COLLAPSE THROUGH FEAR. 393 



Variety of Venoms. 

 The venoms of many of the Indian, Austrahan, American 

 and African snakes differ widely in their poisoning properties, 

 and therefore it is clear that the serum treatment of snake bite 

 is beset with many difficulties. However, if the authorities in 

 each of these countries set themselves in real earnest to immunize 

 animals to the venom of the most poisonous of the snakes of the 

 country, a first-class serum of high anti-toxic power could be 

 prepared and sold to the public. The greatest difficulty seems 

 to be the collection of sufficient venom for the purpose. Those 

 who collect venom lor sale frequently adulterate it with gelatine 

 or gum, and it is often otherwise impure and even inert. 



Hyper-sensibility. 



A remarkable and mystifying fact in the immunizing of 

 animals against snake bite by the injection of graduated doses 

 of venom is, that when an animal becomes highly immune and 

 is able to tolerate a very great number of ordinarily fatal doses 

 without showing any symptoms of poisoning, this high degree 

 of immunity often becomes suddenly reversed, and a condition 

 of extreme sensitiveness (hyper-sensibility) to snake venom 

 sets in, and the animal will succumb even to a very small quantity 

 of venom. 



There seems to be a point beyond which tolerance to any 

 poison cannot go, and some sudden physiological change takes 

 place, doubtless in the cells of the brain, the nerves, and the 

 constituents of the blood, making the body susceptible to the 

 toxic action of only a small quantity of the poison to which 

 the system was hitherto immune, even when given in very large 

 doses. 



It is ever thus in scientific research, when one mystery is 

 solved others arise, and so it will be to the end. 



Collapse through Fear. 



A case came under my observation of a native woman who 



was bitten on the calf of the leg by a large Mole Snake [Pseu- 



daspis cana) which she took to be a Cobra. Now, in spite of 



the fact of the Mole Snake being quite harmless, the woman 



