DETERMINING QUALITY OF MILK FOE CONDENSERIES. 3 
it is considered unsafe from the standpoint that the milk after 
evaporation will not stand the heat necessary for sterilization with- 
out becoming curdy. The test is practical and easy to make at the 
weigh room. The test as used in this work was made by adding 
1 c. c. of milk to a small test tube containing 1 c. c. of alcohol and 
mixing at once by inverting once or twice while holding a finger 
over the top. Any reaction that takes place will be very quickly 
evident, the large majority of tests showing coagulation immediately 
or giving no reaction at all. The gradation of coagulation is shown 
by the size of the curd particles formed. Unless the curd particles 
formed are small the reaction is not at all difficult to distinguish, 
even by one not familiar with the test. A mixture of milk and 
alcohol giving a negative reaction immediately breaks clear from 
the walls of the test tube, while a mixture giving a coagulation 
of fine particles will leave the walls of the test tube cloudy. Mix- 
tures showing a medium or large particle curd formation are readily 
discernible because of the adherence of the curd particles to the 
walls of the test tube. 
In the work of grading the milk at a condensery on a commercial 
basis two small brass dippers of 2 c. c. capacity each were used. 
Thirty test tubes arranged in a block of wood 3 inches wide, 2 inches 
deep, and 18 inches long, having three rows of holes of the proper 
diameter and depth, were first filled with 2 c. c. of the 75 per cent 
alcohol by means of one of the brass dippers. Two men working 
together then went through the individual cans, taking 2 c. c. of milk 
from each and mixing it with the 2 c. c. of alcohol. No more time 
was required than is necessary in making the acidity test. 
The first work attempted with the alcohol test was to determine 
whether any correlation existed between the coagulation and the 
acid content of milk as measured by the usual titration method. 
Samples of milk were taken from individual patrons at the weigh 
room of the Grove City, Pa., creamery for the observations made. 
Reactions with 75 per cent ethyl alcohol and titratable acidity were 
determined shortly after taking samples and at stated intervals on 
those not showing positive coagulation with alcohol, until such action 
occurred. All samples which did not show coagulation with alcohol 
at the outset were held in a water bath at 35° to 37° C. (95° to 
98.6° F.) during subsequent observations. A tabulation of 211 
samples of milk handled according to the method outlined shows 
conclusively that there is no direct relation between the coagulation 
of the milk with 75 per cent alcohol and the acid content of milk 
as measured by the titration method. 
