'&9i THE RURAL NEW-YORKER. 549 
Business. 
A CHEAP AND ACCURATE MiLK TESTER. 
Valuable Home-Made Contrivance. 
J. R. HUTTON. 
The value of milk depends almost entirely upon the 
amount of fat it contains. This is true whether it be used 
for making butter or cheese, or for domestic purposes. 
Hence arises the importance of testing milk, and valuing 
it, not by its weight or volume, but by the amount of fat 
in it. For this reason the only way of ascertaining the 
actual value of a cow for dairy purposes, or of making a 
fair division of the proceeds among the patrons of a cream¬ 
ery or cheese factory is on the basis of the amount of fat 
supplied. While this has been recognized for some time, 
the lack of a satisfactory method of testing the milk has, 
until recently, prevented the adoption of this system of 
valuation. 
In order to prove acceptable, a method for testing milk 
must meet the following requirements : Accuracy, sim¬ 
plicity, rapidity and economy. Thera are at the present 
time at least two methods which in a high degree All the 
fir f t three of these conditions, but not sufficiently the last; 
for it may reasonably be questioned whether many dairy¬ 
men will pay from $10 to $20 for a tester when one that 
will give the same results can be secured for from $1 to $5. 
With the object of supplying this desideratum the method 
here described was devised some months ago. It has proved 
as accurate and simple, while more rapid and very much 
cheaper, than any yet brought out. Though designed es¬ 
pecially for the use of dairymen in testing their cows, it 
may be of equal service in the creamery or cheese factory. 
Whatever of merit it may possess Is given freely with the 
hope that it will prove of use to those for whom it is in¬ 
tended. The principle of the method, a modification of 
the above, Is this : A definite amount of milk, in an ac¬ 
curately graduated flask, is treated with a small quantity 
of amylic alcohol to dissolve the fat, and sufficient strong 
sulphuric acid to dissolve the casein. The tube is then 
rapidly whirled to separate the fat and force it to the top 
within the graduations of the neck, where Its volume is 
read at once. 
Apparatus Needed for the Test. 
In addition to the machine, the method requires the fol¬ 
lowing appliances: 
A pipette (Fig. 198) for measuring the sample of milk. 
It is about half an inch in diameter, and five inches long. 
Flasks like that at Fig. 199 in which the tests are made. 
These are five inches high, with bodies one inch in diam- 
ter containing to the lowest mark 26 c. c. The long, nar¬ 
row neck, in which the fat is measured, is graduated ac¬ 
curately into one-t nths to ten per cent, the ten sp ices con¬ 
taining 15 c. c., and being two inches in length. They are 
made of strong, well-annealed glass and very seldom break. 
Amylic alcohol to dissolve the fat. The rectified kind is 
the more reliable, but the commercial answers quite well 
for ordinary work. 
Sulphuric acid, the strong commercial is the kind need¬ 
ed. The weak acid for filling the necks of the tubes is 
made by carefully mixing equal parts of the strong acid 
and water. 
The Whirling Machine. 
Any machine that will give the rapid centrifugal motion 
required—from 800 to 1,000 revolutions per minute—will 
answer the purpose. Any one of the styles of whirlers 
manufactured for other methods will serve equally well 
for this. The dairyman may provide himself with one of 
these, which cost from $L0 to $50. according to capacity, or 
he can, at a trifling expense, make a machine that will do 
the work equally well. The accompanying drawing (Fig. 
200) represents such a device made at a cost of 25 cents for 
materials. It is only one of a number of forms that can be 
easily made. Both the form and the cost of a machine 
may be varied according to individual taste. The one 
shown in the figure is attached to an ordinary table, and 
consists essentially of two parts—the whirler to hold the 
flasks, and the wheel to drive it. One turn of the wheel 
makes ten of the whirler, thus the required speed is at¬ 
tained by making 100 revolutions of the wheel per minute. 
The whirler is a wooden wheel 12 or 20 Inches in diameter, 
made of two thicknesses of inch lumber with their grain 
crossing, or of two-inch plank with a band of hoop iron. A 
circle of holes, for holding the flasks, is bored in the top of 
the whirler at an angle of about 30 degrees from the hori¬ 
zontal. They should be at least three inches deep, and have a 
tight bottom. A whirler 15 inches in diameter will hold 16 
flasks, but two are enough for ordinary use, and eight for 
any purpose. A holder for two flasks is easily made from 
a piece of scantling, with a hole near each end for the 
flasks. The holes should be bored in pairs directly oppo¬ 
site each other; and when whirling the flasks should be 
arranged on the same plan. This is to preserve the bal¬ 
ance of the machine. If an uneven number of flasks are to 
be whirled the odd one Is balanced by a counter-weight. 
