198 
ON RUNNET AND CHYMOSINE. 
energetic as runnet; that is to say, the quantity of chymosine 
extracted from a given amount of runnet, will not reproduce 
the same amount of runnet. This action proves only that the 
property is not destroyed in chymosine when isolated. 
Water acidulated with sulphuric acid. &c, separates from 
the chymosine the phosphate, which precipitates with it. 
A solution of chymosine is precipitated by all the alkalies, 
the carbonates of potassa and soda, ammonia, and by tannin. 
Iodic acid is decomposed and iodine liberated, when pour- 
ed into this solution. 
Chymosine burns with flame, and leaves a brilliant char- 
coal. 
I may conclude from the preceding statements : 
That the name runnet applies to the mucous membrane of 
the stomach ; 
That runnet may be concentrated without alteration ; 
That runnet does not act upon milk in consequence of the 
acid which it contains, because it operates after saturation, be- 
cause the heat of the solar rays, and a temperature of 60° c, 
deprive it of this power, and because heat produces on the 
mucous membrane an effect similar to that upon runnet ; 
That chymosine is the active principle of runnet; 
That the action of isolated chymosine cannot be attributed 
to the acid used to dissolve it ; 
That chymosine is secreted by the mucous membrane of the 
stomach ; 
That the quantity of chymosine necessary to coagulate 
1000 grammes of milk is excessively feeble, since it may be 
effected by eight drops of liquid runnet, and since a portion 
of mucous membrane of the stomach of a calf, perfectly exhaust- 
ed, did by the assistance of 45° c, coagulate 1800 grammes of 
milk ; 
That the acidity of the runnet favors its action; 
That a temperature of 20° to 25° c, is very favorable to the 
action of runnet ; 
That chloride of soda acts as a stimulant on the mucous 
