder to con- tain the sample while making the reading. The cylinder may be made of tin or copper and should have the following dimensions: Inside diameter, If inches; height, 13 inches. To prevent it from tipping over it should have a base of the same material about 2f inches in diameter. METHOD. Immediately after milking the milk should be thoroughly mixed and a sample of about 1 pint placed in a cream bottle. This should then be put into the refrigerator and kept there for ten or twelve hours, or until the next milking. It is then removed from the refrigerator and again well mixed by pouring back and forth several times from the bottle into another bottle or cup. At this point care must be taken not to mix air with the milk. This can be avoided by pouring against the sides of the receptacle to prevent foaming. After mixing, the bottle is placed in a pan of warm water and heated while being constantly stirred with the thermometer until the tem- perature reaches 60° F. The milk is then poured into the cylinder, which should also have been warmed in the pan so that it will not cool the milk. The lactometer is now quickly lowered into the milk, of which there should be a sufficient quantity in the cylinder to over- flow it, and allowed to come to rest. The point on the graduated scale which is at the same level as the surface of the milk is then read. This reading gives Quevenne degrees, which may be converted into specific gravity if desired by dividing by 1,000 and then adding 1 to the quotient. 22 ESTIMATION OF TOTAL SOLIDS IN MILK. Owing to the tendency of the milk to form a meniscus about the stem of the lactometer, it is impossible to read directly the exact point on the scale that is at the same level as the surface of the milk. A safe rule for obtaining a very close approximation to the correct figure is to add 0.2 to the reading taken where the top of the meniscus strikes the scale. For example, if the scale reads 31.8 at the top of the meniscus, the corrected reading in Quevenne degrees would be 32 and the specific gravity 1.032. Care must be taken that the temperature of the milk when the lac- tometer is read is exactly 60° F.; otherwise a very considerable error will be introduced. After using the lactometer it should be rinsed in clean water, wiped dry, and restored to its case. The percentage of fat should be determined by the Babcock test either on the sample used for the specific gravity determination or on another taken at the same time. Having by this procedure found the specific gravity of the milk and the percentage of fat, the total solids can be found by referring to Table 15, which is a modified form of one published by Babcock.^ In our table the percentage of total solids is given. If percentage of plasma sohds is wanted, it can be found by subtracting the percent- age of fat from the percentage of total solids. DIRECTIONS FOR USING THE TABLE. If the specific gravity as expressed in Quevenne degrees is a whole number, the percentage of total solids is found at the intersection of the vertical column headed by this number with the horizontal column corresponding to the percentage of fat. If the specific gravity as expressed in Quevenne degrees is a whole number and a decimal, the percentage of total solids corresponding to the whole number is first found and to this is added the fraction found opposite the tenth under '^Proportional parts." Two examples may suffice for illustration: (1) Fat, 3.8 per cent; specific gravity, 32. Under column headed 32 we find 12.57 per cent, corresponding to 3.8 per cent fat. (2) Fat, 3.8 per cent; specific gravity, 32.5. The per- centage of total solids corresponding to this percentage of fat and a specific gravity of 32 is 12.57. Under ''Proportional parts" the frac- tion 0.13 appears opposite 0.5. This added to 12.57 makes 12.70, which is the desired percentage. An inspection of the table shows that the percentage of total solids increases practically at the rate of 0.25 for each lactometer degree and 1.2 for each per cent of fat. This gives rise to Babcock's simpler formula Total solids = i Z+1.2/ (Z = lactometer reading in Quevenne degrees, and /= percentage fat). I Twelfth Annual Report of the Wisconsin Agricultural Experiment Station, p. 124. USE OF MODIFIED LACTOMETER AND TABLE. 