LIBRARY OF CONGRESS.
UNITED STATES OF AMERICA.
—
te ty
yh bl
ry
a pss
ATR
:
$
is
i:
:
=
A
:
eo Pesnenrneintavnnennneette err nieces
TESTING MILK
AND TLS, PRODU CTs.
A MANUAL FOR DAIRY STUDENTS, CREAMERY AND CHEESE-
FACTORY OPERATORS AND DAIRY FARMERS.
BY
Yo y
E.H. FARRINGTON and — F. W. WOLL
Professor in Charge of Dairy School Asst. Prof. of Agrl. Chenttstry
Of the University of Wisconsin.
With Dllustrations.
FIRST EDITION.
MADISON, WIS. ARN OF CONG»
ks
@ ‘OCT 25 1897
ALL RIGHTS RESERVE
4
TIO PA DIC eee ee a on bY ss :
iW Ui iKOoRCGEIVED
CopyRIGHT, 1897
By E. H. FARRINGTON anp F. W. WOLL
M. J. CANTWELL, Printer
Madison, Wis.
PREFACE.
The present volume is intended for the use of dairy students,
creamery and cheese-factory operators, practical dairymen, and
others interested in the testing or analysis of milk and its prod-
ucts. The subject has been largely treated in a popular manner;
accuracy and clearness of statement, and systematic arrangement
of the subject matter has, 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 education, but
their work will naturally be greatly lightened by the aid and
guidance of an able teacher.
Complete directions for making tests of milk and other dairy
products are given; the difficulties which the beginner may meet
with, are considered in detail, and suggestions offered for avoiding
them. It is expected that a factory operator or practical dairy-
man, by exercising ordinary common sense and care, can obtain a
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 somewhat
familiar with chemistry and chemical operations, Chapter XIV
has been added giving detailed instruction for the complete chem-
ical 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 factories, and
with factory dividends, a chapter has been devoted to a discus-
sion of the various systems of factory book-keeping, and tables
iv Testing Milk and Its Products.
greatly facilitating the work of the factory secretary or book
keeper have been prepared and are included in the Appendix.
Acknowledgment is due to the following parties for the use of
electrotypes, viz: Vermont Farm Machire Co., Bellows Falls, Vt.;
Cornish, Curtis and Greene Mfg. Co., Fort Atkinson, Wis.; Elgin
Mfg. Co., Elgin, Ill.;.F.B. Fargo & Co., Lake Mills, Wis.; DeLaval
Separator Co., N. Y. City; Henry Troemner, Philadelphia, Pa.;
Springer Torsion Balance Co., N. Y. City; J. H. Monrad, Win-
netka, Ill.; Borden & Selleck Co., Chicago, IIl.; Dairymen’s Sup-
ply Co., Philadelphia, Pa.; and the agricultural experiment sta-
tions at New Haven, Conn., and Madison, Wis.
University of Wisconsin,
Madison, Wis., Oct. 1, 1897.
E. H. FARRINGTON.
F. W. WOLL.
TABLE OF CONTENTS:
Introduction.
The need of a practical milk- and cream test.
Introduction of milk tests. Short’s test. Other milk
tests. The Babcock test. Foreign methods. Gerber’s
method. DeLaval butyrometer. Fyjord’s centrifugal
cream-test, - - - - - - - - - - -
Chap. I. ComposirioN OF MILK AND ITS PRODUCTS.
Water. Fat. Casein and albumen. Milk sugar
(lactose). Ash. Other components. Colostrum milk,
Chap. II. Sampcvine MILK.
Sweet milk. Partially churned milk. Sour milk.
Frozen milk, Beret NR Fly Fey los nt ened ea asic area
Chap. III, THe Bascock TEST.
Directions tor making the test: Sampling. Add-
ing acid. Mixing milk and acid. Whirling bottles. Add-
ing water. Measuring the fat.
Discussion of the details of the test: 1. Glass-
ware. Test bottles. Marking test bottles. Cleaning
test bottles. Pipettes. ‘‘ Fool pipettes.’’ Acid measures.
The Swedish acid bottle. Calibration of glassware. Cal-
ibration with mercury. Cleaning mercury. Calibration
with water. a. Measuring the water. b. Weighing the
water. 2. Centrifugal machines. Speed required for the
complete separation of the fat. Ascertaining the neces-
sary 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 tem-
perature on the separation of fat. 4. Water to be used
in the Babcock test. Reservoir for water. 5. Modifica-
tions of the Babcock test. The Russian milk test. Bart-
lett’s modification, . - - . - - - - -
Pages
1-10
11-19:
20-24--
25-63:
v1 Testing Milk and Its Products.
Chap. IV. CREAM TESTING.
Errors of measuring cream. Avoiding errors of
measuring cream. Cream test bottles. The bulb-necked
cream bottles. The Winton cream bottle. Use of milk
test bottle. Use of 5 cc. pipette. Weighing the cream,
Chap. VY. Bancock TEST FOR OTHER MILK PRODUCTS,
Skim milk, butter milk, and whey. The double-
necked test bottle. The double-sized skim milk bottle.
Cheese. Condensed milk, - - - - - - -
Chap. VI. THE LACTOMETER AND ITS APPLICATION.
The Quevenne lactometer. Influence of tempera-
ture. N. Y. Board of Health lactometer. Reading the
lactometer. Time of taking lactometer readings. Cal-
culation of milk solids. Adulteration of milk. Calcula-
tion of extent of adulteration. Skimming. Watering.
' Watering and skimming. Other methods of adulteration
Pages.
64-73
74-79
80-93
Chap. VII, TEsTING THE ACIDITY OF MILK AND CREAM.
Cause of acidity in milk. Methods of testing
acidity. Manns’ test. Devarda’s acidimeter. The alka-
line tablet test. Acidity of cream. Determination of
acidity in sour cream. The standard solution used. Spill-
man’s cylinder. Rapid estimation of the acidity of ap-
parently sweet milk and cream. Detecting preservaline
in milk. ‘‘ Alkaline tabs,”’ So hE see Dhak ar et ae - 94-110
Chap. VIII. TeEsTiING THE PURITY OF MILK.
The Wisconsin curd test. The fermentation test, 111-115
Chap. IX. TESTING MILK ON THE FARM.
Variations in milk of single cows. Cause of vari-
ation in fat content. Number of tests required during a
period of lactation in testing cows. When to test a cow.
a. As to quality of milk produced. b. As to quantity of
milk produced. Gurler’s method. Record of tests.
Sampling milk of single cows. Size of test sample.
Variations in herd milk. Ranges in variations of 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, - - - - - 116-133
Table of Contents. vil
Chap. X. COMPOSITE SAMPLES OF MILK. Pages.
Methods of taking composite samples. a. Use of
tin dipper. b. Drip sample. c. Scovell sampling tube.
One-third sample pipette. Accuracy of the described
methods of sampling. Preservatives for composite sam-
ples. Bi-chromate of potash. Other preservatives. Care
of composite samples. Fallacy of averaging percent-
ages. A patron’s dilemma, Sp Re ee | hE ES
Chap. XI. CREAM TESTING AT CREAM-GATHERING
CREAMERIES.
The space system. The oil test churn. The Bab-
‘cock test for cream. Sampling tube. Sampling cream
gor composite testing, - - -- - - = - «= 150-159
Chap. XII. CaLcuLaTION OF BUTTER AND CHEESE
YIELDS.
Calculation of yield of butter: Butter fat test
and yield of butter. Variations in composition of but-
ter. Overrun of churn over test. Factors influencing the
overrun. Calculation of overrun. Conversion factor for
butter fat. Butter yield from milk of different richness.
a. Use of butter chart. b. Use of overrun table. Calcu-
tion of yield of cheese: a. From fat. b. From solids not
faeand fat. c. From caseinvand:fat; -"- - + 160-173
Chap. XIII. CaLcuLaTine DIVIDENDs.
Calculating dividends at creameries: Proprie-
tary creameries. Co-operative creameries. Illustrations
of calculations of dividends. Other systems of payments.
Paying for butter delivered. Relative value tables. Cal-
culating dividends at cheese faetories: Proprietary fac-
tories. Co-operative factories. Illustrations of calcula-
tions of dividends, See eee) eee ss hh | £41 BD
Chap. XIV. CHEMICAL ANALYSIS OF MILK AND ITS
PRODUCTS.
A. Milk: Specific gravity. Water. Alternate
method. Fat. Casein and albumen. Van Slyke’s method.
Milk sugar. Ash. Acidity of milk. Detection of preser-
vatives in milk. Boracic acid. Bi-carbonate of soda.
Fluorids. Salicylic acid. Formalin. B. Skim milk, but-
Vili Testing Milk and Its Products.
ter milk and whey. C. Butter. Sampling. Determina- Pages.
tion of water. Fat. Casein. Ash. Complete analysis
of butter in the same sample. Detection of artificial but-
ter. Filtering the butter fat. Specific gravity. Reichert-
Wollny method (Volatile acids). D. Cheese. Water.
Fat. Casein. Ash. Other constituents. Detection of
oleomargarine cheese (‘‘Filled’’ cheese) - - - - 186-203
Appendix.
Table I. Composition of milk and its products.
Table II. Milk standards.
Table III. Quevenne lactometer degrees corres-
sponding to the scale of N. Y. Board of Health lactome-
ters.
Table IV. Correction table for specific gravity
of milk.
Table V. Percent of solids not fat, correspond-
ing to 0 to 6 percent of fat and lactometer readings of
26 to 36.
Directions for the use of tables VI, VII and IX.
Table VI. Pounds of fat in 1 to 10,000 pounds
of milk testing 3 to 5.35 percent.
Table VII. Amount due for butter fat, in dol-
lars and cents, at 12 to 25 cents per pound.
Table VIII. Relative value tables.
Table IX. Butter chart, showing calculated
yield of butter, in pounds, from 1 to 10,000 pounds of
milk testing 3.0 to 5.3 percent of fat.
Table X. Overrun table, showing pounds of but-
ter from 100 pounds of milk.
Table XI. Yield of cheese, corresponding to 2.5
to 6 percent of fat, with lactometer readings of 26 to 36.
Table XII. Comparisons of Fahrenheit and
Centigrade (Celcius) thermometer scales.
Table XIII. Comparison of metric and custom-
ary weights and measures,
Suggestions regarding the organization of co-
operative creameries and cheese factories, - - - 205-232
Index, oe SS SOs a ee eae
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 industry,
and especially with the growth of the factory system of but-
ter and cheese making during the last few decades. So
long as each farmer made his.own butter and sold it to pri-
vate 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 farmers in the dairy sections of
‘our country became to a large extent patrons of one or the
other of these, a system of equitable payment for the milk
or cream delivered became a vital question.
1. The need of a practical milk-and cream test. The
creameries in existence in this country up to within ten
years were nearly all conducted on the cream-gathering plan:
the different patrons set their milk, and cream gatherers.
hauled the cream to the creamery, usually twice or three
times a week, where the mixed lots of cream were 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 in diameter, one inch
high, or 113 cubic inches. This quantity of cream is sup-
2 Testing Milk and Its Products.
posed to make a pound of butter, 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 (140*). 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 deter-
mine 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 of all the
small batches of butter thus obtained.
2, The introduction of the so-called oz] test churn (187)
in creameries, which followed the creamery inch system,
marked a decided step in advance, and it soon came into
general use in cream-gathering districts. In this test, glass
tubes of about 2 inch internal diameter and nine inches
long, are filled with cream to a depth of 5 inches, and the
cream churned; the tubes are then placed in hot water, and
the column of melted butter formed at the top is read off
by means of a scale showing the number of pounds of but-
ter 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, accord-
ing to investigations conducted at the Wisconsin experiment
station, make strictly accurate distinctions between different
grades of good and of poor cream. As a result, perfect
justice can not be done to different patrons of creameries
where payments for cream delivered are made on the basis
of this test.
* Refers to paragraph number.
Introduction. 2
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 different
patrons was no less perplexing than in case of gathered-
cream factories. By the pooling system generally adopted,
each patron received payment in proportion to the number
of pounds of milk delivered, irrespective of its quality.
Patrons delivering rich milk naturally will not be satisfied
with this system when they find out the quality of their
milk as compared with that of their neighbors. The temp-
tation to fraudulently increase the amount of milk delivered,
by watering, or to lower its quality by skimming, will fur-
thermore prove too strong for some patrons; the fact that it
was difficult to prove any fraud committed, from lack of a
reliable and practical 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 private
dairymen and breeders of dairy cattle, who desired to follow
up the butter-producing capacities of the individual cows in
their herds. The only manner in which this could be done,
was by the cumbersome method of trial churnings: by sav-
ing the milk of the cow to be tested, for a day or a week,
and churning separately the cream obtained. This re-
quires a large amount of work when a number of cows are
to be tested, and can not therefore be done except in com-
paratively few cases, with cows of oreat excellence, or by
farmers having plenty of hired help.
5. Introduction of milk tests. The first method
which fulfilled all reasonable demands of a practical and
4 Testing Milk and Its Products.
reliable milk and cream test was the Babcock test, invented
by Dr. S. M. Babcock, chemist to the Wisconsin experiment
station; a description of the test was first published in
July, 1890, as bulletin No. 24 of Wisconsin experiment
‘station, entitled: A new method for the estimation of fat in
milk, especially adapted to creameries and cheese factories.
This test which is now known and adopted in all parts of
the world where dairying is an important industry, was
not, however, the first method proposed for this purpose
which could be successfully operated outside of chemical
laboratories. It was preceded by a number of different
methods, the first one published in this country being
Short’s method, invented by Mr. F. G. Short, and described
in bulletin No. 16 of Wisconsin experiment station in July,
1888.
6. Short’s test. In this ingenious method, a certain
quantity of milk (20 cc.*) was boiled with an alkali solution,
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 some-
what difficult for non-chemists, and because several other
methods were published shortly after it had been given to
the public.
7. Other milk tests. Of these may be mentioned,
besides the Babcock test, already spoken of, the Failyer
and Willard method,t Parson’s method,t Cochran’s test,2
~-* See 44, footnote. + Kansas experiment station report, 1888, p. 149.
{ N. H. experiment station report, 1888, p. 69.
? Journal of Anal. Chem., IIT (1889), p. 331.
L[ntroductton. . 5
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,t Lieber-
mann’s method,|| the Schmid,? Thceerner,{ and Rese-
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 measured as
such in a narrow graduated tube, or brought iato solution
with ether, gasoline, etc., and a portion thereof weighed on
evaporation of the solvent. While this principle is an old
one, having been employed in chemical laboratories for
many years past, the adaptation of it to practical conditions,
and the details as to apparatus.and chemicals 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 originated, and even outside of them, as in case
of the Short, Patrick and Beimling methods. The Babcock
test soon, however, nearly everywhere replaced the different
methods mentioned, and during the past five or six years it
has been in practically exclusive use in creameries and
cheese factories in this country where payments are made
on basis of the quality of the milk delivered, as well as in
* Ta. exp. sta., bull. No. 8. February, 1890; Iowa Homestead, June 14, 1889.
+ Vermont exp. sta., bull. No. 21, September, 1890. For description of these
and other volumetric methods of milk analysis, see Wiley, Agricultural Analysis,
Vol. III, p. 490, et seq; Wing, Milk and its Products, p. 33, et seq; and Snyder,
Chemistry of Dairying, pp. 112-113.
{ Analyst, 1887, p. 6.
| Fresenius’ Zeitschr. 22, 383.
2 Ibid. 27, 464.
§ Chem. Centralbl., 1892, 429.
** Landw. Vers. Stat., 40, 1.
6 Testing Milk. and Its Products.
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 manipulations are
few and easily learned, and it is cheap, both in first cost and
as regards running expenses. i
The test is speedy, and accurate within one or two-tenths
of one per cent.*
Only one chemical is used, and no training in or knowl-
edge of chemistry is required on part of the operator.
The percentages of fat in the samples tested are shown
directly from the readings of the fat column, without refer-
ence to a scale or table.
Only a small quantity of milk is used (about two-thirds
of an ounce, 17.6 cc.)
The apparatus is easily kept in order, and the chances of
accidents in operating the test, with properly made machines,
are very slight indeed,
A small and a large number of samples may furthermore
be tested with equal facility at the same time, up to the
capacity of the tester.
The results obtained may be easily verified by renewed
tests in the same or another machine.
The test bottles when charged with the samples of milk
* For a summary 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, Milchzeitung, 1896, p. 183, et seq.
introduction. - »* 7
or other dairy products may be left for months, if desired,
before the test is completed, and correct results still be
obtained.
The completed tests will keep indefinitely in the bottles,
so that the results may be verified at any future time, if
desired.
Sour milk may be analyzed with perfect: assurance of
accurate results, provided it can be properly sampled.
The test is finally applicable, besides to full milk, to cream,
skim milk, butter milk, whey, condensed milk and (if a small
scale for weighing out the sample is available) to cheese.
10. With all these 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
attention; 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. The test is, however, for
general purposes, in the opinion of the writers, the very
best at our disposal, and in the hands of careful intelligent
operators, will easily give most satisfactory results.
11. Foreign methods. In European countries three
practical milk and cream tests, besides the Babcock test,
are in use at the present time, viz: Gerber’s acid-butyrome-
ter, De Laval’s butyrometer, and Fjord’s centrifugal cream test.*
Of these, the last test given has never been introduced
into this country, to our knowledge, and the former two,
only on a small scale.
* The Lister-Babcock milk test advertised in English papers and known as
such in England, is the regular Babcock test, to which the English manufacturers
have prefixed their name.
8 Testing Milk and Its Products.
12. The Gerber method * (fig. 1) is essentially the
old Beimling method worked out independently by the Swiss
chemist, Dr. N. Gerber.
In this test sulfuric acid
of the same strength is
used as in the Babcock
test, and a small quantity
of amyl alcohol is added.
The amyl alcohol facili-
tates the separation of
the fat, but introduces
a source of error which
may become serious, and
especially so, where the
1 results obtained with a
Fig. 1. The Gerber acid-butyrometer. new lot of amyl aleohol
can not be compared with gravimetric analysis or with
tests made with amyl alcohol known to give correct results.
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
this test; a smaller sample of milk is taken (only 2 cc.)
and a correspondingly small quantity of acid used. The
results obtained are correct. Where a large number of milk
samples are tested every day, as is the case, for instance, in
Kuropean milk control stations, the butyrometer may be
preferable to the Babcock test; but it requires more skill of
the operator and is more difficult to work satisfactorily in
case of milk which cannot be easily sampled, as sour, lop-
pered, or partially churned milk. The machines placed on
* Gerber, Die Praktische Milch-Pruefung.
Introduction. 9
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
Fie. 2. De Laval’s butyrometer.
revolutions per minute, and therefore places greater de-
mands for solidity in the machine than does the Babcock test.
14. Fijord’s centrifugal cream tester* (fig. 3) is ex-
tensively used in Denmark and is mentioned in this connec-
ree : tion as it furnishes a fairly
reliable method for compar-
ing the quality of different
lots of milk. The method
was published in 1878, by
the late N. J. Fjord, director
of the state experiment sta-
Ua tion in Copenhagen, through
Fic. 3. Fjord’s centrifugal cream tester. whose exertions and on
* State Danish experiment station, Copenhagen, sixth and ninth reports,
1885-7,
IO Testing Milk and. Sts Products.
whose authority it was generally 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 2-3 of an inch in diame-
ter, and whirled for twenty minutes at a rate of 2000 revo-
lutions 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. 192 samples of milk
can be tested simultaneously. 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, Babcock
and De Laval tests, will, however, in all probability in time
force the Fjord cream test out of Danish creameries, for
similar reasons that relegated to obscurity the gravity cream
tests (creamometers. )
Before going over to the main part of the present work,
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
preducts, and the relation 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 fac-
tories or private dairies will be treated in this chapter, and
the reader is referred to standard works on dairying for
further information in regard to the composition of dairy
products.
Composition of Milk and Its Products. II
CHAPTER I.
COMPOSITION OF MILK AND ITS PRODUCTS.
15. Milk is composed of the following substances:
water, fat, casein, albumen, milk sugar and ash. nto ema sancnpedee (euennwaee navies 8.90
Catlett Citrate sce ysscc-cccesvest. hae nacn zee teceemae ee eeengene al egies 23.55
Lime combined with casein. 5 tistics sis has cane tecentonene 5.13
100.00
According to the same author, 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-calecium 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 .8 per cent., with an average of
.7 per cent. Milk with a high fat content generally con-
tains 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 of milk are, however,
the components least liable to variations.
91. Other components. Besides the milk constituents
enumerated and described in the preceding pages, normal
milk contains a number of substances which are only pres-
ent in small quantities and have only scientific interest, such
* Wisconsin experiment station, twelfth report, p. 93.
Composition of Milk and Its Products. TQ
as the milk gases (carbonic acid, oxygen, nitrogen), citric _
acid, lecithin, cholesterin, urea, hypoxanthin, lactochrome,
etc.
The percentage composition of cows’ milk will be seen
from the tables given in the Appendix. Tables are also given
showing the average composition of milk products, like skim
milk, butter milk, whey, cream, butter, cheese and condensed
milk.
22. Colostrum milk. The liquid secreted directly after
parturition is known as colostrum milk or biestings. It isa
thick, yellowish, viscous liquid; its high content of albumen
and ash is characteristic, and also its low content of milk
sugar. Owing to the large quantity of albumen which
colostrum contains it will coagulate on being heated to
boiling. The secretion of the udder gradually changes from
colostrum to normal milk in the course of four to five days;
the milk is considered fit for direct consumption, or for the
manufacture of cheese and butter when it does not coagu-
lated on boiling, and is of normal appearance as regards
color, taste, and other properties. For composition of colos-
trum milk, see Appendix.
20 Testing Milk and Its Products.
CHAPTER IL.
SAMPLING MILK.
