
230 REPoRT OF THE CHEMIST OF THE 
layer. In the sixth experiment, the third whey was lost by 
accident before being sampled. 
Analysis of curd.— In several of the experiments, the curd was 
analyzed, but as it proved difficult to get representative samples, 
the analysis was abandoned. The chief difference in composition 
between the curd and green cheese is mainly in moisture and salt, 
and, in a much lesser degree, in fat and nitrogen compounds. 
Analysis of cheese-—In six experiments, the first analysis of the 
cheese was made when the cheese was seven days old; in two 
experiments, the green cheese, as it came from the press, was 
sampled for analysis. In all experiments, each cheese was 
analyzed at the age of seven, twenty-one and thirty-five days, in 
order to ascertain the general changes taking ae before cheese 
goes to market, 
DIFFICULTIES CONNECTED WITH THE INVESTIGATION. 
The principal source of difficulty in carrying on the work has 
been the sampling of cheese for analysis. It is highly desirable 
to get for analysis such a sample as will fairly represent the com- 
position of the whole cheese. If a cheese could be cut up and 
portions selected here and there, the difficulty would be largely — 
removed. But where it is necessary to preserve the cheese to 
continue the study of its composition through a period of several 
months, such a course is not feasible. The only practicable 
method and the one employed has been to use a regular cheese- 
trier, which takes out a cylinder of cheese about six inches long 
and five-eights of an inch in diameter. The samples were taken 
from the cheese at points about half way between the center and 
circumference of the flat surface or face of the cheese. The 
cylinders thus taken are cut up into very thin pieces and the 
whole mixed carefully, pains being taken to prevent loss of mois- 
ture in the operation. From samples thus prepared, portions are 
weighed out for analysis. By comparing the pounds of constitu- 
ents in the cheese as given by analysis of different samples of the 
same cheese, it will be noticed that in several instances the 
results are not consistent. For example, in the sixth experiment, 
the amount of’ casein in the cheese as obtained by analysis of 
different samples, taken at different times, is as follows: In green 
cheese, 9.1 pounds; in cheese seven days old, 8.68 pounds; in vig 

