1878.J 



Prof. Pedler on Cobra Poison. 



19 



at 23° C, the experiment being made on the average poison collected 

 from 16 snakes on November 26th, 1874. Whether evaporated in 

 dry air, or in vacuo, or at 100° C, the fresh poison gave nearly the 

 same amount of solid residue, the mean quantity being 28*28 per cent., 

 the poison extracted from one batch of snakes in the rainy season 

 (July) giving 27*74 per cent., and the poison from 16 snakes on 

 November 24th, after the cessation of the rains, giving 28*82 per cent. 



As these samples were taken the first during the hot and moist 

 rainy season, when these snakes are most active, and yield the largest 

 quantity of poison, and the second during the cold season, when they 

 are very sluggish, and yield only small quantities of virus, it may be 

 hypothesised that throughout the year there is very little change in 

 the actual amount of solid present in the liquid poison shed by the 

 cobra. 



I have tested the fresh liquid poison with polarized light, but found 

 that it was optically inactive. 



With reference to the action of time on cobra virus, my own conclu- 

 sions do not altogether agree with results previously obtained ; thus, in 

 the report of the Snake Commission above referred to, it is stated that 

 the poison undergoes no change by being kept ; but, from my expe- 

 perience, I have found, that although the poison will not alter if kept 

 for two or three months only, yet if it be kept for a year or eighteen 

 months, it alters in its properties very materially, becoming insoluble, 

 and indeed losing to a considerable extent its poisonous action. In 

 fact, I gradually collected a considerable quantity of the poison, with 

 a view to experiment on a larger scale ; but, on commencing work, I 

 found the poison almost inert, and perfectly valueless for any scientific 

 investigation on the subject, and in this way lost much time, and a 

 very considerable amount of material extremely difficult to procure or 

 replace. 



The poison dried in vacuo over sulphuric acid was analysed, and the 

 mean result was found to be : — 



Carbon 49*32 per cent. 



Hydrogen 7*01 ,, 



Nitrogen 17*39 



Ash 6*68 



Oxygen and sulphur by difference 19*60 ,, 



100*00 



If we regard the ash as being foreign to the organic poison, the 

 proportion of the other elements will then become* — 



* A part of these results was submitted by me to the Snake Poison Commission, 

 and published by them at page 42 of their report. 



c 2 



