1 76 On Ihe different Modes in which Death 



resembling those which take place in a person who is 

 dying from haemorrhage. 



There remains an interesting subject of inquiry, "through 

 what medium do poisons influence the brain when appHed 

 to wounds?" That poisons apphed in this manner do not 

 produce their efiects 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 produce their effect, and 

 vice versa. 



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 absorbent 

 vessels. 



3. By passing directly into the circulation through the 

 divided veins. 



Exp. 25. In order to ascertain whether the woorara acts 

 through the medium of the nerves, I exposed the axilla of 

 a rabbit, and divided the spinal nerves supplying the upper 

 extremity, just before they unite to form the axillary plexus. 

 The operation was performed with the greatest care. I not 

 only divided every nervous filament, however small, which 

 I could detect, but every portion of cellular membrane in 

 the axilla, so that the artery and vein were left entirely in- 

 sulated. 1 then made two wounds in the fore-arrp, and 

 inserted into them some of the woorara formed into a paste. 

 Fourteen minutes after the poison was applied, the hind 

 legs became paralytic, and in ten minutes more he died, 

 with symptoms precisely similar to those which took place 

 in the former experiments, and the heart continued to act 

 after apparent death. On dissection, the nerves of the upper 

 extremity were particularly examined, but not the smallest 

 filament could be found undivided. 



I made the following experiment, to ascertain whether the 

 woorara passes into the circulation through the absorbent 

 vessels. 



Exp. 26. I tied a ligature round the thoracic duct of a 

 dog, just before it perforates the angle of the left subclavian 

 and jugular veins. I then made two wounds in the left 

 hind leg, and introduced some of the woorara in powder into 

 them. In less than a quarter of an hour he became affected 

 with the usual symptoms, and died in a few minutes after- 

 wards. 



After 