23 This simple formula can be used in cases not provided for in the table, and the error introduced will be inconsiderable. Table 15. — Table for determining total solids in milk from any given specific gravity and percentage of fat. Per- Lactometer reading at 60" F. (Quevenne degrees). age of fat. 26 27 28 29 30 31 32 33 34 35 36 Per Per Per Per Per Per Per Per Per Per Per cent cent cent cent cent cent cent cent cent cent cent total total total total total total total total total total total solids. solids. solids. solids. solids. solids. solids. solids. solids. solids. solids. 2.00 8.90 9.15 9.40 9. 65 9.90 10. 15 10. 40 10. 66 10.91 11.16 11.41 2. 05 8.96 9. 21 9. 46 9.71 9. 96 10. 21 10. 46 10. 72 10. 97 11.22 11.47 2. 10 9. 02 9. 27 9. 52 9. 77 10. 02 10 27 10. 52 10. 78 11. 03 11. 28 11. 53 2! 15 9^08 9! 33 9. 58 9! 83 10! 08 10! 33 10. 58 10! 84 1L09 11'. 34 11^59 2.20 9. 14 9. 39 9. 64 9.89 10. 14 10. 39 10. 64 10.90 11.15 11.40 11.65 2. 25 9. 20 9.45 9. 70 9.95 10. 20 10. 45 10. 70 10. 96 11.21 11.46 11.71 2. 30 9. 26 9.51 9.76 10. 01 10. 26 10. 51 10. 76 11.02 11.27 11.52 11.77 2.35 9.32 9.57 9. 82. 10.07 10. 32 10. 57 10. 82 11.08 11.33 11. 58 11.83 2. 40 9.38 9. 63 9. 88 10. 13 10. 38 10. 63 10. 88 11. 14 11.39 11.64 11.89 2. 45 9.44 9. 69 9.94 10. 19 10.44 10.69 10. 94 11.20 11.45 11.70 11.95 2. 50 9. 50 9.75 10. 00 10. 25 10. 50 10.75 11.00 11.26 11.51 11.76 12.01 2. 55 9. 56 9. 81 10. 06 10.31 10. 56 10. 81 11.06 11.32 11.57 11.82 12.07 2. 60 9. 62 9. 87 10. 12 10 37 10. 62 10 87 11. 12 11. 38 11. 63 11. 88 12. 13 2. 65 9. 68 9! 93 10. 18 10! 43 10. 68 10! 93 11'. 18 11! 44 11^69 11! 94 12! 19 2. 70 9. 74 9.99 10. 24 10.49 10. 74 10. 99 11.24 11.50 11.75 12.00 12. 25 2.75 9.80 10. 05 10. 30 10. 55 10. 80 11.05 11.31 11.56 11.81 12. 06 12. 31 2. 80 9.86 10.11 10. 36 10. 61 10. 86 11.11 11.37 11.62 11.87 12. 12 12. 37 2. 85 9.92 10. 17 10. 42 10. 67 10. 92 11.17 11.43 11.68 11.93 12. 18 12. 43 2. 90 9.98 10. 23 10. 48 10. 73 10. 98 11.23 11.49 11.74 11 99 12. 24 12.49 2. 95 10.04 10.29 10.54 10. 79 11.04 11.30 11.55 11.80 12. 05 12. 30 12. 55 3.00 10.10 10. 35 10.60 10. 85 11.10 11.36 11.61 11.86 12.11 12. 36 12. 61 3.05 10. 16 10. 41 10. 66 10.91 11.17 11 42 11.67 11.92 12. 17 12. 42 12.68 3. 10 10. 22 10. 47 10. 72 10. 97 11. 23 11. 48 11.73 11.98 12. 23 12. 48 12. 74 3! 15 10! 28 10! 53 10! 78 11! 03 11! 29 11! 54 11! 79 12^04 12! 29 12! 55 12'. 80 3.20 10. 34 10.59 10. 84 11.09 11.35 11.60 11.85 12. 10 12. 35 12. 61 12. 86 3.25 10.40 10. 65 10. 90 11.16 11.41 11.66 11.91 12. 16 12. 42 12. 67 12. 92 3.30 10. 46 10.71 10. 96 11.22 11.47 11.72 11.97 12. 22 12. 48 12. 73 12. 98 3.35 10. 52 10. 77 11.03 11.28 11.53 11.78 12.03 12. 28 12.54 12. 79 13.04 3.40 10. 58 10. 83 11.09 11.34 11. 59 11.84 12.09 12. 34 12. 60 12. 85 13. 10 3.45 10. 64 10.89 11. 15 11.40 11.65 11.90 12. 15 12,40 12. 66 12. 91 13. 16 3. 50 10. 70 10. 95 11. 21 11 46 11.71 11.96 12. 21 12. 46 12. 72 12.97 13.22 3. 55 10. 76 11.02 11.27 11.52 11.77 12. 02 12. 27 12. 52 12. 78 13.03 13. 28 3. 60 10. 82 11. 08 11. 33 11. 58 11. 83 12. 08 12. 33 12. 58 12. 84 13.09 13. 34 3! 65 10! 88 11! 14 11! 39 11! 64 1L89 12! 14 12. 39 12! 64 12. 90 13! 15 13^40 3.70 10. 94 11.20 11.45 11.70 11.95 12. 20 12. 45 12. 70 12. 96 13.21 13. 46 3.75 11.00 11.26 11.51 11.76 12. 01 12. 26 12. 51 12. 76 13.02 13.27 13.52 3.80 11.06 11.32 11.57 11.82 12. 07 12. 32 12. 57 12. 82 13.08 13.33 13.58 3.85 11.12 11.38 11.63 11.88 12. 13 12. 38 12. 63 12. 88 13.14 13.39 13.64 3.90 11.18 11.44 11.69 11.94 12. 19 12. 44 12.69 12. 94 13.20 13.45 13. 70 3.95 11.24 11.50 11.75 12. 00 12. 25 12. 50 12. 75 13.00 13.26 13.51 13. 77 4. 00 11.30 11.56 11.81 12. 06 12.31 12. 56 12. 81 13.06 13. 32 13.57 13. 83 4. 05 11.36 11.62 11.87 12. 12 12. 37 12. 62 12.87 13.12 13.38 13.63 13.89 4.10 11.42 11.68 11.93 12. 18 12. 43 12. 68 12. 93 13.18 13.44 13.69 13.95 4.15 11.48 11.74 11.99 12. 24 12. 49 12. 74 12.99 13.25 13.50 13.76 14. 01 4. 20 11.54 11.80 12. 05 12. 30 12. 55 12.80 13.05 13.31 13.56 13.82 14.07 4. 25 11.60 11.86 12.11 12. 36 12. 61 12. 86 13.12 13. 37 13.62 13.88 14. 13 4.30 11.66 11.92 12. 17 12. 42 1-2. 67 12. 92 13.18 13.43 13.68 13.94 14. 19 4. 35 11.72 11.98 12. 23 12. 48 12. 73 12. 98 13 24 13.49 13. 74 14. 00 14. 25 4.40 11.78 12.04 12.29 12. 54 12. 79 13.04 13.30 13. 55 13.80 14.06 14. 31 4. 45 11.84 12. 10 12.35 12. 60 12. 85 13.10 13 36 13.61 13.86 14. 12 14. 37 4.50 11.90 12. 16 12. 41 12. 66 12. 91 13.16 13. 42 13.67 13.92 14. 18 14. 43 4. 55 11.97 12. 22 12. 47 12. 72 12. 97 13.22 13.48 13.73 13.98 14. 24 14.49 4.60 12. 03 12. 28 12. 53 12. 78 13.03 13.28 13.54 13.79 14. 04 14. 30 14. 55 4.65 12.09 12. 34 12. 59 12. 84 13.09 13.34 13.60 13.85 14. 10 14. 36 14. 61 4. 70 12. 15 12.40 12. 65 12. 90 13. 15 13.40 13.66 13.91 14. 16 14. 42 14.67 4.75 12. 21 12. 46 12.71 12. 96 13.21 13.46 13.72 13.97 14. 22 14. 48 14. 73 4.80 12.27 12.52 12. 