SNAKE-POISON AND ITS ACTION. 29 



on some centres, j)assing others by comparatively little 

 disturbed, is markedly shown by the cobra poison of 

 India as compared with that of our Australian cobra 

 (hoplocephalus curtus.) The unfortunate victims of 

 the former are tortured by an ever-increasing dyspnoea, 

 and finally die from asphyxia, under what are supposed 

 to be carbonic acid convulsions. They retain their 

 consciousness more or less unclouded to the last, the 

 poison spending all its force on the respiratory centre, 

 and leaving the brain intact. Here we hardly ever 

 see actual dyspnoea after the bite of hoplocephalus or 

 any other Australian snake. Respiration becomes 

 quicker at an early stage, and then, from hour to 

 hour, shallower ; but our patients soon pass from sleep 

 into coma, and suffer no respiratory distress even 

 when, in consequence of general paralysis, the respira- 

 tory muscles cease to act, which usually takes place a 

 few minutes before the heart stands still. 



Feoktistow records the following observations on 

 cats with reference to the respiratory centre : — Small 

 intravenous injections of the fresh poison (0'07 0"13 

 mllgr.) produced a great increase in frequency of 

 respirations (280-360 per minute.) Section of both 

 vagi at once reduced this frequency, from which he 

 infers that small doses act as an irritant to the 

 respiratory centre. When small doses were repeated 

 several times, the respiratory movements were gradu- 

 ally retarded, and asphyxia set in through paralysis of 

 the centre. Large doses produced this effect at once, 

 without any previous acceleration. Very large ones 



