8 ON THE NATURE AND ACTION OF THE 



slight poisoning, and probably that, by a sphincteral arrange- 

 ment of fibres, as pointed out by Dr. Weir Mitchell to exist in 

 the rattlesnake, the snake may have the power of imbedding its 

 fangs without shedding its poison at all. 



Much virtue has been recently attributed to one of the oldest 

 and most trusted of all antidotes — ammonia ; but it was long 

 ago shown by Fontana by repeated experiments that the injec- 

 tion of this agent into the veins, as well as its internal 

 administration and external application, were powerless (as 

 may be seen by reference to the following* pages of his works), 

 so it has proved in all the experiments made with it in India. 

 Any complete and satisfactory means of resisting, antagonising, 

 or eliminating the poison and of saving life are, we fear, still 

 unknown ; and it is in the hope that by determining the 

 physiological action of the poison we may make some advance 

 in our knowledge of this important subject, that the following 

 investigations have been undertaken with cobra-virus sent to 

 us from Bengal, and of which we hope to receive continued 

 supplies from Mr. Vincent Eichards, of Balasore, who, at our 

 request, is also carrying on a series of experiments on the 

 subject. 



Appearance and Chemical Characters of Cobra-poison. 



The poison when fresh is a transparent, almost colourless 

 fluid, of a somew^hat syrupy consistence, and not unlike glycerine 

 in its appearance. When quickly dried it forms a transparent 

 mass of a yellowish-brown colour, and resembling some kinds 

 of gum-arabic. The poison may be kept in a fluid state for 

 some months without undergoing any change, but after a certain 

 time it decomposes. 



During decomposition it gives off a quantity of gas, which 

 has been ascertained by Dr. Armstrong to be carbonic anhydride, 

 and at the same time acquires a dark brown colour and a dis- 

 agreeable odour. The dried poison may be kept for a much 

 longer time without undergoing any apparent change. 



* Traits sur le renin de la Vipere, vol. i, pp. 108, 109, 118, 120, 124, 129; 

 vol. ii, pp. 5, 6, 7 (Florence, 1781). Opusculi Scientijiei, Letter iv, pp. 125 

 et sea. 



