250 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



compound of serum and venom possesses entirely different properties from 

 those of its components. 



The theory of dissociable combination of toxin and antitoxin must there- 

 fore be admitted. 



Teruuchi 1 studied the effects of pancreatic digestion upon the neutral 

 compound of cobra venom and antivenin. For the test reaction he used the 

 haemolytic action in the presence of an adequate quantity of lecithin as acti- 

 vator. He first found that the haemolytic power of the venom and the anti- 

 haemolytic power of the antivenin are largely destroyed by the pancreatic 

 ferment, but the activating property of lecithin and the haemolytic power of 

 lecithid are not at all affected. 



Then he prepared a neutral mixture of venom and antivenin, which, after 

 2 hours at room temperature, and 48 hours further on ice, was subjected to 

 the digestion. The result showed that about one-tenth of the original haemo- 

 lytic strength was recovered through the digestion, the liberated amount 

 being somewhat larger than one would expect from the digestion of pure 

 solution of venom under the same conditions. This may be due to the fact 

 that the serum proteins of antivenin have been attacked more readily than 

 cobra venom and the destructive action of the ferment on the latter is some- 

 what restrained. 



The restitution of haemolytic principle by the pancreatic digestion of the 

 neutral mixture of venom and antivenin did not take place when lecithin had 

 previously been added to the mixture and allowed to stand 48 hours on ice. 



THE EHRLICH-MADSEN PARTIAL SATURATION PHENOMENON IN 

 VENOM-ANTIVENIN REACTION. 



Strictly quantitative experiments aiming at gaining a more profound insight 

 into the mode of interaction between snake venom and its antivenin were 

 first made by Walter Myers. He employed the partial saturation method of 

 Ehrlich and Mad sen, originally introduced for the study of the constitution 

 of diphtheria toxin and tetanolysin. Myers used the haemolytic power of 

 cobra venom as the test-reaction. The mixtures of venom and antivenin 

 were allowed to stand at laboratory temperature for 2 hours before testing 

 their action on blood. In order to neutralize 0.001 gm. of this venom for 

 haemolysis 1.3 c.c. of antivenin were required. The results obtained from 

 the partial neutralization showed that when one-thirteenth of the serum is 

 necessary to neutralize the cobralysin, the minimal hasmolyzing dose rises 

 from 0.000005 gm. to 0.000025 gm., a quantity 5 times as great. The venom, 

 in other words, has lost four-fifths of its toxic action. On adding 0.2 c.c. of 

 serum or two-thirteenths of the serum necessary for complete neutralization 

 the minimal hamolyzing dose rises to 0.00005 gm., or nine-tenths of its 

 haemolytic power has disappeared. 



1 TVnmrhi Die Wirkung des Pankreassaftes auf das Hamolysin des Cobragiftes und seine Verbin- 

 dun'gen mit dem Antitoxin und Lecithin. Hoppe-Seyler's Zeitschrfft £. Physiol. Chemie, 

 1907, LI, 478. 



