ANTIBODY OF INTESTINAL WORMS. 485 



It was found by trial that gelatine tubes placed in a mixture of 2 c.c. trypsin and 

 1'5 c.c. worm extract showed no sign of digestion at the end of five days. Therefore, 

 a mixture of 2 c.c. trypsin and 1-5 c.c. worm extract was taken as a neutral or balanced 

 mixture. To two lots of such a mixture (2 c.c. trypsin 4 1*5 c.c. W) were added 1 c.c. Ek 

 and 2 c.c. Ek respectively. A third portion without any Ek was kept as a control. The 

 volumes in all the flasks having been made equal by the addition of water, gelatine tubes 

 and toluol were added. At the expiration of four days no digestion had taken place in any 

 of the flasks ; at the end of the fifth day 2 mm. of gelatine had disappeared in each flask. 



It will be noticed that the neutrality of the mixtures persists for 

 a time, but that eventually their tryptic activities become manifest. 

 The mere disappearance of the inhibitory effect need not detain us in 

 this connection. It is, however, important to notice that it persists for 

 the same length of time in all the flasks, and that digestion, when it 

 does begin, proceeds with equal rapidity in all three mixtures. The 

 presence or absence of enterokinase in no way affects the balance between 

 antibody and trypsin. 



If then, as this experiment seems to show, the antibody devotes all 

 its energies to the suppression of tryptic activity, the addition of a small 

 quantity of a balanced mixture of pancreatic juice, enterokinase, and 

 worm extract to pancreatic juice should cause activation of the latter; 

 whereas, if the antibody were purely antikinasic no such activation 

 should occur. 



To test this, Ek, W, and PJ were mixed together, the amounts of W 

 being varied till a balance was attained. Finally, a mixture of 1 c.c. 

 Ek + 2'5 c.c. W + 2 c.c. PJ was found to remain inactive for five days. 

 Therefore, two lots of 1 c.c. Ek + 2'5 c.c. W + 2 c.c. PJ were made up ; 

 one, to which gelatine tubes were added, was kept up as a control ; half 

 of the other lot was added to 2 c.c. PJ after the lapse of 10 hours, and, 

 at the same time, a control of ^ c.c. Ek + 1'2 c.c. W + 3 c.c. PJ was set 

 up. Gelatine tubes were added to both mixtures. After the lapse of 

 16 hours digestion was equal in both flasks (6 mm.). The balanced 

 control showed no digestion. 



This experiment proves that in the balanced mixture the enterokinase 

 was not appropriated, either in whole or in part, by the antibody; that 

 is to say, c.c. of active enterokinase must have been added to the 

 2 c.c. PJ in order that digestion by both it and the control tube should 

 have been equal. Thus, here also the inhibition must have been purely 

 antitr^ptic in character. 



