THEIE NATURE AND EPrECTS. 119 



has been long in captivity and has been frequently 

 handled will often contain numerous cells. But the 

 purest and most active poison has but few structures in 

 it. Sometimes a whole microscopic field may not pre- 

 sent a single object. The structures usually seen are 

 cells of different diameters, some of them clearly being 

 epithelial cells from the mouth and lining membrane of 

 the duct. Besides these there will be seen some much 

 smaller very highly refracting bodies. The appearances 

 of dahoia-venom are similar. There is, then, nothing 

 characteristic in the microscopic appearances of snake- 

 poison, and the fact that the most active venom shows 

 the fewest structures demonstrates that no importance 

 is to be attached to those that are present. 



The ultimate analysis of the poison by Dr. Armstrong 

 gave the following percentage composition : — Carbon 

 45"76, nitrogen l4"3, hydrogen 6"6, sulphur 2"5. 



When kept in the liquid state cobra-poison quickly 

 becomes first neutral and then alkaline, and a few 

 feathery and cubic crystals will form. If preserved in 

 a loosely-corked test tube, it will become cloudy, smell 

 .offensively, and will swarm with bacteria in active move- 

 ment, but it is still poisonous. The alkalinity now 

 lessens, and the reaction becomes again acid, and the 

 fluid then coagulates into a firm whitish opaque sub- 

 stance, somewhat like the coagulated white of egg, but 

 of a lemon colour. If a small quantity of fluid is left 

 uncoagulated it is poisonous, and the washings of the 



