VEGETABLE POISONS. 63 



the brain or lungs. The convulsions, which occur 

 when the circulation has nearly ceased, probably 

 arise from the diminution of the supply of blood 

 to the brain, resembling those which accompany 

 death from hemorrhage. 



There remains an interesting subject of in- 

 quiry, "through what medium do poisons in- 

 fluence the brain when applied to wounds ? " 

 That poisons applied in this manner do not 

 produce their effects precisely in the same way 

 as poisons taken internally, is rendered probable 

 by this circumstance ; that some poisons, which 

 are very powerful when applied to wounds even 

 in small quantities, are either altogether in- 

 efficient when taken internally, or require to be 

 given in very large quantities, in order to pro- 

 duce their effect, and vice versd. 



A poison applied to a wounded surface may 

 be supposed to act on the brain in one of three 

 ways : 



1. By means of the nerves, like poisons taken 

 internally. 



2. By passing into the circulation through the 

 lymphatic vessels. 



3. By passing directly into the circulation 

 through the divided veins. 



EXPERIMENT XXV. 



In order to ascertain whether the woorara 

 acts through the medium of the nerves, I ex- 

 posed the axilla of a rabbit, and divided the 