93. 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 atendency to rise to the surface of the milk. If, there-
fore, a sample of milk is left undisturbed for even a 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 leaving a quantity of sweet
milk undisturbed in acylinder or milk can for a few minutes,
and testing separately the top, middle and bottom layer of
this milk.
ExpPeERIMENT. Fill the cylinder used for making the lactometer
test (100) with milk, thoroughly mixed by pouring; measure a pip-
etteful of milk immediately into test bottle A. Allow the milk in
the cylinder to remain undisturbed for ten minutes, and then
measure a pipetteful of milk from the top of that in the cylinder,
into test bottle B. Next pour out most of the milk from the
cylinder, and measure into test bottle C, a pipetteful of the last
portion of the milk in the cylinder.
After completing the tests of A, B, and C, in the usual manner
(32), record the results of each test in the note book.
94, MTheamountof mixing necessary to evenly distribute
the constituents of milk throughout its mass, can also be
Sampling Milk. 21
demonstrated by adding a few 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. Stirring with a stick or a dipper will not produce an
even mixture so quickly orso completely as pouring the milk
a few times from one vessel to another, and 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.
25. 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 very
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 taking special measures which will
be explained in the following. 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 so 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
22 Testing Mitk and Its Products.
at the factory, the butter granules are caught by the strainer.
cloth through which the milk is poured, and 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, with-
out running the risk of making mottled butter, and it will
not enter into the sample of milk taken for testing purposes.
When milk samples are sent in small bottles by mail or
express, or carried to the place of testing, they very often
arrive with lumps of butter floating in the milk or sticking
to the glass. Tbis churning of the milk can be easily pre-
vented by filling the bottle or the can completely with milk.
If there is no space left for the milk in which to splash
around, the fat will not be churned out in transit.
26. Approximately accurate results may generally be
obtained with a partially churned sample of milk, if a tea-
spoonful of ether is added to it. After adding the ether,
cork the bottle and shake it until the lumps of butter are
dissolved in the ether. This ether solution of the butter
will mix with the milk, and from the mixture a uniform
sample may generally be taken without difficulty. The
dilution of milk by the ether introduces an error in the test-
ing, and only the smallest quantity of ether necessary to
dissolve the lumps of butter should be used. If desired, a
definite quantity of ether, say 5 or 10 per cent. of the volume
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. ,
EXAMPLE. To a4 oz. sample (120 cc.) of partially churned
milk, 5 per cent.,or 6 cc., of common ether are added: the mixture
gives an average test of 4.2 percent. The test must be increased
by ,354.2=.21, and the original milk, therefore contained 4.2
+ .21=4.41 per cent. of fat.
Sampling Milk. 23
Instead of adding ether to partially churned samples, it
has been suggested to warm the milk to 110° F. for a suffi-
ciently long time 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 drawn from
the sample.
97. Sampling sour milk. When milk becomes sour, the
casein is coagulated and the mechanical condition of the milk
thereby changed so as to render a proper sampling very diffi-
cult. The butter fat is not, however, changed in the process
of souring; this has been shown by one of us 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 ap-
proximately 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, the souring of it: 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 is 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 produce this effect.
Only avery small quantity of powdered alkali is 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 ex-
*See Hoard’s Dairyman, April 8, 1892. The same holds true for cream, as
shown by Winton, (U. S. Dept. Agr., Div. of Chemistry, bull. 45, p. 112.)
24 Testing Milk and Its Products.
cess of alkali will often cause such a violent action of the
sulfuric acid on the milk to which the acid is added, (on ac-
count of the heat generated or the presence of carbonates in
the alkali) that the mixture will spurt out of the neck of
the test bottle, when it is shaken in mixing the milk and
the acid. When powdered alkali is added to the milk, it
should be allowed to stand for a while, with frequent stirring,
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 dis-
solved in water (soda or potash lye), or strong ammonia
water, may be used for the purpose of dissolving the coagu-
lated casein in a sample of sour milk. In this case, a defi-
nite proportion of alkali solution must, however, 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. 22).
28. Sampling frozen milk. When milk freezes, it
separates 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 there-
fore essential that both the liquid and the frozen part be
warmed and mixed thoroughly on the disappearance of the
crystals, 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 (32).
The Babcock Test. 25
CHAPTER IIT.
THE BABCOCK TEST.
29. The Babcock test is founded on the fact that strong
sulfuric acid will dissolve all non-fatty solid constituents of
Fig. 4. The first Babcock tester made.
milk and other dairy
products, and will set
free the fat. This will
separate on standing,
but to effect a speedy
and complete separa-
tion, the bottles holding
the mixture of milk
and acid are placed in
a centrifugal machine
—a so-called tester, and
whirled for five min-
utes; hot water is then
added so as to bring
the liquid fat into the
graduated neck of the
test bottles, and after
a repeated whirling,
the length of the col-
umn of fat is read off,
showing the per cent.
of fat contained in the sample tested.
26 Testing Milk and [ts Products.
Sulfuric acid is preferable to other strong mineral acids
for the purpose mentioned, on account of its affinity for
water; when mixed with milk, the mixture heats greatly,
thus keeping the fat liquid without the application of arti-
ficial heat, and rendering possible a distinct reading of the
column of fat brought into the neck of the test bottles.
30. 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 in using this method,
so long as a fair sample of the milk can be secured. Sam-
ples of milk or other dairy products, rich in solids, require
a little more effort to perfect a thorough mixture with the
acid than thin milk or other dairy products low in solids,
like whey, which may be readily mixed with the acid.
A—Drrections FoR MAKING THE TEST.
31. 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
meet with in working 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 unfamiliar with the test may turn to
the pages of this book for help in any difficulties which they
may encounter in their work in this line.
32. Sampling. The sample to be tested is first mixed
by pouring the milk from one vessel to another two or three
times so that every portion thereof will contain a uniform
amount of butter fat. 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 completed, by
The Babcock Test.
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 loosening a little the pressure of the
finger on the end of the pipette, the milk is now al-
MPICHECEET
cu asad " iw IT
glools
'} i >“)
Wo
ii } | if 4
1 Wl |
| NHI Hill
; | A
iil WHI}
Wie i i] i
Hi | Wil i |
Wid tt II 4) |
a ro Sa ! i
Ht mn { |
Wat ity itty HHA |
' eT
| Ni
| | 1
Hut | NHI }
Fie 5. Babcock
milk test bottle.
lowed to run down until it just
reaches the mark on the stem;
the quantity 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 meas-
uring out the milk so that the de-
livery of milk may be checked by
gentle pressure on the upper end
of the pipette.
The point of the pipette is now
placed in the neck of a Babcock
test bottle (fig. 5) and the milk is|
allowed. to flow slowly down the ‘I716¢q
inside of the neck. Care must be |
taken that none of the milk meas-|
ured out is lost in this transfer. |
The portion of the milk remaining \
in the point of the pipette is blown
into the test bottle.
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 holding
ff
/
27
|
|
|
{
|
|
eit
|
|
i
y |
Me
Fie. 6.
17.6 ce. pipette,
1
,
y.
y.
t,
if
!
}
|
|
|
| .
il
28
Testing Milk and Its Products.
the bottle in this way, there is a danger that some of the
milk may completely fill the neck of the bottle, and as a
result, flow over the top of the neck.
dd.
17.5 cc., is then filled to the mark with sulfuric acid of a
specific gravity of 1.82-1.83. This amount of acid is care-
fully poured into the test bottle containing the milk. In
adding the acid, the test bottle is conveniently held at an
Fie. 7. The right way of emptying pipette into test bottle.
Adding acid. The acid cylinder, (fig. 9), holding
The Babcock Test.
=
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. By pouring
the acid into the
middle of the neck
of the test bottle,
there is also a dan-
ger of completely
filling this with acid,
in which case the
plug of acid formed
will be pushed over
the edge of the neck
by the expansion of
the air in the bottle,
and may be spilled
on the hands of the
operator.
The milk and the
acid in the test bot-
tle should be in two
distinct layers, with-
out any black por- -
tion of Beal is.
mixed liquids be-~@
tween them. Such
Fie. 8. The wrong way of emptying pipette into
followed by an indistinct separation of the fat in the final
reading. The cause of this is possibly that a partial mix-
ture 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 portion may
30 Testing Milk and Its Products.
be slightly charred by the strong acid. The appearance of
black flocculent matter in or below the column of fat which
generally results, in either case renders a cor-
rect measurement of fat difficult, and at
times even impossible; if the black specks
occur in the fat column itself, the readings are
apt to be too high; if below it, the difficulty
comes in deciding where the column of fat
begins.
34. Mixing milk and acid. After ad-
ding the acid, this is carefully mixed with the
=, milk by giving the test bottle a rotary motion.
oe Tee eo Ome this, care should be taken that none
acid cylinder. of the liquid spurts into the neck of the test
bottle. When once begun, the mixing should be continued
until completed; 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 per-
sistent and careful shaking of the bottle. Beginners some-
times 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 bottom of
the bottle, unless this is vigorously 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 the milk.
Colostrum milk, or milk from fresh cows will form a
violet colored mixture with the acid, owing to the action of
The Babcock Test. 31
the latter on the albumen present in considerable quantities
in such milk (22).
When milk samples are preserved by means of potassium
bichromate (172), and so much of this material has been added
that the milk has a dark yellow or reddish color, the mix-
ture of milk and acid will turn greenish black, and a com-
plete solution is rendered extremely difficult on account of
the toughening effect of the bichromate on the precipitated
casein. An indistinct separation of the fat is also some-
times obtained in such samples, but this difficulty can gen-
- erally be overcome by using a little less than the regular
quantity of acid.
35. 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 to
five minutes at a speed of 600 to 1,200 revolutions per min-
ute, the proper speed being determined by the diameter of the
tester (57). It is not absolutely necessary to whirl the test
bottles in the centrifuge as soon as the milk and the acid are
mixed; they may be left in this condition for any reasonable
length of time (24 hours, if necessary) without the test be-
ing 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 usually sufficient for the
first whirling of the test bottles in the centrifuge; this will
bring the fat to the surface of the liquid in the body of the
bottle.
36. Adding water. Hot water is now added by
means of a pipette, or some special device, until the bottles
are filled up to the beginning of the neck. The bottles are
32 Testing Milk and Its Products.
whirled again at full speed for one minute, and hot water
added a second time, until the lower part 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, owing to the gradual cool-
ing 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 read-
ing uncertain or even too high. A final whirling for one
minute completes the separation of the fat.
37. Measuring the fat. The amount of fat in the neck
of the bottle is measured by the scale or graduations on
the neck. Each division of the scale represents two-tenths
of one per cent. of fat, and the space which the fat occupies
shows the per cent. of butter fat contained in the sample
tested.
The fat obtained should form a clear yellowish liquid dis-
tinctly separated from the acid solution beneath it. There
should be no black or white sediment in or below the col-
umn of fat, and no bubbles or foam on its surface. The
bottles should be kept warm until the readings are made, so
that the column of fat will have a sharply defined upper and
lower meniscus.
The fat is measured from the lower line of separation be-
tween the fat and the water, to the top of- the fat column,
at the point b, shown in the figure 10, the reading being thus
taken from a to 6, and not to c or to d.. Comparative gray-
imetric 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,
The Babcock Test. 33
and errors in the reading of the column are therefore easily
made, unless the preceding rule is observed.
The readings should be made when
the fat has a temperature 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
solidifies at about 100° F. No read-
ings should be attempted if the fat is
partly solidified, as it is impossible to
get an accurate reading in this case.*
A pair of dividers will be found
convenient for measuring the fat,
and the liability of error in reading
is decreased by their use. The points
of the dividers are placed at the up-
Fig. 10. Measuring the col- pil #2
umn of fat in a Babeock per and lower limits of the fat column
~ A (from a to 6 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 then show the per cent. of fat in the sample
tested.
* The effect of differences in the temperature of the fat on the readings ob-
tained will be seen from the following: If 110 and 1£0° F. be taken as the extreme
temperatures, at which readings are made, this difference of 40° F. (22.39 C) would
make a difference in the volume of the fat column obtained in case of 10 per cent.
milk, of .00064 x 2 x 22.3 — .028544 ce. 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 ce. 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.
3
34 Testing Milk and Its Products.
B.— Discussion OF THE DETAILS OF THE Baspcock TEsT.
38. Although the manipulations of the Babcock test are
few and comparatively simple, various difficulties may be
met with in using it, particularly in the hands of beginners.
The main points that have to be observed as to apparatus
and testing materials in order to obtain correct and satisfac-
tory 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 milk
samples, apparatus, and accessories.
1.— GLASSWARE.
39. Test bottles. When 17.6 cc., or 18 grams of milk,
are measured into the Babcock test bottle, the scale on the
neck of the bottles shows directly the percent 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 120° F.), is 0.9, 1.8 grams of
fat will occupy a volume of }*=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 repre-
senting one per cent., and each of these are again sub-divid-
ed into five equal parts. Each one of the latter divisions
therefore represents two-tenths of one per cent. of fat when
17.6 ec. 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.
The Babcock Test. 35
The figures and lines of the measuring scale become in-
distinct 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 necks with a cloth, or a piece of paper,
the black color will show in the etchings of the glass, mak-
ing these plainly visible.
40. The test bottles should have a capacity of about
50 cc., or less than two ounces; they should be made of
well-annealed glass that will stand sudden changes of tempe-
rature 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 not
on the average be very far from 30.65 lbs. (see 57) or 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.
41. 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 rub off 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 meth-
ods, that the lead pencil marks made on such ground labels
are easily erased during the test, unless the bottles are
carefully handled. Small strips of tin or copper with a
36 Testing Milk and lis Products.
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 into
the glass directly above the scale on the neck of the bottles,
In ordering an outfit, or test bottles alone, the operator may
specify that the 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 sam-
ple of milk is measured. Mistakes are often made when
the operator trusts to his memory for locating the different
bottles tested at the same time.
42, Cleaning test bottles. The fat in the neck of the
test bottles must be liquid when these are cleaned.
The bottle should be shaken in emptying the acid, in order
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 this being shaken during the emptying, this residue
will be found to stick very tenaciously to the bottom in the
subsequent cleaning with water.
A convenient method of emptying the test bottles is
shown in the illustration (fig. 11). After reading the fat,
the bottles are taken from the tester and placed, neck down,
in the + inch holes of the board cover of a five-gallon stone-
ware 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
The Babcock Test. 34
of an apparatus, devised by one of us* (see fig. 12) is gen-
erally sufficient to remove all grease and dirt, as well as
: acid solution,
= l from the inside
= of the bottles.
When the bottles
have been rinsed,
they are placed
in an inverted po-
sition to drain, on
| ui ~
or inl TR
=
aS == mageieage fae they are kept un-
Fig. 11. Waste acid jar. til needed. The
outside of the bottles should occasionally be wiped clean
and dry.
43. ‘The amount of unseen fat that clings to glassware
is generally not sufficient to be noticed in the results ob-
tained in testing whole milk, but it plays an important part
in testing samples of separator skim milk. It may be readily
noticed by making a blank test with clean water in bottles
which have been used for testing ordinary milk, and 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 often find that a few drops of fat — sometimes
enough to condemn a separator —will collect in the neck
of the bottles, although the water tested has not been near
a separator.
Boiling hot water wiil generally clean the grease from
glassware for a time, but all test bottles should, in addition,
a galvanized iron
* Farrington.
38 Testing Milk and Its Products.
be given an occassional bath in some weak alkali, or other
grease-dissolving solution. Persons doing considerable
milk testing will find it of advantage to provide themselves
with a small copper tank, which can be filled with a weak
alkali-solution (figs. 14 and 15). . After having been rinsed
z
Fie. 12. Apparatus for cleaning test bottles. A, apparatus in position; the
water flows frum the reservoir through the iron pipe bd into the inverted test bot-
tle d through the brass tube c, screwed into the iron pipe. B shows construction
of the rubber support on which the top of the test bottle rests; f, draining sink.
with hot water, the test bottles are placed in the hot solu-
tion kept in the tank, where they may be left completely cov-
ered with the liquid. If the tank is provided with a small
The Babcock Test. 39
faucet at the bottom, the liquid can be drawn off when the
test bottles are wanted. A tablespoonful of Savogran to
about two gallons of water will make a very satisfactory
cleaning solution; sal soda, Gold Dust, Lewis lye or Babbitt’s
potash are equally efficient. The cleansing properties of
solutions of any of these substances are increased by warm-
ing the liquid. The test bottles must be rinsed twice with
hot water after they are taken from this bath.
Fig, 13. Draining-rack for test bottles.
The black stains that sometimes stick to the inside of test
bottles after prolonged use, can be removed with a little
muriatie acid.
44, Pipette. The difference in the weights of various
samples of normal milk generally falls within comparatively
narrow limits: if a given quantity of water weighs 1 pound,
the same quantity of the usual grades of normal milk will
weigh from 1.029 to 1.033 pounds, or on the average 1.03
Ibs. 18 grams* of water measures 18 cc.; 18 grams of
* Cubic centimeters (abbreviated: cc.) are the standard used for measuring
volume in the metric system, similar to the quart or pint measure in our ordinary
system of measures. 1 quart is equal to a little more than 1000 cubic centimeters.
In the same way, grams represent weight, like pounds and ounces. 1 cc. of
water at 4° Centigrade weighs 1 gram. 1000 grams (~ 1 kilogram) is equal to 2.2 lbs.
Avoir. (See Appendix, for Comparisons of Metric and Customary Weights and
Measures).
40 Testing Milk and Its Products.
milk will therefore take up a smaller volume (measure less)
than 18 cc., viz: 18 divided by 1.03, which is very nearly
= 17.5. This is” the
quantity of milk
taken in the Bab-
cock test. A certain
amount of milk will
adhere to the walls
of the pipette when
it is emptied, and
this thin film has
been found to weigh
about one-tenth of
a gram; conse-
quently 17.6 cc. has
been adopted as the
_ capacity of the pip-
ei ette used for deliv-
ering 18 grams of
Fig. 14. Tank ae adanthar REE oy SHV,
For convenience in measuring the milk, the ga
shape of the pipette is of importance. The] |
mark on the stem should be two inches or more } i
from the upper end of the pipette. The lower |
part should be small enough to fit loosely into |
the neck of the test bottle, and not contracted ||
to a fine hole at the point; the point should be
large enough to allow a quick emptying of the
4 ; Fie. 16. Pip-
pipette. (Fig. 16). ette points—
45. Fool pipettes. Soon after the Babcock test A, proper con-
struction; B,
undesirable
of paying for the milk, a creamery supply house put construction.
began to be generally used at creameries as a means
The Babcock Test. 41
on the market a 20 cc. milk-measuring pipette, which was
claimed to show the exact butter value of milk, instead
of its content of butter fat, as in the case in using the
ordinary 17.6 cc. pipette. A 20 cc. pipette will deliver 2.4 cc., or
13.6 per cent. more milk than a 17.6 cc. pipette, and it follows
that the results obtained by measuring out milk for Babcock tests
with these pipettes will be about 13.6 per cent. too high. In con-
sidering the subject of Overrun it is noted that the excess of butter
yield over the amount of fat contained in a certain quantity of
milk will range from about 10 to 15 per cent., or on the average
12-13 percent. The 20 ce. pipettes may, therefore, give approxi-
N N
B b
POOR LS.
ae ae
inna
Fic. 15. Rack for holding test bottles in tank shown in fig. 14.
mately 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 maker, and according to conditions beyond his control,
and cannot therefore be used as a standard in the same manner as
the fat content of the milk. Similar 22 cc. pipettes were also sent
out. These pipettes created a great deal of confusion during the
short time they were on the market, and were popularly termed
“fool pipettes,’’ as the tests obtained by them did not give, what
they professed to do, an accurate and definite measure of the but-
ter-producing qualities of different lots of milk. It is not known
that any of these pipettes are on the market at the present time.
42 Testing Milk and Its Products.
46. Acid measures. A 17.5 cc. glass cylinder 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, or a quan-
tity of acid sufficient for the number of test bottles to be
whirled at a time, is poured into a small glass beaker, pro-
vided with a lip, or into a porcelain 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 regularly,
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, automatic pipettes, buret-
tes, etc., although they will often give good satisfaction for
a time while new. Sulfuric acid is so corrosive, and opera-
tors as a rule take such poor care of such apparatus, that it
is a very difficult matter to design a form which will remain
in good working order for any length of time. Automatic
pipettes attached to acid bottles or reservoirs, to prove
satisfactory, must be made entirely of glass, and strong, of
simple construction, tightly closed and quickly operated.
44. The Swedish Acid Bottle answers these requirements
better than any other device for this purpose known to the
writers at the present time. Its use is easily understood (see
fig. 17); it gives good satisfaction if the hole in the glass
stop 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 various dealers
The Babcock Test. 43
for delivering the acid, but cannot recommend them for use
in factories, or outside of chemical laboratories.
48, Instead of measuring out the acid, Bartlett* re-
cently suggested adding it directly to the milk in the test
bottles, till the mixture rises to a mark
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 (74).
This method of adding the acid is in
the line of simplicity and may in time
become generally adopted. The marks
should, however, be put on by the man-
ufacturers, as the operator in attemping
to do so will be apt to weaken or break
_ the bottles.
Fic. 17. Swedish acid
Calibration of glassware. 1.—TEST bottle; the side-tube is
BOTTLES. The Babcock milk test bot- meee ie ne.
tles are so constructed that the scale or graduation of the
neck measures a volume of 2 cubic centimeters, between
the zero and the 10 per cent. marks (39). The correctness
of the graduation may be easily ascertained by one of the
following methods:
49, Calibration with mercury. 27.18 grams of metallic
mercury are weighed into the perfectly clean and dry test
bottle; since the specific gravity of mercury is 13.59, double
this quantity will occupy a volume of exactly 2 cubic centi-
meters (44*). 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
* Maine experiment station, bull. No. 31.
