02 
Composition of Cheese. 
Result : Curd separated in 20 minutes ; whej Lad the same 
reaction as milk. 
The experiment was repeated, and found correct. 
It will thus appear that too high a temperature is not so favour- 
able to the coafjidation of the milk as a less elevated one. 
The separation, which at 12(^° took place in 10 minutes, at 130° 
occupied 20 minutes. 
'dtli Exp. — Heated 1 pint of milk to 150°, added \ ounce of 
rennet. 
Result: Milk did' not coagulate after 24 hours. 
10//( Exp. — Heated milk to 140°, added rennet. 
Result : No coagulation. 
11^/i Exp. — Heated milk to 135°, added rennet. 
Result : No coagulation took place, even after 3 hours. I then 
added another J ounce ; the milk by this time had cooled 
down, and the fresh quantity of rennet caused the separa- 
tion of curd in less than 20 minutes. 
Thus, at 120°, milk coagulates most readily ; at 130°, it takes 
a somewhat longer time ; and at 135°, and upwards, it ceases to 
coagulate. 
\2tli Exp. — Heated 1 pint of milk to boiling-point, added ounce 
of rennet. 
Result: No curd had separated when examined, after 24 hours' 
standing. 
13/A Exp. — Heated another pint of milk to boiling-point, and 
added \ ounce of rennet. 
Result : Milk did not coagulate after 24 hours. I then 
added a little more fresh rennet to the cooled milk, and 
again gently heated it, when the curd separated in less 
than \ hour. 
Thus the temperature of boiling water, and even a much lower 
heat, destroys the action of rennet, but docs not so permanent!}- 
change the casein of milk that it cannot be separated. 
The whey in the last experiment, again, was neutral, like the 
milk. 
l^th Exp. — To 1 pint of fresh milk I added 10 grains of car- 
bonate of potash, raised the temperature to 88° Fahr., and 
added \ ounce of rennet. 
Result : Curd separated in ^ hour. The milk and the whey 
were strongly alkaline. After 24 hours the whey was 
neutral, and then it became acid by degrees. 
l^th Exp. — To 1 pint of milk I added 20 grains of carbonate of 
potash, heated to 90° Fahr., and added ^ ounce of rennet. 
