A POPULAR TREATISE ON THE COMMON INDIAN SNAKES. 55? 



mouth, at the same time stimulating the flow of saliva. The same 

 authority remarks that the dried particles have a pungent action 

 upon the nostrils. Lamb describes the taste as very bitter and 

 astringent. 



Quantity of poison secreted. — This, of course, varies with the size 

 of the cobra, but even in specimens of similar length other factors 

 affect the yield. Lamb says: "it is an observation of common 

 occurrence in this laboratory (Parel), that a cobra newly caught will 

 yield from 20 to 30 large drops of poison, while after he has been 

 a captive for some time this quantity will have diminished to from 

 6 to 10 drops and in time to nil. " Dr. Nicholson observed that the 

 yield was more abundant in wet weather. Under the influence of 

 anger poison is. secreted unduly copiously. Doubtless age, health, 

 and individual vitality also influence the quantity secreted. 



The venom in its fluid state is found to vary a good deal in 

 concentration, a cobra's yield is therefore calculated by the amount 

 of solid residue left after drying. Cunningham's average for 9 

 cobras was 254 mgms. Lamb's for 14 cobras 231, and Eogers's 

 for 2 cobras 249 mgms. Lamb found that by provoking cobras, 

 so as to make them bite viciously, the yield collected in glasses 

 w T as considerably augmented, as compared with that collected by 

 simple pressure over the glands, and amounted to an average of 

 373 mgms. for 3 cobras. Cunningham obtained from one cobra 

 the enormous quantity of 726 mgms. The amount of solid, it will 

 be seen, ranges between 200 and 726 mgms. in healthy adult 

 cobras. 



Toxicity of cobra poison. — Lamb has shown that even the dried 

 product varies in its degree of toxicity, as he found the minimal 

 lethal dose for rats was *07 mgms. with one sample and -04 with 

 another. 



Lethal dose of cobra poison in man. — It is a well established fact 

 that cobra venom may be swallowed in large quantities without 

 producing any baneful results. Elliot gave a dog 1 drops — a dose 

 sufficient to kill 10 dogs, if injected into the tissues — without 

 producing any ill-effect. On another occasion he gave 20 drops to 

 a goat with the same result. Fraser by graduated doses internally 

 succeeded in giving a cat 1,000 times the lethal dose by injection 

 beneath the skin. Calmette repeated the experiment, giving 1,000 

 times the lethal subcutaneous dose to a cat internally, without pro- 

 ducing symptoms of poisoning. It is the access of the venom into 

 the blood stream that constitutes its extreme danger to all animals. 

 The lethal dose of the poison so introduced has been accurately 

 ascertained for many animals by experiment, but in man must 

 remain to some extent conjectural. Various estimates have been 

 made, based on experiments on the lower animals. Fraser's estimate 

 is 31 mgms. whilst Calmette made it about 10 mgms. Lamb, 



