VOL. LXX.J PHILOSOPHICAL TRANSACTIONS. 601' 



even in rabbits of scarcely a pound weight it did not produce any sensible 

 alteration. 



I pierced the skin of several animals with the arrows, and let them remain in 

 it several whole days, without being able to perceive that the animal was affected 

 with the poison ; but when I perforated the muscles with the arrows, and left 

 them there, its effects were very observable. Several animals died in this 

 manner, and that with all the visible signs of the poison, and with all the signs 

 or symptoms with which animals die who are killed by the American poison : it 

 is true however, that none of them died, or were even sensibly affected, till 

 after several hours ; so that this poison seems not to differ essentially from the 

 other. It perfectly agrees with it when examined with the microscope, when 

 mixed with turnsol, when thrown into the eyes of animals, when tasted with the 

 tongue, and when chewed between the teeth ; on the other hand, it does not 

 dissolve so well in water as the other poison, for indeed a great part of it remains 

 insoluble in that fluid. The only consequence which can be deduced from the 

 facts above-mentioned, is, that the poison is much more noxious when applied 

 to the muscles, than when applied to the skin, in which respect also it agrees 

 very well with the other poisons. This still more convinces us, that the imme- 

 diate action of these poisons is not against the nerves, since it is certain, that the 

 skin is more sensible than the muscles, and that it is all intersected with nerves. 



I have also made a few experiments on the oil of tobacco, the results of which 

 I thought it might not be improper briefly to relate in this place. 



Experiments made tvith Oil of Tobacco. — I made a small incision in the right 

 thigh of a pigeon, and applied to it 1 drop of the oil of tobacco, and in 2 mi- 

 nutes it lost the pse of the right foot. I repeated the same experiment on 

 another pigeon, with exactly the same effect. I made a slight wound in the 

 muscles of the breast of a pigeon, and applied the oil of tobacco to it ; and in 3 

 minutes the animal could not stand on its left foot. And this same experiment 

 was repeated on another pigeon, with the same success. Into the muscles of the 

 breast of a pigeon I introduced a tooth-pick steeped in the oil of tobacco, and a 

 few seconds after the pigeon fell down seemingly dead. Having applied the oil 

 of tobacco to 2 other pigeons, they threw up several times all the food they had 

 eaten. Two others, treated in the same manner, but with empty stomachs, 

 made many efforts to vomit. In general, I found the vomiting to be a constant 

 effect of this poison ; but the loss of motion in the part to which the poison is 

 applied, is only accidental. None of the animals however died by the applica- 

 tion of the oil of tobacco. 



Experiments with the JVater of the Lauro-Cerasus. — I shall conclude my ex- 

 periments on poisons with an account of some that I have made on a poison, 

 which has for some years become remarkable in Europe. This poison is the 