The whirler fits securely on the upper end of the axle by a 
square hole through the center. The axle is a piece of 
five-eighth inch rod iron, eight inches long, turning in a 
hole in the top of the table, and in a block at the side. 
Wearing of the holes is prevented by making bearings of 
tin. One end of the axle is squared and slightly tapered to 
fit into the whirler. A close fit is secured while the iron is 
hot. The small pulley is an inch and a half in diameter, 
and keyed to the axle. The wheel may be of wood or iron, 
15 inches in diameter, turning on a bolt through the table 
leg. 1 he most essential thing to secure in the construc¬ 
tion of the machine is the accurate centering of the whirler 
on the axle. If properly constructed the machine will run 
w.th a steady motion at a high speed. When not in use 
the whirler can be quickly removed and the table cleared, 
by loosening the key of the pulley and withdrawing the 
axle. 
The Method. 
Sampling the Milk. —The accuracy of the test depends 
on the correctness of the sample. It should represent 
the whole lot from which it is taken. Owing to the ten¬ 
dency of cream to rise, uniformity can be secured only by 
thorough mixing. If samples are to be taken at one time 
from a number of cows or cans, it is well to have for each 
a small bottle or jar with a distinguishing number or 
label. Milk fresh from the cow is easily sampled by pour¬ 
ing it a few times from one pail to another, and straining 
a portion at once into the bottle. Before taking a test- 
sample from this, mix again by gently shaking and in¬ 
verting. Milk that has stood long enough for the cream to 
rise requires more thorough mixing to get an even distri¬ 
bution of the cream, but in doing this care must be taken 
not to churn it. Before taking a sample from a large can 
or vat the contents must be well mixed by stirring with 
a dipper. The use of a sampling tube, to collect either 
while the milk is running Into the vat, or after it has 
stood, obviates this labor. Milk that has become sour, or 
on which the cream has become dry on the surface or been 
gathered into small butter granules, cannot be sampled 
satisfactorily. 
Making the Test. —The samples that have been collected 
may be tested within a few hours, or may be kept a num- 
Fig. 198. Fig. 199. 
bar of days by the use of a preservative. Number the 
flasks with a small label or ring to prevent the confusion 
of results. In making the test proceed with each flask as 
follows: 
1. Add amylic alcohol, about two c. c. 
2 Add measure of milk, 13.08 c. c. 
3. Add acid ; shake, whirl. 
4. Read per cent of fat. 
Adding the Alcohol —The amount of alcohol required is 
from 1.5 to 2 c. c., equal to a depth of nearly a quarter of an 
inch in the flask. No measure is needed, as this can be 
easily estimated by the eye. Have too little rather than 
too much. 
Adding the Milk. —Measure the milk with the pipette. 
Place the round end to the lips and the other in the well 
mixed milk, draw up until the milk touches the end of 
the tongue, press the tongue over the hole, withdraw the 
pipette, and deliver its contents into the flask, blowing out 
the last drop. 
Adding the Acid— Add strong sulphuric acid up to the 
neck, close the flask with a small cork, shake vigorously 
until all the casein is dissolved, add weak acid to near the 
top, place the flasks in the machine, whirl rapidly until 
the fat appears in the neck as a clear yellow oil above the 
dark brown or purple solution. 
Reading the Fat. —Remove the flasks from the machine, 
hold in an upright position, and read the per cent of fat in 
each by subtracting the reading opposite the bottom of the 
fat from the reading next above the one opposite the 
curved line at the top of the fat, e g.,2 9 from 7.3 gives 4 4 
per cent fat in the sample. The reading taken immediately 
after whirling is sufficiently correct for ordinary work ; if 
greater accuracy is desired, allow the flasks to stand for a 
few minutes in water at 120 degrees to 140 degrees Fahren¬ 
heit before reading. The result Is practically the same if 
.1 be added to readings over five per cent. 
The time required to make a test decreases with the 
number made. Changing the flasks takes about one min¬ 
ute, and the whirling usually half a minute; thus a test 
can be made in two minutes. 
Cream, Butter, Cheese. —These may be tested by modify¬ 
ing the method of getting the sample. Owing to their 
higher ptr cent of fat, smaller test samples must be taken. 
Fresh cream from deep cans ma/ be sampled by diluting 
with water, by using a smaller pipetta, or by weighing the 
sample. The test may be made with the milk pipette and 
flask by diluting. In a clean vessel mix one measure of 
creim with two of water, and take one pipette measure of 
this for the test sample. Test in the same way as milk, 
and multiply the reading by three for the per cent .of fat. 
By using the cream pipette, delivering 4.5 grams of cream, 
the work is done more rapidly without diluting. It is more 
difficult to get a fair sample of cream than of milk. Care 
must be taken in mixing to avoid churning or frothing. 
