OF THE VENOM OF THE RATTLESNAKE. 33 



appearance so much resembling starch granules, as to have induced me to neglect 

 them at first, and to suppose them to be really that substance, accidentally 

 present. These corpuscular bodies were marked with delicate radiating lines. 

 Iodine stained them of a yellowish-brown. They were doubtless due to some 

 concrete modification of albiuninous material. 



Occasionally, when the snake had been seriously maltreated, the venom contained 

 more or less blood. 



Chemical Examination. — I much regret having been unable to collect the venom 

 of the Crotalus in such amount as would have enabled a competent chemist to 

 make of it an ultimate analysis, to which I believe it has never yet been submitted. 

 In the following examination, I have contented myself with a qualitative ana- 

 lysis, which, although not so perfect as I could have desired, appears to me to have 

 thrown some light on this novel and curious subject. 



The fresh venom of the Crotalus begins to coagulate at 140° P., and is almost 

 solid at 160°. The mode in which I accomplished this observation upon minute 

 amounts of venom, without desiccating it, will be found detailed in the account of 

 the influence of temperature upon the virulency of the venom.^ 



When a drop of the pure poison was thrown upon platinum foil and heated, it 

 boiled, whitened, and at last became charred before it took fire. 



When a drop of venom was thrown into cold distilled water, it fell rapidly, and 

 presented a white appearance, which became marked, as it dispersed through the 

 fluid. It finally dissolved in the water, without residue. This phenomenon of the 

 whitening of the venom in water, has also been noticed in regard to fresh white of 

 egg similarly treated. 



The pure venom of the Crotalus was subjected to the action of various chemical 

 reagents, either with the primary object of learning how they would affect it, or 

 with the purpose of observing whether or not they altered its power to poison. 



Nitric acid threw down from Crotalus venom a dense precipitate. Added in 

 excess, it re-dissolved the larger part of the precipitate, and formed a thin yellow- 

 ish fluid, in which floated undissolved minute yellow flocculi. Liquor ammonia), 

 added in excess, did not re-precipitate the dissolved material. 



Chlorohydric acid threw down a dense white precipitate, and, added in excess, 

 completely re-dissolved it, forming a solution colorless, or of a pale yellow, from 

 which ammonia in excess re-precipitated the dissolved substance in opaque white 

 masses. 



Sulphuric acid threw down from the venom a white precipitate, which, if the 

 acid were hastily added, or if heated, became yellow or brown. 



Acetic acid caused no precipitate from the venom, whether added to it in large 

 or small amount. 



Tannic acid produced a dense white precipitate, which proved to be insoluble in 

 water, and in an excess of the acid, but was re-dissolved on the addition of a small 

 amount of ammonia. 



• These observations were amply verified at another time, when larger quantities of venom were used. 

 5 



