658 PHILOSOPHICAL TRANSACTIONS. [aNNO l/SO. 



nerves. I prepared therefore the sciatic nerve of a rabbit as above, and I pierced 

 it several times through with a lancet, before I applied the poison to it, and then 

 put the poison exactly on the wounded part of the nerve. The rabbit lived 5 

 days, and then died without any apparent illness. I repeated the experiment on 

 another rabbit with the same circumstances, and it was still living 8 days after. 



I varied the experiment a little on the nerves of 3 other rabbits. Instead of 

 wounding the nerve in many places, I made an incision, above -p^ of an i"ch 

 long, into it, and introduced into the slit some threads, well soaked in the 

 poison, and covered the whole up very well. One of these died in 6o hours, but 

 seemingly not from the poison ; the other 2 were living 8 days after. I thought 

 it necessary to vary also this 2d kind of experiment, and to cut the nerve as I 

 had done in examining the poison of the viper. In consequence I cut the sciatic 

 nerve as far as I could from the top, to be able easily to wrap the rags about it. 

 The detached part of the nerve in the largest rabbits might be about an inch 

 and a half. Having placed the nerve on the rags I covered it well with poison 

 in the part where it was cut, and covered the whole up with the rags as usual. 

 I performed this experiment on 6 rabbits. Two of them died in 40 hours ; 2 

 others in 3 days ; but the remaining 2 were living 4 days after. For a compara- 

 tive experiment I prepared, as above, the nerves of 2 other rabbits, which I cut, 

 but did not apply the poison to : one of them died in 36 hours, but the other 

 was living the 3d day after. 



The uniformity of the results of these experiments on the nerves induced me 

 to think it quite superfluous to repeat them ; and I am persuaded they will leave 

 no doubt with anyone who is accustomed to experiments, and not prejudiced in 

 favour of ill-grounded hypotheses. Hence it follows, that the American poison 

 is not poisonous when applied to the nerves ; and that in such cases it produces 

 no sensible disorder in the economy of living animals : this is what the experi- 

 ment directly establishes. But to suppose what has not been observed ; to be- 

 lieve what is contradicted by experiments, is dreaming in philosophy, running 

 after error instead of truth, and adopting mere fancies for facts. The American 

 poison, similar in this respect to the poison of the viper, is not poisonous, but 

 quite innoxious, applied in any manner whatever, to the nerves. But it kills in 

 a moment, and with the smallest quantity, when introduced immediately into the 

 blood by the jugular, as does likewise the poison of the viper. Its action is 

 therefore all upon the blood, and not in the least on the nerves, whatever may 

 be the principle or the mechanism by which death is produced. The effects and 

 alterations caused in the blood by the poison of the viper are more determinate 

 and more evident. Here a coagulation undeniably happens, wliich is not ob- 

 servable in the blood of animals killed by the American poison ; but the latter 

 produces a great change in the lungs, which are greatly disordered by it. 



