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