77 13.02 13.27 13.52 13.78 14.03 14. 28 14.54 '.1.79 4.85 12.33 12.58 12.83 13.08 13.33 13.58 13.84 14.09 14.34 14.60 14.85 4.90 12. 39 12.64 12.89 13.14 13.39 13. 64 13.90 14.15 14.40 14.66 14.91 4.95 12.45 12.70 12.95 13.20 13. 45 13.70 13.96 14.21 14.46 14.72 14.97 24 ESTIMATION OF TOTAL SOLIDS IN MILK. Table 15. — Table for determining total solids in milk from any given specijic gravity and percentage of fat — Continued. Per Lactometer reading at 60° F. (Quevenne degrees). age of fat. 26 27 28 29 30 31 32 33 34 35 36 Per Per Per Per Per Per Per Per Per Per Per cent cent cent cent cent total total total total total total total total total total total solids. solids. solids. solids. solids. solids. solids. solids. solids. solids. 5. 00 12. 51 12. 76 13. 01 13. 26 13. 51 13. 76 14.02* 14. 27 14. 52 14. 78 15. 03 5.05 12. 57 12.82 13. 07 13. 32 13. 57 13. 83 14.08 14. 33 14. 58 14. 84 15. 09 5. 10 12. 63 12.88 13. 13 13. 38 13. 63 13. 89 14. 14 14. 39 14. 64 14. 90 15. 15 5. 15 12. 69 12! 94 13. 19 13. 44 13. 69 13. 95 14. 20 14. 45 14. 70 14. 96 15. 21 5. 20 12! 75- 13. 00 13* 25 13! 50 13. 75 14.01 14! 26 14! 51 14. 76 15. 02 15. 27 5. 25 12. 81 13. 06 13! 31 13. 56 13. 81 14. 07 14. 32 14. 57 14^82 15. 08 15. 33 5' 30 12. 87 13. 12 13.37 13. 62 13. 87 14. 13 14. 38 14. 63 14.88 15. 14 15! 39 5. 35 12. 93 13 18 13. 43 13. 68 13. 93 14. 19 14. 44 14. 70 14. 95 15. 20 15. 45 5^40 12! 99 13! 24 13". 49 13^74 14! 00 14! 25 14^50 14'. 76 15^01 15! 26 15! 51 5. 45 13. 05 13. 30 13.55 13.80 14. 06 14.31 14.56 14.82 15. 07 15. 32 15. 57 5. 50 13. 11 13. 36 13. 61 13.86 14. 12 14. 37 14. 62 14. 88 15. 13 15. 38 15. 63 5. 55 13. 17 13. 42 13. 67 13. 93 14. 18 14. 43 14. 69 14. 94 15. 19 15. 44 15! 69 5. 60 13. 23 13. 48 13. 73 13! 99 14. 24 14. 49 14. 75 15. 00 15. 25 15. 50 15. 75 5. 65 13. 29 13. 54 13! 79 14! 05 14! 30 14. 55 14! 81 15*06 15! 31 15. 56 15. 81 5. 70 13. 35 13. 60 13. 85 14. 11 14. 36 14. 61 14. 87 15. 12 15. 37 15. 62 15. 87 5. 75 13. 41 13. 66 13. 91 14. 17 14. 42 14. 68 14. 93 15. 18 15. 43 15. 68 15. 93 5. 80 13. 47 13. 72 13. 97 14. 23 14. 48 14. 74 14. 99 15. 24 15. 49 15. 74 15. 99 5. 85 13. 53 13 78 14. 04 14. 29 14. 54 14. 80 15. 05 15! 30 15. 55 15. 80 16. 06 5! 90 13^59 13^84 14! 10 14! 35 14! 60 14! 86 15! 11 15! 36 15! 61 15^86 16! 12 5. 95 13. 65 13.90 14.16 14. 41 14.66 14. 92 15.17 15.42 15. 67 15. 92 16. 18 6. 00 13. 71 13. 96 14. 22 14. 47 14. 72 14. 98 15.23 15. 48 15. 73 15. 98 16. 24 6. 05 13. 77 14. 02 14! 28 14! 53 14. 78 15.04 15. 29 15. 54 15. 79 16. 04 16. 30 6. 10 13. 83 14. 08 14. 34 14. 59 14. 84 15. 10 15. 35 15. 60 15. 85 16. 10 16. 35 6. 15 13. 89 14. 14 14. 40 14. 65 14. 90 15! 16 15. 41 15. 66 15. 91 16. 16 16. 42 6. 20 13. 95 14. 20 14. 46 14. 71 14. 96 15.22 15. 47 15. 72 15. 97 16^ 22 16. 48 6. 25 14. 01 14. 26 14. 52 14. 77 15. 02 15. 28 15. 53 15. 78 16. 03 16. 28 16. 54 6. 30 14. 07 14! 32 14. 58 14. 83 15. 08 15. 34 15. 59 15. 84 16.09 16. 34 16. 60 6. 35 14. 13 14. 38 14. 64 14. 90 15. 14 15! 40 15. 65 15. 90 16. 15 16. 40 16. 66 6.40 14! 19 14! 44 14! 70 14! 96 15. 20 15! 46 15! 71 15! 96 16! 21 16! 46 16!72 6. 45 14. 25 14.50 14.76 15. 02 15. 26 15.52 15. 77 16.02 16. 27 16.52 16. 78 6.50 14.31 14.56 14.82 15.08 15. 32 15.58 15.83 16.08 16. 33 16.58 16.84 6.55 14.37 14. 62 14.88 15.14 15. 38 15.64 15.89 16.14 16. 39 16.64 16.90 6.60 14.43 14.68 14. 94 15. 20 15. 44 15. 70 15. 95 16. 20 16. 45 16.70 16. 96 6. 65 14. 49 14. 74 15.00 15. 26 15.50 1.5. 76 16.01 16. 26 16. 51 16. 76 17.02 6.70 14.55 14.80 15.06 15. 32 15. 56 15. 82 16.07 16. 32 16. 57 16.82 17.08 6. 75 14. 61 14. 86 15.12 15. 38 15. 62 15.88 16. 13 16. 38 16.63 16.88 17.14 6.80 14.67 14.92 15.18 15. 44 15.68 15. 94 16.19 16. 44 16. 69 16. 94 17.20 6.85 14. 73 14. 98 15. 24 15.50 15. 74 16.00 16. 25 16.50 16. 75 17.00 17. 26 6. 90 14. 79 15. 04 15. 30 15. 56 15. 80 16.06 16. 31 16. 56 16.81 17.06 17. 32 6. 95 14.85 15.10 15. 36 15. 62 15. 86 16.12 16. 37 16.62 16.87 17.12 17.38 PROPORTIONAL PARTS. Lactometer fraction. Fraction to be added to total solids. Lactometer fraction. Fraction to be added to total solids. Lactometer fraction. Fraction to be added to total solids. 0.1 0. 03 0.4 0. 10 0.7 0. 18 _ 2 .05 . 5 .13 .8 .20 !3 .08 .6 .15 .9 .23 SUMMARY AND CONCLUSIONS. 25 SUMMARY AND CONCLUSIONS. 1. For purposes where exact percentages of total solids are de- nianded the use of any formula will not fulfill the requirements. 