New York AGRICULTURAL EXPERIMENT STATION. 103 
with 4, and the actual difference here was small. In the case of 
the cheese made from unpasteurized skim-milk, experiments 3 
and 7, we have a little more soluble nitrogen than in cheeses 2 
and 6, which were made from pasteurized skim-milk. There was 
little or no change in the amount of milk-sugar except in the case 
of experiment 5. Taking all our data into consideration, we 
are unable to see any marked evidence of proteolytic change. 
These results are not unexpected, since we should hardly expect 
to find just such changes occurring in cottage cheese as occur in 
cheddar cheese, because in one case our proteid is paracasein 
monolactate and in the other paracasein dilactate and the reac- 
tion is practically neutral in one case and decidedly acid in the 
other. 
STUDY OF ARTIFICIAL DIGESTION OF SOME COMPOUNDS OF CASEIN AND 
PARACASEIN CONTAINED IN COTTAGE CHEESE. 
There is a popular belief, which appears to have some founda- 
tion in experience, to the effect that fresh cottage cheese is more 
readily digestible than cheddar cheese, especially new cheddar 
cheese. It seemed desirable to ascertain by artificial digestion 
to what extent laboratory experiments are in harmony with this 
popular belief. We have worked with the following materials: 
Paracasein, paracasein monolactate of cheddar cheese, paracasein 
dilactate, casein monolactate, casein dilactate (cottage cheese) 
prepared by normal souring of milk and by direct addition of lac- 
tie acid to milk, and casein dihydrochloride. These materials 
have been treated with varying amounts of pepsin, with and 
without hydrochloric acid. Experiments were also made to study 
the influence of the fineness of the materials upon the rate of 
digestion. 
(1) Comparison of digestibility of paracasein and paracasein 
monolactate without acid The paracasein used in this experi- 
ment was prepared by coagulating fresh milk with rennet-extract 
and was carefully washed. Freshly prepared cheddar cheese, in 
which over 75 per ct. of the nitrogen existed as paracasein 
monolactate, was used as the source of this monolactate. The 
samples (25 grams) were ground with sand and in each of 
several bottles there was placed material equivalent to 0.694 gram 
