1881.] Poisons of certain Indian Venomous Snakes. 353 



daboia poison in solution were then injected, subcutaneously into its 

 leg. Immediately on the injection being completed, artificial respira- 

 tion was commenced. 

 2.23 p.m. Injection. 



2.23^ p.m. Artificial respiration commenced. 

 2.26 p.m. Convulsions, in which the bird died. 



Here, though ample means were employed to keep the blood oxy- 

 genated, the bird died at once in convulsions. The convulsions of 

 asphyxia that occur after the paralysis of cobra poisoning are removed 

 by artificial respiration. It is clear, therefore, that the convulsions of 

 daboia poisoning are 'primary, and in no way due to defective aeration 

 of the blood. 



The convulsions are exceedingly violent in character, the whole of 

 the voluntary muscular system being affected, even to the muscles of 

 the eyeball. Sometimes, but rarely, the convulsion is tonic, the 

 muscles clasping, as it were, the frame of the victim. The convul- 

 sions may be due either to the direct action of the poison on the 

 muscles, or on the muscular terminations of the nerves, or on the 

 central nervous ganglia. The following experiment determines 

 this. 



Experiment XVI. ' 



A fowl was placed under the influence of chloroform, and its right 

 crural nerve divided ; the left crural nerve was then isolated, and 

 a ligature placed round all the other structures so as completely to 

 obstruct the circulation, but the nerve was left uninjured. The 

 moment the bird became conscious, a small quantity of solution of 

 daboia poison was subcutaneously injected into the tissues at the 

 back of the neck. Almost directly after, convulsions occurred, but, 

 in these convulsions, the muscles supplied by the right or divided 

 nerve took no part, remaining perfectly flaccid, while the muscles of 

 the left leg were violently tetanized. Here the muscles of the right 

 leg which were freely supplied with the poisoned blood, but the nerve 

 to which was divided, escaped the convulsions ; while those of the left 

 leg, which had no contact with the poisoned blood, but whose nerve 

 was still in communication with the central nervous system, took part 

 in them. It is evident, therefore, that the convulsions depend upon 

 the direct irritation of the central nervous system by the poison, and 

 in no way on the contact of the poison with the muscles or with the 

 terminations of the nerves. 



These primary convulsions occur in from one to ten minutes after 

 the infliction of the bite, and they may have any degree of severity, 

 from those producing almost instant death to merely a few mus- 

 cular twitchings. The course of the symptoms after the convulsions 

 also varies. Respiration may never be thoroughly re-established, the 