44 Testing Milk and Sis Products.
inverted so that the mercury will run into its neck. If the
total space included between the 0 and 10 marks is just
filled with the two cubic centimeters of mercury, the grad-
uation is correct. Bottles, the whole length of the scale of
which vary more than two-tenths of one per cent., are inac-
curate, 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 bottles, and one
weighing of mercury will thus suffice for a number of cali-
brations. 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 of it.
Unless the bottles to be calibrated are thoroughly cleaned
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 scale, fig.
28, shown in (84) is sufficiently delicate for making these
weighings.
50. Cleaning mercury. ven with the best of care, mer-
cury used for calibration of glassware will gradually 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, leay-
ing the impurities on the filter paper. Mercury may be
*.
The Babcock Test. 45
freed from foreign metals, zinc, 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 cov-
ered to keep out dust. The acid solution is then carefully
poured off and the mercury washed witb water; the latter is
in turn poured off, and the last traces of water absorbed by
means of heavy clean 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 calibra-
tions 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 manipulated.
Equally correct results may, however, with proper care be
obtained by using one of the following methods:
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 calibration with
mercury.
D1. 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 with a piece of filter
paper or clean blotting paper; then measure into the bottle
2 cc. of water from an accurate pipette or a burette, divided
to eo Of a cubic centimeter. If the graduation is correct,
2 ce. will fill the neck exactly to the 10 per cent. mark of
the scale.
46 Testing Milk and Its Products.
52. 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 difference be-
tween 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 with strong sulfuric acid, or soda lye,
and washed repeatedly with pure water, and dried. Glass-
ware is not clean unless water will run freely over its sur-
face, without leaving any adhering drops.
53. 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 (39)
representing 1 per cent. Since these intermediate divisions
are generally made with a dividing machine, they are as a
rule correct, but it has happened that the divisions have
been inaccurately placed, although the space between 0 and
10 was 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 compare the space with those of each
per cent. on the scale.
54. 2.—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 necessity of pre-
vious thorough cleaning of the glassware is evident from
The Babcock Test. 47
what has been said in the preceding. The pipette and the
acid measure may be weighed empty and then again when
filled with pure water to the mark, 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 the acid measure is ob-
tained 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 accu-
racy of the test.
2.— CENTRIFUGAL MACHINES.
55. 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-five
to thirty bottle tester is generally large enough, even if
toward a hundred samples of milk are to be tested at a
time. The operator can use his time more economically
in running a machine of this size than one holding fifty or
sixty bottles; the work of filling or cleaning the bottles and
measuring the fat can be done while the centrifuge is run-
ning if a double supply of bottles are at hand. Large test-
ers require more power than smaller ones, and when sixty
tests are completed, many of the bottles will cool, and the
fat column crystalize, before the operator has time to read
them, unless special precautions are taken for keeping the
bottles warm.
* 1 cubic centimeter of distilled water weighs 1 gram, when weighed ina vacuum
at the temperature of the maximum density of water (4° C); for the purposes of
calibration of glassware used in the Babcock test, sufficiently accurate results are,
however, obtained by weighing the water in the air and at a low room temperature
{60° F.)
48 Testing Milk and Its Products.
56. 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 when empty. A machine
that trembles and shakes when in motion is neither satis-
factory nor safe, and the results obtained are apt to be too
low. High-standing machines are more apt to cause trou-
ble 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 op-
posite 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 on while
the bottles are whirled, and should not be removed until the
machine stops; the cover should be tight-fitting and may be
fastened with hooks soldered on the side of the machine;
test bottles have sometimes been broken while the machine
has been running at full speed, and every possible precau-
tion should be taken to protect the operator from any dan-
ger from spilled acid or broken glass.
57. 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
- 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 bot-
tles seven to eight hundred revolutions per minute, in order
to effect a maximum separation of fat; later work has
7
The Babcock Test. 49
shown that this speed is ample. Taking therefore this
as a standard, the centrifugal force to which the con-
tents of the test bottles are subjected when supported on
an eighteen inch wheel and turned 800 revolutions per
minute, can be calculated as follows :
The centrifugal force, F, acting on the bottles is expressed by the
formula
w.v?
39.2r
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.
(I)
When the wheel is turned 800 times a minute, a bottle supported
on its rim will travel 27rX ®8° =2 3.1415 X 3 X 829° =62.83
feet per second. The weight of a bottle, with milk and acid, is
very near 3 ounces, or 3; of a pound. Substituting these values
for v and w, gives
fe X 62.83?
32.2 X #5
The bottles are therefore, under conditions given, subjected to a
pressure of 30.65 lbs. In order to calculate the speed required
for obtaining this force in case of machines of other diameters,
the value of vin formula (1) is found from
OF ss 4/ 32.2 F Xr
= 30.65 lbs.
(11)
w
Substituting the values for F and w,
va 32:2 280.584 — 1/5264r
16
In this equation the values r=5,6,7, . . . 12 inches are
substituted in each case (+5, 3, #s, . - . 4% feet), and the velo-
city 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 case to a centrifugal force of 30.65 Ibs. As the number of
Vv
>=~, V being as before the velo-
revolutions per minute =
2ar
4
50 Testing Milk and Its Products.
city in feet per second, and r the radius of the wheel, the speed at
which the wheel must be turned, is found by substituting 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 of revolutions of
of wheel, d. per second, v. 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, 25 inches in
diameter, requires less that 700 revoiutions per minute for a per-
fect separation of the fat in Babcock bottles, while a ten-inch tes-
ter must have a speed of nearly 1100 revolutions, in order to
obtain the same result.
58. 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
7°2=63 (see table), or about once every second, in order to
effect a maximum separation of fat. By counting the num-
ber of revolutions, watch in hand, and consulting the pre-
ceding 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 is always kept up;
if through carelessness, worn-out or dry bearings, slipping
belts, etc., the speed is slackened, the result will come too
The Babcock Test. 51
low; it may be a few tenths, or even more than one percent.
Care as to this point is so much the more essential 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.
59. 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, within the probable
error of the test (say, less than one-tenth of one percent.)
the first whirling was sufficient, as it is believed will gener-
ally 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 indi-
cate 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 previous to taking
out a pipetteful for each test) should not vary more than
three-tenths of one percent. at the outside, and in the hands”
of a skilled operator will come within two-tenths of one per-
cent. If greater discrepancies occur, the test bottles giving
too high or too low results should be further examined, and
calibrated according to the directions already given (49).
52 Testing Milk and Its Products.
60. 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 smail hand -tester
answers every purpose. These may be had in sizes from
two to twelve bottles. In selecting a particular make of
tester the dairymen has the choice of a large number of
different kinds of machines. It is a source of regret that
most of the machines placed on the market for this purpose
in the past have been so cheaply and poorly constructed as to
prove very unsatisfactory after having been in use for a time.
The sharp competition between manufacturers of dairy
supplies, and the clamor of dairymen for something cheap,
fully account for
this condition of
affairs. This ap-
plies especially to
the many machines
made with belts or
friction application
of power. The
main objection to
‘jain \ : a |
| ' any ¥ these machines is
I " : ' the uncertainty of
the speed obtained,
when they have
been in use for some time, and the belt or friction appliance
begins to slip. Hand testers made with cog gear wheels —
are more to be depended on for giving the necessary speed
than belt or friction machines; they are generally noisy,
but the bottles are always whirled at the speed which the:
number of turns made by the crank would indicate.
Fig. 18. “ No-tin” test.
The Babcock Test. 53
The “ No-tin” test (see fig. 18) is, in the Opinion of the
authors, worthy of special mention among the hand testers
made at the present time; it is a six-bottle geared machine,
durable of construction, and runs smoothly and without
noise.
61. Power testers. For factory purposes, steam tur-
bine machines (fig. 19) 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 purpose of
knowing that sufficient speed is attained, and also to pre-
vent what may be serious accidents from a general smash-
up, if the turbine “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 centrifu-
gal force, thus
avoiding seri-
ous accidents.
The swinging
pockets which
hold the test
bottles in some
machines,
should be so
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 end of the neck catching at the center, the bottles
thus failing to take an upright position when the whirling
stops.
Fig. 19. Type of Babcock steam turbine testers.
54 Testing Milk and Its Products.
3.—SuLFruric ACID.
62. 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 rub-
ber stoppered ones, since a cork stopper is soon dissolved
by the acid and rendered useless. If the bottle is left un-
corked, 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.
63. 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.
64. 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. 27 (84).
aor
x
°o
Hudugi iga gh fall
——
rn
~
fl o
Lian
©u
Gylinder P @ylinder
Piette
Fie. 34. Apparatus used for determining the acidity of cream or milk.
a. Use of 20 cc. pipette. When a 20 cc. pipette is used for
measuring the sample to be tested, the tablet solution is
prepared by dissolving one tablet for every 17 cc. of water;
for five tablets 85 cc. of water are therefore taken. When
made in this way, each cubic centimeter of solution repre-
* By Mr. C. L. Fitch, of Hoard’s Creameries, (Hoard’s Dairyman, Sept. 3, 1897).
102 Testing Milk and [ts Products.
sents .01 percent of acid in the sample tested, 20 cc. of cream
being taken; the number of cubic centimeters required
to produce a pink color in the sample tested as read off
directly from the graduations of the cylinder used for mak-
ing the tablet solution gives the percent of acid in the sam-
ple, 10 cc. being equal to .10 percent acid, 32 cc. to .32 per-
cent, 65 cc. to .65 percent, etc.
b. Use of 17.6 cc. pipette. The 17.6 cc. milk pipette of the
Babcock test may be used for measuring the sample for
acidity testing, and the results read directly from the grad-
uated cylinder, if the tablet solution is prepared by taking
one tablet for every 19.5 cc. of water; five tablets are there-
fore dissolved in 97 cc. of water.
123. Ascream during its ripening process should gen-
erally have from .5 to .6 percent of acid, before it is ready
to churn, a 50 ce. cylinderful of tablet solution of this
strength will not be sufficient to make a test of cream con-
taining over .5 percent of acid, although it is enough for
testing the cream up to this point during the ripening pro-
cess. The acid-testing outfit should therefore contain a 100
cc. graduated cylinder, instead of one of 50 cc. capacity, so
that cream of any amount of acidity up to one percent can
be tested. A tablet solution of the strength given has not
only the advantage over the solution previously recom-
mended * (5 tablets to 50 cc. of water) of showing the per-
cent of acidity directly, without tables or calculations, but
being weaker, the unavoidable errors of determination are
decreased by its use.
Equally accurate results may be obtained by using solu-
tions made up according to method a or method 8, explained
* Ill. exp. sta., bull. 32; Wis. exp. sta., bull. 52.
Testing the Acidity of Milk and Cream. 103
in the preceding. The latter method (17.6 cc. cream, 5
tablets per 97 cc. of water) has, however, the advantage in
point of economy of apparatus, since a 17.6 cc. pipette is
found in creameries and dairies with the Babcock test out-
fit and is therefore most likely already available for use in
testing the acidity of cream. This method is therefore con-
sidered preferable and referred to as
124. The standard solution. The preparation of this
solution is as follows: Five tablets are added to the 100 ce.
cylinder which is filled to the 97 cc. mark with clean soft
water, tightly corked, shaken and laid on its side, as the
tablets will dissolve more quickly when the cylinder is
placed in this position than when left in an upright position
with the tablets at the bottom. Several cylinders con-
taining the tablet solution may be prepared; as soon as
one is emptied, tablets and water are again added,
and the cylinder is corked and placed in a horizontal posi-
tion. In this way fresh solutions ready for testing are
always at hand. The cylinder is kept tightly corked, while
the tablets are dissolving, so that none of the liquid is lost
by the shaking. It is well to put the tablets in the cylinder
with water at night; the solution will then be ready for use
in the morning. Excepting a flocculent residue of inert
matter, “settlings,’’ which will not dissolve, the tablets must
all disappear in the solution before this is used. The
strength of the tablet solution does not change perceptibly
by standing fur twenty-four hours; but a change takes place
in solutions more than a day old. The solid tablets will not
change if kept dry. The only precaution necessary is to
use a fresh solution when acidity tests are made.
125. Making the test. The cream to be tested is thor-
oughly mixed, and 17.6 cc. is measured into the cup. The
104. Testing Milk and Its Products.
pipette is rinsed once with water, and the rinsings added to
the cream in the cup. A few cc. of the tablet solution pre-
pared as given above are now poured from the cylinder into
the cream, and mixed thoroughly with it by giving the cup
a gentle rotary motion. The tablet solution is added in small —
quantities until a permanent pink color appears in the sam-
ple. The number of cc. of tablet solution which have been
used to color the cream is now found from the scale of the
cylinder.
In comparing the results of one test with another,
the same shade of color should always be adopted. The
most delicate point is the first change to a uniform pink
color which the sample shows when the acid contained there-
in has just been neutralized. This shade of color is easily
recognized with a little practice. The pink color is not per-
manent unless a large excess of alkaline solution has been
added, on account of the influence of the carbonic acid of
the air (116), and the operator should not therefore be
lead to believe by the reappearance of the white color
after a time, that the point of neutralization was not
already reached when the first uniform shade of pink was
observed.
126. Acidity of cream. 17.6 cc. of sweet cream is gen-
erally neutralized by 15-20 ce. of this tablet solution, rep-
resenting from .15 to .20 percent. of acid. A mild sour
cream is colored by 35 cc. tablet solution, and a sour cream
ready for churning, by about 50 cc. tablet solution. As the
cream ripens, its acidity increases. The rate of ripening
depends largely on the temperature at which the cream is
kept. Cream containing .5 to.6 per cent. of acid will make
such butter as our American market demands at the present
time. Cream showing an acid test of .55 per cent. may not
Testing the Actdity of Milk and Cream. 105.
be too sour, but .65 per cent. of acid is very near, if not on
the danger line, since such cream is likely to make strong
flavored, almost rancid butter. Hach lot of cream should be
tested as soon as it is ready for ripening, and the result of
the test will show whether the cream should be warmed or
cooled in order to have it ready for churning at the time
desired. Later tests will show the rate at which the ripen-
ing is progressing, and the time when the cream has reached
the proper acidity for churning.
127. Spillman’s cylinder. The graduated cylinder,
shown in fig. 35, was devised by Prof. Spillman of Wash-
ington experiment station, for use in testing
the acidity of milk and cream with Farring-
ton’s alkaline tablets. The following direc-
tions are given* for making tests with this
fil
xa
piece of apparatus.
‘“ All that is needed in addition to the acid
test graduate shown in the accompanying
illustration is a common prescription bottle
of six or eight ounce capacity, and a package
of Farrington’s alkaline tablets. [ill the
bottle with water and add one tablet for each
ounce of water in the bottle. Shake the bot-
tle frequently to aid in dissolving the tablets.
(IPH UIPHP
Fie. 35. Spill-
man’s cylinder, “ Making the test. In making the test, the
used in determin- - .
ing the acidity of acid test graduate is filled to the zero mark
cream ormilk. with the milk or cream to be tested. The tab-
let solution is then added, a little at a time, and the
graduate shaken after each addition, in order to thoroughly
mix the milk and the tablet solution. In shaking the
* Washington experiment station, bulletin No. 24.
106 Testing Milk and Its Products.
graduate, give it a rotary motion to prevent spilling any of
the liquid. Continue adding the tablet solution until a per-
manent pink color can be detected in the milk. The level
of the liquid in the graduate, measured by the scale on the
oraduate, will then be the percent. of acidity of the milk.
It is best to stand the graduate on a piece of white paper,
so that the first pink coloration of the milk may be easily
detected.”
128. Rapid estimation of the acidity of appar-
ently sweet milk or cream. a, Milk. The alkaline tab-
let method offers a ready means of estimating the acidity
of fresh milk or cream that is still apparently sweet. The
selection of the best kinds of milk is especially important
in pasteurizing milk or cream. Investigations have shown
that milk which gives the highest acid test contains, as a
rule, a larger number of bacteria and spores, not destroyed
by pasteurization, than does milk giving a low acid test; the
acidity test may therefore be used to advantage for the
purpose of selecting milk best adapted for pasteurization, as
well as such as is to be retailed or used in the manufacture
of high-grade butter and cheese.
In distinguishing milk fit for pasteurization purposes
from that which is doubtful, an arbitrary standard of two-
tenths of one percent of acid may be taken as the upper
limit for milk of the former kind. The apparatus used in
making this test is shown in the accompanying illustra-
tion, (fig. 36), and consists of a white tea cup; either a four,
six or eight ounce bottle, and a No. 10 brass cartridge shell,
or a similar measure. A solution of the tablets in water is
first prepared, one tablet being always added for each ounce
of water: four tablets in a four ounce bottle; six, in a six
Testing the Acidity of Milk and Cream. 107
ounce bottle, etc., the amount of tablet solution prepared
depending on the number of tests to be made at one time.
The bottle is filled up to its neck with clean soft water, and
the solution prepared in the manner previously given (124).
The manner of operating the test is as follows:
li
ie
ee |
C aw
uP & Ounce Bottle. Measure
Fic. 36. Apparatus used for rapid estimation of the acidity of apparently sweet
milk or cream.
129. Operating the test. As each lot of milk is brought
to the creamery in the morning and poured into the weigh
car, it is weighed, and the cartridge-shell dipper filled with
the milk; this is then poured into the white cup. The same
_or another No. 10 shell is now filled twice with the tablet
solution, and emptied into the milk in the cup. Instead of
dipping twice with one measure or a No. 10 shell, a tin
measure can be made holding as much as two No. 10
shells. The liquids are then mixed in the cup by giving
this a quick rotary motion. The color of the mixture is now
108 Testing Milk and Its Products.
noticed. If the milk remains white it contains more than
two-tenths of one percent of acid, and should not be used
for pasteurization. If it is colored after having been thor-
oughly mixed with two measures of tablet solution, it con-
tains less than this amount of acid and may be safely used,
as far as acidity goes, for pasteurization or any other pur-
pose for which it is necessary to have thoroughly sweet
milk. The shade of color obtained will vary with different
lots of milk; the sweetest milk will be most highly colored,
but a milk retaining even a faint pink color with two
measures of tablet solution to one measure of milk contains
less than .2 percent acid.
By proceeding in the manner described, the man at the
factory weigh can is able to test the acidity of the milk de-
livered nearly as quickly as he can weigh the milk; and ac-
cording to the results of the test he will send the milk to
the general delivery vat, or to the pasteurization vat, as the
weighing can may be provided with two conductor spouts.
130. Size of measure necessary. It is not necessary to
use a No. 10 shell for a measure in working the preceding
method; one of any convenient size that can be filled ac-
curately and quickly, will answer the purpose equally well,
if a measure of the same size is used for. both the sample
and the tablet solution. When this is done, each measure-
ful of tablet solution made up as directed, will represent.
one-tenth percent of acid in the sample tested.
131. b, Cream. Cream can be tested in the way already
described for testing the acidity of fresh milk, by adding to
one measureful of cream in the cup, as many measures of
tablet solution as are necessary to change the color of the
cream when the two liquids are thoroughly mixed. If one
Testing the Acidity of Milk and Cream. 109
measure of tablet solution colors one measure of cream, this
contains less than .1 percent acid; if five measures of tablet
solution are required, the cream contains about .5 percent
acid, etc. By proceeding in the manner described, the ope-
rator can estimate the acidity to within .05 per cent. of
acid, if half measures of tablet solution used are observed.
The results thus obtained are sufficiently delicate for all
practical purposes.
132. Detecting preservaline* in milk. The tablet solution
furnishes a simple method of detecting preservaline in milk. The
application of the alkaline tablets for this purpose was first dis-
cussed in bulletin No. 52 of Wisconsin experiment station. The
acidity of the milk is increased by the addition of preservaline, but
neither the odor nor taste of the milk is affected thereby. By ad-
ding to sweet milk the amount of preservaline which the manu-
facturers claim will keep it sweet for 36 hours, its acidity may be
increased to .35 per cent., in a sample of milk which before adding
the preservaline tested perhaps only .15 per cent. acid.
As before stated, unadulterated milk will usually smell or taste
sour, or “‘turned’’, when it contains .30-.35 per cent. acid; milk
testing as high as this limit, which neither smells nor tastes sour
in any way, is therefore in all probability adulterated with pre-
servaline or some other preparation containing boracic acid, or a
similar compound.
133. «Alkaline Tabs.’’ These are not alkaline tab-
lets, but a substitute which was put on the market by a
New York firm. The outfit furnished consisted of four
packages of paper discs made of filter paper, each of about
the size of an old-style copper cent; two packages of square
paper; one glass of about 10 cc. capacity, and one small
* Preservaline is the trade name of an antiseptic extensively advertized for
preserving milk and cream. It consists essentially of boracic acid and borax, the
use of which in milk and other dairy products offered for sale, is prohibited by
law in many states.
110 Testing Milk and lis Products.
glass bottle. The directions stated that each paper disc
represented .1 per cent. acidity when added to the small
glassful of milk or cream, with two of the square papers,
the whole to be well shaken in the long glass bottle. The
acidity of the sample of milk or cream was claimed to be
measured by counting the number of round papers required
to produce a pink color in the sample tested.
An investigation of the reliability of these “Tabs” soon
disclosed the fact that they were entirely inaccurate, and
that no dependence could therefore be put on the results
obtained by their use. A report of the comparative work
done in testing the acidity of milk or cream by a one-tenth
normal alkali solution and these ‘‘ Alkaline Tabs ” was pub-
lished in the dairy press in 1895, to which reference is here
made as to the details sf the results obtained.*
* Hoard’s Dairyman, Sept. 6, 1895.
Testing the Purity of Milk. 1
Fig. 37. Students operating the Wisconsin curd test.
CHAPTER VIII.
TESTING THE PURITY OF MILK.
