34 PHYSIOLOGY AND TOXICOLOGY 



Chlorine water caused a dense precipitate. A solution of iodine and iodide of 

 potassium Caused a precipitate whicli redissolved in an excess of the reagent.^ 



Soda and potassa had no visible effect on the venom. 



Ammonia was also without action upon it, as was also lime-water. 



Bichloride of mercury gave with the venom a dense white precipitate. 



Sulphate of soda produced a dense precipitate, which redissolved on the addition 

 of water in excess. The precipitate was, therefore, soluble in a weak solution 

 of the salt employed. 



Sulphate of magnesia, in like manner, caused a precipitate which proved soluble 

 in an excess of water, as in the last observation. 



In both cases the precipitate could be reproduced by increasing the amount of 

 the salt present, and again, an added excess of Avater was competent to redissolve 

 the new precipitate. 



Alcohol invariably produced in the venom a heavy, flocculent precipitate, which, 

 when carefully dried, turned of a pale yellow, and was still more or less soluble in 

 water. The latter fact was observed, even when the poison had been kept in 

 alcohol during five wrecks. I have also examined the poison found in the ducts of 

 Rattlesnakes, which had remained in alcohol for two years or more. It proved to 

 be very slightly soluble in water. There is in this observation, however, a cause 

 of error ; since in snakes which die violent deaths, the whole gland is often filled 

 with blood, so that the coagulated substance in the ducts -can, with no certainty, 

 be regarded as venom alone; unless we are informed very fully as to the condition 

 of the organs, when first immersed in the preserving fluid. This question is one 

 of considerable interest, and will engage our attention in another place. 



An aqueous solution of the venom was evaporated to dryness. A drop of a 

 solution of sulphate of copper was then added, and the mixture treated with a 

 solution of caustic potassa in excess. In a few minutes it exhibited the violet 

 color characteristic of albuminous matters thus tested. 



The venom was next examined for sulphocyanide of potassium, a constituent of 

 human saliva, although with slight expectation of detecting it. Five drops were 

 tested with sulphate of sesquioxide of iron. It produced a heavy white precipitate, 

 but no red color was observed. Seven drops of the venom were evaporated to 

 dryness, and treated with the same salt of iron, but without any appearance of the 

 red hue which indicates the presence of the sulphocyanide mentioned. These 

 examinations were repeated several times on as many specimens of the poison, but 

 always with a negative result. From the small amount of venom employed, they 

 did not entirely satisfy me, and the subject may still repay a fuller examination. 

 At present it is only safe to affirm that the sulphocyanide, if it exist in the venom 

 at all, can only be present in a very minute amount, and can in no way be con- 

 sidered as a causative element, in the production of the symptoms which follow 

 upon the insertion of the venom into the tissues of living animals.^ 



' Brainard's antidote — lod. potass, gi-s. xxx; iodine grs. x; water sj. 



' In the following work by M. Bernard: Leyons sur les Proprietes Physiologiques, et les Alt6ratious 

 Pathologiques des Liquides de I'Organisme, vol. ii. p. 242, he says : " Ainsi on a dit d'abord, que la 

 presence du sulfocyanure de potassium dans la salive, rappelait les glands a venin des serpents vemineux." 



