VEGETABLE POISONS. 43 



but, though I never failed to find urine in the 

 bladder, I never detected rhubarb in it. 



The including the termination of the thoracic 

 duct in a ligature does not prevent spirits, when 

 taken into the stomach, from producing their 

 usual effects on the nervous system: but sub- 

 sequent observations, which Mr. Home has already 

 communicated to this Society, have shown that no 

 conclusion can be drawn from this experiment. 



That a poison may affect a distant organ, 

 through the medium of the nerves, without enter- 

 ing the circulation, is proved by the well-known 

 circumstance of a solution of the extract of bella- 

 donna, when applied to the tunica conjunctiva 

 of the eye, occasioning dilatation of the pupil of 

 the same eye, though no other part of the system 

 is affected. 



It has been formerly supposed by Dr. Mead 

 and other physiologists, that a poison may 

 produce death by acting on the extremities of 

 the nerves of the stomach and intestines, without 

 being absorbed into the circulation. That it 

 should by these means be capable of affecting 

 the brain is in no degree remarkable, considering 

 the numerous and various sympathies between 

 this organ and the alimentary canal, evidently 

 independent of any other communication than 

 the nerves. * 



* See Additional Note B. 



