SNAKE VENOM 319 



The cobra, after having bitten, remains attached for a short time while the 

 daboia strikes with the greatest rapidity and immediately releases itself. 



Cobra and krait bites (colubrine snakes) produce more or less 

 similar symptoms such as paralysis of articulation with nausea and 

 vomiting and later paralysis of the respiratory apparatus. There is 

 only an insignificant reaction at the point of bite. 



The venom is mainly neurotoxic, causing death by paralysis of cardiac and re- 

 spiratory centers. Cobra venom is also very haemolytic. This haemolysin is acti- 

 vated by the normal complement of the serum of the animal poisoned, the haemolysin 

 as contained in the venom not being toxic when alone. Lecithin also has the 

 property of activating the hemolytic amboceptor of venom. 



In rattlesnake bites (viperine snakes) there is marked pain at the 

 site of the wound with much swelling and haemorrhagic infiltration. 

 The swelling and petechial mottling spread up the limb from the point 

 of entrance of the venom. Cold sweats, nausea, weak heart, and syn- 

 cope are common. 



Rattlesnake venom is active chiefly on account of it's haemorahagin or rather 

 endotheliolysin, which destroys the endothelial lining of blood-vessels. 



Venoms may also contain proteolytic ferments which may account for the 

 softening of muscles in snake bite cases. The toxic effect of the venom takes place 

 without an appreciable incubation period, hence different from true toxins. 



The most venomous snakes seem to be the sea-snakes (Enhydrina). This 

 venom is almost entirely neurotoxic. 



The tiger snake of Australia is almost equally venomous and the krait (B. 

 cceruleus) next. The rattlesnake is about one-fifth as venomous as the krait. 



Certain venoms greatly increase the coagulability of the blood so that intravas- 

 cular thromboses may occur. It is chiefly with the venoms of Daboia and Bun- 

 garus that such thromboses are likely to occur and this accounts for the almost 

 instantaneous death which at times results from bites of such snakes. 



The nonspecific treatment of snake-bite poisoning is i. by applying a tight 

 ligature above the site of the bite. The ligature, which should preferably be a 

 rubber band, is to be applied about a single bone extremity, not about one with 

 two supporting bones. 2. The making of deep incisions about the fang punctures 

 and thorough irrigation with a strong solution of potassium permanganate. Rogers 

 has recommended that the punctures be enlarged with a lancet and the resulting 

 wound packed with crystals of permanganate. 



Recently Bannerman has shown that a dog bitten by a cobra cannot be saved 

 by free incision and the rubbing in of permanganate crystals. It may however be 

 saved by the immediate injection of 10 c.c. of a 5% solution of permanganate, but 

 not if two minutes has elapsed. Bites from the daboia are fatal, however the per-' 

 manganate be applied. 



He therefore does not consider the permanganate treatment of any practical 

 value. Rogers thinks that Bannerman's experiments with dogs do not give a true 