2. Of the formulas in general use that known as the Babcock (revised) formula gave results closest to those obtained gravimetri- cally. In 430 composite samples analyzed for total solids 256, or nearly 60 per cent, when calculated with this formula agreed within 0.25 per cent of the figures obtained gravimetrically, and 389, or over 90 per cent, agreed within 0.50 per cent. In another test with 84 samples of milk obtained from four individual cows under official testing conditions, determinations made on each milking showed that the total solids calculated by the formula in 53 cases, or 63 per cent of the total, agreed within 0.25 per cent of the gravimetrically deter- mined figures; and in 78 cases, or 93 per cent of the total, they agreed within 0.50 per cent. 3. Neither individuality nor breed in the cows seemed to exert any notable influence upon the application of the formulas. 4. The Babcock formula may be safely used with normal milk where only comparatively close approximations are required. It must be left to the decision of those in need of such figures as to whether or not the formula will fulfill their particular requirement. 5. The lactometers in common use for determining specific gravity of milk are not sufficiently sensitive to be used in connection with the Babcock fat test for estimating total solids in milk by formula. A modification of the Quevenne lactometer was, however, devised which was found to yield results quite as accurate as those obtained with the Westphal balance and at the same time so constructed that it may be used successfully by those unskilled in the use of chemical apparatus. / APPENDIX. Table 16. — Comparative determinations of total solids in milk. Test No. Cow No. gl a V 1 l/j' ( Quevenne degrees). Fat. Total solids. Gravi- metric. Babcock. Richmond. Fleisch- mann. Per cent. Per cent. Per cent. PeT cent. Per cent: 1 4 33.2 5. 07 14. 39 11. oo 14. 51 14. 6.5 2 4 34.5 4. 66 14. 40 11. /iZ 14. 40 14. 48 3 4 33.7 5.06 L't. 01 11. OU 14. 63 14. 70 4 4 33.0 4. 93 1%. 41 14 17 ^ A 07 11. Zl 14. 43 5 4 33.6 4. 83 14 18 14 20 1 A 07 11. Zl t A AR 11. 10 6 4 34.5 4. 80 14. 26 1 A QQ 11. oy 14. 52 14. 65 7 4 34.0 5. 02 14. 31 11. oz 1 4 AQ 11. 00 14. 79 8 4 33.7 4. 83 1 Q QQ 1 A 00 11. zz 1 A O"? 11. Zl 14. 48 9 4 33.0 5. 14 11. 18 14 42 1 4 (;i 11. 01 14. 68 10 4 34.0 5.00 1 A 11 11. 11 14 50 1 4 AQ 11. Oo 1 4 7A 11. 113 11 4 31.5 4.97 13. 98 lo. ol 14. 02 14. 10 12 4 33.5 4.68 13. 85 1 Q QQ lo. yy 14. 15 14. 25 13 4 32.5 4. 77 16. oo 10. oO 1 A no 11. \]Z 14. 11 14 4 33.0 4.50 1 Q 7ft lo. (D 10. DO 1 Q 7Q 10. /y 13. 91 15 4 32.2 4. 38 13. 48 1 Q Q1 lo. Ol 13. 42 13. 57 16 4 33. 1 4. 44 13. 61 1 ■} AH lo. DU 13. 67 13. 87 17 4 33.0 4. 26 14. 23 lo. OO 16. 00 13. 63 18 4 33.6 4. 57, 13. 96 10. OO 11. uo 14. 15 19 4 33.0 4. 65 1 Q OQ lo. zy 1 Q CQ 10. oo 1 A (Yi 11. Uo 14. 09 20 4 34.0 4. 85 14. 03 1 A QO 11. oZ 14. 51 14. 58 21 4 34.0 5. 15 14. 70 1 /I AC l^t. Do 14. 87 14. 94 22 4 34.0 4.82 14. 55 1 A OS 11. Zo 1 4 QQ 11. oy 14. 55 23 • 4 32.8 5. 39 14. 75 1 il A7 1 4 C7 11. Ol 14. 93 24 4 34.0 5. 68 11. oU 1 t; QO 10. oZ 1 1; 47 10. 11 15. 58 25 4 33.6 5. 61 15. 15 15. 13 15. 23 15. 40 26 99 33.3 4. 37 13. 09 13. 57 13. 79 13. 83 27 99 33.4 4.55 13. 54 13. 81 14. 03 14. 07 28 99 33.0 4. 51 13. 49 13. 66 13. 79 13. 93 29 99 34.0 4.53 13. 43 13. 94 14. 03 14. 20 30 99 32.6 4.14 12. 72 13. 12 13. 18 13. 38 31 99 32.3 4. 50 13. 20 13. 48 13. 66 13. 74 32 99 32.7 3.86 12. 87 12. 81 12. 94 13. 07 33 99 32.9 4. 74 13. 50 13. 91 14. 03 14. 18 34 99 32.4 4. 50 13. 04 13. 50 13. 66 13. 76 35 99 32.0 4. 39 12. 84 13. 27 13. 42 13. 63 36 99 33.0 4.32 12. 95 13. 43 13. 55 13. 70 37 99 32.7 4. 31 12. 88 13. 35 13. 42 13. 61 38 99 31.0 4. 28 12. 99 12. 89 13. 06 13. 15 39 99 31.8 4. 32 12. 87 13. 13 13. 30 13. 40 40 99 32.2 4.23 12^84 13^13 13! 18 13^39 41 99 30.5 4.43 12.90 12. 94 13. 05 13. 20 42 99 31.0 3.90 12.42 12.43 12. 58 12.69 43 99 31.0 4.27 13.04 12. 87 13.06 13.14 44 99 30.9 3.93 12.67 12.44 12. 58 12. 70 45 99 32.0 4. 30 12.50 13. 16 13.30 13. 42 46 99 33.0 4. 42 13. 13 13.55 13. 67 13. 82 47 99 33.0 4.07 12.95 13.13 13.31 13.40 48 99 34.0 4. 37 13. 13 13. 74 13. 91 14. 01 49 99 32.5 4. 80 13.34 13. 89 14.02 14.15 50 99 32.7 4. 70 13.66 13. 82 13.90 14.08 51 99 32.0 4.63 13. 26 13.56 13.66 13. 82 52 99 32.4 4. 74 13. 85 13. 79 13.90 14. 05 53 99 35.5 4.71 14. 00 14.53 14.64 14.79 54 99 34.5 5.08 14. 55 14. 72 14. 88 14. 98 55 99 32.5 5. .39 14.66 14. 59 14. 74 14. 86 .56 99 34.0 5.26 14.83 14.81 14. 99 15.08 57 99 35.0 5. 78 15.32 15. 69 15.84 15. 95 58 99 36.0 6.00 15.61 16.20 16.32 16. 46 59 99 32.3 5.42 14. 85 14.58 14. 74 14. 84 60 99 34.6 5.99 15.89 15.84 15.96 16. 