THEIR NATUEE AND EFFECTS. 63 



Mammals, as it has been stated, are very easily- 

 affected by the convulsion-producing agent; but am- 

 phibia only have symptoms of gradual paralysis. 



Experiment XIII. 



A medium-sized frog {Rana iigrina) had one centi- 

 gramme of dried cobra-poison in solution injected into 

 its dorsal sac. 



1.12 P.M. Injection. 



4.40 P.M. 'Violent respiratory efforts. 



4.89 P.M. Becoming paralysed. 



4.53 P.M. Paralysed. 



5.11 P.M. Dead. 



It is important to notice this difference of power in 

 producing a fatal result in different classes of animals 

 by these two poisons. 



Experiment XIV. 



Five centigrammes ("77 grain) of dried cobra-poison 

 dissolved in water, were injected into the dorsal sac of a 

 frog {Rana Iigrina). 



12.43 P.M. Injection. 



1.40 P.M. Paralysed. 



1.50 P.M. Dead. 



Experiment XV. 



Five centigrammes ("77 grain) of dried daboia-poison, 

 dissolved in water, were injected into the dorsal sac of a 



