OF THE VENOM OF THE RATTLESNAKE. 79 



Ea-periment. — A large frog wfis poisoned with woorara. This active agent 

 possesses the power to paralyze the motor nerves, and to leave the muscles in a 

 highly irritable state.^ The animal was thus placed in the same condition as though 

 the whole motor nervous system had been removed by dissection, without serious 

 injury to the remaining parts. It was found that in a frog so prepared, and in 

 which the motor nerves no longer responded to irritants, the muscles still quivered 

 as long as usual when bitten by the snake, so that I felt free to infer that this 

 interesting local phenomenon was in reality due to the direct influence of the 

 venom upon the ultimate sarcous elements. 



After a few minutes, or at the utmost, half an hour, these spasmodic movements 

 cease; but without entirely exhausting the irritability of the muscles, which will, 

 sometimes, continue to respond to other stimulants until their structure is more 

 profoundly altered by the continued action of the veu9m. The quivering often 

 extends to the whole muscular system, but although a frequent, this is not an in- 

 variable symptom, and is liable, in dogs, to be confounded with the fremitus of 

 terror, to which they are very subject. It is in them a more common symptom of 

 the poisoning than it is in rabbits, while in birds the general quivering is very 

 rarely met with. 



The influence of the venom upon the duration of muscular irritability I have 

 examined in many animals, but especially in frogs. Many of these observations 

 were made in very hot weather, but were finally resumed in the early autumn 

 under more favorable conditions for the preservation of the muscular functions. 



Both in the cases of acute and of chronic poisoning, the muscular irritability of 

 the frog was lost earlier than is usual in other modes of death. 



Notwithstanding this result, the property in question was perfect at the time of 

 the death, and for a short space afterwards, especially in acute cases, while, in some 

 rare instances, it survived in the chin muscles during twentj'-four houi's. 



The muscular irritability of the warm-blooded animals left them very rapidly, 

 but was often so well marked at, or just after, death, as to forbid us to refer the 

 death to the loss of muscular irritability as the immediate, or even the remote 

 cause. 



Rigor Mortis. — The action of the venom did not seem to prevent the occurrence of 

 the strongest rigor mortis. It came on in different animals at varying periods, but, 

 so far as I have observed, was never entirely absent in any case. Even when the 

 blood was perfectly diflluent, this post-mortem phenomenon was noted, a fact which 

 should utterly forhid us to connect its occurrence with the coagidation of the blood, as 

 teas at one time a not uncommon opinion. 



Ultimate Effect of Venom on Muscles. — The final influence of venom upon the 

 muscular structure was extremely curious. In every instance it softened it in pro- 

 portion to the length of the time during which it remained in contact with it, so 

 that after even a few hours in warm-blooded animals, and after a rather longer 

 time in the frog, the wounded muscle became almost diffluent, and assumed a dark 



' CI. Bernard, Legons sur les effets des substances toxiques et medicamenteuses. Bailliere et fils. 

 Paris, ISST, p. 239 et seq. 



