1874.] Poison of Indian Venomous Snakes. 93 



the stomach after ligature of the renal vessels), convulsions occur just 

 as in death from cobra-poison. Although the motor nerves have their 

 function so much impaired that they no longer transmit to the muscles 

 of respiration the ordinary stimuli from the medulla, which usually keep 

 up the movements of breathing, they can still transmit those stronger 

 impulses which proceed from it when greatly stimulated by the increasing 

 venosity of the blood, and which cause the respiratory as well as the other 

 muscles of the body to participate in the general convulsions. The loss of 

 coordination which occurs in poisoning by cobra-venom, has also been 

 noticed by Voisin and Liouville in poisoning by curare. 



That the peripheral terminations of the motor nerves are actually 

 paralyzed by cobra-venom is shown by Experiment XXXVI., in which the 

 animal was able to move the leg which had been protected from the action 

 of the poison for some time after the rest of the body was perfectly 

 motionless, as well as by Exp. XXXYII. and those succeeding it. Its 

 occurrence in man is indicated by the symptoms of a case described by 

 Dr. Hilson (Ind. Med. Gaz., Oct. 1873, p. 254). 



But paralysis of motor nerves is not the only effect of cobra-poison on 

 the nervous system. The spinal cord is also paralyzed, as is seen from 

 Exp. XLL, where motion ceased in the frog's leg which remained free 

 from poison, although it answered with great readiness to a very weak sti- 

 mulus applied to its nerve. In some instances paralysis of the spinal cord 

 appeared to cause death when little or no affection of the motor nerves 

 could be observed (Exp. XL VII. &c.); but in others the peripheral para- 

 lysis was strongly marked. In no case was it more obvious, and in few 

 was it so distinct as in Exp. XXXVI., made with the virus itself, which 

 had neither become coagulated nor dried. In experiments made with the 

 coagulated poison, death seemed invariably to be caused by paralysis of 

 the spinal cord, the motor nerves being little affected (Exp. XI.) ; while, 

 in those made with the dried venom, sometimes the action on the cord 

 predominated, and sometimes that on the nerves. In this respect, as 

 well as in some of the symptoms it produces, cobra-poison agrees very 

 closely with conia. This alkaloid, as Crum-Brown and Eraser have 

 shown, often contains a mixture of true conia and methylconia. Conia 

 alone paralyzes the motor nerves without affecting the spinal cord ; but 

 when mixed with methylconia, sometimes the one is affected first, and 

 sometimes the other. When the dose is small, the motor nerves are 

 usually paralyzed before the reflex function of the cord ; but when the 

 dose is large, the cord is paralyzed before the nerves. Methylconia also 

 affects both ; but a small dose of it paralyzes the cord before the nerves, 

 while a large one paralyzes them first. The paralysis of the hind legs, 

 often observed in snake-poisoning (Exp. VI. & VII.), is probably partly 

 due to the local action of the poison in the nerves and muscles of the bitten 

 member, and partly to its action on the cord. This paralysis is noticed 

 in G-enesis xlix. 17, where Jacob says, "Dan is an adder in the path, 



