VOL. LXX.] PHILOSOPHICAL TBANSACTIONS. 605 



amount of 5 drops or upwards, in the same manner as I had done the poison of 

 the viper and the American poison, yet the animal showed no signs of suffering. 

 I suspected I had not performed the operation right ; that I had not introduced 

 any of the water into the vessels; and that the syringe had insinuated itself into 

 the cellular membrane. I therefore repeated the experiment, and again intro- 

 duced into the jugular a quantity of poison, perhaps 3 or 4 times greater, and 1 

 was very careful to make the point of the syringe enter the jugular properly be- 

 fore I introduced the poison, that the poison should not by any means turn back 

 again ; yet still the animal was not affected by it, but continued as lively as ever. 

 I was more surprized than satisfied with all this. I could not persuade myself, 

 that the water of the Lauro-Cerasus was not a poison, and a very powerful one 

 too, when introduced into the blood, since it was poisonous when applied to 

 wounds in the flesh, and taken by the mouth, though inactive and harmless 

 when applied to the nerves. I therefore again repeated the experiment, and this 

 time I introduced by the jugular a whole tea-spoonful of the Laurel-water ; and 

 yet still the animal was not affected. I also tried the same experiment on another 

 rabbit, into the jugulars of which I introduced a large tea-spoonful of the same 

 poison ; yet neither did this rabbit show any signs of suffering, either then or 

 afterwards. 



The unexpected result of these experiments threw me into a very great uncer- 

 tainty concerning the action of this poison : I could neither comprehend the 

 mode of its operation, nor even on what parts it acted when taken by the 

 mouth or applied to wounds. Here all was confusion : it was found neither to 

 act on the nerves nor on the blood, and yet it killed, and that in an instant, 

 when introduced into the stomach by the mouth. 



Is there then a new way of destroying the life of animals different from that 

 of the blood and of the nerves ? The loss of motion, and that too in a few 

 seconds, in such animals as eels, which in other cases continue to move for hours 

 after the head is cut off, and even after they are cut in pieces, would make one ■ 

 believe, that the irritability of the muscular fibres was affected by this poison. 

 It is true indeed, that the heart continues to move in those animals ; but that 

 motion is very much lessened, and lasts but for a very short time. In the warm- 

 blooded animals, just killed by this poison, there still exists some motion, but it 

 is very little ; and though their heart continues to beat for some time, it beats 

 much less than when they are killed by other means. The irritability is cer- 

 tainly diminished very much in many animals, and in many others entirely 

 destroyed ; by whatever means the poison kills in so short a time, and however 

 obscure the mechanism may be by which the muscular fibres lose their irritability. 

 We must confess our ignorance in our researches into nature. When we think 

 we have accomplislied every thing, we suddenly find ourselves just where we 



VOL. XIV. 4 Q 



