Nuw YorK AGRICULTURAL EXPERIMENT STATION. 83 
6. Artificial Digestion of Some Compounds of Casein and Para- 
casein contained in Cottage Cheese.—According to popular belief, 
fresh cottage cheese is more readily digested than cheddar cheese. 
To test this by laboratory methods, we have subjected to pepsin 
digestion, without hydrochloric acid and with hydrochloric acid 
in varying proportions, fresh cottage and cheddar cheese, in which 
we had one or more of the following substances: Paracasein, 
paracasein monolactate in cheddar cheese, paracasein dilactate, 
casein monolactate, casein dilactate (cottage cheese) prepared by 
normal souring of milk and also by direct addition of lactic acid 
to milk, and casein dihydrochloride. (1) In the absence of acid, 
paracasein fails to be digested by pepsin, while paracasein mono- 
lactate (the chief nitrogen compound of fresh cheddar cheese), 
paracasein dilactate, casein monolactate and casein dilactate 
(cottage, or Dutch, cheese) are partially digested. Paracasein 
monolactate and casein monolactate, in the absence of acid, are 
digested more than are paracasein dilactate and casein dilactate. 
(2) In the presence of 0.4 per ct. of hydrochloric acid, para- 
casein dilactate is digested by pepsin more than is paracasein 
monolactate. Paracasein monolactate and dilactate and casein 
monolactate and dilactate and casein dihydrochloride digest more 
readily and completely in the presence of free hydrochloric acid 
than in its absence. (38) Casein dilactate and casein dihydro- 
chloride do not differ in the rapidity and extent to which they are 
converted into soluble compounds by pepsin. (4) The addition 
of acid after the beginning of the digestion increases the amount 
of proteid digested, whether we use cottage cheese or cheddar 
cheese. (5) Cottage cheese made from whole milk digests more 
rapidly than that made from skim-milk, owing to the loose tex- 
ture of the former. Fat in such cases does not impede digestion. 
(6) The rapidity of digestion is dependent in part upon the fine- 
ness of division of the material to be digested. Cottage cheese 
as ordinarily consumed is in a state of finer division than cheddar 
cheese. (7) Cottage cheese may be properly regarded as more 
readily digestible than new cheddar cheese for two reasons :— 
First, the casein dilactate, the chief constituent of cottage cheese, 
is more digestible by pepsin in the presence of free hydrochloric 
acid than is paracasein monolactate, the principal nitrogenous 
