1874.] Poison of Indian Venomous Snakes. 91 



troduction of a solution of dried cobra-poison in water into the lymph-sac 

 on the back, at about 12.30 P.M. The irritability of the muscles was 

 tested by single induced currents applied to the denuded muscles, about 

 2.30. 



Distance of Coil. 



Left leg ; 7*5 .... Contraction. 



Eight leg 7-2-7-5 do. 



Another frog was curarized and similarly prepared, with this excep- 

 tion that the vessels of the right leg only were ligatured, the muscles, 

 as well as the nerve, being left free. This frog was also examined in 

 the same way; and the irritability of the muscles in both legs was 

 found to be almost exactly the same three to four hours after poisoning. 

 Both contracted with the coil at about 7'5. 



Secondary Action of the Poison on Muscles. 



The muscles of the part into which the poison has been introduced are 

 very apt to undergo rapid decomposition. "We have already shown that 

 their irritability is either lessened, or completely destroyed, by the action of 

 the venom ; and it seems very probable that the mere contact of any other 

 foreign body, containing Bacteria or their germs (as the water in which 

 the cobra-poison was dissolved in our experiments certainly did) would 

 suffice to explain the decomposition of the muscle without assuming any 

 special putrefactive action on the part of the poison; for the muscle, 

 which has been at least temporarily killed by the poison, is placed in the 

 body in the most favourable conditions of temperature and moisture for 

 the occurrence of decomposition whenever any germs are brought into con- 

 tact with it. However, Weir Mitchell found that the venom of the rattle- 

 snake had a curious influence upon muscle, which could hardly be explained 

 without the supposition that the poison had a peculiar disorganizing 

 action upon the muscular tissue. In every instance the venom softened 

 the muscle in proportion to the length of time it remained in contact 

 with it ; so that, even after 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 colour and somewhat jelly-like ap- 

 pearance. The structure remained entire until it was pressed upon or 

 stretched, when it lost all regularity, and offered, under the microscope, 

 the appearance of a minute granular mass. In order to ascertain whether 

 cobra-poison had a similar action, the following experiment was tried. 



Experiment XXXIV. 



September 1873. The gastrocnemii of a frog were removed and laid in 

 two watch-glasses. One was then covered with several drops of a solution 

 of dried cobra-poison, dissolved in a sufficient quantity of |-per-cent. salt 

 solution to form a mixture about the consistence of fresh poison, while 

 the other was covered with a few drops of salt solution alone. They 



