484 



J. M. HAM ILL. 



factorily on the assumption that worm extract possesses antitryptic 

 powers only. 



I will now pass to experiments devised with the object of proving 

 in a positive manner that worm extract can function as an antitryptic 

 agent only. 



Series (a). '5 c.c., 1 c.c., 1-5 c.c., and 2 c.c. W were each added to separate lots of 



1 c.c. Ek and the whole left for 4 hours at 15 C. 1 c.c. Ek without W (WO) was kept as 

 a control. At the end of 4 hours, 2 c.c. PJ were added to each and the volume of liquid 

 made equal in each flask by the addition of water. 



Series (b). -5 c.c., 1 c.c., 15 c.c., and 2 c.c. W were each added to separate lots of 



2 c.c. PJ at the same time as the corresponding operation was performed in (a) and left 

 for 4 hours at 15 C. 2 c.c. PJ without W (WO) were kept as a control. At the end of 

 4 hours 1 c.c. Ek was added to each and the volume of the liquid made equal in each flask 

 by the addition of water. Gelatine tubes aud toluol were added to (a) and (b). After the 

 lapse of 20 hours the tubes were measured with the following result : 



Series (a) 



WO 



W-5 



Wl-0 



Wl-5 



W2-0 



Mm. of gel. digested 

 12 

 11 

 10 



7 



2 



Series (b) 



WO 



W-5 



Wl-0 



Wl-5 



W2-0 



Mm. of gel. digested 



12 

 : 11 



10 



: 7 



* 3 



Digestion proceeds equally in both (a) and (b}. If the antibody 

 were antikinasic in nature- we should expect to find a difference in 

 digestive power between (a) and (b) such as Bayliss and Starling 16 ' 

 obtained when using an antikinasic serum prepared by injecting animals 

 subcutaneously with enterokinase solutions. We find, however, that it 

 is a matter of complete indifference in which order the worm extract is 

 added to the mixtures ; that, in fact, the worm exerts its activity only 

 when trypsin is formed; that is to say, is antitryptic only. 



Further investigation on entirely different lines leads us to the 

 same conclusion, namely, that worm extract possesses no antikinasic 

 power. If worm extract be added to a trypsin solution in such quantity 

 as just to inhibit the activities of the latter, addition of enterokinase 

 to this neutral mixture should (if the worm antibody has any affinity 

 for enterokinase) cause a redistribution of the antibody in such a way 

 that it shares itself between the enterokinase and the trypsin in pro- 

 portion to its affinity for these two substances. If this occurred, some 

 of the trypsin would become unmasked, and gelatine tubes added to 

 the hitherto neutral solution would now undergo digestion. This was 

 tested in the following way : 



