358 COMMON REPTILES OF AN INDIAN GARDEN 



of viperine snakes, because the suddenly explosive 

 action of the nervously irritant element in the poison 

 affords no time for the application of any remedial 

 measures in cases in which any slight excess of it 

 has been administered. The local muscular action 

 attending the introduction of the venom continues 

 to show itself in any uninured site long after a very 

 considerable degree of exemption from dangerous 

 centric irritation has been established. It does not, 

 however, seem to be accompanied by pain, as a very 

 intelligent fowl, who was for some time artificially 

 immunised by frequent injections of venom, soon 

 became quite eager for its daily dose, because this 

 was regularly followed by a plentiful dole of grain. 

 The essential differences between the natures of 

 colubrine and viperine venoms can be unequivocally 

 demonstrated by artificially immunising two animals 

 of like nature, one to the action of the one, and the 

 other to that of the other poison, and then treating 

 them with minimal lethal doses of the materials 

 to which they have not been inured. In such cases 

 it will be found that the immunity that has been 

 established is of a purely specific nature, so that 

 protection against the action of viperine venom 

 has provided none against colubrine venom, and 

 immunity from the latter no power of resisting 

 intoxication from the former poison. 



