THEIB NATUEE AND EFFECTS. 37 



seconds longer. The whole time from injection to death 

 was under 100 seconds. 



Chart No. V. is a continuous tracing of the respira- 

 tion of this animal from the administration of the poison 

 till death. It will he seen that the normal respiratory 

 rhythm is suddenly displaced hy violent alternate up- 

 heavings and depressions of the chest walls, and that 

 then all movement at once stops. But it will he 

 noticed that the convulsions, though, of course, irregu- 

 lar, have a distinctly respiratory character. When 

 cobra-poison, then, enters the circulation in large 

 ■quantity, it stimulates the respiratory centre to such a 

 degree that convulsive action of the respiratory muscles 

 is produced, but after a very brief period complete and 

 permanent paralysis of "the respiratory apparatus is 

 induced. It is worthy of note that rapid as death in 

 this case was, the action of the heart continued after 

 that of the respiration had ceased. 



To sum up the different modes in which cobra-poison 

 destroys the respiratory function : — First, almost in- 

 stantaneous paralysis of the respiratory centre, a primary 

 stimulation of a very violent but very transient cha- 

 racter having occurred. This form of death must be 

 exceedingly rare, if it ever occur, in the human subject, 

 as the shortest period of fatal poisoning in man on 

 record appears to have been a little under a quarter of 

 an hour. Secondly, a more gradual method, the poison 



