New YorK AGRICULTURAL EXPERIMENT STATION. 175 
Table I shows our cheeses to be normal in composition. The 
low water and high fat figures are due to the fact that we used 
whole milk which was rich in fat, aad also to the fact that in 
Europe in some factories, it is said, the milk is first separated and 
then remixed in order to give a milk with a lower fat content. 
It will be noticed that our figures agree very closely with those 
given by Duclaux. 
Table II shows that there is no dennis standard by which to be 
guided when we come to examine the amount of nitrogen in the 
different groups of nitrogen compounds. A wide variation is found 
among cheeses known to be true camembert cheeses and of good 
quality. This we should expect; for when we are considering a 
question where enzyms are concerned there are many factors 
which influence the activity and no two cheeses could be handled 
in such a manner as to give the same absolute results. 
The main point in this connection is to secure a type of proteolysis 
similar in action to that in true camembert cheese. This has been 
done, as Table II shows. The details of controlling this to secure 
uniform results is another problém which is left to the practical 
cheese maker. 
CHEMICAL CHANGES IN CHEESE. 
RENNET. 
The rennet when added to the milk causes the casein to coagu- 
late. This precipitate, or curd, carries down with it most of the 
fat and some of the milk sugar, together with some of the inor- 
ganic salts. In this type of cheese this seems to be the only func- 
tion of rennet. 
BACTERIA. 
In order to study the chemical changes due to bacterial action 
two sets of cheeses were made and examined and the results are 
given in Tables III, 1V and V. The figures in Table IV are 
obtained from those in Table III and will be readily understood. 
The first set of cheeses was made as follows: Milk from the 
previous evening’s milking was heated to 86° F. and a small 
amount of starter added. Rennet was added in amount to curdle 
to the proper thickness in one and a half hours. The curd was 
then cut, allowed to stand in the whey one half hour, and then 