134. The Wisconsin curd test. Cheese makers are
often troubled with so-called floating or gassy curds which
produce cheese defective in flavor and texture. These faults
are usually caused by some particular lot of milk containing
112 Testing Milk and Lts Products.
impurities that cannot be detected by ordinary means of in-
spection. The Wisconsin curd test is used to detect the
source of these defects and thus enable the cheese maker
to exclude the milk from the particular farm or cow to
which the trouble is traced. This test is similar in princi-
ple to tests that have for many years past been in use in
cheese-making districts in Europe, notably in Switzerland,*
but was worked out independently at the Wisconsin Dairy
School in 1895 and has become generally known as the Wis-
consin curd test’ from the description of it in the report of
Wis. experiment station for 1895., The method of operat-
ing this test is as follows (see fig. 37).
135. Method of making the test. Pint glass jars, thor-
oughly cleaned and sterilized with live steam, are provided;
they are plainly numbered or tagged, one jar being pro-
vided for each lot of milk to be tested. The jars are filled
about two-thirds full with the milk from the various sources
{it is not necessary to take any exact quantity); they are
then placed in a tank or vat containing water, which is
heated until the milk in the jars has a temperature of 98° F.
The thermometer used must not be transferred from one
sample to another, unless special precautions are taken, for
fear of contaminating the pure lots of milk by impure ones.
When the milk has reached a temperature of 98°, add to
each sample, 10 drops of rennet extract, and mix by giving
the jar arotary motion. The milk is thus curdled, and the
curd allowed to stand for about twenty minutes until it is
firm. It is then cut fine with a case knife, and after settling,
the whey is poured off. The best tests are made when the
separation of the whey is most complete. By allowing the
* Herz, Unters. d. Kuhmilch, Berlin, 1889, p. 87.
+ Twelfth report, p. 148.
Testing the Purity of Milk. LE
samples to stand for a short time, more whey can be poured
off, and the curd thereby rendered firmer. The water around
the jars is kept at a temperature of 98°, the vat is covered,
and the curds allowed to ferment in the sample jars for six
to twelve hours.
During this time the impurities in any particular sample
will cause gases to be developed in the curds so that by
examining the same carefully, by smelling of them, and
cutting them with a sharp knife, those having a bad flavor
or a spongy or in any way abnormal texture may be easily
detected, and the lot of milk from which it was made,
thereby picked out.
136. By proceeding in the same way with the milk from
the different cows in a herd, the mixed milk of which pro-
duced abnormal curds, the source of contamination in the
herd may be located. Very often the trouble will be found
to come from the cows’ drinking foul stagnant water or from
fermenting matter in the stable. In the former case the
pond or marsh must be fenced off, or the cows kept away
from it in other ways; in the latter, a thorough cleaning
and disinfection of the premises are required. If the milk
of a single cow is the source of contamination, it must be
kept by itself, until the milk is again normal; under such
conditions the milk from the healthy cows may of course
safely be sent to the factory.
137. The fermentation test. The Gerber fermenta-
tion test (see fig. 38) furnishes a convenient method for
discovering the cause of abnormal fermentations which show
themselves in tainted, pin-holey, gassy, or floating curds,
and is also useful in examining the purity of different lots
of milk. The test consists of a tin tank which can be heated
8 :
‘II4 Testing Milk and Its Products.
by means of a small lamp, and into which a rack fits, hold-
ing a certain number of cylindrical glass tubes; these are
all numbered and provided with a mark and a tin cover. In
muking the test, the tubes are filled to the mark with milk,
the number of each tube being recorded in a note book,
opposite the name of the particular patron whose milk was
placed therein. The tubes in the rack are put in the tank,
which is two-thirds full of water; the temperature of the
(hee
iH
it s rt
eee TTI
Fig. 38. The Gerber fermentation test.
water is kept at 104-106° F. for six hours, when the rack is.
taken out, the tubes gently shaken, and the appearance of
the milk, its odor, taste, etc., carefully noted in each case.
The tubes are then again heated in the tank at the same
temperature as before, for another six hours, when observa-
tions are once more taken of the appearance of the milk in
each tube. The tainted milk may then easily be discovered.
by the abnormal coagulation of the sample.
Testing the Purity of Milk. II5
According to Gerber,* good and properly handled milk
should not coagulate in less than twelve hours, when kept
under the conditions described, nor show anything abnor-
mal when coagulated. Milk from sick cows and from cows
in heat, or with diseased udders will always coagulate in less
than twelve hours. If the milk does not curdle inside of a
day or two, it should be tested for preservatives (240).
* Die praktische Milch-Pruefung; Woll, Handbook f. Farmers and Dairymen,
pp. 253-5,
116 Testing Milk and Its Products.
CHAPTER IX.
TESTING MILK ON THE FARM.
139. Variations in milk of single cows. The varia-
tions in the tests of milk of single cows from milking to
milking, or from day to day, are greater than many cow-
owners suspect. There seems to be no uniformity in this
variation, except that the quality of the milk produced
generally improves with the progress of the period of lacta-
tion; even this may not be noticeable, however, except when
the averages of a number of tests made at different stages
during the lactation period are compared with each other.
When a cow gives her maximum quantity of milk, shortly
after calving, the quality of her milk is generally poorer (by
one percent of fat, or less) than when she is drying off.
Strippers’ milk is therefore as a rule richer in fat than the
milk of fresh cows.
140. By testing separately every milking of a number
of cows through their whole periods of lactation, the results
obtained have seemed to warrant the following conclusions
in regard to the variations in the tests of the milk from
single cows, and it is believed that these conclusions allow
of generalization.”
1. Some cows’ milk tests about the same at every milking.
Such cows generally give a uniform quantity of milk from
day to day.
* Illinois experiment station, bulletin 24.
Testing Milk on the Farm. 117
2. Other cows give milk that varies in an unexplainable
way from one milking to another. Neither the morning nor
the evening milking is always the richer, and even if the
interval between the two milkings is exactly the same, the
quality as well as the quantity of milk produced will vary
considerably. Such cows are mostly of a nervous, excitable
temperament, and are easily affected by changes in feed,
drink, or surrounding conditions.
3. The milk of a sick cow, or of a cow in heat, generally
tests higher than when the cow is in a normal condition;
the milk yield generally decreases under such condition;
marked exceptions to this rule have, however, been observed.
4. Starved or underfed cows may give milk testing higher
than when the cows are properly nourished, probably on
account of an accompanying feverish condition of the ani-
mal. The milk is, however, more generally of an abnor-
mally low fat content, which may be readily increased to
the normal percent of fat in the milk by liberal feeding.
5. Fat is the most variable constituent of milk, while the
solids not fat vary within comparatively narrow limits. The
summary of analysis of 2400 American samples of milk cal-
culated by Cooke* shows that while the percentage of fat
varies from 3.07 to 6.00 percent, or nearly three percent,
that of casein and albumen varies only from 2.92 to 4.30
percent, or less than one and one-half percent, and the milk
sugar and ash content increases but little (about .69 percent),
as the milk grows richer, within the range given.
6. A test of only one milking may give a very erroneous
impression of the average quality of a certain cow’s milk.
A composite sample (see below) taken from two or more
* Woll, Handbook for Farmers and Dairymen, p. 195.
118 Testing Milk and Its Products.
successive milkings will more nearly represent the quality
of the milk which a cow produces at the time of the samp-
ling.
141. The variations that may occur in testing the milk
of single cows, are illustrated by the following figures ob-
tained in an experiment made at the [Illinois experi-
ment station,* in which the milk of each of six cows was
weighed and analyzed daily during the whole periods
of lactation. Among the cows were pure-bred Jerseys,
Shorthorns, and Holsteins, the cows being from 3 to 8 years
of age, and varying in weight from 850 to 1350 lbs. During
a period of two months of the year, the cows were fed a
heavy grain ration consisting of 12 lbs. of corn and cob
meal, 6 lbs. of wheat bran, and 6 lbs. of linseed meal, per day
per head. This course of feeding was tried for the purpose
of increasing, if possible, the richness of the milk. The
influence of this heavy grain feed, as well as tbat of the first
pasture grass feed, on the quality and the quantity of the
milk produced is shown in the following table which gives
the complete average data for one of the cows (No. 3). The
records of the other cows are given in the publication re-
ferred to; they were similar to the one here given, in so far
as variations in quality are concerned.
* Bulletin No. 24.
Testing Milk on the Farm. 119
Average results obtained in weighing and testing a cow's milk
daily during one period of lactation.
es
Daily milk Tests of one day’s|| Yield of fat per
= yield. milk. day.
tot 9) $=
"D> o » o . ~~ o re)
S283 |) me / 62 os | ms] Fs | os | we | bs
4 cated Oe ee ea aa = all ON ca tae << Lael
December........... 920 || 12.1 | 16.0 | 10.0 3.8 | 4.9 3.0 46 60 34
SUEY sn sshc5cess- ODF WbsO leat pda 3.7 4.6 2.7 59 76 44
FGbruary:...3....... 1035 || 16.1 | 17.7 | 13.5 || 3.6] 5.8] 3.2 58 | .84 51
MV ANG Pies scct cece aoe: 1047 |} 14.3 | 16.0 | 12.5 3.8 4.7 3.4 54 .61 50
PAST) cseautsoesetpnas c= 1054 || 13.8 | 16.5 | 11.5 4.0 | 5.8 3.0 5d 12 46
WTO tecasnnss see 1079 |) 14.5 | 17.2 | 10.0 3.8 4.6 3.4 55 .70 44
DUNe... 1105 j) 12.1 |.14.0) 9.2 3.9 4.6 3.2 47 .O7 35
PERN ttesacccase coscces 1180 9.3] 12.2) 6.0 4,2 6.2 2.8 39 . 60 27
POEMS Das s.2s0c cress 1130 6.4] 9.3 3.5 4.7 728 2.9 30 .50 16
142. The average test of this cow’s milk for her whole
period of lactation was 3.8 per cent. of fat (i. e. the total
quantity of fat produced -- total milk yield, 100) ; the milk
of the cow twice during this time tested as high as 5.8 per
cent., and once as low as 2.7 per cent., while tests of 3.0 and
4.6 per cent. were obtained a number of times. The aver-
age weight of milk produced per day by. the cow was 14 lbs. ;
this multiplied by her average test, 3.8, shows that she pro-
duced on the average .53 lbs., or about one-half a pound
of butter fat per day during her lactation period. If, how-
ever, her butter-producing capacity had been judged by the
test of her milk for one day only, this test might have been
made either on the day when her milk tested 5.8 per cent.,
or when it was as low as 2.7 per cent. Both of these tests
were made in midwinter when the cow gave about 16 lbs. of
milk aday. Multiplying this quantity by 5.8 gives .93 lbs.
of fat, and by 2.7 gives .43 lbs. of fat. Hither result might
show the butter fat produced by the cow on certain days,
but neither gives a correct record of her actual average
daily performance for this lactation period.
120 Testing Milk and Its Products.
A sufficient number and variety of tests of the milk of
many cows have been made to prove that there is no defi-
nite regularity in the daily variations in the richness of the
milk of single cows. The only change in the quality of milk
common to all cows is, as stated, the natural increase in fat
content as the cows are drying off, and even in this case the
improvement in the quality of the milk sometimes does not
occur until the milk yield has dwindled down very materially.
143. Causes of variations in fat content. The quality
of a cow’s milk is as arule decidedly influenced by the fol-
lowing conditions:
Rough treatment.
Exposure to rain or rough weather.
Change of feed.
Change of milkers.
Rapidity of milking.
Length of interval between milkings.
Unusual excitement or sickness.
144. Disturbances like those enumerated frequently in-
crease the richness of the milk for one, and sometimes for
several milkings, but a decrease in quality follows during
the reaction or the gradual return to normal conditions, and
taken as a whole, there is a considerable falling off in the
total production of milk and butter fat by the cow, on ac-
count of the nervous excitement which she has gone through.
Aside from changes due to well-definable causes, like those
given above, the quality of some cow’s milk will often
change very considerably without any apparent cause. The
dairyman who is in the habit of making tests of the milk of
his individual cows at regular intervals, will have abundant
material for study in the results obtained, and he will soon
Testing Milk on the Farm. 121
be able to tell from the tests made, if these are continued
for several days, whether or not the cows are in a normal
healthy condition, or have been subjected to excitement or
abuse in any way.
145. Number of tests required during a period of
lactation in testing cows. The daily records of the six
cows referred to on p. 118 give data for comparing their total
production of milk and butter fat during one period of lac-
tation, as found from the daily weights and tests of their
milk, with the total amount calculated from weights and
tests made at intervals of 7, 10,15 or 30 days. The aver-
ages of all results obtained with each of the six cows show
that weighing and testing the milk of a cow every seventh
day, gave 98 per cent. of the total milk and butter fat,
which according to her daily record was the total product.
Tests made once in two weeks gave 97.6 per cent. of the
total milk, and 98.5 per cent. of the total butter fat, and
- tests made once a month, or only ten times during the period
of lactation, gave 96.4 per cent. of the total milk, and 97 per
cent. of the total production of butter fat.
146. The record of one of the cows will show how these
calculations are made: It was found from the daily weights
and tests that cow No. 1, in one lactation period of 307 days,
gave 5,044 lbs. of milk which contained 254 lbs. of butter
fat. Selecting every thirtieth day of her record as testing
day, the total production of milk and fat is shown to be as
follows:
2 Testing Milk and Its Products.
Production of milk and butter fat per day.
Testing day. Weight of milk. Test of miik. | Yield of butter fat.
Ibs. per cent. Ibs.
NY. oa todesenn) coene 20.5 4.7 .96
MCC Ace eascinseese 13-7 4.6 .86
Jah. Sis. nant LES 4.9 .86
PBT e set cicecaneeaze 20.0 4.5 .90
Dy ies ee ee ee 18.2 4.7 .86
DW) 2 st) pe ee 19.5 4.4 81
MAY Di ccscccesctties sy a 4.8 .85
Wane Ob eit ate 1331 5.5 X 4.0= 5.2, or may go below 2.8 per-
cent, (viz. 4.0 — io» X 40); if the average specific gravity is
1.031 (lactometer degrees 31), the specific gravity of the
milk on a single day may vary between 1.0279 and 1.0341
(31 + goo X 31 = 34.1; 31 — Ph X 3.1 = 27.9.
* Book of the Dairy, p. 32.
t See page 81.
9
130 Testing Milk and Its Products.
156. Influence of heavy grain feeding on the quality
of milk. If cows are not starved or underfed, an incrase
in the feeding ration will not materially change the richness
of the milk produced, as has been shown by careful feeding
experiments, conducted under a great variety of conditions
and in many countries. Cows that are fairly well fed will
almost invariably give more milk when their rations are in-
creased, but the milk will remain of about the same quality
after the first few days are passed as before this time, pro-
vided the cows are in good health and under normal condi-
tions. Any change in the feed of cows will usually bring
about an immediate change in the fat content of the milk, as
a rule increasing it to some extent, but in a couple of days
when the cows have been accustomed to their new feed, the
fat content of the milk will again return to its normal
amount.
157. The records of the cows included in the feeding
experiment at the [llinois station, to which reference has
been made on p. 118, furnish illustrations as to the effect of
heavy feeding on the quality of milk. The feed as well as
the milk of the cows were weighed each day of the experi-
ment; during the month of December each cow was fed a
daily ration consisting of 10 lbs. of timothy hay, 20 lbs. of
corn silage and 2 lbs. of oil meal; the table on p. 119 shows
that cow No. 3 produced on this feed, on the average, 12.1
Ibs. of milk, testing 3.8 percent of fat. In January the grain
feed was gradually increased until the ration consisted of 12
lbs. of timothy hay, 8 lbs. of corn and cob meal, 4 lbs. of
wheat bran, and 4 lbs. of oil meal. All cows gained in milk
on this feed; cow No. 3 thus gave an average of 4 lbs. more
milk per day in. January than December, but the average
test of her milk was 3.7 percent, or one-tenth of one percent
Testing Milk on the Farm. 13
lower than during the preceding month. The heavy grain
feeding was continued through February and March, when
it reached 12 lbs. of timothy hay, 12 lbs. of corn and cob
meal, 6 lbs. of wheat bran and 6 lbs. of oil meal per day.
The records show that the flow of milk kept up to 16
Ibs. per day in February, in case of this cow, but fell to 14
lbs. in March and April, the average test of the milk being,
in February, 3.6; in March 3.8, and in April, 4.0 percent. —
The milk was, therefore, somewhat richer in April than in
December, but not more so than is found normally, owing to
the progress of the period of lactation.
158. Influence of pasture on the quality of milk.
On May 1, the cows were given luxuriant pasture feed and
no grain; a slight increase in the ‘average amount of milk
produced per day followed, with a reduction in the test, this
being 3.8 percent, — the same as in December.
During all these changes of feed, there was, therefore, not
much change in the richness of the milk, while the flow of
milk was increased by the heavy grain feeding for several
months, as well as by the change from grain feeding in the
barn to pasture feed with no grain.*
159. The increase in the amount of butter produced by
a cow, which has often been observed as a result of a change
in feed, doubtless as a rule, comes from the fact that more,
but not richer milk is produced. The quality of milk which
a cow produces is as natural to her as is the color of her
hair, and is not materially changed by any special system of
normal feeding.t
* For further data on this point, see Cornell (N. Y.) exp. sta., bulletins 13, 22,
36 and 49; N. D. exp. sta., bull. 16; Kansas exp. sta., report 1888; Hoard’s Dairy-
man, 1896, pp. 924-5.
7 On this point almost endless discussions have in recent years taken place in
the agricultural press of this and foreign countries, and the subject has been under
132 Testing Milk and Its Products.
160. Method of improving the quality of milk. The
quality of the milk produced by a herd can generally be im-
proved by selection and breeding, i. e., by disposing of the
cows giving poor milk, say below 3 percent of fat, and by
breeding to pure-bred or high-grade bulls of a strain that is
known to produce rich milk. This method cannot work
wonders in a day, or even in a year, but it is the only cer-
tain way which we have to improve the quality of the milk
produced by our cows.
It may be well in this connection to call attention to the
fact that the quality of the milk which a cow produces is
only one side of the question; the quantity is another, and
equally important one. Much dissatisfaction and grumbling
about low tests among patrons of creameries and cheese
factories would be stopped if this fact was more generally
borne in mind. A cow giving 3 percent milk should not
be condemned because her milk does not test 5 percent; she
may give twice as much milk per day as a 5 percent cow,
and will therefore produce considerably more butter fat.
debate at nearly every gathering of farmers where feeding problems have been con-
sidered. Many farmers are firm in their belief that butter fat can be *‘ fed into”
the milk of a cow, and would take exception to the conclusion drawn in the pre-
coding. The results of careful investigations by our best dairy authorities point
conclusively, however, in the direction stated, and the evidence on this point is
overwhelmingly against the opinion that the fat content of the milk can be mate-
rially and for any length of time increased by changes in the system of feeding.
The most conclusive evidence in this line is perhaps the Danish co-operative cow
feeding experiments, conducted during the past ten years, with over 2,000 cows in
all. The conclusion arrived at by the director of the Copenhagen experiment sta-
tion, und +r whose supervision and direction the experiments have been conducted
has been stated over aud vver againin the published reports of the station: that
the changes of feed made in the different lots of cows included in the experiments
have had practically no influenc? on the chemical composition (the fat content) of
the milk produced. Jn these experiments grain feeds have been fed against roots,
against oil cake, and against wheat bran or shorts; grainand oil cakes have further-
more been fed against roots, and roots have been given as an additional feed to the
standard rations tried,—in all cases with the same negative results as far as
changes in the fat contents of the milk produced are concerned,
Testing Milk on the Farm. 133
The point whether or not a cow is a persistent milker is also
of primary importance; a production of 300 lbs. of butter
fat during a whole period of lactation is a rather high dairy
standard, but one reached by many herds, even as the aver-
age for all mature cows in the herd. Dairymen should re-
member that a high production of butter fat in the course
of the whole period of lactation is of more importance than
a very high test.
134 Testing) Milk and Its Products.
CHAPTER X.
COMPOSITE SAMPLES OF MILK.
161. Shortly after milk testing had been introduced to
some extent in creameries and cheese factories, it was sug-
gested by Patrick, then of Lowa experiment station,* that a
great saving in labor, without a coincident diminution in the
accuracy of the results, could be obtained by mixing the
daily samples of milk from one source, and testing this mix-
ture, instead of each sample contributing thereto. Sucha
mixture is called a composite sample. The usual methods of
taking such samples at creameries and cheese factories dur-
ing the past few years have been as follows:
162. Methods of taking composite samples. a. Use
af tin dipper. Hither pint or quart Mason fruit jars, or milk
bottles provided with a cover, are used for receiving the
daily samples. One of these jars is supplied for each patron
of the factory and is labeled with his name or number. A
small quantity of preservative (bi-chromate of potash,
bichlorid of mercury, etc., (see 172) is added to each jar;
these are placed on shelves, or somewhere within easy reach
of the operator inspecting and weighing the milk as it is re-
ceived at the factory. When all the milk delivered by a
patron is poured into the weighing can and weighed, a small
portion thereof, usually about an ounce, is put into the jar
labeled with the name or number of the patron. The samples
* Bulletin No. 9, May 1890.
Composite Samples of Milk. 135
are conveniently taken by means of a small tin dipper holding
about an ounce. This sampling is continued for a certain
number of days, a week, ten days, or sometimes two weeks,
a portion of each patron’s milk being added to his particular
jar every time he delivered milk. Each of these composite
samples are then tested; this test takes the place of separate
daily tests, and gives accurate information regarding the
average quality of the milk delivered by each patron during
the period of sampling. The weight of butter fat which
each patron brought to the factory in his milk during this
time, is obtained by multiplying the total weight of milk
delivered during the sampling period by the test of the
composite sample.
