ANTIBODY OF INTESTINAL WO EMS. 481 



2 c.o. Trypsin + c.c. W. extract = 13 

 ,, i. + '1 c.c. ,, = 12 



+ "2 ,, -11 



+ "3 =10 



,, + '4 ,, =9 



,, + '5 ,, ,, =8 



2 c.c. Trypsin + -6 c.c. W extract = 6 



+ -7 =4-5 



+ '8 =3 



+ '9 =1 



+1'0 =0 



Each mixture was made up to 3 c.c. with water. Gelatine tubes and a drop of toluol 

 were added to each. The digestion in mm. after 16 hours is given opposite each mixture. 



That the trypsin used contained no enterokinase free to such a 

 degree as to be able to activate pancreatic juice was proved by adding 

 1 c.c. trypsin to 2 c.c. pancreatic juice ; and 1 c.c. to 2 c.c. water. 

 Gelatine tubes were digested with equal rapidity in both mixtures, thus 

 proving that the pancreatic juice had not been activated. Similar 

 experiments with other commercial trypsins have yielded exactly similar 

 results ; no trace of free enterokinase could be detected in any of them. 

 Nevertheless, Dastre and Stassano (3) , adhering to the conception of 

 the dual nature of trypsin, believe that enterokinase exists in trypsin, 

 although modified to some extent in combination. They assert that the 

 slowing and ultimate cessation of proteolysis which occurs as successive 

 portions of proteid are added to an activated pancreatic juice (trypsin) 

 are due to the using up of one or other of the components of the trypsin, 

 and that such exhausted trypsin can be restored to activity by the 

 addition of enterokinase or inactive pancreatic juice. 



To test this the following experiments were performed : 



5 grs. of gelatine were added to 20 c.c. trypsin ; and 20 c.c. of the same trypsin were 

 kept as a control. Toluol was added to each. After the lapse of a week the following 

 mixtures were made and gelatine tubes added. 



Dig. in. mm. 



2 c.c. Ex. T. + l c.c. Ek =1 

 2 c.c. Ex. T. + l c.c. B.Ek = l 

 2 c.c. C.T. +lc.c. Ek =4-5 

 2 c.c. C.T. + 1 c.c. B.Ek = 4-5 



Dig. in mm. 



2 c.c. Ex. T. + l c.c. PJ = 1 

 2 c.c. Ex. T. + l c.c. B.PJ = 1 

 2 c.c. C.T. +1 c.c. PJ =4-5 

 2 c.c. C.T. +lc.c. B.PJ = 5-0 



Control. 2PJ + 1 drop Ex. T. = 0. 



The tubes were measured at the end of 16 hours. 



Ex. T. = " exhausted " trypsin; C.T. = control trypsin; B.Ek = boiled enterokinase; 

 B.PJ = boiled pancreatic juice. 



We see that it is a matter of complete indifference whether we add 

 enterokinase and pancreatic juice, or boiled enterokinase and boiled 

 pancreatic juice to the exhausted trypsin. Obviously, therefore, entero- 

 kinase and pancreatic juice are incapable of restoring proteolytic activity 

 to an "exhausted" trypsin solution. Bayliss (5) has shown that dilution 



32 2 



