NOTES ON THE POISON OF VENOMOUS SNAKES. 



By J. W. Agnew, M.D. 



[Read at a meeting of the Royal Society.] 



"When a wound has been inflicted by a venomous snake, it is well known that 

 the first efforts should be directed to prevent the poison from being absorbed 

 into the system. To effect this it is recommended that a tight ligature should 

 be immediately applied close to the bite, between it and the centre of the 

 circulation, and that suction should then be practised to the wound itself. 

 This suction is of extreme importance, and though it is generally understood 

 to be unattended by danger, I am aware that very many persons do not 

 consider it to be altogether so. and that they would hesitate before taking into 

 their mouth even the smallest quantity of a poison so virvJent as that of the 

 snake. 



I am not aware if experiments have ever been conducted for the purpose of 

 proving from actual observations whether or no the snake-poison cm be 

 swallowed with irnpunity,aud I have thought it of some importance to endeavor 

 to set the question at rest, not by the collection of hear-say evidence, but by 

 experiments on living animals. 



Having obtained therefore a common black snake, I dissected out both 

 poison glands, having previously put a ligature round the ducts to prevent the 

 loss of any ot the venom. I then took a young chicken, and having its bill 

 held open, thrust down its throat the entire of one gland — having first snipped 

 it once or twice across in order to ensure the free escape of its contents when 

 received into the stomach. After the act of deglutition was evidently complete, 

 observation was continued for a considerable time, lest the contents of the 

 stomach might be rejected, and the experiment be thus vitiated. No 

 symptom however of the slightest distress ever manifested itself, and when 

 food was offered it was readily seized and swallowed. Another chicken of the 

 same age was next taken, and an incision having been made through the skin 

 of the leg, the remaining poison-gland— previously snipped across as before, in 

 order that the venom might freely escape — was pressed into the wound. The 

 lips of the wound having been brought together by sutures, the chicken was 

 then placed under observation. In twelve (12) minutes distinct symptoms of 

 poisoning were manifested, — the eyes became dull, the wings dropped, the 

 head fell — and death ensued in twenty-eight minutes and a hafi (282) after the 

 application of the poison. 



Thinking it advisable to repeat the experiment on animals of a totally 

 different nature, two very young cats were secured. The two poison glands 

 having been taken as before from a black snake, one, after being cut across, 

 was laid on the tongue of one of the cats, and was immediately swallowed. In a 

 short time afterwards, a tea-spoonful of milk was placed before the cat, and as 

 it was at once lapped up, it was vei-y evident that the poison had been fairly 

 taken into the stomach. Observation was continued for several hours, but not 

 the slightest symptom was shewn of any effect having been produced by the 

 poison, either on the stomach or the system at large. The second gland was 

 now cut open, and inserted into a wound made on the hind leg of the remaining 

 cat. Symptoms of poisoning were very soon manifest — the animal trembled — 

 appeared disinclined to move— became dull and lethargic ; but death did not 

 take place until the expiration of two hours. 



Now it is a generally understood fact, that the snake-poison acts with much 

 greater certainty and rapidity in very young and small animals, than in those 

 of greater age and size. The size and age of the subjects of the above experi- 

 ments, rendered them therefore peculiarly susceptible of the influence of the 

 poison, yet no effect whatever was produced when it was swallowed, although 

 its influence was sufficiently marked when introduced into the system in the 

 usual way, that is, by a wound on the surface. The results thus obtained 

 were so decisive, that I did not think it necessary further to repeat observations 

 which could only necessitate pain and loss of life, without adding anything to 

 the certainty or truth of the conclusions arrived at. 



In conducting these experiments in the manner indicated, one decided 

 source of fallacy was avoided Had the entire poison of a snake been admin- 

 istered internally to oncjanimal, while to another the poison of a second snake 

 was externally applied, the results would have been the same as above. But 

 it might then have been objected, that the poison-glands which were swallowed, 

 had perhaps been exhausted of their venom before the death of the snake ; 

 or that the poison contained in them was not equal in virulence to that which 

 was applied to the wound ; and many experiments would have been necessary 

 to set these points at rest. By applying however the poison of a single gland 

 only, to a wound in one animal, the fellow-gland being given to another to be 

 swallowed, it is certain that each subject of tne expeiiment had not only an 



