The nature of the coagulation is not yet completely understood.
If the latex is warmed or an acid, an alkali or astringent plant juice is added to it, " coagulation " usually takes place more or less readily, the caoutchouc separating in solid flakes or curds.
The efficacy of heat or of an acid, an alkali or other agent in promoting coagulation depends on the character of the latex, and varies with that obtained from different plants.
When exposed to air the latex gradually undergoes putrefactive changes accompanied by coagulation of the caoutchouc. The addition of a small quantity of ammonia or of formalin to some latices usually has the effect of preserving them for a considerable time.
The salts of iron quickly cause coagulation of the blood, and the clot plugs the bleeding vessels.