THEIR NATURE AND EFFECTS. Ill 



the Indian viper in its effects, the chief difference heing 

 that the primary convulsions are very much less fre- 

 quently seen — hirds seeming to have in place of them 

 special respiratory irregularities. In regard to its power 

 of destruction, contrasted with that of other snakes, 

 there is some evidence to he considered. In Dr. Weir 

 Mitchell's work four cases of fatal Crotalus poisoning in 

 dogs gave an average of two hours and twenty-six 

 minutes before death, but no fewer than five dogs re- 

 covered completely after being bitten. With the Indian 

 cobra and the Australian Hoplocephalus the average 

 length of the period of fatal poisoning was 34"4 minutes 

 and one hour and twenty-four minutes respectively. It 

 is, therefore, much less dangerous than either of these 

 poisons. 



As to the probable duration of human life after the 

 bite of a cobra, it is difficult to obtain trustworthy 

 evidence, as the species of snake from which death 

 resulted is, in India, very rarely identified ; and it is for 

 this reason, also, that it is impossible to assign fo 

 each species its exact share in the general mortality. 

 However, disregarding the species of snake, there is 

 stifficient evidence in Sir Joseph Fayrer's " Thanato- 

 phidia" to give a close approximation to the probable 

 duration of life in Indian snake-poisoning. In that 

 work sixty-five cases are given in which the time that 

 elapaed between the infliction of the bite and death is 

 stated. The average length of time of the whole sixty- 