Cream that has become thick, sour, churned or frothed, 
cannot be sampled by the pipette. For testing such, as well 
as butter and cheese, the sample must be wtighed. Of 
cream take about six grams, of cheese about four, of bntter 
about two, and test in the usual way. The reading divided 
by the weight taken and multiplied by 13.5 gives the per 
cent of fut in the sample. 
Skim-milk, Buttermilk, Whey. —The amount of fat in 
these may be determined quite closely if a fair sample can 
be obtained. Treat the samples in the same way as milk. 
To those unaccustomed to testing it may not be amiss 
to state that the average p jr centof fat in the common dairy 
products is about as follows: 
Milk 4 Skim-milk .4 Cheesa 33. 
Cream 20 Buttermilk .6 Butter 85. 
Hints.— Work in a room with temperature near 70 de¬ 
grees. Keep both solutions corked. Have a small bottle 
for each in which to keep a supply for testing. Pour di¬ 
rectly from these into the tubes. Before taking a test- 
sample with the pipette, mix the milk well and allow any 
air bubbles to escape. The pipette must be completely 
full. If it is dry, the first filling will do ; if not, reject the 
first and take the second for a test. Empty the pipette 
by blowing out the last drop into the fl «sk. Fill the flasks 
slowly to allow the air to escape. A little practice in Ail¬ 
ing the pipette and tubes with water will enable any one 
to do the work easily and rapidly. Avoid getting acid on 
the skin or clothing. In case it gets there bathe the skin 
freely, and apply ammonia to the clothing. Mix the con¬ 
tents of the flask at once after adding the acid. Hold the 
cork in firmly to prevent its being blown out. The flask 
must be whirled until the fat is clear. This requires fre¬ 
quently only 15 seconds, usually half a minute, occasion¬ 
ally longer. If the bottom of the fat is below the lowest 
graduation, add weak acid to raise It. The fat should not 
appear cloudy or have much undissolved casein below it. 
The former is due to too low a temperature; the latter to 
insufficiently strong acid. In either case the test must be 
repeated. Empty the flask while still hot, and rinse with 
hot water. Any number of tests within the capacity of 
the machine can be made at one time; but since the time 
of whirling is so short, nothing is gained in whirling 
more than eight at once. In a warm room, with rapid 
work, this number can be made without the use of hot 
water; with more than this, or in a cooler room, the 
flasks have to stand in hot water a moment to keep the 
fat melted. The tests need not be completed at once. 
After adding the milk the flasks may stand some time be¬ 
fore adding the acid. The order of the work may be 
varied without altering the results ; thus the alcohol may 
be added before or after the milk, the acid in one or more 
portions, the weak acid before or after whirling. 
The Cost. 
The only expense in making the tests is for the chemicals 
required. The cost of these varies with the amount pur¬ 
chased. At the ordinary prices of amylic alcohol and sul¬ 
phuric acid, the cost per test is about one-third of a cent; 
at the lowest wholesale prices it does not exceed one-eighth 
of a cent. Since a machine can be made by any one for 
less than the cost of transportation, it scarcely enters into 
the cost of an outfit. All that is required then is a pipette, 
a few flasks, and the chemicals. One pint of the alcohol, 
and one gallon of the acid are sufficient for 300 tests. The 
chemicals may be obtained from any druggist, the pipette 
and flasks from Eimer & Amend, 211 Third Avenue, New 
York. The pipettes cost 25 cents each, and the flasks 50 
cents each, with discount to the trade. 
BUSINESS BITS. 
The Department of Agriculture seems to believe that a 
successful machine for preparing ramie fiber is on the way. 
Stocks of Evaporated Raspberries—I live where 
raspberries are grown by the acre, chiefly for commercial 
purposes, and I do not know of a single barrel unsold. I 
would advise growers not to take alarm and sell at a low 
figure, as the chances are good for a fair price. c. L. f. 
Naples, N. Y. 
Road Machine.— The township in which the writer lives 
bought a road machine of the American Road Machine 
Company, Kenrntt Square, Pa. It has now been in use 
about three months and everybody seems pleased with it 
except the men who used to enjoy “soldiering” on the 
road with plow and scraper. It will “ plow, scrape or dig” 
and rounds the road up to just the curve required. It is a 
good thing—worth any dozen teams we have ever had. 
When the agent came to test it, several old farmers caution¬ 
ed him to go slow because they knew of several big rocks 
buried in the ro d. “ Go ahead ! ” he said, “ I’m here to test 
this machine.” They went ahead and the machine Is un¬ 
hurt. We like to see a man with faith in his machine ! By 
the way, a road machine is just as liable to rust and decay as 
any other tool. A friend of ours saw in a New York town- 
sh p a machine that had bean “ housed” in a fence corner 
all winter. Of course the roads in that township were 
“no good.” 