10 61 99 33.5 6.15 16.11 15.76 13.95 16.02 26 APPENDIX. Table 16. — Comparative determinations of total solids in milk — Continued. Test No. Cow No. Specific gravity (Quevenne degrees). Fat. Total solids. Gravi Babcock. Richmond. mann. PCT C€7ltt Per cent. Per cent. Per cent. Per cent. 62 99 34. 9 6. 07 ' 16. 24 16.01 16. 20 16. 27 63 118 30. 0 5.06 13. 93 13. 57 13. 77 13.83 64 118 31. 0 5. 10 14. 19 13.87 14. 02 14. 13 65 118 29. 7 5. 77 14. 12 14. 35 14.48 14.61 66 118 32.0 5. 58 14. 55 14. 70 14. 86 14. 96 67 118 34. 0 5. 80 15. 10 15. 46 15. 59 15. 72 68 118 35. 0 5. 60 15. 40 15. 47 15. 60 15. 73 69 118 34. 5 5.69 15. 41 15. 45 15. 60 15. 72 70 118 34. 5 5. 76 15. 30 15. 54 15. 72 15.80 71 118 34. 2 5. 44 14. 71 15. 08 15. 11 15. 34 72 118 34.0 5.86 15. 28 15. 53 15. 71 15. 80 73 118 34.5 5.87 15. 49 15. 67 15. 84 15. 93 74 118 34.5 6. 10 15. 50 15. 95 16. 08 16. 20 75 118 35.0 5. 95 16. 12 15. 89 16. 08 16. 15 76 118 35.0 5. 28 15. 35 15. 09 15. 24 15. 35 77 118 34.0 5.86 15. 47 15. 53 15. 71 15. 80 78 118 35.0 5. 37 15. 36 15. 19 15. 36 15. 46 79 118 33. 8 5. 41 15. 20 14. 94 15. 11 15. 21 80 118 34.0 4.89 14. 55 14. 37 14. 51 14. 63 81 118 33.4 4. 99 14. 06 14. 34 14. 51 14. 60 82 118 32.0 4. 51 13. 98 13. 41 13. 54 13. 68 83 118 35.0 4. 83 14. 83 14. 55 14. 64 14. 81 84 118 34.2 5. 00 14. 53 14. 55 14. 63 14. 81 85 118 34.2 4.61 14. 33 14. 08 14. 15 14. 35 86 118 35.4 5. 15 14. 65 15. 03 15. 24 15. 29 87 118 35.0 4.57 14. 29 14. 23 14. 40 14. 50 88 118 35.0 5.21 14. 55 15. 00 15. 12 15. 26 89 118 36.0 4.86 14. 93 14. 83 15. 00 15. 09 90 118 34.5 5. 54 15. 25 15. 27 15. 36 15. 54 91 118 37.0 5. 49 15. 58 15. 84 15. 97 16. 10 92 118 35.0 5. 74 16. 30 15. 64 15. 72 15. 90 93 118 35.0 5. 42 15. 75 15. 25 15. 36 15. 52 94 118 39.5 5. 14 16. 26 16. 04 16. 14 16. 30 95 118 33.5 6. 29 16. 18 15. 92 16. 07 16. 19 96 205 34.0 3. 19 12. 08 12. 33 12. 47 12. 59 97 205 34.0 2. 09 11. 32 11. 73 11. 87 11. 99 98 205 34.0 3.30 10. 95 12. 46 12. 59 12. 72 99 205 34.0 3. 05 11. 88 12. 16 12. 35 12. 42 100 205 32.5 3. 14 11. 80 11. 89 11. 98 12. 16 101 205 33.0 3.38 11. 59 12. 31 12. 47 12. 57 102 205 31.4 3.00 11. 03 11. 45 11. 62 11. 71 103 205 32.0 2. 81 12. 00 11. 37 11. 50 11. 64 104 205 34.5 3.01 11. 07 12. 24 12. 36 12. 60 105 205 33.0 3. 17 11. 66 12. 05 12. 23 12. 32 106 205 31. 5 3.07 11. 46 11. 56 11. 74 11. 82 107 205 32.5 3. 10 11. 95 11. 85 11. 98 12. 11 108 205 33.0 3. 10 11. 64 11. 97 12. 11 12. 23 109 205 33. 5 3. 58 12. 45 12. 67 12. 83 12. 93 110 205 31.4 3. 21 11. 76 11. 70 11. 86 11. 97 111 205 32. 1 3. 33 12. 20 12. 02 12. 10 12. 29 112 205 31.2 3.34 11. 95 11. 81 11. 86 12. 07 113 205 32.5 3.32 11. 96 12. 11 12. 22 12. 37 114 205 34.0 3. 17 12. 34 12. 30 12. 47 12. 57 115 205 33.7 3.01 11. 66 12. 04 12. 11 12. 30 116 205 32.8 3.30 11. 70 12. 16 12. 35 12. 42 117 205 33.0 2. 87 11. 77 11.69 11. 87 11. 96 118 205 32.5 3.06 11. 96 11. 80 11. 98 12. 06 119 205 33.0 3. 54 12. 19 12. 50 12. 59 12. 76 120 205 32.0 3. 21 11. 76 11. 85 11. 98 12. 12 121 205 32.0 3.38 12. 13 12. 06 12. 22 12. 32 122 205 34.0 2.89 11. 83 11. 97 12. 11 12. 23 123 205 33.0 3.26 11. 99 12. 16 12. 35 12. 43 124 205 32.7 3. 19 12. 10 12. 00 12. 10 12. 27 125 205 32^7 3.38 12. 25 12. 23 12. 34 12. 50 126 205 34. 6 3. 15 12. 31 12. 43 12. 60 12. 69 127 205 33! 6 3. 17 12. 06 12. 20 12. 35 12. 47 128 205 32. 5 3. 28 12^04 12! 06 12! 22 12! 33 129 205 33. 0 2. 94 11.74 11.78 11.87 12.04 130 205 32! 5 3! 23 12.01 12.00 12. 10 12.27 131 205 32.2 3.36 ' 12.10 12.08 12.22 12.35 132 205 31.7 3.38 12. 15 11.98 12. 10 12. 24 133 205 32.5 3.26 12.20 12.04 12.22 12.30 134 205 33.0 3.25 11.90 12. 15 12.35 12.41 135 205 33.0 3.27 12.27 12. 17 12. 35 12. 44 136 205 33.7 3.22 12.42 12.29 12.35 12.55 137 205 32.0 3.50 12.19 12. 20 12.34 12. 64 138 205 33.5 3.74 12. 71 12.86 12.95 13. 13 ESTIMATION OF TOTAL SOLIDS IN MILK. Table 16. — Comparative determinations of total solids in milk — Continued. Test No. Cow No. Specific gravity (Quevenne degrees). Fat. Total solids. Gravi- metric. Babcock. Richmond. Fleisch- mann. Per cent. Per cent. Per cent. Per cent. Per cent. 139 205 33. 6 3. 20 12. 70 12. 24 12.35 12.50 140 205 33.5 3. 63 12. 96 12. 73 12.83 12.99 141 205 33. 4 3. 40 11.64 12. 43 12.59 12.84 142 205 32. 6 3. 82 12. 99 12. 73 12.82 13.00 143 206 31. 5 3. 48 11.97 12.05 12.22 12.31 144 206 29.0 3. 17 11.04 11.05 11.24 11.32 145 206 28. 2 2. 58 9. 95 10. 15 10.27 10. 41 146 206 29. 0 3. 06 10. 84 10. 92 11.12 11.18 147 206 29. 2 2. 63 10. 10 10. 46 10. 52 10.72 148 206 29.0 2. 76 10. 04 10. 56 10.76 10.82 149 206 29. 0 2. 29 9. 62 10.00 10. 16 10.26 150 206 29. 5 2. 70 11.02 10. 62 10.76 10.88 151 206 30. 0 2. 58 10.04 10.60 10.77 10.86 152 206 27. 5 2. 94 10. 23 10.40 10.51 10. 