New York AGRICULTURAL EXPERIMENT STATION. 173 
will hold its own form. It is then rolled in salt, and carried to the 
ripening room, where it remains during the process of ripening, 
being turned occasionally to insure an even growth of mold on the 
surface. This ripening requires about four to five weeks to become 
coniplete, during which time the cheese is changed in texture and,» 
composition. The active agent, an enzym produced by the mold 
which grows upon the surface of the cheese, begins to produce 
proteolysis at or near the surface and works toward the center of 
the cheese until the entire curd has been acted upon, being trans- 
formed from a compact, insoluble curd to a soft, creamy mass which 
is very soluble in water. With this change a peculiar flavor de- 
velops, characteristic of this type of cheese. 
METHODS OF ANALYSIS. 
Van Slyke and Hart? have published methods for the separa- 
tion of the groups of proteolytic compounds found in cheddar 
cheese. For comparative studies their methods serve very well 
and have been used for the work contained in this paper, with 
but slight modifications. As the cheese is cylindrical in form, 
being about 4 inches in diameter and one and one fourth inches 
high, a sample the whole thickness of the cheese was taken for 
analysis. In taking a sample. therefore a wedge-shaped piece, 
weighing about 25 grams, with the apex at the vertical axis of 
the cheese, was taken. This was placed in a covered dish, 
weighed, and then rubbed up in a mortar with two successive 
portions of 200 cc. each of water. This was then heated in a 
water bath at 50° C. for half an hour, with occasional shaking, 
the supernatant liquid decanted onto a cotton filter and the 
extraction continued with 150 cc. portions of water until 1,000 
cc. of solution was obtained. 
To secure the salt extract, the residue from the water extract 
was treated with a 5 per ct. salt solution in the same manner 
as described for obtaining the water extract. 
In determining peptones, tannic acid was always used. In 
this case 100 cc. of the water extract was placed in a 500 cc. 
flask, diluted to about 400 cc. and salt and tannic acid added 
according to the methods mentioned above, and allowed to stand 
over night. It was then made up to the 500 cc. mark filtered, 
and 100 cc. portions used for the determinations. : 
Phosphotungstic acid was tried but seemed to possess no par- 
ticular advantage for the work. ] 
2N. Y. Agri. Expt. Sta. (Geneva) Bul. 215. 
