130 ADDITIONAL NOTES. 



the insensibility which it occasioned began to 

 subside at the end of 40 minutes. It is easy 

 to understand that the effects of the impression 

 made by the poison on the sentient extremities 

 of the nerves, like those of a concussion of the 

 brain, should thus subside, but it does not seem 

 very probable that so large a quantity of spirit 

 should have been absorbed into the circulation 

 and then ejected from it in so short a space of 

 time ; nor does this at all correspond with what 

 happens where intoxication is gradually induced 

 in the human subject, and where there can be 

 no doubt as to the alcohol having entered the 

 circulation. 



3. That poisons may have a local action on 

 the nerves, so as to affect distant organs, in- 

 dependently of their admission into the blood, 

 is proved by the well known fact to which I 

 have adverted elsewhere, of the pupil of one 

 eye becoming dilated in consequence of the ap- 

 plication of the extract of belladonna to the 

 conjunctiva of the same eye, or the neighbour- 

 ing part of the integuments, while the pupil of 

 the other is wholly unaffected by it. 



4. There are numerous examples of mecha- 

 nical impressions on the sentient extremities of 

 the nerves, the influence of which can be propa- 

 gated only through the medium of the nerves 

 themselves, affecting the brain so as to occasion 

 a temporary suspension of its functions. Every 

 practical surgeon will recal to his mind numerous 

 instances of a common, simple, and bloodless 