66 153 206 28. 2 2.76 9.99 10. 36 10.51 10.62 154 206 27. 5 2. 96 10. 27 10.43 10.63 10.69 155 206 29. 0 2. 71 10.57 10.50 10.64 10. 76 156 206 30. 0 3. 10 10.57 11.22 11.37 11.48 157 206 30. 0 2. 72 10. 43 10. 76 10.89 11.03 158 206 29. 0 2. 94 10. 67 10. 78 10.88 11.04 159 206 29. 0 2. 78 10.49 10.59 10.76 10.85 160 206 29. 0 3. 06 10.40 10. 92 11.12 11.18 161 206 30. 0 3. 13 10. 86 11.26 11.37 11.52 162 206 27. 8 3. 01 10.80 10.56 10. 75 10.82 163 206 28. 6 3. 05 10. 87 10. 81 10.99 11.07 164 206 28. 1 3. 05 10. 82 10. 69 10.87 10. 94 165 206 29. 0 3. 08 10.83 10.95 11.12 11.21 166 206 29. 0 3. 01 10. 92 10.86 11.00 11.12 167 206 29. 0 2. 39 10. 44 10.12 10. 28 10.38 168 206 29. 5 3. 08 10. 03 11.07 11.24 11.33 169 206 29. 0 2. 86 10. 71 10.68 10.88 10. 94 170 206 29. 0 2. 82 11.00 10. 03 10. 76 10.90 171 206 29. 0 3. 23 10. 85 11.13 11.24 11.39 172 206 29. 5 3. 09 10. 87 11.08 11.24 11.34 173 206 29. 3 3. 13 11.05 11.08 11. 24 11. 34 174 206 31. 0 2. 70 10. 93 10. 99 11.14 11.25 175 206 31. 0 3. 06 11.19 11.42 11.62 11.69 176 206 30. 0 2. 93 11.28 11.02 11.13 11.28 177 206 31. 0 3. 35 12. 10 11.77 11.98 12.03 178 206 32. 6 3.03 12. 18 11.79 11.86 12.05 179 206 32. 4 3. 03 12.03 11.74 11.86 12.00 180 206 33. 8 3. 39 12. 87 12.52 12. 71 12.78 181 206 34. 3 3. 44 13.09 12. 70 12. 84 12.97 L82 206 35. 3 3. 40 13.09 12.91 13.08 13. 17 183 209 31. 0 3. 95 12. 84 12.49 12.70 12.75 184 209 32. 0 3. 14 11.23 11.77 11.86 12.03 185 209 .32. 0 2.59 10. 44 11.11 11.26 11.37 186 209 32. 0 2. 80 10. 45 11.36 11.50 11.62 187 209 32. 0 2. 40 10.20 10.88 11.02 11.14 188 209 30. 0 2. 64 10. 09 10. 67 10.77 10. 93 189 209 30. 0 2. 68 10. 22 10.72 10.89 10.98 190 209 29. 8 2. 67 10.41 10.65 10.89 10.92 191 209 29. 0 2. 54 10. 99 10.30 10.40 10.56 192 209 30. 3 2. 72 10.21 10.84 11.01 11.10 193 209 31. 0 2.96 10. 63 11.30 11.50 11.57 194 209 29. 5 2. 72 10. 70 10.04 10.76 10.90 195 209 30. 5 3.00 10. 77 11.23 11.37 11.49 196 209 31. 5 3.09 11.39 11.58 11.74 11.85 197 209 28. 5 2.96 11.04 10.68 10.87 10. 94 198 209 28. 6 3.00 10.81 10.75 10.87 11.01 199 209 29.8 3. 14 11.18 11.22 11.37 11.48 200 209 29.5 3.35 11.21 11.40 11.60 11.66 201 209 31. 0 3.05 11.41 11.41 11.62 11.67 202 209 30.8 2. 54 10.81 10.75 10.90 11.01 203 209 31. 0 3.24 11. 46 11.64 11.74 11.90 204 209 30. 0 2. 73 10. 93 10. 78 10.89 11.04 205 209 29. 5 2. 74 10.62 10.66 10. 76 10. 92 206 209 30.5 3.00 11.20 11.23 11.37 11.49 207 zuy oU. u 2. 95 10.97 11.04 11.25 11.30 208 209 30.0 3.08 llr44 11.20 11.37 11.40 209 209 31.4 2. 72 11.20 11.11 11.26 11.38 210 209 31.0 3. 15 11.34 11.53 11.74 11.79 211 209 29.8 2. 95 10.87 10.99 11.25 11.25 212 209 30.9 3.08 11.39 11.42 11.62 11.68 213 209 30.7 2. 87 11.30 11.12 11.25 11.38 214 209 31.5 2.94 11.53 11.40 11.50 11.67 215 209 31.5 3.06 11.57 11.55 11.74 11. SI APPENDIX. Table 16. — Comparative determinations of total solids in mi^^— Continued . Test No. Cow No. Specific gravity (Quevenne degrees). Total solids. Gravi- metric. Ricliiiiond. Fleisch- mann. Per cent. Per cent. Per cent. Per cent. Per cent. 216 209 31.0 3. 18 11.59 11.57 11.74 11.83 217 209 31.3 2.85 11.62 11.25 11.50 11.51 218 209 31.3 3.69 12.49 12.25 12. 46 12. 52 219 209 32.2 3.75 12.68 12.55 12.62 12.81 220 209 33.0 3.32 12. 61 12.23 12.35 12. 50 221 209 33.3 3. 33 12.53 12.32 12.47 12. 58 222 209 32.6 3.29 12.28 12.10 12. 22 12.36 223 209 33.5 3.27 12. 76 12.30 12.47 12. 56 224 209 35.6 3.52 13.20 13. 12 13.20 13.39 225 209 36.0 3. 74 13.70 13.49 13.56 13.75 226 209 34. 4 3.75 13. 70 13.10 13.25 13. 36 227 209 37.0 3.76 13.98 13.76 13.93 14 02 228 209 34.4 4.05 13. 56 13. 46 13.68 13.72 229 300 33.0 5. 19 14 53 14 48 14 63 14 74 230 300 33.3 4. 54 13.76 13.77 13.91 14. 04 231 300 33. 4 4. 18 13.76 13.37 13.55 13.63 232 300 33.5 4. 49 13.94 13.76 13.91 14 03 233 300 33. 4 4.38 13.93 13.61 13.79 13.87 234 300 33.5 4.22 13.51 13. 44 13.55 13. 70 235 300 33.5 4. 46 13.42 13.73 13.91 13.99 236 300 33. 1 4.07 13. 76 13. 16 13.31 13.42 237 300 33.7 4. 23 13.53 13.50 13.55 13.76 238 300 33.6 4.22 13.53 13.46 13.55 13.73 239 300 33.5 4.05 13.41 13.24 13. 43 13. 50 240 300 33. 7 4.01 13.20 13.24 13.31 13.50 241 300 33.0 4. 16 13.24 13.24 13.43 13.51 242 300 32. 8 4. 08 13.39 13.10 13. 31 13. 36 243 300 32. 7 4. 11 13.44 13.11 13. 18 13. 37 244 300 32. 4 3. 98 13. 26 12.88 13.06 13. 14 245 300 32. 6 3. 55 12. 89 12. 41 12. 58 12. 67 246 300 32. 0 4. 13 13. 42 12. 96 13.06 13. 22 247 300 31. 8 4 29 13. 13 13. 10 13. 30 13. 36 248 300 32. 0 4. 20 12. 69 13. 04 13. 18 13. 30 249 300 34. 0 4. 10 13. 04 13.42 13. 55 13. 68 250 300 33. 4 4. 12 13. 07 13.29 13. 43 13. 56 251 300 34 0 4. 