163. This method of taking composite samples has been
proved to be practically correct. It is absolutely correct
only when the same weight of milk is delivered daily by the
particular patron. If this is not the case, the size of the
various small samples should bear a definite relation to the
milk delivered; one-sixteen hundredth, or one-two thousandth
of the amount of milk furnished should, for instance, be
taken for the composite sample from each lot of milk. This
can easily be done by means of special sampling devices
(see 165). As the quantities of the milk delivered from day
to day by each patron vary but little, perhaps not exceed-
ing 10 percent of the milk delivered, the error introduced
by taking a uniform sample, e. g., an ounce of milk, each
time is, however, too small to be worth considering in fac-
tory work, and the method of composite sampling described
is generally adopted in separator creameries, and in cheese
factories, where the payment of the milk is based on its
quality.
136 Testing Mitk and Its Products.
164. By this method of composite sampling each lot of
rich, medium or thin milk receives credit for the amount of
butter fat which it contains, and complications that might
arise from testing only one day’s milk at irregular intervals
are avoided. In order to obtain reliable results by com-
posite sampling it is essential that each lot of milk sampled
shall be sweet and in good condition, containing no lumps
of curdled milk or small butter granules churned out. The
milk is of course always evenly mixed before the sample is
taken.
165. b. Drip sample. Composite samples are sometimes
taken at creameries and cheese factories by collecting the
milk that drips through a small hole or tube placed in the
conductor spout through which the milk runs from the
weighing can to the receiving vat or tank. A small portion
of the drip is then each day placed in the composite sample
jar, or the quantity of drip obtained is regulated so that all
of it may be taken. In the latter case the quantity of milk
delivered will enter into the composite sampling as well as
its quality, and the sample from, say 1000 lbs. of milk will
be twice as large as the sample from 500 Ibs. of milk.
Where it is desired to vary the size of the sub-samples,
according to the quantity of milk delivered from day to day,
it is necessary to adopt the method of collecting drip sam-
ples, just explained, or to make use of special sampling de-
vices, like the “milk thief,’ a Scovell sampling tube, etc.
The principle of both these tubes is the same, and it will be
sufficient to describe here only one.
166. ¢. The Scovell sampling tube.* This convenient de-
vice for sampling milk (fig. 41), consists of a drawn copper
* Kentucky experiment station, 8th report, pp. xxvi-xxxili.
Composite Samples of Milk. 137
or brass tube, one-half to one inch in diameter; it is open
at both ends, the lower end sliding snugly in a cap provided
with three elliptical openings at the side, through
which the milk is admitted. The milk to be
sampled is poured into a cylindrical pail, or the
factory weighing can, and the tube, with the cap
set so that the apertures are left open, is lowered
into the milk until it touches the bottom of the
can. The tube will be filled instantly to the
level of the milk in the can, and is then pushed
down, thereby closing the apertures of the cap
and confining within the tube a column of milk
representing exactly the quality of the milk in
the can, and forming an aliquot part thereof.
The milk in the sampling tube is then emptied
into the composite sample jar by turning the tube
upside down.
167. If the diameter of the sampling pail
used is 8 inches, and that of the sampling tube +
inch (these dimensions will be found convenient
in sampling milk from single cows), then the
sapling ture, antity of milk secured in the tube will always
stand in the ratio to that of the milk in the pail, of
(4)° to 8°, * that is, very nearly 1:256; no matter how much
or how little milk there is in the pail, the sample will repre-
sent 54, part of the milk. For composite sampling of the
milk of single cows, this proposition will prove about right;
if more milk is wanted for a sub-sample, the milk to be
* The contents of a cylinder are represented by the formula zr?h,
r being the radius of the cylinder, and A its height. The relation
between two cylinders of the same height, the radii of which
are R andr, is, therefore, as 7 R*h to zr*h, or as R? to r®.
138 Testing Milk and Its Products.
sampled may be poured into a can of smaller diameter. If
the mixed milk from a number of cows is to be sampled, a
wider sampling can is used. By adjusting the diameters of
the tube and the can, any desired proportion of milk can be
obtained in the sample.
For factory sampling, with a 26-inch weighing can, a tube
three-quarters of an inch in diameter will be found of proper
dimensions.
168. The sampling tube will furnish a correct sample of
the milk in the can, even if this has been left standing for
some time; it is better, however, to take out the sample soon
after the milk has been poured into the can, as the possible
error of cream adhering to the side of the sampling tube is
then avoided.
169. The accuracy of the sampling of milk by means of
the Scovell tube was proved beyond dispute in the breed
tests conducted at the World’s Columbian Exposition in
1893, in which tests this method of sampling the milk pro-
duced by the single cows, and the different herds was
adopted.* The data obtained in these breed tests also fur-
nish abundant material proving the accuracy of the Babcock
test.
In using any one of these tubes, the size of the sample
is regulated by the amount of milk in the sampling can, as
the milk always rises to the same height in the tube as in
the can. In all cases cylindrical sampling cans must be used.
170. Composite sampling with a « one-third sam=-
ple pipette.’’ Milk is sometimes sampled directly from
the weighing can into the Babcock test bottle by means of a
* Kentucky experiment station, 8th report, pp. xxx-xxxi. Another form of
a milk sampling tube in use at the Iowa experiment station is described and illus-
trated by Mr. Eckles, in Breeder’s Gazette, May 19, 1897.
Composite Samples of Milk. 139
pipette holding 5.87 cc, which is one-third the size of the
regular pipette. This quantity is measured into the test bottle
from three successive lots of milk, and the test then made in
the ordinary manner. In this way one test shows the average
composition of the milk delivered during three successive
days, or deliveries. When this method is adopted, as many
test bottles are provided as there are patrons; there is no
need of using any preservatives for the milk in this case.
Fig. 42 shows a convenient rack for holding the test bottles
used in composite sampling with a ‘one-third sample pipette.”
Accurate results can be obtained by this method of sam-
pling, if care is taken in measuring out the milk, and if it
is not frozen or contains lumps of cream. It is doubtful if
the method has any advantage over the usual method of
composite samp-
ling. If milk is
delivered daily
and each lot is
sampled with the
one-third pipette,
twice or three
times the num-
ber of tests are
required as when
composite sam-
ples are taken
and tested once
every week, or
every ten days.
This method fur-
Fig. 42. Test bottle rack for use in creameries and
cheese factories. thermore takes
more time in the daily sampling than the latter, as the
140 Testing Milk and Its Products.
quantity of milk must be measured out accurately each
time. If the test bottle is accidentally broken, or some
milk spilled, the opportunity of ascertaining the fat con-
tent of the milk delivered during the three days is lost; if
a similar accident should occur in testing composite samples
collected in jars, another test can readily be made.
171. Accuracy of the described methods of sam-
pling. An experiment made at the Wisconsin Dairy
Scbool may here be cited, showing that concordant results
will be obtained by the use of the drip sampling method and
the Scovell tube. Two composite samples were taken from
fifty different lots of milk, amounting to about 6000 lbs.
in the aggregate. One sample was taken of the drip from
a hole in the conductor spout through which the milk passed
from the weighing can; the other was taken in the weighing
can by means of a Scovell sampling tube. The following
percentages of fat were found in each of these samples:
Babcock test. Gravimetric analysis.
Drip composite sample........ ..... 4.0 percent. 4.04 percent.
Scovell tube composite sample. 4.0 “ 4 OG =
PRESERVATIVES FOR COMPOSITE SAMPLES.
When milk is kept for any length of time under ordin-
ary conditions, it will soon turn sour and become lop-
pered, and further decomposition shortly sets in, which
renders the sampling of the milk both difficult and unsatis-
factory (19). The changes which occur are due tu the forma-
tion of lactic acid through the action of bacteria on milk sugar;
the acid in turn coagulates the casein of the milk, but does
not destroy or attack the butter fat (27). The period dur-
ing which milk will remain in an apparently sweet, or fresh
condition varies, with the temperature at which it is kept,
Composite Samples of Milk. I4I
and with the cleanliness of the milk, from less than a day
to a week or more; milk will not generally remain sweet
longer than two days at the outside, at ordinary summer or
room temperature.
In order to preserve composite samples of milk in a
proper condition for testing, some chemical which will check
or prevent the fermentation of the milk must be added to
it. A number of substances have been proposed for this
purpose.
172. Bi-chromate of potash. Of these, bi-chromate
of potash is to be preferred, in the opinion of the authors,
on account of its relative harmlessness, its cheapness and
efficiency. The bi-chromate method for preserving samples
of milk was proposed by Mr. J. A. Alen, city chemist of
Gothenburg, Sweden, in 1892,* and has been generally
adopted in dairy regions in this country and abroad. While
not perfectly harmless, the bi-chromate is not a violent
poison like other chemicals proposed for this purpose, and
no accidents are liable to result from its use; at least none
have been known to the writers to occur during the years
that it has been used in creameries or dairies as a preserv-
ing agent.
173. The quantity of bi-chromate necessary for preserv-
ing half a pint to a pint of milk for a period of one or two
weeks is about one-half gram (nearly 8 grains). As there
are about 900 half-grams in a pound, this quantity will suffice
for nine weeks for a creamery having one hundred patrons,
if tests are made once a week, or for three months (90 days),
if tests are made every ten days.
According to Winton and Ogden,7 a .22-inch pistol cart-
* Biedermann’s Centralblatt, 1892, p. 549.
+ Connecticut experiment station report 1884, p. 222.
142 Testing Milk and lis Products.
ridge shell cut to } inch long, or a .32-inch calibre shell cut
to 4 inch long will hold, when loosely filled, enough of pow-
dered bi-chromate to preserve 4 pint, a .32-inch calibre shell
cut to 4 inch long will hold enough to preserve one pint.
These shells may be conveniently handled by soldering on to
them a piece of stiff wire to serve asa handle. The amount
of bi-chromate placed in each composite sample jar would
fill about half the space representing one percent in the neck
of the Babcock milk test bottle.
174. The first portions of milk added to the composite
sample jars containing the specified amount of bi-chromate
will be colored almost red, but as more milk is added, day
by day, its color will become lighter yellow. The complete
sample should have a light straw color; such samples are
most easily mixed with acid when tested. If more bi-chromate
is used, the solution of the casein in the acid is rendered
difficult and calls for more persistent shaking. Bi-chromate
can be bought at drug stores or from dairy supply dealers at
about 30 cents a pound, and will cost about 25 cents a pound
at wholesale. Powdered bi-chromate of potash should be
ordered, and not crystals, as the latter dissolve only slowly
in the milk. Farrington’s bi-chromate tablets contain the
correct quantity of preservative for a quart sample, and will
be found convenient; price per 1,000 tablets, $2.00.
175. Other preservatives for composite samples.
Among other substances recommended for use in butter or
cheese factories as milk preservatives for composite samples
are boracic acid compounds, formalin, chloroform, carbon bi-
sulfid,* copper-ammonium sulfate, sodium fluorid, ammonia-
*Delaware experiment station, eighth report, 1896, which also see for trials
with a large number of different preservatives,
Composite Samples of Milk. 143
glycerin (sp. gr. 1.031), and mixtures containing mercuric
chlorid (corrosive sublimate) with anilin color (rosanilin).*
The coloring matter in the latter compounds is added to
give a rose color to the sample preserved, thus showing that
the milk is not fit for consumption; the bi-chromate giving
naturally a yellow color to the milk, renders the addition of
any special coloring matter unnecessary.
None of the substances mentioned are as cheap as bi-
chromate or more effective for the purpose for which they
are used, when milk is to be kept not to exceed two or three
‘weeks. ‘The compounds containing corrosive sublimate are
violent poisons, and must always be handled with the greatest
care, lest they get into the hands of children or persons un-
familiar with their poisonous properties; they will preserve
the milk longer than bi-chromate when applied in sufficient
quantities, but for factory use the latter is amply effective,
and has, as already stated, the advantage in several other
respects.
176. Care of composite samples. The composite
sample jars should be kept covered to prevent loss by
evaporation, and in a cool place. They: should be kept in the
dark, in a special closed closet, or at least out of direct sun-
light; the chromic acid formed by the reducing influence of
light on chromate solutions produces a leathery cream which
is very difficultly dissolved in sulfuric acid.
A coating of white shellac will protect the labels of the
composite sample jars so that they may be used for a long
time, allowing the jars to be washed and cleaned after each
period of testing. The shellac is applied after the names of
the patrons have been written on the labels, and these have
* Towa experiment station, bulletins 9, 11, 32.
144 Testing Milk and Its Products.
been put on the jars. Gummed labels, 1x24 in., answer this
purpose well.
In keeping the milk from day to day, care should be taken
that the cream forming on the milk does not stick to the
sides of the jars in patches above the level of the milk.
Unless the daily handling of the jars, and the addition of
fresh portions of milk, be done with sufficient care, the cream
will become lumpy, and will dry on the sides of the jars. In
some cases it is nearly impossible to evenly distribute this
dried cream through the entire sample so as to make the
composite sample a true representative of the different lots
of milk from which it has been taken.
177. Every time a new portion of milk is added to the
jar it should be given a gentle horizontal rotary motion,
thereby mixing the cream already formed in the jar with the
milk, and rinsing off the cream sticking to its side. This
manipulation also prevents the surface of the milk from be-
coming covered with a layer of partially dried leathery cream.
Composite samples having patches of dried cream on the
inside of the jar are the result of carelessness or ignorance on
the part of the operator. If a little careful attention is given
to the daily handling of the composite samples, the cream
which is formed in the jars can be evenly mixed again with
the milk without difficulty,
178. Fallacy of averaging percentages. A compos-
ite sample of milk should represent the average quality of
the various lots of milk of which it is made up. This will
invariably be true if a definite aliquot portion or fraction of
the different lots of milk is taken. If the weights of, say
ten different lots of milk are added together, and the sum
divided by ten, the quotient will represent the average
Composite Samples of Milk. 145
weight per lot of milk, but the average obtained in this way
of the tests of the different lots, may not be the correct aver-
age test of the entire quantity of milk. The accuracy of
such an average figure would depend on the uniformity in
the composition and weights of the ten lots of milk. When
there is no uniformity, the weights of the different lots of
milk as well as their tests, must be considered. An average
of a number of weights can be calculated directly, but not
average percentages. The following example illustrates the
difference between the arithmetical average of a number of
single tests, and the true average test of the various lots.
Methods of calculating average percentages.
I. Milk varying in weights and tests. Il. Milk of uniform weights and tests.
Weight] Test |Weight Weight} Test | Weight
Lor. of of of Lor. of of of
milk. | milk. fat. miik. | milk. fat.
lbs. | per ct Ibs Ibs. | perct.| Ibs.
1-2 a eee 120 3.5 4.2 Nae sossvezewccoeneeee 250 4.2 10.5
a 570 5.0 28.5 DL e Si scstecvpavsseses 225 4.0 9.0
ON foes ot choc 2 3 von 360 5.2 18.7 Mi eee aeracs cesses 240 4.3 10.3
WN cate denncssscscss- 55 3.0 1.6 i ea Ree 238 4.1 Bil
Wisscusectasasccsoss8 2-3 82 4.0 3.2 Widextie scans Saeveetes 234 4.4 10.3
Totals... ¢:-e- Ye Reteee ees 56. 2 Total; *s0<..205 ADB e ilcskesecssees 49.8
Average..... 237 4.14 | 11.24 Average.....| 237 4.20 10.0
nUety Se Lest.:|:.:5.<0<0055 ASO e Weesastiooss3e True av’ge test):........... ADD i lasctansesese
* 56.2 < 100 + 49.8 < 100
anh hy ome =—= 4.73. Som i see = 4.22.
179. 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 lbs. of milk is not
found by dividing the sum of these tests by five, which
would give 4.14 percent; but the percentage which 56.2 (the
total amount of fat in the mixed milk, in lbs.) is of 1187
10
146 Testing Milk and Its Products.
(the total amount of milk, in lbs.) 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 comparatively
small, and both methods of calculation give therefore
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 percent,
instead of 4.20 percent, 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.*
180. The second example represents more nearly than
the first one the actual conditions met with at creameries
and cheese factories. Asarule the mixed milk from a herd
of cows does not vary more in total weight or tests, within
a short period of time like one to two weeks, than the fig-
ures given in this example. On account of this fact, sam-
ples taken, for instance, with a small dipper may give per-
fectly satisfactory results to all parties. If the different
lots of milk varied in weight and test from day to day, as
shown in the first case, it would be necessary to use a ‘ milk
thief’ or a Scovell sampling tube for taking the composite
samples, as the size of the samples taken would then repre-
sent an exact aliquot portion of each lot of milk (166).
181. A patron’s dilemma. The following incident
which occurred at the Wisconsin Dairy School creamery
during the past winter, will further explain the difficulties
met with in calculating the average tests of various lots of
milk.
* In the experiment given on p. 122, the arithmetical mean of the tests given is
5.15 percent, while the true average fat content of the milk is 4.89 percent.
Composite Samples of Milk. 147
The weekly composite sample of the milk supplied by a
patron of the creamery from his herd of 21 cows tested 4.0
percent. 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 single 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 aver-
age test of the milk from his cows ought to be 5.1, instead
of 4.0, and naturally asked for an explanation.
182. The first thing done was to show him that while
9.1 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 con-
sidered in calculating this average, the quantities of milk
yielded by each cow; the following illustration was used:
Cow No. 1. yield 25 lbs. of milk, test 3.6 percent, = 0.9 lbs. of butter fat.
Cow No. 2, yield 61bs. of milk, test 5.0 percent, — 0.3 lbs. of butter fat.
PR GUA ese sese: 31 Ibs. 2)8.6 6 1. 2 lbs,
4.3 percent.
The two cows gave 31 lbs. of milk containing 1.2 lbs. of
fat; the test of the mixed milk would therefore not be 4.3
percent —. pape a = 3.87 percent. If the fat in the
mixed milk was calculated by the average figure 4.3 percent,
1.33 lbs. of fat would be obtained, i. e., .13 lbs. 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 pro-
duced the following total number of pounds of milk and fat:
148 Testing Milk and Its Products.
Morning milking, 113.3 lbs. of milk, containing 5.17 Ibs. of fat.
Night milking, 130.9 lbs. of milk, containing 4.98 lbs. of fat.
The morning milk contained esa e ai 7) percent of
113.3
4.98 X 100
fat, and the night milk ace =3.80 percent of fat.
The average of 21 tests of morning milk was 4.8 percent,
and of 21 tests of night milk, 3.8 percent. The sum of the
morning and night milkings gave: milk 244.2 lbs. fat 10.15
lbs. The mixed morning and night milk, therefore, con-
10.15X100
244.2
age 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.
tained =4,.1 percent of fat. This is the true aver-
183. 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 taken in each case 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 re-
sults from the individul tests.
Morning milk. Night milk.
Sample taken at the farm, with dipper.. 4.4 percent. 3.8 percent.
Sample taken at creamery, with Scovell
TAS IDE 15 vce Sep acute ag har Ov > Od Se HS? Gd G2 Od
aa
26 | 27 | 28 | 29 | 30
04/6
64/6
5616.
58/6.
.60)6.
62/6.
. 66/6.
68/6.
.70)6.
75|7.
777.
AOE.
81]7.
83)7.
85]7.
87|7.
Sh ie
91]7.
93/7.
95/7 .
5. O77.
997.
.O1|7.
OPK:
05/7.
.07]7 .:
LACTOMETER READINGS AT 60° F.
307,
O77,
39/7.
ALT.
43/7.
45/7.
47/7.
49/7 .
.51)7.
.03|7.
.OOl7.
O77.
0917.
617.
63/7.
.65]7.
SAN
69]7.
ste:
JOH.
79/8.
178,
798.
81/8.
83/8.
20/7 .
.2717,
29/7.
.oll7,
30/7 .
32 | 33
34 | 35 | 36
Percent. of
ear
peed ped be peed peed
(Wil W => >) ocoococcoco
DWNHO CHOr-Inn Powrwe
bo bo bo bo bo bo bo bo bo bo
fat.
WCOURMN PWNMHO wMr~IdD.
210 Testing Milk and Its Products.
Table V. Percent. of solids not fat (Continued)
LACTOMETER READINGS AT 60° F.
26 | 27 | 28 | 29 | 30 | 31 | 82 | 33 | 34] 385 | 36
Percent. of
fat.
