154 REPORT OF THE CHEMIST OF THE 
due to the same causes in both camembert and cheddar cheese; 
the only essential difference is the extent of the changes, which 
go somewhat farther in camembert than in cheddar cheese. This 
is what would be expected from differences in the methods of 
manufacture, since camembert cheese is made without under- 
going pressure to expel whey and it therefore contains more 
lactose, resulting in the formation of more lactic acid, which is 
the active agent in causing the first changes that appear in the 
cheese-making process. 
Reviewing briefly the interpretation of the results secured in 
the work previously done? it was thought (1) that the calcium 
paracasein, formed from calcium casein of milk by the action 
of rennet enzym, was converted by the action of lactic acid into 
free paracasein with simultaneous formation of calcium lactate, 
that is, the calcium paracasein was decalcified; (2) that the free 
paracasein thus formed was soluble in warm 5 per ct. solution 
of sodium chloride; (3) that the proteids of cheese-curd and 
cheese fresh from the press were a mixture, in varying propor- 
tions, of calcium paracasein and free paracasein, a maximum ot 
78 per ct. of the total nitrogen of the cheese having been found 
in the form soluble in dilute salt solution; (4) that not all of the 
calcium paracasein was changed into free paracasein; (5) that 
the plastic and ductile properties of cheese-curd were due to the 
formation and presence of free paracasein; (6) that free para- 
casein appeared to be the body in which began to take place the 
various chemical changes grouped under the general term of 
cheese-ripening. 
It now appears, as we shall show later, that a lack of knowi- 
edge as to the extent and character of changes occurring in 
cheese while in press led to an interpretation of results that must 
be very materially modified in order to harmonize with our: 
recent work. 
Another point of importance, not studied in previous work at 
this Station is the relation of some of the inorganic salts to the 
changes taking place in the early history of cheddar cheese. 
Somewhat extended and detailed studies of the calcium and 
phosphoric acid compounds have been made in some of our work 
and the results are presented in this bulletin. These results are 
intimately associated with the changes taking place in the chief 
proteid in the early history of cheese and appear to be essential 
to a correct understanding and interpretation of these changes. 
*N. Y. Agri. Exp, Sta? Buls 261,-pp.: 36; 37. 