02 13. 44 13. 32 13. 43 13.59 252 300 35. 0 4. 13 13. 40 13. 71 13. 80 13. 97 253 300 35. 0 4. 22 13. 13 13. 81 13. 92 14 08 254 300 35. 0 4. 08 13. 34 13. 65 13. 80 13. 91 255 300 34. 0 4. 17 13.76 13. 50 13. 67 13. 77. 256 300 33. 0 4. 32 13. 39 13.43 13. 55 13. 70 257 300 33. 0 3. 89 12. 56 12.92 13. 07 13. 18 258 300 31. 5 3. 65 12. 57 12.26 12.46 12. 52 259 300 33. 0 3. 22 12. 04 12. 11 12. 23 12. 38 260 300 32. 0 3. 94 12. 40 12.73 12. 82 12. 99 261 300 33. 0 3. 65 12. 35 12. 63 12. 83 12.89 262 300 32. 0 3. 61 12. 28 12. 33 12.46 12. 60 263 300 32. 5 3. 31 12. 13 . 12. 10 12. 22 12. 36 264 300 32. 9 3. 37 12. 28 12. 27 12. 47 12. 53 265 300 33. 0 3. 45 12. 17 12.39 12.59 12.65 266 300 32. 0 3. 38 11.98 12. 06 12. 22 12. 32 267 300 31. 4 3. 36 12. 07 11. 88 12. 10 12. 15 268 300 30. 2 3. 50 11. 89 11. 75 11.85 12. 01 269 300 31. 2 3. 23 11. 70 11. 68 11. 74 11. 94 270 300 30. 5 3. 35 11. 57 11. 65 11. 85 11.91 271 300 30. 4 3. 15 11. 58 11. 38 11. 61 11. 64 272 300 31. 3 3. 47 11. 96 11.99 12. 22 12. 25 273 300 32. 0 3. 30 11. 70 11. 96 12.10 12.22 274 300 31. 6 3. 35 11. 38 11. 92 12. 10 12.18 275 300 30. 1 3. 44 11. 26 11. 65 11. 73 11. 92 276 300 31. 0 3. 40 11. 38 11. 83 11. 98 12.09 277 300 30. 2 2. 98 11.40 11. 13 11. 25 11.39 278 300 30. 2 3. 20 11.34 11. 39 11.49 11. 65 279 301 34. 0 4. 22 13. 38 13. 56 13. 67 13. 83 280 301 33. 0 4. 15 13.43 13. 23 13. 43 13.49 281 301 32. 3 4. 66 13. 55 13. 67 13. 90 13. 93 282 301 32. 0 4. 44 13. 43 13. 33 13.42 13.59 283 301 33. 0 4. 29 13. 41 13.40 13. 55 13. 66 284 301 32 4 4 72 13. 44 13. 76 13. 90 14 03 285 301 32! 9 4 22 13. 36 13.29 13.43 13. 55 286 301 32.5 4 37 13. 35 13. 37 13. 54 13. 63 287 301 32.8 4 61 13. 51 13.73 13. 91 14 00 288 301 31.5 4 72 13. 78 13. 54 13. 66 13. 80 289 301 34.2 416 12. 98 13.54 13. 67 13. 81 290 301 33.2 4 40 13. 33 13.58 13. 67 13. 84 291 301 32.2 4 31 13. 54 13. 22 13. 30 13. 49 292 301 33.0 442 13. 67 13.55 13.67 13.82 ESTIMATION OF TOTAL SOLIDS IN MILK. Table 16. — Comparative determinations of total solids in milk — Continued, Test No. Cow No. Specific gravity (Quevenne degrees). Fat. Total solids. Gravi- metric. Babcock. Richmond. Fleisch- mann. Jr^CT cent. Per cent. Per cent. Per cent. Per cent. 293 301 66. 7 4. 02 13. 47 13. 25 13. 31 13. 51 294 301 OO. 0 0 SQ 6. OO 13. 41 13.03 13.19 13.29 /yo cSUi 0%. ii 1 QO 0. yz 13. 27 13. 25 13. 31 13.52 296 301 34. 0 A no 13.99 13. 41 13.55 13.67 297 301 iA n o4. u A OA 13.31 13.59 13. 67 13.85 298 301 66. o A on 12.83 13.42 13. 55 13.68 301 OO. u A 1A 13.37 13.46 13.55 13.72 300 301 OO. u 3 72 12.91 12. 71 12.83 12.98 301 301 11 n OO. u 4. zo 13.46 13.33 13.43 13.59 302 301 iA n 6%. u £iO 13.36 13.60 13.79 13.86 303 301 11 n OO. tl 4 32 13.23 13.43 13.55 13.70 304 301 OO. o /« 1 1 4. 11 13. 71 13. 81 13. 92 14.07 305 301 34. 0 O CQ 0. oy 13. 34 13. 17 13.31 13.43 306 301 34. 0 0 t;R O. 00 12. 94 12. 77 12. 95 13.04 307 301 11 k; OO. 0 0 on o. yu 12.80 13.06 13. 19 13.32 308 301 34. 0 O QC o. yo 13.02 13. 28 13.43 13.54 309 301 61. 1 o t;c o. 08 12.54 12. 22 12.34 12.48 310 301 Ol. 1 o" ^? 12.37 12. 20 12. 34 12. 47 311 301 33. 8 3. 71 12.05 12. 90 13.07 13.17 312 301 32. 0 3. 75 12.36 12.50 12.70 12.76 313 301 33. 0 3. 83 12. 61 12.85 12. 95 13.11 314 301 in K o/. o 3. 80 12.64 12.69 12.82 12. 95 315 301 33. 0 3. 85 12.66 12.87 13.07 13. 13 316 301 32. 0 O 71 0. /I 12. 74 12.45 12.58 12. 72 317 301 6Zi. o O 7!i 0. /O 12.67 12.63 12.82 12.89 318 301 32. 0 4. 01 12.80 12.81 12.94 13.08 319 30l 33. 0 3. 75 12.53 12. 75 12.95 13.01 320 301 32. 5 4. 12 13. 11 13.07 13. 18 13.33 321 301 32. 6 3. 86 12.93 12.78 12.94 13. 05 322 301 33. 6 4. 24 13. 31 13.49 13.55 13. 75 323 301 oZ. i 4. 09 13.01 13.01 13. 18 13. 27 324 301 OO fi 4. 00 12.74 13.00 13. 19 13.26 325 301 33. 6 O 71 O. /I 13.01 12.85 12.95 13. 12 326 301 32. 9 3. 65 12. 77 12.61 12.83 12.87 327 301 33. 0 3. 76 12.90 12.76 12.95 13.03 328 301 32. 6 4. 07 12.90 13.03 13. 18 13.30 329 30l 33. 0 3. 77 12.50 12.77 12.95 13.04 330 301 32. 1 4. 00 12. 26 12.83 12.94 13.09 331 301 32. 0 3. 96 12. 85 12.75 12.94 13.02 332 301 31. 2 4. 16 12. 38 12.79 12.94 13 06 333 301 31. 4 3. 76 12. 71 12.36 12.58 12.63 334 301 32. 7 3. 76 12.67 12.69 12.82 12.95 335 301 OO K 61. o 4. 07 12.79 13.01 13. 18 13.27 336 301 32. 9 O KK o. oO 12.86 12.49 12. 71 12. 75 337 301 31. 5 3. 84 12. 16 12.48 12.58 12. 75 338 301 31. 3 3. 61 12.09 12. 16 12.34 12. 42 339 301 32. 5 3. 67 12. 84 12.53 12.70 12.79 340 301 31. 2 O 71 6. 11. 12. 34 12.25 12. 34 12.52 341 302 31. 8 4. 88 13.98 13.81 14. 02 14.07 342 302 31. 0 4. 73 13.70 13.43 13. 54 13.69 343 302 32. 