ORDER OPHIDIA. 359 



pigeon in eight or twelve minutes, while a cat will sometimes 

 resist it, and a sheep escape from its effects very frequently. 

 These effects are always less severe in England and France 

 than in Italy. 



A hundredth part of a grain of this poison introduced into 

 a muscle, kills instantaneously a warbler or a canary, while 

 Fontana tells us that it requires six times as much to destroy 

 a pigeon. Nearly two grains was found to have no effect 

 upon a raven ; according to this calculation three grains at 

 least would be necessary to destroy a man, and twelve to 

 produce the death of an ox under ordinary circumstances. 



The organ which is wounded has a great influence on the 

 nature and severity of the symptoms. Wounds in the neck, 

 for example, are far more perilous than wounds in the limbs, 

 in consequence of the neighbourhood of the larynx, the pha- 

 rynx, the pneumo-gastric nerves, the multiplicity of absorbent 

 vessels and lymphatic ganglia in that part, and its connections 

 with the head and the principal centres of sensation, and with 

 the respiratory and digestive viae. 



A considerable number of experiments and observations 

 have, besides, demonstrated that the poison of the viper may 

 be swallowed with impunity, if the mouth be not the seat of 

 any excoriation or ulceration. Dr. Cloquet had occasion to 

 verify this fact in his own person : being bitten by a reptile 

 of this species in one one of his zoological excursions, on the 

 forefinger, he instantly sucked the wound, Avhich healed as 

 quickly as would the prick made by a sharp pin, and no un- 

 pleasant consequences ensued. 



The symptoms which, in man, succeed the bite of a viper, 

 follow each other in this order : a sharp pain is first felt in 

 the bitten part, which swells, becomes shining, red, hot, 

 violet, then livid, cold, and almost insensible. The pain and 

 inflammation seem to follow the course of the large nervous 

 trunks and those of the lymphatic vessels. They acquire 