Percent. of
fat
. 85/8. 10/8. 36/8 61/8 .86/9.11/9.36) 9.61
.87|8. 1318. 38/8 .63!8 . 88/9 .13}9.38) 9.64
89/8. 15/8 . 40/8 .65)8 .90)9.15]9.41| 9.66
.92,8.17/8. 42/8 .67|8 .92/9.18]9.43) 9.68
.94)8 . 19/8. 44/8 69/8 .94/9.20/9.45) 9.70
|
|
|
a>
—
NT
ww OO WW OO
717. 96)8 21/8 . 46)8 . 71/8 . 96/9 .22/9.47| 9.72
22/7 .48|7. 73/7 .98]8 .23/8 . 48/8 . 73/8 98/9. 24/9 .49| 9.74
.24|7 .50/7 . 75/8 .00)8 . 25/8 .50/8 75/9 . 00/9. 269.51} 9.76
.26|7 .52/6 .77/8 02/8 . 27/8 .52/8 .77/9 .02)9 . 28/9 .53
.28|7 .54/7 79/8 04/8 . 29/8 54/8 .79/9 04/9. 30/9 .55
.30)7 .56/7 .81/8.06)8 . 31/8 .56/8 . 81
827 5817 .83)8 .03]8 .33)8 .58/8 . 83
.84|7 . 607 . 85/8. 10/8 .35)8 . 60/8 . 85
36|7 . 62/7 .87|8.12)8 37/8. 62/8 . 88
.88|7 .64/7 .89/8.14)8 . 39/8 . 64/8 .90
.66)7 . 91/8. 16]8 .41|8 . 66/8. 92
.43]7 .68)7 . 93/8. 18/8 .43)8 . 68/8. 94
.45|7.70|7 . 95/8. 20/8 . 45)8 . 70/8 . 96
477 .72/7 .97|8 .22)8 47/8. 72/8 .98
.49|7 .74]7 . 9918 . 2418 .49)8 .74/9 00
51/7 .76)8 .01/8 . 26/8 .51)8. 76/9 . 02
.538|7 .78)/8 .( 3/8 . 28/8 .53)8 . 79/9 . 04
.55|7 . 80/8 .05]8 . 30)8 . 55/8 81/9. 06
57|7 .82)8 .07|8 32/8 .57/8 .83]/9.08 :
59/7 84/8 .09/8 .34]8 . 60/8 . 85/9. 10/9. 36/9 .61/9. 86/10. 11
Occ OOD OO CO OH OO CO
v) —
ive)
eo)
i
—
ite)
~J
i=)
.61/7 . 86/8 .11]8 .36)8 . 62)8 . 87/9. 12/9. 38/9 63/9. 88/10. 13
.68)7 .88]3 13/8 .39)/8 64/8 89/9. 1519 .40,9 65/9. 90/10. 15
.65|7 .90|8 .15]8..41]8 . 66/8 .91/9.17)9.42)9 67/9. 92/10. 17
67/7 .92/8.17/8. 43/8 .68)/8 . 94/9. 19/9 .44,9.69/9 .94/10.19
69/7 .94|8 . 20|8 . 45/8 . 70|8 . 96/9. 21/9 .46,9.71|9.96)10. 22
7117. 9618. 2218. 47/8 .7218 98/9. 23/9.48.9-7319. 98/10. 24
HANK NAA PPR BEEBE CODED O09090909
SO CONRAN PWNWHO CBOYNMRT PWHHO CHONON Pwpwpro
SC CONAN PBWNHHO DCHOHAN BWNDHO CONDOM PwNWHO
ES SS OS SS SS SS SS SS
x yer roe ee
=
~J
co
~J
A Annan THT PEER BRBBRRP FTO OO
lor)
SSS 6.508»
Appendix. 21
Directions for Use of Tables VI, VII, and IX.
TABLE VI. Find the test of the milk in the first or last hori-
zontal row of figures; the amounts of fat in ten thousand, thou-
sands, hundreds, tens, and units of pounds of milk are then given
in this vertical column. By adding the corresponding figures in
any given quantity of milk, the total quantity of butter fat con-
tained therein is obtained.
Example. How many pounds of fatiscontained in 8925 lbs. of milk testing 3.65
percent? On p. 213, second column the test 3.65 is found, and by going downward
in this column we have:
tL EUECOMIN Ouest 292. lbs.
YU) gas eS oe eae 3 O70 a
Oke, Saree e weiseteetcce aes
uamstnrsec tae varstaiweos tae 2; 5%
8925 lbs. of milk. 325 8 lbs. of fat.
8925 lbs. of milk testing 3.65 percent, therefore, contains 325.8 lbs. of butter fat.
TABLE VII. The price per pound is given in the outside ver-
tical 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 placeto 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 1514 cents per
pound? In the horizontal row of figures beginning with 16%, we find:
SOOM AIDR Se Soaks er costa feces $ 46.50
UN aye de soses ies snes s esate 3.10
Se nage SR eR as cee ord,
BU ee ae da crsset ase s oho Peebe 12
325. 8 Ibs. $50. 49
325,8 lbs. of butter fat at 1514 cents per pound, therefore, is worth $50.49.
TABLE IX. Find the test of milk in the upper or lower hori-
zontal row of figures. The amount 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 VI.
Example. How much butter will 5845 lbs. of milk testing 3.8 percent be apt to
make under good creamery conditions? In the column headed 8.8, we find:
OO Te csinees canon nad 209.0 lbs.
BOO aS cee ek asst Seeecet 33.4 “
2 18 ae Sok Serceti Seae aie Ligh tee
HIN s dupe sue aaqeren, ode te ee
5845 lbs. 244.3 lbs.
5845 lbs. of milk testing 3.8 percent of fat will make about 244.3 lbs. of butter,
under conditions similar to those explained on pp. 168-69 of the present work.
252 Testing Milk and Its Products.
Table VI. 3
3.0 to 5.35 percent. (See p. 211).
2 3.00/38. 05/3. 10/3. 15/3. 20/8 . 25)13.. 30/3. 35/3. 40/3. 45/3. 5013.55
a)
10, (00|} 300! 305] 310
9, 000|| 270 275] 279
8, 000|| 240) 244] 248
7, 000/| 210) 214} 217
6, 000] 180 183] 186
5, 000|) 150, 153} 155
4, 000|| 120| 122} 124
3, 000/90.0191.5/93.
2, 000|160. 061.0162.
1, 0001/30. 0/30.5/31.
9001/27 .0|27 . 5/27.
800/124. 0/24. 4/24.
700 |21.0/21 . 4/21.
600/18 .0118.3)18.
500)|15.0)15.3)15
400/}12.0)12.2}12
300}| 9.0) 9.2
200|| 6.0) 6.1
100}| 3.0} 3.1
90}, 2.7} 2.8
80|| 2.4) 2.4
70}| 2.1) 2.1
60)| 1.8) 1.8
50|| 1.5) 1.5
40} 1.2, 1.2
30), -9| ~.9
20), .6] .6
TS car
Bie SS}. 2a
oil ae ne
Gl ee 4 (emer
Ge 2p. 2
Olle alee ae
4) 20 a
eee | eee |
7)) wees Ha
1
Test.
et t+ FDO DO bO G2 S> 6c
G2 CO nD DON wr
a et = DD DON DO OD
eat eet eet INU END IND C2 SO bo
128
130}} 132] 134] 136
96 0/97 . 5/99 .0} 101) 102
St = Wb bh WOO bo oO
DPDOWAOW DSO
0165
0/82.
*
~
©
s@eeeelscoeees| eeees| seees| seves|sssees
3.00)/3.05 rie ay 3.30
et bb DO DO DO DO Oo WO
01166. 0187 . 0168.
51/33. 0/33. 5}34
ete DD DO bY CO Co 2
AS (COIS Oi Ss1c (Stor yve)
et bt = DD DO DO CO Sora)
207
173
138
104
Mere DONE WOO
3.35!3 40/3 .45]3 .50)3 55
ee)
—
ou
—
~J
O1 GO bo Dern waowoke aoc
Lbs. of fat in 1 to 10,000 Ibs. of milk, testing
350} 355)/10, 000
315) 320
tet kt DS DS DO OO on
4 bh r= DD DO bo CO on
Ho enmrmnmwo BO pow
9, 000
8, 000
7, 000
6, 000
5, 000
4, 000
3, 000
2, 000
1, 000
900
800
700
600
500
400
300
mt bo Go ® Oro 100
“WSO,
Appendix.
213
Table VI. Lbs. of fat in 1 to 10,000 Ibs. of milk oe
.
—
n
3. 60}3.65/3.70|3.75|3.80
108] 110
2.0/73.0/74.0|75
1, 000)/36. 0/36.
900||82 . 4/32.
800)/28 . 8/29
001/25 . 2/25
600)/21 . 6/21
me bo Co He Oro SIO CO
Test.
Pree bbw cc com
Hee ppwowd BUI Bomeoonw on
hot b+ Rt DD DO HO OO wn
HHH wwo BIH MON aow ~T0
5|37
9|33
.2|29
6/25.
9/22
500/18 .0/18.
400114 .4/14.,
00)/10.8)11.
3/18
6/14.
j=)
_—
—
ht et re bo bo GO CO wn
MH wwt RW MONROwW We
111| 113
mt re DD DD CO CO con
.3133.8)34.
-6|30.0)30.
9126 . 3/26.
2122522.
.5/18.8/19.
8|15.0/15.
1|11.. 3/11. 4)
Is Apo bobo G09 69 HOO ENO OONIS Ro
iS
—
ie)
OnIDhWeH OO sI
eae
~I le)
or
—
io)
oO
i)
c=)
(=)
LS)
(=>)
(J)
bo
(=)
oo
|
3.85)||3. 903. 954. 004. wees 104. 15
347|| 351) 356) 360) 365) 369) 374)
308|| 312, 316 320) 324) 328) 332
270|| 273| 277| 280) 284| 287) 2911|
231|| 234| 287) 240| 243) 246) 249
193]| 195) 198 200) 203) 205) 208:
154|| 156 158, 160 162) 164 166
| 116}| 117] 119] 120} 122/ 123] 125)
.0/76.0.77 .0|/78.0'79.0'80.081.0.82.083
0137 .5/38
15.6 15.816.(16.216.416
e po
hk Fe bo bo bo Co CO H= GO
Mebononowc woo
MHD rmmwwPr PRomwaroctw-t
et et DD DOD DOD CO CO ne ~T
HE DDD WWOR RON RORDONIR
HeeErrwo ow
eHow WOR PRoONMARORDNa OF
MH norm wwo BRaANMaAwowwIeE]Y
Ht DD bO bO 09 09
HED NWWh RONWNrAowwIE)S
het het DD DOD DO CO CO
Fe ES BS BO OE ee Oo NS So SH CO.NS
85.135.636.036.5.36.937.
312/31 .6|32.0/32.4/32.833.
27 3/27 .7/28 0/28 .4/28.7/29.
23.423.7/24.0.24.324.624.
520.
9}12.0)12.2)12.3)12.
>
kt kt DO DO DO CO CO
rt Fr! DOD DO DO CO GO H= CO DD ST 4 O10 Co ~I
0
.0 38 .5|/39.039.540.040.5 41.041.
Low OND OOH hm
|
Peeees |eeeess (seeee, |Feeee: |seeee: CHeees |S eeees FESESs SEESes FHSOe: FHEeet Sesee |
3.60/38. 65/3. 70/3 .75|3 . 80
3.85|3.903.954.004.054.104.15
480
405 410 415 10, 000
9, 000
8, 000
7, 000
6, 000
5, 000
4, 000
3, 000
2, 000
1, 000
900
800
700
600
rt bo CO He O1 OD MI 00 6
"489,
214 Testing Milk and Its Products.
Table VI. Lbs. of fat in 1 to 10,000 Ibs. of milk (Continued)
|| {
@ 4.204.254.304.354.404.45 4.504.55 4.60 4.65 4.704.75 ?
ae i | nen 1 ies 7
Milk | | Milk
Ibs. || | Ibs.
10,000 420 425 430) 485 440 445 450 455 460) 465 470 475/10, 000
9,000, 378 383 387 392 396 401 405 410 414) 419 423) 428) 9, 000
8,000) 336 340 344 348) 352 356, 360 364 368 372 376 380) 8, 000
7, 000) 294) 298) 301| 305) 308 312)| 315) 319 322) 326) 329] 333) 7, 000
6, 000) 252) 255 258) 261) 264 267) 270) 273, 276 279) 282) 285) 6, 000
5, 000) 210) 213, 215) 218) 220) 223) 225) 228 230) 233) 235) 238)| 5, 000
4,000! 168) 170) 172' 174| 176 178) 180! 182 184) 186) 188) 190) 4, 000
8, 000|| 126] 128] 129) 131] 132| 134) 135) 137] 188] 140] 141} 148] 3, 000
2, 000 84.085.086.087.088.089.0 90.091.092.093.094.095.0) 2, 000
1, 000) 42.042.543.043.544.044.5 15.045.546.046.547.047.5) 1, 000
900) 37.8 38.338.7/39.229.640.1 40.541.041.4/41.942.342.8, 900
80033. 6134.0134.4/34.8'35.235.6/36.036.4 36.837 .2:37.6/38.0) 800
700/29. 4.29.8 30.1/30.530.831.2 31.531.932.232.6/32.933.3) 700
600 25.225 .5 25.8\26.126.4 26.7 27.0.27.3 27.627 9/28 2128.5 600
500|21 .0/21.3[21.5/21. 8/22. 0/22.3/22 .5/22.823.0/23.3/23.5)23.8) 500
400 16.817.0/17.217.417.617.8 18.018.218.4)18.618.819.0) 400
300/12 .6/12.812.9/13.1]13.2/13.4)13.5 13.7)18.8|14.014.1/14.3)| 300
200) 8.4) 8.5) 8.6} 8.7) 8.8| 8.9] 9.0| 9.1) 9.2) 9.3) 9.4) 9.5)| 200
100 4.2) 4.3) 4.3) 4.4) 4.4) 4.5) 4.5) 4.6) 4.6) 4.7) 4.7) 4.8) 100
| | | | | H
90|| 3.81 3.8] 3.9| 3.9) 4.0) 4.0] 4.1] 4.1) 4.1) 4.2) 4.2) 4.3) 90
80|| 3.4| 3.4) 3.4} 3.5] 3.5) 3.6] 3.6) 3.6) 3.7/ 3.7| 3.8) 3.8 80
70|| 2.9] 3.0) 8.0] 3.0] 3.1) 3.1] 3.2) 3.2) 3.2) 3.3) 3.3) 3.3) 70
60) 9.5] 2.6) 2.6] 2.6] 2.6] 2.7] 2.7) 2.7| 2.8) 2.8) 2.8) 2.9 60
50|| 2.1] 2.1] 2.2) 2.2) 2.2) 2.2) 2.3) 2.3) 2.3) 2.3) 2.4) 2.4) 50
40) 1 7) 1.7 1.7] 1.7\-¥.8| 1.8) 1.8] 1.8) 1.8) 19) a eae 40
30|| 1.3) 1.3| 1.3) 1.3) 1.8) 1.3] 1.4) 4.4) 1.4) 14) dea 30
Oo .8} 9} 29). 9]- 9) 91] 9). 9) 9) Oa ee
10). 24) .4) 4) 4) 4) 4 Bole Bae
| | | |
QU A A) 4b Al ap A a a A a eee 9
Sit 38) BB BE AL 4 4 A a Ae 8
Te BB) Bh BBR BI G8) Bae) oe eee 7
6) alec ah gle 30 8) alas) aia ei 2 eee 6
Bl gh gl oP oo) ll al 9 cool a 5
ANS Be BOD) 2) DN SO OI ek eee 4
Sh Doced owls AAR Tos As al ee Ale eh oe 3
QW Tl ah a ae To U1 a oe lee 2
ji PR eae OSA Ce | Rani aes Ness elacsene |sitscac lesteetl autre aaa | ce
|__| |__| ---—
me) | iar |
& |4.204.254.30/4.35/4 404.45 4. 50|t.55 4.60.4,054,704.75 &
eee Jee ee ee Se ee
SS See nna nnn
e
Appendix.
215
— VI. Lbs. of fat in 1 to 10,000 Ibs. of milk hie Ja
2 Se eee 5.00)5.05]15.10)5.15)5. 205. 25 5. | =
= Lae
Milk | | | Milk
Ibs. | | || Tbs.
10,000, 480 485, 490} 495] 500) 505|| 510) 515} 520 525 530) 535 10, 000
9,000 432 437) 441) 446) 450} 455/| 459) 464) 468, 473 477| 482) 9, 000
8, 000 384) 388 392) 396) 400) 404|| 408} 412) 416 420 422) 428 8, 000
7,000 336 340, 343) 347 350] 354]! 357| 361) 864 368 371) 375]|| 7, 000
6, 000)| 288) 291) 294} 297} 300) 303]| 306) 309) 312) 315 318) 321) 6, 000
5, 000) 240) 243) 245} 248) 250) 243]| 255) 258) 260, 263 265) 268, 5, 000
4, 000); 192; 194) 196) 198] 200) 202}} 204) 206] 208) 210, 212) 214) 4, 000
3, 000|| 144) 146) 147} 149} 150} 152) 153) 155) 156, 158 159, 161) 3, 900
2, 000/96 .0|97 .0.98.0)99.0, 100! 101]} 102) 103 104 105, 106) 107. 2, 000
1, 000 18 0/48 5.49. 0/49 .5]50.0/50.5 51.0/51.5/52. 0.52.553.053.5 1, 000
900)|43 .2/43.7.44.1/44.6]/45. 0/45. 5/45. 7/46 .4146.8/47 .3.47.748.2 900
800//38 . 4/388 .8 39. 2/39 .6/40.0/40.4|/40. 8/41. 2/41.6.42.042.442.8 800
700//33 . 6/34. 0:34. 3/34. 7/35. 0/385. 4!135 .7/36.1/386 436.8 37.137.5 700
600}/28 . 8/29. 1/29. 4/29. 7/30. 0/30.3)|30.6/30.9 31.2.381.5)31.8/32.1) 600
500//24 . 0/24 .3)24.5/24. 8125 0/25 .3|/25 5/25 .8/26.0/26.3 26.5 26.8 500
400//19 . 2/19 .4'19.6/19.8]/20. 0/20. 2!/20. 4/20. 6/20.8,21.0/21.2.21.4 400
300/14. 4/14.6 14.7|14.9115.0)15.2 15.3/15.5/15.6 15.8 15.9 16.1 300
200) 9 6 9.7) 9.8) 9.9)10.0)10.1 10.2)10.3)10.4,10.510.6 10.7 200
100}) 4.8) 4.9) 4.9] 5.0} 5.0} 5.1]) 5.1) 5.2) 5.2) 5.3, 5.3 5.4 100
90|| 4.3) 4.4| 4.4] 4.5] 4.5) 4.5]| 4.6] 4.6] 4.7) 4.7 4.8) 4.8 90
80 3.8 3.9} 3.9! 4.0) 4.0) 4.0] 4.1] 4.1 4.2) 4.2} 4.2 4.3 80
Wito.4i-a.4) o-4| S25. 3. a).d.5 2.6.3.6) 3:6] 3.7 Sev Abe er fi
GO, 2.9) 2-9) 259) 3.0) 3.0) 3.0) 3.1) 3.1/ 3.1) 3.2) 3.2) 3.2) 60
ao 2. 4| 24) 2.5) 2.5) 2-5) 2.5) 2.6) 2.6 2.6) 2.6) 2.7) 2.7 50
40|| 1.9) 1.9] 2.0] 2.0] 2.0} 2.0] 2.0) Bo 2s Be Ap 2yti 2. hy 40
30]| 1.4) 1.5) 1.5) 1.5) 1.5) 1.5] 1.5) 1.5) 1.6) 1.6) 1.6) 1.6 30
Set OL OF Ol P36) PO POF EO YO) 2 Ohol ay Bea 1 2 20
SS Ie". Ol s< «Dl epee .5|| mi Bebe | reg =) 5 3) 10
Beate. He - ale eA ia Bika Bin aeons aie Sel 6 9
seal ect) Sear aba aA Al So Ales Ae Alek Avot Al. 4 8
Bieter OL me cal AGS AES Alea Al At 4 i
6 Poe ot Solna. Sob uA sae alent 8 8) 8 6
5) ie te | Nd See Nie | cae ce Penal cere’) Sol ca 130 5
ered Rs | Sy a = eB 2 .2| ae 4
ieee tb SA Sa “ae 29) -28 eZ 7. S| a taay 4 eal] Vara) o
2S SS 6 ae Re: 2 ca | a | il peas Hier |) ae aS | 2
MMe eshte evnasa| sees ng oa oa ce ae | a: pe ge | 1 1
= |e Lean aren (ea | ad | 2
& 4.80/4.85/4.90)4.95/5.00/5.05//5.10)5.15)5. 205. 255. 305.35, &
216
Testing Milk and Its Products.
Table VII. Amount due for butter fat, in dollars and cents, at 12
to 25 cents per pound.
Price per
pound, cents.
18
18}
183
183
mn |
1,000] 900] 800} 700
1,000} 900} 800 | 700
$ $ $ $
120.00)108
122.50)110
125.00)112
127 .50/114
135.00)121
140. 00/126
175. 00|157
1177 .50)159
180.00)162
}182.50)164
185 .00)166
1187 .50)168
130.00)117.
132.50)119.
1387 .50)123.
142 .50}128.
145 .00/130.
147 .50/1382.
150.00)135.
152.50}137.
155.00)139.
157 .50}141.
160. 00/144.
162.50/146.
165.00/148.
167 .50}150.
170.00)153.
172.50/155.
.00} 96.00! 84.
. 25} 98.00} 85.
.50/100.00} 87.
.75|102.00} 89.
00/104.00) 91.
25)106.00) 92.
.50}108 00} 94.
75|110.00) 96.
.00)112.00} 98.
25|114.00} 99.
50/116 .00)101.
75/118 .00)103.
00|120.00!105.
25/122 .00}106.
50/124 .00)108.
75|126 .00)110.
00|128 . 00/112.
25}130.00}113.
5€}182.00)115.
75]134.00/117.
00/136 .00)/119.
25/138 .00]120.
.00)140 ,00)122.
.75|142 .00]124.
.00)144 00/126.
. 25}146 .00)127.
.50}148 .00)129.
.75|150.00/131.
Pounds of butter fat.
75|109.
50}i11.
25/112.
Price per
pound, cents.
—_— $$. | << —| —_____ —————
eee
OOOO TFT 6
Table VII. Amount due for butter fat ( Continued.)
Appendix.
Price per
pound, cents.
|
19 |/190.00]171.
193||192.
193]|195.
193||197
20 |/200.
203||202.
203||205.
-50|L86
203||207
21 ||210.
213)|212.
213|/215.
213||217.
22 |/220.
.50/200.
00/202.
50/204.
221/229
293||295
293||297 .
23 ||230.
233/232.
233||235 .
233||237 .
24 |/240.
241]/242..
943)|245.,
943)/247
25 ||250.
1, 000} 900
50\173.
00|175.
.50)177.
00/180.
50|182.
00/184.
.75|166 .00)145. 25)124,50)103.75) 83.00} 62.25
00/189
50/191
00/193.
50/195.
