VEGETABLE POISONS. 157 



in that case, with some few exceptions, injuring 

 principally the brain and nervous system; and 

 the mineral, the internal parts to which they are 

 immediately applied, and more remotely, the 

 distant organs. 



There ivS another class of poisons which may 

 be derived from any of the three kingdoms sepa- 

 rately, or in combination, that produce their 

 effects only through the medium of the lungs ; 

 and these have been denominated the gaseous 

 poisons, which we shall notice in another place; 

 confining ourobservations for the present, to those 

 which act upon the system through the medium 

 of the blood vessels and of the stomach; com- 

 mencing with the animal poisons. 



Animal poisons may be divided into three 

 classes. First, those which are introduced into 

 the system by the bite or sting of some venomous 

 animal. Secondly, certain animal subtances, 

 which, received into the stomach, produce poi- 

 sonous effects. And, thirdly, contagious poisons, 

 as the plague, contagious fever, small pox, and 

 the like; a history of which, as belonging more 

 especially to the province of medicine, we shall 

 omit in these lectures. 



In treating of venomous animals, it is not my 

 intention to give an account of each species, or 

 to enter into a particular history of their struc- 

 ture and economy. This would be foreign to 

 my present plan, and would serve to throw no 



