POISON OF SOME INDIAN VENOMOUS SNAKES. 49 



This experiment shows that the venom paralyses the motor 

 nerves when applied to them locally, a strong current applied 

 to the sciatic causing no contraction in the left leo- of No 1 

 while a moderate one caused movement in the right foot, at 

 a time when the muscles of both were nearly equally irritable. 



Its deleterious action on the muscles, when conveyed by the 

 blood, is also evident in the rapid loss of irritability after 

 death in both legs of No. 1 as compared with No. 2. The pale 

 muscles seemed to retain their irritability longer than those 

 having a doep colour. 



The power of cobra-poison to paralyse muscle when applied 

 to it, even in a diluted condition, is shown by th.e following 

 experiment. 



Experiment XXVI. 



July 18th, 1873. — The legs of a large frog were cut off close 

 to the body, and the skin removed. Each was then placed in 

 a glass, and a sufficient quantity of fresh ox-blood serum 

 poured over it to cover it. In one glass, the serum contained 

 about 5 centigrams of cobra-poison dissolved in about 20 c.c. of 

 serum ; but, with this exception, all the conditions under which 

 the two legs were placed were exactly alike. 



July 19th. — About 19 hours after the immersion of the leo-s 

 in serum their irritability was examined. 



The muscles of the leg in the pure serum did not contract at 

 all when the strongest irritation was applied to the sciatic 

 nerve, but contracted very vigorously when irritated directly. 

 The muscles of the leg in the poisoned serum were whiter than 

 those of the other one. They had a faint yellowish tinge, and 

 were somewhat stiff. They did not contract in the least when 

 the strongest irritation by a Du-bois coil was applied either to 

 them or the sciatic nerve. 



. When the poison is injected directly into the circulation, or 

 is very rapidly absorbed, so that the quantity circulating in the 

 blood is large, it destroys the irritability of the voluntary 

 muscles rapidly, and, occasionally at least, liastens in a most 

 remarkable manner the occurrence of rigor mortis. This is 

 well seen in the Experiment XXV, wtiere rigor mortis super- 

 (95) E 



