134 PHYSIOLOGY OF ALIMENTATION. 



and may at the end of twenty-four hours be filtered off. 

 After washing in 96 percent, then 100 percent alcohol, and 

 finally with ether, the precipitate is dried over sulphuric acid. 



The antiproteinase obtained in this way is a somewhat 

 sticky powder w y hich is readily soluble in water, and which is 

 still contaminated with some impurities. The isolation of the 

 antiferment is accompanied by a falling off in its activity. 

 The activity of the alcohol-precipitated antiproteinase when 

 redissolved in water is less than half that of the original juice 

 obtained from extraction of the ground-up worms. 



The following experiments carried out with fibrin obtained 

 from pig's blood, which is exceedingly sensitive toward pro- 

 teolytic ferments, may serve to show how markedly anti- 

 proteinase inhibits the action of alkali- and acid-proteinase. 



Exp. A. Two tubes each containing 8 c.c. water, 0.04 gm. sodium 

 carbonate, 0.015 gm. alkali proteinase, and several pieces of fibrin, but 

 the one in addition 7 c.c. of ascaris extract, the other an equal amount 

 of water, are both put into the incubator at 37 C. At the end of two 

 hours the fibrin in the tube containing no ascaris extract (antiprotein- 

 ase) has entirely disappeared. The fibrin in the tube containing the 

 antiproteinase is still entirely unchanged after six days, and even on 

 the eleventh day of the experiment one-third of the fibrin is still un- 

 digested. 



Exp. B. Two tubes each containing 7 c.c. water, 0.23 gm. hydro- 

 chloric acid, 0.015 gm. acid-proteinase, and several pieces of fibrin, but 

 the one 8 c.c. of ascaris extract, the other an equal amount of water, 

 are put into the incubator at 37 C. The fibrin in the tube contain- 

 ing no antiproteinase is dissolved at the end of one hour. The fibrin 

 in the tube containing the ascaris extract is unchanged on the fourth 

 day, and on the ninth day only a trace of the fibrin seems to have been 

 dissolved. 



Antiproteinase is comparatively sensitive toward heat. 

 Boiling for one and a half minutes suffices to entirely do away 

 with the protective properties of an ascaris extract. Heating 

 for ten minutes to 60 C. does not injure the antiproteinase, 

 but heating for the same length of time to 80 C. reduces its 



