82 



VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



Thus in Crotalus adamanteus 24.6 per cent, in Ancistrodon piscivorus 7.8 

 per cent, and in Cobra only 1.75 per cent of globulins were found present. 



In 1886 Norris Wolfenden published some interesting studies upon the 

 constitution of the venom of Naja tripudians and that of Daboia russellii. 

 He first denied the presence of Blyth's cobric acid, which he affirmed to be 

 nothing but calcium sulphate crystals. The bacterial as well as Gautier's 

 alkaloid theory has been completely discarded, the presence of alkaloidal 

 principles in crotalus venom being disproven before this by the Mitchell- 

 Gibbs experiments. Wolfenden first established that the toxic power of 

 cobra venom resides in the protein constituents of the secretion, and is lost 

 when the proteins are removed, and diminished as these are diminished. He 

 carefully sets up the possibility that the venomous body is something so 

 intimately linked to the proteins that it varies in intensity with the amount of 

 these bodies present and is precipitated, coagulated, or destroyed by all such 

 means as those which precipitate, coagulate, or destroy proteins. By employ- 

 ing the magnesium sulphate precipitation he succeeded in separating three 

 distinct proteins from cobra venom. 1 



Globulin: This was fractionated by saturating the venom solution with 

 MgSO 4 . It coagulates at 68 to 75 C. when in solution in water. It is not, 

 however, a pure globulin, but a mixture of acid albumin and globulin. Wolf- 

 enden states that the amount of acid albumin is very small and can be coagu- 

 lated, when the solution minus the coagulated globulin is heated again with 

 MgSO 4 . A precipitate is yielded by acid albumin upon the addition of 

 acetic acid and ferrocyanide of potassium. The prolonged dialysis of the 



1 Armstrong (quoted by Fayrer in Proc. Roy. Soc. Lond., 1884, 156) has made, in 1873, the following 

 analysis of cobra venom. 



Pedler held it possible that the poison is a mixture of albuminous principles with some specific poisons. 

 (Report of Commission on Indian and Australian Snake Poisoning, Calcutta, 1874.) His ele- 

 mentary analysis gives the following figures: C 52.87 per cent, H 7.1 per cent, N 17.58 per cent. 

 Liquid venom contained 27.74 per cent of solid matter and 6.68 per cent ash. Sir Joseph Fayrer 

 and Lauder Brunton compared the action of cobra venom to the alkaloid conin. (Loc. cit., 

 idem.) 



Lacerda at first considered the venom to be an organized ferment like bacteria, but later modified this 

 view only to adopt another enzyme theory in which venom is thought to be analogous to the 

 digestive ferment of the pancreas. His discovery that potassium permanganate stops the action 

 of venom came from the idea that oxidation destroys the ferment. 



Winter Blyth described a cobric acid as the sole toxic principle of cobra venom. It is not a protein, 

 but microscopic needles crystallized out from the alcoholic filtrate of the venom by means of pre- 

 liminary precipitation with acetate of lead, and then the removal of the lead with HsS and sub- 

 sequent evaporation in vacuo. Another method of Blyth is to shake up the alcoholic filtrate with 

 ether, removing the ether, evaporating it off, dissolving in water, passing through a wet filter, 

 and finally evaporating down. (The Analyst, 1877, I, 206.) 