00/198
00/207 .
50/209.
.90)188 .00)164.50)141.00/117.50) 94.00} 70.506
50/213.
00/211
00/216.
50|218.
00/220.
50/222.
00|225.
800
Pounds of butter fat.
00/152 .00/133.00)114.00} 95.00} 76.00} 57.00
25/154 .00/134.75)115.50} 96.25) 77.00) 57.
50/156. 00/186 .50/117.00) 97.50} 78.00} 58.50
75/158 .00/138 . 25)118.50) 98.75) 79.00} 59.25
00/160 .00)140.00)120.00)100.00) 80.00! 60.00
25/162 .00/141.75)121.50/101.25) 81.00] 60.75
50/164 .00/143. 50/123 .00)102.50) 82.00) 61.50
.00)168 .00)147 00/126 .00/105.00) 84.00) 63.00
. 25,170. 00/148 .75)127 .50)106. 25) 85.00} 63.75
50/172 .00/150.50)129 .00)107 .50) 86.00) 64.50
75/174.00)152. 25/130 .50)108.75) 87.00} 65.25
.00|176 . 00/154. 00]132.00/110. 00 88.00} 66.00
25/178 .00|155 .75)133 .60)111.25) 89.00} 66.75
50/180 . 00/157 . 50)135.00)112.50) 90.00) 67.50
79|182 .00)159 . 25)136 .50)113.75) 91.00) 68.25
00/184 .00}161 .00)138.00/115.00) 92.00] 69.00
25/186 .00)162.75)139 .50)116.25] 93.00} 69.75
75/190 .00)166 . 25)142.50)118.75) 95.00} 71.25
00)192.00)168 .00/144.00)120.00} 96.00} 72.00
25)194 00/169 .75)/145 .50/121.25) 97.00] 72.75
50/196 .00)171 .50)147 .00)122.50) 98 00} 73.50
79/198 .00)173 . 25/148 .50/123.75} 99.00) 74.
00/200 .00)175 .00)150.00)125.00)100.00} 75.06
1,000} 900} 800
700 | 600} 500} 400
(For directions for use, see page 211).
300
200
2147
Price per
pound, cents.
218 Testing Milk and Its Products.
Table VIII. Relative value tables.
(For directions for use, see pp. 180-81).
PRICE OF MILK PER 100 POUNDs, IN DOLLARS AND CENTS.
Percent.
fat
ew — © CO O~1 93 C1 Hq CO be © co con OD C1 Lwnwere ©
is
bo
we
po
tS
fp)
i
[e 6)
ou
(=>)
1]
bo
or
On
ol
=~]
or
ites}
(or)
—
[=P]
oo
S> Or Or Or Or Or Oror1 or orcn He oe He He Ho ee ee G2 G9 GO OO OO Go OO Co OO
Soo ONO ON
ov
GO
=r)
—
for)
eo
(oP)
~I
~]
(<=) >
~]
bo
~J
on
~J
[o.0)
oo
—
oO
i
(o 2)
~J
Appendix. 219
Table VIII. Relative value tables (Continued).
PRICE OF MILK PER 160 POUNDS, IN DOLLARS AND CENTS.
Percent.
fat.
BD UGG Gren AAIaanr PPP PR PP RRR Cott ODO 09 00 G9 00 0
DODIAMN PWNHO OONAM PWNMHO CONDON pwweo
~J
S
~J
bo
~I
ns
~J
=
Et 80 | .82 85 Si. 90 F927) 90 ||P 97.) 1200
Ob) ciOeet 3 4G 87 SOM OE 294) | OF te 99. 2. 02
81 83 | .86 88 91 94-47-96) 9.99. 1t. 01 | 1204
83 85 .87 90 + -98 | .95 |°.98)/l.0L jT.03 | 1.06
84 86 89 92 94 | .97 {1.00 |1.03 |1.05 | 1.08
85 88 “ol .93 .96 | .99 {1.02 |1.04 {1.07 |1.10
87 903) 2928 fe. 95 .98 |1.01 {1.04 |1.06 |1.09 | 1.12
88 91 94 97 | 1.00 1.03 1120511208. |1:11 | 1.14
90 93 | .96 99 | 1.01 |1.04 j1-07 |1.10 {1.13 |.1.16
91 94; .97 | 1.00 | 1.03 {1.06 {1.09 {1.12 [1.15 | 1.18
93 96 .99 | 1.02 | 1.05 {1.08 }1.11 {1.14 |1.17 | 1.20
220
Percent.
D> OV Ot Ot Or Or Cr Or1gr1 order He ee a ot es Owwww Oo G2 Oo
Oooo WSO a Se) Nolo oi Kerk)! th Sl Oo O~I0 Or Be whe ©
fat.
_
Se pe
ee
Testing Milk and Its Products.
ee
ee ee
fat fk ek ed ped pe
pad feed pet
et pe Re
Ss Sy eS ea ea
64
|
|
bed fe pe
feed foe fed fod fod pat
Peon frmed feed fed feed
ee a ee
=a
ee rn
Seni cueniilL amet cuenta’
pod beet feed ped ped ped
ee et
ey Sea
famed peek ped ped et
ayy
14
Ft et hk pd pe ek peek pe
ft ed ped pe
bt pe ep
Table VIII. Relative value tables (Continued).
PRICE OF MILK PER 100 POUNDS, IN DOLLARS AND CENTS.
ee a On a a ee ee ee eae
ee
Appendix. 221
Table VIII. Relative value tables (Continued)
Percent.
fat.
poms) fecal) peed teed fed,
a ee
pot et ee pet pe
PRICE OF MILK PER 100 POUNDS, IN DOLLARS AND CENTS.
PER e ye TH Ol Rea io owas Ba) 287 88 hae
Mae Oise Oe le 84 Boris YRT.) .288.\.° 90) 291 tos
SO eo ees Heesole G08). 90:1: 91). .98) .94) 296
Bele 8S esi eo | .91) .92|. .94) .96! 97]. 99
Seer ase 90) 92). 93) .95| -.97| -.99| 1.00)1,02
Boe -91| 7.98). .94| .96) ..98| 1.00) 1.01) 1,03) 1-05
92} °.94| .95| .97| .99] 1.00] 1.03] 1.04| 1.06/ 1.08
Oe 2967 5.98 | 1,00! 1.02 11.03) 1.05} 1-07 | 1/09) FT
Of} 2.99) 1.01) 1,03) 4204) 1.06) 1,08) 1.10) 1,12.) 114
99| 1.01] 1.03) 1.05/ 1.07| 1.09] 1.11] 1.13] 1.15] 1.17
0204-04 1. 06.|' 1.08 | 1,10 }.1512).1,.14| 1.16| 1.18] 1,20
Oar 071209: 1.11) 1.13) 1.16 )1,171 4.19) 1/21) 1.938
Det 08.) 1-11), 1.13,| 1.15) 1-18 1.20). 1.22) 1.24) 1.26
Pp ote tet. 14 P06 | P18) 12011228) 1.25) 1.97 + 1,29
12| 1.14 1.17 PPOs ied 2a 2h 028) SO 3
15| 1.17/ 1.19] 1.21] 1.24) 1.26] 1.28] 1.30] 1.38] 1.35
ie het 22.2024) 126 1.29) 1.81 | 1.38) 1.36) b.38
Died 22)| 4-25). 27 | 1.29) 1.321.384) 1.36) 1,39) 1.41
Bene Sol 27) 1.30); 1,32 | 1/34) 1.387) 1.39) 1.421.44
Oo) 4.27) 1:30)1,382) 1.35) 1.87) 1.40} 1.42.) 1,45 )-1,47
See leas siesta, 1401.42, 145°, 1,47, 1.50
$0) 1.33)'1.35| 1,38] 1.40) 1.43) 1.45] 1.48} 1.50] 1.53
331.35) 1.37| 1.40| 1.43] 1.46] 1.48] 1.51| 1.53] 1.56
35| 1.38| 1.40} 1.43) 1.46] 1.48] 1.51] 1.54| 1.56] 1.59
38| 1.40| 1.48] 1.46] 1.48} 1.51/ 1.54| 1.57] 1.59] 1.62
40| 1.43) 1.46] 1.48| 1.51| 1.54] 1.57| 1.60) 1.62) 1.65
AS 1.46| 1.48: 1.51 | 1.54) 1.57) 1.60) 1.62) 1.65) 1.68
A5)1.48| 1.51 | 1.54) 1.57| 1.60] 1.62} 1.65) 1,68 | 1.71
48) 1.51) 1.54) 1.57| 1.59| 1.62] 1.65| 1.68] 1,71] 1.74
BO) tiba | 1,56) 1.59) 1.62 2.65)-1.68 1.71 | 1.74) 1.77
53| 1.56| 1.59| 1.62| 1.65| 1.68] 1.71| 1.74| 1.77| 1.80
222
Testing Milk and Its Products.
Table IX. Butter chart, showing calculated yield of but-
ter (in Ibs.) from 1 to 10,000 Ibs. of milk, testing 3.0
(See directions for use, p. 211).
to 5.3 per cent.
Test.
mM bo co BR OO I
3.00/3.10
rt re r= bb DS tO CO © o>
wntonwnnritownns
bo 09 wo
8.00.3. 10
3,203.30
Oorobh oO HO
mre bpObDO w-~T
PTI RONTON AnNwWhRODMNwoh CO
hr 4 DOD DS DD OO G2 Od
[eV ISIC)
eee nwnwnwwo BTOSOR UH poH
3203.30
|
3.403 .50
ho
Jo)
=
NIP OOwors
rt r+ E44 BS DO CO OO oon
Herpnwmnwmwww BPI MON ROwW
ht r+ et DO DO CO CO ee |
3.60
hte bo bo bo CO OO CONTR O11
seewee
3.70/3.80)/3.90/4. 00/4. 1¢
rt k= DO bO bo CO CO = CO
Keb DD DD OD 09
MHpmwmwwor BowtIesMOR WOOD
Dh OnmAaOKRDWWOS
Se MmNrmnwpwwe
seeee |r oeee
129
. 8/88 .2)90.4
9/44. 1145.2
.6/39.7|40.7
. 3/385. 3/36. 2
or
—_
bo
r+ e BO DOD Co CO OO 4 CO
Menno wow hs BROWINRORD Woonmearci:
= [eeewerlreece
132) 136
mr bo DD OO =)
ASDH QHD
me pone moo
MHLW MNoOoROwWwIWw ae
3.70/3.80)3. 90/4. 00/4.10
|
mt bo CoH Or S100
ae ee i
er
sf r Date
mrt bo DO OO Co He CO :
hm bo Com O11 OC
Test.
Ts
iw)
=
Appendix. 223
Table IX. Butter chart eed),
||
| | | |
2 4,304.40 4,504.604.70 4.804.906, 005. 10)5. 205.30 =
| Sage aya Milk
| Had | | | | | Tbs.
476| 487) 499| 510) 522) 534) 545 557 568 580 592 10, 000
| 428) 438) 449) 459) 470) 481) 491) 501) 511) 522) 533) 9, 000
| 881) 390) 399] 408) 418] 427) 436) 446 454) 464) 474! 8, 000
333] £41| 349) 357) 365) 374) 382) 390) 398) 406) 414) 7, 000
986! 292 299| 306 313 320 327 334 341 348 355, 6, 000
238| 244| 250| 255) 261) 267) 273 279 284 290) 296|| 5, 000
190! 195! 200! 204) 209) 214) 218) 223) 227) 232) 2371) 4, 000
148, 146) 150 153 157] 160 164, 167, 170 174) 178) 3, 000
95.297 .4)99.8| 102) 104] 107) 109 111] 114) 116) 118) 2, 000
47 .6.48.7/49.9151.052.2153.4/54.5155.7/56. 858.059.2 1, 000
|
|
42.843.844.945.947.0/48.149.150.151. 152.253.3 900
38.139.039.940.841.8/42.743.6 44. 6/45.446.4/47.4 800
5 33.334.134.935.736.5|37.438.239.0139.840.6141.4) 700
28 6/29. 2/29. 930.6131. 3]32.0/32.7/83. 4/34. 1/84.8/35.5|| 600
123. 8|24..4/25 . 0/25 .5/26. 1/26 .7|27 3/27 .9\28. 4/29 .0/29.6/ 500
19.0|19.5/20.0/20. 4/20. 9/121 .4/21 .8/22.3/22.7/25.2/23.7|| 400
14.3/14.6/15.0/15.3)15.7/16.0|16.4/16.7|17.0|17.4/17.8] 300
9.5) 9.7/10.0/10.2|10.4/10.7/10.9)11.1)11.4)11.6111.8] 200
4.8] 4.9] 5.0| 5.1/ 5.2) 5.3) 5.5) 5.61 5.7/ 5.8) 5.97 100
2) 4.3) 4.4] 4.5) 4.6) 4.7] 4.8) 4.9) 5.0) 5.1) 5.2) 5.3) 90
7| 3.8] 3.9] 4.0] 4.1] 4.2] 4.3) 4.4) 4.5) 4.5) 4.6] 4.7 80
3) 3.3) 3.4] 3.5] 3.6] 3.7] 3.7] 3.8) 3.9) 4.0) 4.1] 4.1 70
S229) 29/9320) 3.4) 3.1/3.2) 3.3.8.3) 3.4] 3.5) 3.6 60
3| 2.4) 2-4) 2.5) 2.6|-2.6]| 2.7| 2.7] 2.8] 2.8] 2.9] 3.01] 50
OF 4-9) 2-0) 2.0) 2.0) 2e1)/-2.1) 2.2) 2:2) 2.3] 2.3] 2.4! 40
Mt A a oh sai bold 6) 4. Ted 27) 1.7) 1.8) 30
O)b Ol iO) 12 OO) ASOD 1d 41) 1 9-2. ll 20
Pahl Pairs. Ole Paine sole wali ap BT “ble ee|- 6). Gi 10
|
Ber AR a SS BI eel Som. bani aso! 5) 5 9
eaagc die cdl s aay cA A ed inoe Aloe. bl LE 8
eee aes Ae A ai Ads Al 4) | 4 7
Pate 8) Sranlassa\e so) ean ssomelteeao: 63.4)! .4 6
i ie oases ais es! 63) 3] |. Sil 5
| aR db eb lags) oer. ee. a rh | 4
Mi ieliaene| twa eo eeeeibee mene OY, Ol Dh Oly hl 3
Sel tee der tiered wih Il. ls ate 2
UES ge a) An eae ders As Ua bs We 1
4.304.404.504.604.70 4.804.905.005.105.205.30) &
224 Testing Milk and Its Products.
Table X. Overrun table, showing pounds of but=
ter from one hundred Ibs. of milk. See direc-
tions for use, p. 170.
Pe
ope He yOlL. Ait .1911.13/1.14]1.1511.16/1.17|1.18|1.19/1. 201 cont.
fat. pe
Go Co CY OO
SOMO hwWNHO DONO BWDHO OCBHNAOT PWNHHS
Soa Nnrann aNnonne BERK BE KRwWwW Wwwwer
co
on
on
o
S
on
o
ms
Ou
=
S
Ou
rp"
20
or
fmt
oa
or
bo
we
Or
ho
~I
Or
(Sts)
—
or
ao
ox
Gx
po
oS
ANAK TANIA PPR RRR RB coCDcrd coos
SWNT PWONMWHO OCHBNSHN PWNHO DHONSS® PWNHHO
SH Or Or S191 cn Cr S91 or orcn He He He He He He He He He os OO Co Co CO
S
or
lor)
pmel
—
(or)
—
or)
lor)
bo
Li)
lor)
bo
Su : — rr
Sd D> Sd G2 Gd Od OO orci
< Ww
= co
lor)
isu)
eZ)
lor)
=
tS
lor)
pf
eo}
oO
Or
or
for)
lor)
=)
Appendix. 225
Table XI. Yield of cheese, corresponding to 2.5 to 6 percent
of fat with lactometer readings 26 to 36. (See p. 172).
LACTOMETRR DEGREES.
s ro
Bo B43
sé | S&
s 26 yi 28 29 | 30 31 OZ 30 34 39 36 s
2.5 || 7.28) 7.41) -7.54) 7.67) 7.81) 7.94) 8.07) 8.20) 8.33) 8.47) 8.60)| 2.5
2.6 || 7.44) 7.57| 7.70) 7.83 7.96) 8.09) 8.22) 8.35) 8.49) 8.62) 8.76]] 2.6
2.7 | 7.59| 7.72) 7.85) 7.99) 8.12) 8.25) 8.38] 8.51] 8.64) 8.77] 8.91]} 2.7
2.8 || 7.74) 7.87) 8.00) 8.14) 8.27] 8.40} 8.53) 8.67) 8.80) 8.94] 9.07)| 2.8
2.9 || 7.9u| 8.03] 8.16) 8.30] 8.34) 8.56) 8.69} 8.82) 8.95} 9.09] 9.22]| 2.9
3.0 || 8.05) 8.18] 8.31] 8.45) 8.58) 8.71) 8.81 8.97) 9.11) 9.24) 9.37)| 3.0
3.1 |} 8.21) 8.34! 8.47| 8.60) 8.74] 8.87) 9.001 9.13) 9.26} 9.39] 9.53]| 3.1
3.2 || 8.36) 8.49] 8.62) 8.75) 8.89) 9.02) 9.15| 9.28) 9.42) 9.55} 9.68]| 3.2
3.3 || 8.52) 8.65) 8.78) 8.91) 9.05] 9.18) 9.31] 9.44) 9.57) 9.70] 9.84]| 3.3
3.4 || 8.67) 8.80) 8.93} 9.06) 9.20] 9.33) 9.46} 9.59) 9.73] 9.86) 9.99]| 3.4
3.5 || 8.82) 8.96) 9.09} 9.22) 9.35] 9.48] 9.62] 9.75) 9.88/10.01}10.15]] 3.5
3.6 || 8.98) 9.11| 6.24! 9.37) 9.50} 9.63) 9.77] 9.90)10.03/10.17/10.30]| 3.6
3.7 || 9.13) 9.26] 9.39) 9.52) 9.65} 9.78) 9.92/10.05/10.19)10.32/10.46]| 3.7
3.8 || 9.29) 9.42) 9.55) 9.68) 9.81) 9.94/10.08/10.21/10.34/10.48)10.61]| 3.8
3.9 |} 9.44! 9.57] 9.70) 8.84) 9.97/10. 10)10.23)10.36)10.50)10.64/10.77]| 3.9
4.0 || 9.60) 9.73] 9.86/10.00)10. 13/10. 26)10.39}10.53)10.66/10.79)10.93}) 4.0
4.1 || 9.75) 9.88)L0.02/10. 15)10. 28/10. 39)10.54)10.68/10.81)10.94}11.08)| 4.1
4.2 || 9.90)10.03}10.17/10.30)10.43/L0.57/10. 70)/10.84/10.97/L1.10)11.24)| 4.2
4.3 |10.06)10.19)10.32)10.45)10.58)10.72/10.85]10. 99/11. 12/11. 25}11.39)| 4.3
4.4 110.21)10.34)10.48)10.61)10.74)10.87)11 .00)11.14)11.27|11.41/11.55]| 4.4
4.5 |}10.36)10.49|10.63/10.76/10.79)11.03/11. 16/11 .29)11.42)11.56)11.70)| 4.5
4.6 1}10.52/10.65)10.78/10.92)11 .05]11.18/11.31/11.45)11.58}11.71}11.85]| 4.6
4.7 ||10.67|10.81/10.94/11.07|11.20)L1 34)11.47/11.60)11.73)11.87/12.01]} 4.7
4.8 |110.83)10.96/11.09)11.22}11.36)11.49)11 .62)11.76/11.89)12.02)12.16)| 4.8
4.9 }10.95)11.11/11.25)11.38)11.51)11.65)11.78)11.91)/12.04/12.18]12.32)| 4.9
5.0 }11.14)11. 27/11. 40)11.54)11.67)11.80)11.93)12.07)12.20)12.34/12.48]} 5.0
5.1 11.29/11 .42)11.55)11.69}11.82)11.96)12.09)12 23)12.36)12.49]12.63)]| 5.1
5.2 |11.45)11 58/11 .71)11.85)11.98)12.11)/12. 24/12. 38]/12.52)12.66}12.80)} 5.2
8.3 {11.60/11 .73)11.86]11.99)12.13'12.27|12.40)12.53/12.67)12.71}12.85)| 5.3
5.4 |11.76)11.89)12.02)12. 16)12.29)12.42)12.55)12.69)12.83)12.97}13.01]| 5.4
5.5 11.91/12.04/12.17|12. 31/12. 44)12.58/12. 71/12. 85)12.99}13.12)138.25)| 5.5
5.6 |12.07|12.20)12.33)12.47)12.60)12.73)12.87/13.00]13. 14/138. 28]13.41]| 5.6
8.7 (12.22/12. 35/12. 48)12.52)12.75)12.89)13.02)13.16/13.30)13.44)13.57]| 5.7
5.8 |12.38)12.51|12.64)12.77|12.91/13.05)18.18)13. 31/13. 45)13.59}13.72)| 5.8
5.9 12.53'12.66/11.79,12.93/13.06 13.19)13.3313.47 13.60,138.74)13.87]) 5.9
6.0 pee 12.95}/12:09)13.22/138.35 13.49]13 .6218.79 13.89}14.02)| 6.0
226 Testing Milk and Its Products.
Table XII. Comparisons of Farenheit and centigrade
(celsius) thermometer scales.
Fahren- Centi- Fahren- Centi- Fahren- Centi-
heit. grade. heit. grade. heit. grade.
