128 Dr. Davy's observations on the 



have ascertained, the following properties. The greater 

 part of it is soluble in alcohol and water. The aqueous 

 solution is slightly viscid, and does not pass readily through 

 a common philter. It is not precipitated by acetate of lead ; 

 and its transparency is very slightly impaired by corrosive 

 sublimate. The substance obtained by evaporation, both 

 from the aqueous and alcoholic solution, is light yellow, and 

 transparent ; has a faint and peculiar smell different from 

 that of the toad, and it is slightly bitter, and very acrid, 

 acting on the tongue like the extract of aconite prepared in 

 vacuo, and even occasioning a smarting sensation when 

 applied to the skin of the hand, and its effect lasts two or 

 three hours. When heated, it readily melts, burns with a 

 bright flame, and does not emit an ammoniacal odour. It is 

 neither acid or alkaline, judging from its not changing the 

 colour of litmus or turmeric paper. Caustic ammonia dis- 

 solves it ; the solution remains acrid. Nitric acid also 

 dissolves it ; the solution is of a purple colour ; neutralized 

 by an alkali it is less acrid, as if partially decomposed. The 

 small portion of the fluid, not soluble either in water or 

 alcohol, and to which it owes its consistence, is probably a 

 variety of albumen ; and its appearance when burning would 

 seem to warrant this idea. 



Though this fluid of the toad is more acrid than the poisoi> 

 of the most venemous snakes, I do not find that it has any in-v 

 jurious, and much less fatal effect, when absorbed and carried 

 into the circulation. A chicken punctured with a lancet 

 dipped in it, received no inj ury : and in confirmation of this 

 statement I may remark, that though, as already observed, 

 it abounds chiefly in the integuments, it is not confined to 