0 3. 92 12.80 12.70 12. 82 12. 97 344 302 01 R ol. D 4. (Jo 12.88 12.80 12.94 13.06 1AK o4o 302 OO n Oil. u 4. 47 12. 97 13.36 13.54 13.63 346 302 OO Q o^. y 4 11 4. 11 12.52 13. 16 13.31 13.42 347 302 32. 8 4. 48 13.45 13.58 13.79 13.84 348 302 ol & ol. O 4. 48 13.31 13. 33 13. 54 13.59 349 302 ol ol. D J 71 4. / I 13. 67 13.55 13. 66 13.82 ooU 302 OO c 6^. o /( A7 4. U/ 12.87 13.08 13.31 13.35 OKI 302 31. 0 /I 71 4. /I 13.15 13.40 13.54 13.67 352 302 29. 5 K 1 O 0. 18 13.54 13.59 13. 76 13.85 353 400 34. 5 4. 48 14. 16 14.00 14. 16 14.26 354 400 35. 5 4. 07 13.83 13.76 13.92 14.02 355 400 36. 0 3.88 13. 51 13.66 13.80 13.92 356 400 36. 0 4. 03 13.35 13.84 13.92 14. 10 357 400 34. 0 4. 33 13.58 i3.ro 13. 79 13.96 358 400 31. 3 3.95 13.25 12. 57 12.82 12.83 359 400 33. 7 3. 92 12.98 13. 13 13. 19 13.39 360 400 33.6 4. 17 13. 35 13. 40 13. 55 13.67 361 400 33. 0 4 13 13. 58 13.21 13. 31 13.47 362 400 3215 4131 13.23 13. 30 13.42 13.56 363 400 33.5 3.99 12. 87 13. 16 13.31 13.43 364 400 34.0 3.54 12.52 12. 75 12.83 13.01 365 400 32.0 3.30 12.05 11.96 12.10 12.22 366 400 33.0 3.99 12.81 13.04 13. 19 13. 30 367 400 34.0 3.57 12.11 12.78 12.95 13. 05 368 400 32.8 3.73 12.96 12. 68 12.83 12.94 369 400 33.1 3.53 12.91 12.51 12.71 12.78 APPENDIX. Table 16. — Comparative determinations of total solids in milk — Continued. Test No. Cow No. Specific gravity (Quevenne degrees). Fat. Total solids. Gravi- metric. Babcock. Richmond. r leiscn- mann. xCT cent. Per cent. Per cent. Per cent. Per cent. i7n O/U 400 ic; 1 00. L 1 09 0. 13.28 13.48 13.56 13. 74 171 400 14 n 3 78 12.94 13.04 13. 19 13.30 372 400 It; o oO. u 0. 00 13.11 13. 01 13. 20 13.27 o/o 400 34 6 3. 62 13.17 12.99 13. 08 13.26 174 400 11 4 00. * 3. 72 13. 01 12. 81 12.95 13.08 375 400 33 7 3. 61 13. 01 12. 76 12.83 13.02 14 1 o4. 0 1 70 0. /y 13.00 13. 12 13.32 13.39 Q77 Oil 4nn It; o oo. u 1 e:9 0. 0^ 12. 69 12. 97 13.08 13.24 378 400 34. 0 4. 07 12.99 13.38 13. 55 13.65 Q7Q 4nn ^uu 14 o oi. u 1 8"; 0. 00 13. 18 13.12 13. 31 13.38 Qfin OoU 4nf» 11 9 00. ^ 1 ot; 0. yo 12. 97 13.04 13. 19 13. 30 QOI ool Ann 11 7 00. / 3 53 12. 88 12.66 12. 71 12.92 QQ9 OO^ Ann 14 4 0^. % 3 90 13.26 13.28 13.44 13.54 OOO Ann 34 6 3. 96 13.34 13.40 13.56 13.66 OO^ Ann 14 7 3. 53 12. 85 12.94 12.96 13. 17 OOO 400 32 6 3. 43 12.40 12. 27 12. 34 12.53 OOD Ann 32 0 3. 91 13.03 12. 69 12.82 12.96 187 Af\n 34 0 A. 52 13.48 13.92 14.03 14. 19 OOO 409 36 0 4. 49 14.06 14. 39 14. 52 14. 65 180 402 35 0 5. 14 14. 32 14.92 15.00 15. 18 402 32 9 4. 48 13.62 13.60 13.79 13.87 1Q1 4n9 32 6 4. 08 12. 94 13.05 13. 18 13.31 402 32 8 4. 31 13. 18 13. 37 13.55 13.64 oyo 402 33 0 4. 20 13.34 13.29 13.43 13.55 394 402 34 5 4. 20 13. 41 13. 67 13. 80 13.93 iQt; oyo 402 34 0 3. 96 13.23 13. 25 13.43 13.52 396 402 34. 0 4. 21 13.46 13.55 13. 67 13.82 1Q7 oy< 402 33 5 3. 92 12. 91 13. 08 13. 19 13.34 108 oyo 402 32 5 3. 77 12.83 12. 65 12.82 12.91 100 oyy 402 34. 0 3. 99 13.07 13.29 13.43 13. 55 400 402 33. 7 3. 61 12. 78 12. 76 12.83 13.02 401 402 34. 0 4. 03 13. 41 13. 34 13. 43 13.60 402 402 34. 4 3. 69 13.01 13.03 13. 20 13.29 403 402 34. 0 3. 86 13. 06 13.13 13.31 13.40 AHA 4n9 11 o oo. u 1 09 0. y^ 13.06 12. 95 13. 07 13.22 405 402 34. 0 3. 84 13.26 13.11 13. 19 13. 37 406 402 34. 4 3. 80 13. 21 13.16 13. 32 13.42 407 402 33. 4 3. 80 13.11 12.91 13. 07 13. 17 408 402 33! 7 3 yg 13. 15 12. 97 13.07 13. 24 409 402 34. 0 3. 93 12. 94 13.22 13. 31 13.48 41 o 409 14 4 1 78 0. 10 12. 86 13.14 13.32 13.40 41 1 402 11 fi 00. D 4 Ifi 12. 94 13.39 13. 55 13.66 412 402 19 7 0^. / 3 94 13.10 12. 90 12. 94 13. 17 411 *iO 409 19 7 4. 12 12. 69 13.12 13.18 13. 38 41 4 409 11 4 00. ^ 3. 76 13.02 12. 86 13. 07 13. 13 no 409 14 1=; 0*. 0 4 no ^. uy 13. 26 13.53 13.68 13.80 41 R 402 14 n O'i. u 4. 20 13.46 13. 54 13.67 13.80 417 401 Wo 35 8 4 OR 13.63 13. 82 14. 04 14.08 418 401 36. 0 1 t;i 0. 00 12. 85 13. 24 13. 32 13.50 41 Q ^ly 403 33. 8 3 45 12. 42 12.59 12. 83 . 12.85 401 33. 4 1 27 0. ^/ 12. 49 1 0 07 12. 47 12. 54 491 Ant 33. 3 1 It; 0. 00 12. 21 12. 35 12.59 12.61 422 403 32! 7 3.35 12. 07 12. 20 12. 34 12.46 423 403 33.3 3. 45 12. 12 12.47 12. 71 12. 73 424 403 32.0 3.36 12. 22 12.03 12. 22 12. 30 425 403 32.0 3.33 11.61 12.00 12. 10 12. 26 426 403 32.3 2.96 11.86 11.63 11.86 11.89 427 403 32.9 3. 16 11.53 12.02 12.23 11.28 428 403 33.6 3.26 12.00 12. 31 12. 47 12.58 429 403 32.3 3.01 11.32 11.69 11.86 11.95 430 403 31.6 3. 19 11.40 11.73 11.86 11.99 Note.— Cows Nos. 4, 99, and 118 are Jerseys; Nos. 205, 206, and 209 are Holstein- Friesians; Nos. 300, 301, and 302 are Ayrshires, and Nos. 400, 402, and 403 are Shorthorns. O