042 PHILOSOPHICAL TRANSACTIONS. [aNNO 1780. 



longed; but my experiments proved it was of the same strength with that of the 

 Ticunas, so that I do not think it at all material to distinguish the one from the 

 other. 



Much has been written by authors concerning the activity of these American 

 poisons: so that I thought it proper to make my experiments by degrees, and 

 with all possible precaution. The very smell of them was thought to be noxious, 

 on the bare opening of the vessel; and if the least of their particles was suffered 

 to diffuse itself through the air, some grievous disorder, and even death itself, 

 was apprehended; so, at least, we read in the best authors. I began therefore, 

 as soon as the vessel which contained the poison was open, by making a young 

 pigeon breathe the air of it; for which purpose I held its head within the vessel 

 for a few minutes. On taking it out I found it as well as at first. I loosened 

 with a pen-knife many pieces of the poison, in order to have a little dust in the 

 vessel, and then again immersed the head of the pigeon; but I found that in this 

 2d experiment also the animal suffered nothing. 



From that moment I made no more difficulty of exposing myself to that va- 

 pour, and of smelling the effluvia, which seemed disagreeable and nauseous. 

 Many of the particles entered my mouth with the air, and I found that they had 

 a taste something like liquorice. The smell therefore of this poieon, when dry, 

 is perfectly innocent; as are also the particles which enter with the air into the 

 mouth and nose, and thence go to the lungs. 



But the case in which it seems that this poison is most dreaded, though its 

 application be still external, is, when it is reduced to vapour or smoke by burn- 

 ing on the coals, or when, after boiling a considerable time, it rises in dense 

 fumes. I wished to try it in both these ways, and therefore threw many pieces 

 of the dry poison on burning coals, and caused the pigeon to breathe the fumes, 

 by holding its head in the middle of them ; but it never showed any signs of suf- 

 fering pain. I went still further: I took a glass tube 6 inches long, and 4 wide, 

 and filled it full of this dense and white fume, and then introduced the same 

 pigeon into it; but it showed no more signs of suffering than if it had been lield 

 in the fumes of burning sugar. I afterwards boiled a good quantity of it in an 

 earthen vessel. I exposed the pigeon to the vapours both when the poison began 

 to have some consistence, and when, by more boiling, it began to burn to the 

 sides of the vessel, and to be reduced into very dense vapours, and to a coal ; 

 but still the animal suffered nothing from these trials. I then made no scruple 

 of freely smelling it and exposing myself to tlie fumes of it. The odour of the 

 dry poison, when burnt on the coals, is very disgusting, and smells like burnt 

 excrement. 



From all these experiments I draw this conclusion, to wit, that the vapours 

 or fumes of the American poison, when smelled or breathed, are innocent. Mr. 



