316 CLASS REPTILIA. 



du Roi," who, having at his disposal a rattle-snake, which 

 had been dead two days, discovered that the poison of this 

 animal, even in so northern a climate, and at a very advanced 

 time of the year, still preserved all its maleficent properties. 

 A pigeon, in the pectoral muscles of which the doctor infixed 

 the venomous fangs of the reptile, died within a very short 

 period indeed. 



The poison of the viper, and of some other serpents which 

 inhabit countries remote from the torrid zone, loses its 

 strength during winter, and in the more northern climates. 

 Its energy, on the other hand, is augmented during summer, 

 and in warmer regions. 



The danger arising from the bite of serpents is in relation 

 to the degree of anger with which the reptile is animated — 

 for, in pressing with greater force, it more completely squeezes 

 out the poison, and distils a larger quantity of it into the 

 wound. It is also more or less great, according to the time 

 which has elapsed since the poison vesicles were emptied by 

 the last bite. 



The bulk of the animal which is bitten, and the degree of 

 terror which the wound has caused, also increase or diminish 

 the quantity of danger. 



The experiments of Fontana, of which he made more than 

 six thousand, proved that the bite of a single viper was suffi- 

 cient to kill a mouse, a pigeon, or other small animal. Many 

 of them repeated, were found necessary to cause the death of 

 an ox or a horse. 



The danger of this bite besides^ evidently depends on the 

 nature of the poisonous inoculation by which it is accom- 

 panied. Notwithstanding the circumstance related by Mat- 

 thiali, of a peasant who died immediately from having sucked 

 the blood from a wound made on himself by a viper, and 

 notwithstanding the assertion of Fontana to the same effect, 

 it is very certain that this poison (at all events that of the 



