DETERMINING QUALITY OF MILK FOR CONDENSERIES. 11 
A composite sample of the milks showing coagulation with alcohol, 
along with a sample of that showing no coagulation, was run in 
the laborator} 7 apparatus as a means of comparison. Out of 4 trials 
the raw milk showing coagulation with alcohol gave an evaporated 
milk that in all 4 cases showed curdiness after sterilization at the 
standard temperature, while the evaporated milk from the raw 
milks showing no coagulation with alcohol showed curdiness in 3 
out of 4 cases. The 4 batches of milk, the individual cans of which 
showed no coagulation with alcohol and which were run in the 
large factory pan, all showed curdiness after sterilization. Several 
laboratory runs made on milk taken from the large receiving vat 
at different times, to get representative samples of the milk received, 
failed in all instances to give an evaporated milk that would meet 
the required standard and not show curdiness after sterilizing and 
shaking. 
The general failure of milk, accepted on the acid test at this con- 
densery, to withstand the necessary heat after being evaporated, 
suggested that it might be due to a deficiency in the composition 
and balance of milk salts, as reported by Sommer and Hart (2). 
The fact that the addition of a small amount of dibasic potassium 
phosphate, which is a normal constituent of milk, corrected the 
excessive tendency of the milk to curdle in sterilization indicates 
that this assumption was correct. 
Consideration of the manner in which milk at this plant was 
handled, in connection with the results obtained, indicates that the 
conditions were quite different from those that the average con- 
densery has to contend with, and for this reason it appeared highly 
desirable to try out the alcohol test at another place. 
WORK AT FACTORY B. 
The work was then continued in a condensery, designated Factory 
B, located in a region where dairying forms a minor part of the 
farm operations. As a result of this condition the milk received 
was not of good quality. All the work done at this plant was on a 
commercial basis, the milk being graded at the intake and run into 
separate tanks according to its reaction with alcohol. Separate runs 
of the milk showing, respectively, coagulation and no coagulation 
with alcohol, were made in the factory pans, and after retaining the 
required amount of each batch of evaporated product for the experi- 
mental work, they were mixed in one tank and handled in the usual 
manner by the factory. Because of the small proportion of milk 
received that showed coagulation with alcohol, the batches from this 
kind of milk were smaller and in some cases it was necessary to hold 
them over until the next day in order to get enough for a run in the 