+212 +100 +176 +80 +140 +-60
PAI 99.44 175 79.44 139 59.44
210 98.89 174 78.89 138 58.89
209 98.33 173 78.33 137 58.33
208 97.78 Ao Vig ergs. 136 57.78
207 OF 222 17k Tis2e 135 57 22
206 96.67 170 76.67 154 56 .67
205 96.11 169 76.11 153 56.11
204 95.55 168 75.99 152 55.55
203 95 167 1D 1aL 55
202 94.44 166 - 74.44 130 04.44
201 93.89 165 73.89 129 53.89
200 93.33 164 foo 128 58-38
199 92.78 163 Toe Ae 127 §2.78
198 92.22 162 Toe 126 i a ay
197 91.67 161 TP 67 125 51.67
196 Oech 160 Ta U1 124 51.11
195 90.55 159 70.55 125 50.55
194 90 158 70 122 50
1938 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 BI 2Ts 154 67.7 118 47.78
189 87222 153 67.22 117 47 .22
188 86.67 152 66.67 116 46 .67
187 86.11 15] 66.11 115 46.11
186 85.55 150 65.55 114 45.55
185 85 149 65 118 45
184 84.44 148 64.44 Hz 44.44
183 83.89 147 63.89 | ETS: 43.89
182 83.33 146 63.33 110 43.36
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
Appendix. 227
Table XII. 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 —0.55
102 38.89 66 18.89 30 1541
101 38.33 65 18.33 29 1. 67.
100 37.78 64 7.78 28 2. 22
99 ai. 22 63 i7.22 rah 2.78
98 36.67 62 16.67 26 aan
97 36.11 61 16.11 25 3.89
96 35.00 60 15.55 24 4.44
95 35 59 15 93 5
94 34.44 58 14.44 29 5.55
93 33.89 564 13.89 21 6.11
92 32 ESB! 56 13.33 || 20 6.67
91 32.78 55 12.78 4 19 F 22
90 nes Bo 54 12,22 18 7.78
89 31.67 53 11.67 17 82308
88 ark 52 11.31 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 11.11
83 28.33 47 8.33 dA. 11.67
82 27.78 46 y dag ee 10 12,22
81 27 .22 45 Tipe see 9 12.78
80 26.67 44 6.67 8 13 oo
79 26.11 43 6:11 7 13.89
78 25 .55 42 5.55 6 14.44
it 25 41 5 5 15.00
76 24.44 40 4.44 4 15.55
75 23.89 39 3.89 5 16,11
74 23.33 38 3.00 2 16.67
73 92.718 Sif yet igs: il li eee
fp. 29 22 36 Meio 0 7278
ra 2D: 87 35 1.67 —] 18.33
70 arid 34 fat 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 to 110° F.? 110 — 32 = 78;
78 X 5= 390; 390 — 9 = 43.33.
To convert deg. Centigrade to corresponding deg. Fahrenheit :
Multiply by 9, divide product by 5, and add 32 to quotient.
Example: Which degree Fahrenheit corresponds to 95.59 C.? 95.5 x 9 — 859.5;
859.5 —- 5 = 171.9; 171.9 + 32 = 203.6.
“
Table XIII. Comparison of metric and customary weights and
measures.
Metric wei ; ‘
saan wed Equivalents in metricsystem. ied Equivalents in customary
measures. measures. a ig
SNE este « eeernes 2.54 centimeters. > SIMEBCT c ciconessee 39.37 inches.
ROGUE: 2 disso cee .3048 meter. BEB ester ghee eae 1.0936 yards.
aia | RMA mA 1.6094 kilometers. i ‘kilometer: a.. .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.
HE VAIRTE: ae shone. .4047 hectare. f hectares skccvesst 2.471 acres.
1 cubic ineh.;.7/-16.387 exc. BB GAs Cen Forge Bn .061 cubic inch.
1 cubic foot....| .0283 cub. meter. 1 cub. decimeter.| 61.023 cubic inches.
1 cubic yard...| .765 cub. meter. d- Cros Meter. 35.314 cub. feet.
i bushel <......: .38525 hectoliter. i hectoliter:. ..c2 2.8377 bushels.
1 fluid ounce...| 29.57 c. c. ; Cae Ca pe ae eS .0338 fluid ounce.
i qQuart.iccc.. .9464. liter. a WCET? 5.8, sac cae 1.0567 quarts.
1 gallon.....:.«: 3.7854 liters. 1 déeealiter a... xe 2.6417 quarts.
1 grain...........) 64.8 milligrams. il Sram saccee 15.43 grains.
1 ounce (av.)..| 28.35 grams. it -SRAM 5 eases core .035274 ounce.
1 pound (av.)| .4536 kilogram. 1 kilogram’. 223 2.2046 pounds (av.)
(228)
Appendix. 229
SUGGESTIONS regarding the organization of co=
operative creameries and cheese factories.
When the farmers of a neighborhood are considering the estab-
lishment of a creamery or cheese factory, they should first of all
make an accurate canvasof the locality to ascertain the number 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 sepa-
rator creamery will need at least 400 cows within a radius of
four to five miles from the proposed factory.* Small cheese fac-
tories 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 con-
tributing to the enterprise must be fully settled before further
steps are taken, since this is the vital point, and one 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 who expect to join the
association. When a sufficient number of cows has been pledged
to insure the successful operation of a factory, the farmers agree-
ing to supply milk should meet and form an organization. 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 be-
fore a given date for a certain number of shares or stock in the
company At ...:2:.-.0. dollars per share; or,
Second.—An elected board of directors may be authorized to
borrow a sum of money not exceedieg .........++. 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 payment of this borrowed money.
* Bull. 56, Wisconsin experiment station.
230 Testing Milk and Its Products.
Constitution and by-laws of co-operative associations are
drawn up and signed by the prospective members of the associa-
tion as soon as possible after it has been determined to form such
an association. As it is impossible to include in an illustration
all the articles and rules that may be found useful in each partic-
ular instance, the following suggestions in regard to some of the
points to be included 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 ...... sooo. ASSOCIATION.*
1. The undersigned, residents within the counties of.............4. :
state of.............. hereby agree to become members of the anus
co-operative association, which is formed for the purpose of man-
ufacturing butter or cheese from whole milk.
2. The regular meetings of the association shall be held annu-
aly og tite!t ees day. of the month of ...22.1:... Special meetings
may be called by the president, or on written request of one-third
of the members of the association, provided three days’ 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. The 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, secre-
tary, treasurer, one of whom is also elected manager, and these
officers together with three other members of the association
VG The follawdag publications have been freely used in preparing this constitu-
tion and by-laws: Woll, Handbook f. Farmers and Dairymen; Minn. experiment
station, bull. No. 35; Ontario Agricultural College, special bulletin, May 1897.
T i
a
a
Appendix. 235
shall constitute the board of directors. Each of these six officers
shall beelected at the annual meeting and hold office for one year,
or until their successors have been elected and qualified. Any va-
cancies in the board of directors may be filled by the directors un-
til 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 pre-
siding 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 whenever it is deemed necessary.
In the absence of the president, one of the board of directors
shall temporarily fill the position.
6. The secretary shall attend all business meetings of the asso-
ciation and of the board of directors, and shall keep a careful rec-
ord of the minutes of the meetings. He shall also give notices of
all meetings and all appointments on committees, etc. He shall
sign all papers issued, conduct the correspondence and general
business of the association, and keep a correct financial account
between the association and its members. He shall have charge
of ali property of the association, not otherwise disposed of, give
bonds for the faithful performance of his duties, and receive such
compensation for his services as the board of directors may deter-
mine.
7. The treasurer shall receive and give receipt for all money
belonging to the association, 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 asso-
ciation, invests its funds, appoint agents, and determine all com-
pensations. They shall prescribe and enforce the rules and regula-
tions of the factory. They shall cause to be kept a record of the
weights and tests of the milk or cream received from each patron,
the products sold, the running expenses, etc., and shall divide
among the patrons the money due them each month. They shall
232 Testing Milk and Its Products.
also make some provision for the withdrawal 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 pro-
ducts sold, and all other receipts, the amount paid for milk, also
for running expenses, and a complete statement of all other
methods pertaining to the business association.
9. Among the rules and regulations to be enforced by the board
of directors may be included some or all of the following:
a. Patrons shall furnish all the milk from allthecows promised
at the organization of the association.
b. Only sweet and pure milk will be accepted at the factory,
and any tainted or sour milk milk shall be refused.
c. 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 taking
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 patron’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 sam-
ples of the milk of his cows for examination when it is deemed
necessary.
10. Any changes or amendments 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 associa-
tion, the members shall be entitled to one vote for each cow sup-
plying milk to the factory, or for each share of the stock owned
by them, as agreed upon.
TINIE.
The numbers refer to pages in the book.
Acid measures, 42.
Acidity of cream, 104; estimation of, 106.
Acidity of milk, cause of, 94; determina-
tion of, 94, 195; methods of testing, 95.
Adulteration of milk, 88; calculation of,
90.
Adulterated butter, 200; cheese, 203.
Albumen 13, determination of, in milk,
191, 193.
Albaminoids, 13.
Albumose, 14.
Alkaline tablet test, 99.
Alkaline tabs, 109.
Amphoteric reaction of milk, 94.
Appendix, 205.
Artificial butter, detection of, 200.
Ash, determination of, in butter, 198; in
cheese, 298; in milk, 17, 194.
Automatic milk scale, 124.
Babcock test, the, 6, 25; Bartlett’s modi-
fication of, 63; directions for, 25; dis-
cussion of details, 34; for butter milk,
74,77; for cheese, 77; for condensed
milk, 79; for cream, 64, 154; for skim
milk, 74; for whey, 74, 77; glassware
used in, 34; modificitions of, 62; scales
for weighing cream, cheese, etc., 71;
water to be used in, 60.
Bartlett’s modification of Babcock test,
63.
Beimling test, 5.
Bi-carbonate of soda, detection of, in
milk, 196.
Bi-chromate of potash, 141.
Board of health degrees, 83.
Buracic acid, 195.
Borax, 195.
B. & W. bottle, 76.
Butter, artificial, 13; detection of, 200.
Butter chart, 222; use of, 168.
Butter, chemical analysis of, 197; com-
plete analysis in same sample, 199;
composition of, 205; determination of
ash, 198; casein, 198; fat, 198; water, |
197; sampling for analysis, 197; varia-
tions in composition, 161; yield, cal-
culation of, 160.
Butter fat, conversion factor for, 167;
determination of specific gravity, 200;
volatile fatty acids, 201; expansion co-
efficient, 33; price per pound, 174;
table showing amcunts due for, at 12
to 25 cents per pound, 216; test and
yield of butter, 160.
Butter milk, Babcock test for, 74, 77;
chemical analysis of, 197; composition
of, 205.
Calculation of adulteration, 90; of milk
solids, 85; of yield of butter, 160, 167,
169; of cheese, 171; of dividends, at
creameries, 174; at cheese factories,
182.
Calibration of glassware, 43.
Carbohydrates, 15.
Casein, 13; determination of, in butter,
198; in cheese, 203; in milk, 191, 192.
Centrifugal machines, 47.
Chamberland filters, 14.
Cheese, 77; calculating yield of, from
casein and fat, 173; from fat, 171; fiom
solids not fat and fat, 171; composltion,
205; chemical analysis of, 202; deter-
mination of ash, 263; casein, 203; fat,
202; water, 202; “‘filled’”’, detection of,
208; sampling, 77; yield, calculation of,
160, 171; yield of, and quality of milk,
relation between, 171.
Cheese factories, calculating dividends
at, 182; co-operative, 185; proprietary,
184,
Chemical analysis of butter, 197, 199;
butter milk, 197; cheese, 202; milk, 186;
skim milk, 197; whey, 197.
Cholesterin in milk, 19.
Citric acid in milk, 19.
Cleaning solutions for test of bottles, 39.
Cleaning test bottles, 36; anparatus for,
38.
Cochran’s test, 4.
Coloring matter, foreign, in milk, de-
tection of, 92.
Colostrum milk, 19; composition of, 205.
Composite samples, 134; care of, 143;
234 Testing Milk and Its Products.
case for holding, 157; methods of tak-
ing, 134; preservatives for, 140.
Composite sampling, by use of drip
sample, 136; one-third sample pipette,
138; Scovell sampling tube, 136; tin
dipper, 134.
Composition of butter, 205; butter milk,
205; cheese, 205; colostrum milk, 205;
cream, 205; milk, 205; skim milk, 205;
whey, 205.
Condensed milk, composition of, 205;
testing of, 79.
Conversion factor for butter fat, 167.
Conversion tables for thermometer
scales, 226; for weights and measures,
228.
Cow, a, when to test, 123.
Cows, number of tests required in test-
ing, 121.
Cows’ milk, composition of, 205,
Cream, acidity of, 104; avoiding errors
of measuring in testing, 67; Babcock
test for, 154; bottles, the bulb-necked,
68; the Winton, 69; care in sampling,
necessity of, 154; determination of
acidity in, 100, 108; errors of measur-
ing in testing, 65; separation of, in-
fluence of temperature, 159; spaces,
150; specific gravity, 66; testing, 64;
testing outfit, 155; testing at cream-
eries, 150; use of 5c. c. pipette in, 71;
use of milk test bottles in, 69; test
bottles. 67; weighing in cream testing,
71; weight delivered by a 17.6 cc. pi-
pette, 66.
Creameries, calculating dividends at,
174, 176; co-operative, 175; cream test-
ing at, 150; proprietary, 175.
Creamery inch, 1.
Curd test, the Wisconsin, 111.
DeLaval’s butyrometer, 8.
Devarda’s acidimeter, 99.
Diameter of tester and speed required,
relation between, 50.
Dividends, calculating, at cheese
factories, 182; at creameries, 174.
Draining rack for test bottles, 39.
Expansion coefficient for butter fat, 33.
Failyer and Willard’s test, 4.
Farrington’s alkaline tablet test, 99.
Fat, 12; color of, an index to strength
of acid used, 58; content, causes of
variation in, 120; determination of, in
butter, 198; in cheese, 202; in milk,
190; globules, 12; influence of tem-
perature on separation of, 59; measur-
ing of, in cream testing, 73; in milk
testing, 32; pounds in 1-10,000 lbs. of
milk, testing 3 to 5.35 per cent., 212;
speed required for complete separa-
tion of, 48.
Fermentation test, the, 113.
Filled cheese. detection of, 203.
Fjord’s centrifugal cream test, 9.
Fluorids, detection of, in milk, 196.
Food, influence of, on quality of milk,
131.
Fool pipettes, 40.
Formaline, detection of, in milk, 197.
Frozen milk, sampling of, 24.
Gauges of cream, 150.
Gerber’s acid-butyrometer, 7; fermenta-
tion test, 113.
Glassware used in the Babcock test, 34;
calibration of, 43.
Globulin, 14.
Glycerides of fatty acids, 12.
Goat cheese, 14.
Grain feeding, heavy, influence of, on
quality of milk, 130.
Hand testers, 52.
Hemi-albumose, 14.
Herd milk, variations in, 128; ranges in
variation, of 129.
Hypoxanthin, 19.
Introduction, 1.
Towa station test, 5.
Lactie acid in milk, 16.
Lactocrite, 5.
Lactose, 15.
Lactochrome, 10.
Lactometer, the, and its application, 80;
degrees, 81; N. Y. board of health, 83;
Quevenne, 80; reading the, 84; time
of taking readings, 85.
~~ i oe ee
Index.
Lecithin in milk, 19.
Leffmann and Beam test, 5.
Legal standards for milk, 89, 206.
Liebermann’s method, 5.
Manns’ test, 96.
Measuring fat column in testing cream,
73; in testing milk, 32.
Meicury,calibration with, 43; cleaning,
44,
Metric and customary systems of
weights and measures, comparison of,
228.
Milk, acidity of, 94; adulteration of, 88;
amphoteric reaction of, 94; ash, com-
position of, 18; chemical analysis of,
186; cholesterin in, 19; citrie acid in,
19; colostrum, 19; composition of, 11;
table showing composition of, 205;
composite sampling of, 134; condensed,
79,205; correction table for specific
gravity of, 208; detection of preserva-
tives in, 109; determination of acidity,
106, 195; of ash, 194; of casein and
albumen, 191, 192, 193; of fat, 190; of
milk sugar, 193; of specific gravity,
186; of water, 188, 190; fat available for
butter in different grades of, 165; from
cows in-heat, 89; from sick cows, 89;
from single cows, sampling of, 126;
variations in, 116; frozen, sampling of,
24; gases, 19; hypoxanthin, 19; lacto-
chrome, 19; lecithin, 19; mineral com-
ponents, 17; partially churned, sampl-
ing of, 21; quality of, influence of
food, 131; of heavy grain feeding, 130;
of pasture, 131; method of improving,
132; sampling, 20; scales, 124; serum,
11; skimming, 90; solids, 11; calcula-
tion of, 85; sour, sampling of, 23, 26;
standards, 89, 206; sugar, 15; testing
purity of, 111; urea, 19; watering of,
91; watering and skimming, 91.
Milk test, a practical, need of, 1; re-
quirements of, 6; bottle, use of, in
_ testing cream, 69; Russian, 62.
Milk tests, Beimling (Leffmann and
Beam) 5; Cochran, 4; DeLaval
butyrometer, 8; Failyer and Wil-
lard, 4; Fjord, 9; foreign, 7; Gerber
acid-butyrometer, 8; introduction of,
65)
3; lactocrite, 5; Liebermann, 5; Par-
son, 4; Patrick (Iowa station test,) 5;
Roese-Gottlieb, 5; Sechmied, 5; Short,
4; Thoerner, 5.
Milk testing, 26; on the farm, 116.
N. Y. board of health lactometer, 83;
degrees corresponding to Quevenne
lactometer degrees, 207.
Non-fatty milk solids, 11.
Normal solutions, 96.
“‘No-tin” test, 52.
Nuclein, 14.
Oil test churn, 2, 151,
Ohlsson test bottle, 76.
Oleomargarine, detection of, 200; cheese,
detection of, 203.
One-third sampling pipette, use of, 138.
Organization of co-operative creameries
and cheese factories, suggestions con-
cerning, 229.
Overrun, 163; calculation of, 167; factors
influencing, 163; table, 224; use of, 170.
Parson’s test, 4.
Pasture, influence of, on quality of
milk, 131.
Patrick’s test, 5.
Patron’s dilemma, a, 146.
Percentages, average, methods of cal-
culation, 145; fallacy of averaging,
144,
Phenolphtalein, 97.
Pipettes, 39; proper construction of
points, 40,
Potassium bi-chromate, 141.
Power testers, 53.
Preservaline, 109; detection of, in milk,
109.
Preservatives, for composite samples,
140; in milk, detection of, 196.
Primost, 14.
Proteose, 14.
Quevenne lactometer, the, 80; degrees
corresponding to scale of N. Y. board
of health lactometer, 207.
Record of tests of cows, 126.
Reichert number, 202.
Reichert-Wollny method, 201.
236
Relative value tables, 178, 180, 218.
Reservoir for water in Babcock test, 61.
Roese-Gottlieb method, 5.
Russian milk test, the, 62.
Salicylic acid, in milk, detection of,
196.
Sampling cheese, 77; milk. 20, 26; milk
from single cows, 126.
Schmied method, the, 5.
Scovell sampling tube, 136.
Serum solids, 11.
Short’s test, 4.
Skimming of milk, detection of, 90.
Skimmilk, Babcock test for, 74; chemi-
cal analysis of, 197; composition of,
205; test bottles, 76, 77.
Solids not fat, 11; formula for calculat-
ing, 86; table showing, corresponding
to 0-6 per cent. fat and 26-36 lacto-
meter degrees, 209.
Sour milk, sampling of, 23.
Space system, the, 150.
Specific gravity, 80; cylinders, 84; in-
fluence of temperature, 81; of butter
fat, determination of, 200: of milk,
determination of, 186; temperature
correction table, 208.
Speed required for complete separation
of fat, 48
Spillman’s cylinder, 195.
Steam turbine testers, 53.
Sulfuric acid, 54; table showing strength
of, 56; testing strength of, 54.
Swedish acid bottles, 42.
Swedish acid tester, 57.
Tank for cleaning test bottles, 40.
Test bottles, 34; apparatus for cleaning,
38; cleaning, 86; double-necked, 76;
draining-rack for, 39; marking, 35;
for cream testing, 67; for skim milk
testing, 76, 77; rack for use in cream-
eries and cheese factories, 139; tank |
for cleaning, 40.
Testing Milk and Its Products.
Testers, hand, 52; p wer, 53.
Testing cows, number of tests required
during a period of lactation, 121.
Testing milk and its products, 1; on the
farm, 116.
Test sample, siZe of, 128.
Tests of cows, record of, 126.
Thermometer scales, comparison of, 226,
Thoerner’s method, 5.
Total solids in milk, 11; determination
of, 189,
Volatile acids, 201.
Waste acid jar, 37.
Water, calibration with, 45; determina-
tion of, in butter, 197; in cheese, 202;
in milk, 188, 190; reservoir for, 61; to
be used in the Babcock test, 60.
Watering of milk, detection of, 91.
Watering and skimming of milk, de-
tection of, 91.
Weights and measures, comparison of
metric and customary, 228.
Whey, Babcock test for, 74, 77; chemical
analysis of, 197; composition of, 205.
Winton cream bottle, the, 69.
Wisconsin creamery butter, summary
of analyses, 162.
Wisconsin curd test, the, 111.
World’s Fair breed tests, composition of
butter from, 161.
Yield of butter, calculation of, 160; and
butter fat test, 160; from milk of dif-
ferent richness, 16%; table showing,
from 1 to 10,000 ibs. of milk, testing
3 to 5.35 per cent. , 222
Yield of cheese, calculation of, 160, 171;
relation between,and quality of milk,
171; table showing, corresponding to
2.5to6 per cent. of fat, with lacto-
meter readings of 26 to 36, 225.
2)
el eri Ba OT Aik ie
LIBRARY OF CONGRESS
ADMIT
UOO0S9S4bh1b
bai