46 ON THE NATURE AND ACTION OF THE 



by Dr. Klein. It presented exactly the same characters as 

 those of the former specimen. Blood from another healthy rat 

 showed numerous rouleaux, and the corpuscles were not 

 crenated. 



Action on Muscles. 



Cobra-poison has the power of destroying the irritability of 

 voluntary muscular fibre when applied directly to it, either in 

 a concentrated or diluted condition. It does not produce any 

 quivering of the fibres ; and in this particular it differs from 

 the poison of the rattlesnake as described by Dr. Weir 

 Mitchell. 



The local action of cobra-poison on muscle is illustrated by 

 Experiments XXIII, XXIV, XXV, and XXVI. 



Experiment XXIII. 



September 4th. — A frog was decapitated, and the skin 

 removed from both hind legs. A longitudinal cut was then 

 made in the muscle of both thighs. A strong solution of dried 

 cobra-poison in distilled water, of such a strength as to 

 resemble the fresh poison closely in appearance, was then 

 applied to the cut in one thigh, while the other was moistened 

 with distilled water. Immediately after the application an 

 almost imperceptible trembling in the muscles occurred equally 

 in both thighs ; but it ceased after a few seconds, and did not 

 reappear. On testing the muscles soon afterwards, by an 

 induced current applied directly to them, those of the poisoned 

 leg contracted feebly, but those of the non-poisoned leg, 

 forcibly. 



In this experiment, the quivering occurred equally in both 

 thighs, and was therefore obviously due to the water in which 

 the poison was dissolved, and not to the poison itself. 



As Weir Mitchell found that the quivering produced by the 

 poison of the rattlesnake was not prevented by paralysis of the 

 motor nerves by curare, the previous experiment was repeated 

 on a curarised frog. 



