248 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



protection against venom and vice versa. The serums of animals naturally 

 refractory to the toxins rarely possess antitoxic properties against these toxins. 

 They took these facts as in favor of the vital theory. 



A little later C. J. Martin and Cherry * demonstrated the chemical nature 

 of the reaction of venom and antivenin by means of filtration. They pre- 

 pared the mixture of venom and antivenin in neutral proportion and allowed 

 it to stand for a certain time at 37° C, after which it was filtered through a 

 porcelain bougie covered with gelatin. The filtrate was harmless, showing 

 that the venom, which should have passed through, had been previously 

 destroyed. 



The same authors ^ also showed that if the neutral mixture of venom and 

 antivenin is heated within 10 minutes after its mixing the venom is present 

 still undestroyed by the antivenin, as the heated mixture is quite lethal. On 

 the other hand, the toxic action of venom does not reappear if the mixture is 

 heated after 20 minutes or later. These experiments are regarded as con- 

 clusive for the chemical nature of the interaction of venom and antivenin, 

 which has lately been accepted by Calmette.^ 



Stephens and Myers * studied the effects of antivenin upon the haemolytic, 

 anticoagulating, and toxic properties of cobra venom and showed that the 

 neutralization of the first two biological properties of the venom can be effected 

 in vitro, looking upon this phenomenon as conclusively chemical. 



REGENERATION OF VENOM AND ANTIVENIN FROM THEIR NEUTRAL 



COMBINATION. 



In 1905 and 1906 Morgenroth made some interesting observations concern- 

 ing the interaction of venom and antivenin. He^ first showed that the neutral 

 mixture of cobra venom and antivenin has no power to enter combination 

 with lecithin to form haemolytic lecithid, but if a small amount of the normal 

 solution of hydrochloric acid is added to such mixture the lecithid is formed. 

 Then he " demonstrated another important phenomenon. If a small amount 

 of hydrochloric acid is added to the neutral mixture of venom and antivenin, 

 there appears after heating the whole to 100° C. for 30 minutes, in the heated 

 fluid at least half of the amount of the neurotoxin originally introduced. The 

 failure of total regeneration of the neurotoxin is ascribed by him to the irrep- 

 arable modification of the toxin molecule under the action of its antitoxin. 



In the first instance, hydrochloric acid modified the haemolytic amboceptor 

 so as to prevent combination with antitoxin, but still permitting union with 

 lecithin. Lecithid, which is formed by subsequent addition of lecithin to the 



» C. J. Martin and Cherry. The nature of the antagonism between toxins and antitoxins. Brit. Med. 



Jour., 1898, II, 1 1 20. 

 2 C. J. Martin and Cherry. Proc. Roy. Soc, 1898, LXIII, 420. C. J. Martin. Relation of the toxin 



and antitoxin of snake venom. Proc. Roy. Soc, 1899, LXIV, 88. 

 ^ Calmette. Les venins. Paris, 1907, 766. 

 ^ Stephens and Myers. Test-tube reactions between cobra toxin and its antitoxin. Brit. Med. Jour., 



1898, II, 627, and also: The action of cobra poison on the blood, a contribution to the study 



of passive immunity. Jour, of Path, and Bact., 1898, V, 279. 

 5 Morgenroth. Ueber die Wiedergewinnung von Toxin aus seiner Antitoxinverbindung. Berl. kiln. 



Woch., 1905, XLII, 1550. 

 " Morgenroth. Weitere Beitrage z. Kenntnis der Schlangengifte und ihrer Antitoxinen. Arbeiten aus 



dem patholog. Institut zu Berlin, 1906, 437. 



