HYDROCYANIC ACID AND COBRA POISON. ?>H1 



Bernard's experiments, however, Sir Benjamin Brodie* observed 

 that, in animals apparently killed by this poison, the heart con- 

 tinued to beat for a lono- time ; and the idea occurred to him 

 that, if he could keep up respiration for a sufficient length of 

 time, the poison would be eliminated, and the animal com- 

 pletely restored. His first attempts were unsuccessful, but after 

 a little while he succeeded completely ; and since then his 

 experiment has been so frequently repeated, that no physiolo- 

 gist can doubt that the complete restoration of an animal 

 poisoned in this way is merely a matter of time, unless the dose 

 has been so overwhelmingly great as to paralyse the heart. I 

 have myself twice restored to life rabbits which a dose of 

 woorara had apparently completely killed, by keeping up arti- 

 ficial respiration in the one case for one, and in the other for 

 four hours ; and in foreign laboratories I have seen them par- 

 tially restored, and only rendered motionless by repeated doses 

 of woorara, oftener than I can well recollect. Hydrocyanic acid 

 is a much more dangerous poison than woorara ; for it seems 

 not only to arrest respiration by paralysing the brain, spinal 

 cord, nerves and muscles, but also to stop the circulation by 

 destroying the power of the heart. The heart, however, is not 

 so soon affected as the respiratory organs ; and Brodie succeeded 

 in restoring animals poisoned by small doses of it given in the 

 form of oil of almonds. 



The poison of the cobra di capello resembles prussic acid 

 rather than woorara in the universality of its action ; for some 

 experiments which I made about a year ago in the laboratory of 

 Dr. Burden Sanderson seem to show that it paralyses the spinal 

 cord, the motor nerves and the muscles themselves. The lieart 

 also, as Dr. Fayrer and I have found, seems to be paralysed if 

 the dose be very large, as it may be also by an excessive dose 

 of woorara ; but it almost always continues to beat for a long 

 time after respiration has ceased. To this fact I have drawn 

 particular attention in my appendix to Dr. Fayrer's admirable 

 work on the Thanatophidia of India. The same thing was 

 observed by Fontana (op. cit, tom. i, p. 80) in poisoning by the 

 bite of the viper, and by Weir Mitchell in poisoning by the 



* Fhil. Trans.. 1812. 



