70 On Pithing Cattle. 



seem to proceed from pain, are not always really accom- 

 panied with sensation. 



" To constitute pain, there must be a communication 

 between the injured organ and the brain. 



*' The heart of a viper pulsates after being taken out of 

 the body ; and that pulsation is increased it it be goaded 

 with a pin. Limbs suddenly separated from the human 

 body sometimes start and twitch for a few moments. The 

 viper cannot be said to feel pain on its heart being pricked 

 with a pin : nor would any man who saw his own fintrcr 

 contract from electricity or heat, after it was cut oft', fancy 

 it suffered pain. The pain in both instances is in the part 

 only from whence the separation took place. 



" Perception, and the power of exertion, are derived 

 from the brain in the skull and back-bone. That part 

 which lies in the skull seems principally to supply our 

 senses and appetites with nervous energy ; and that part 

 which lies in the spine, and is called marrow, is more par- 

 ticularly appropriated to the action of the large locomotive 

 muscles, 



'* An injury to the skull not sufficient immediately to 

 take away life, often leaves the patient with the power of 

 moving his limbs, though without any feeling or perception, 

 lying in a profound apoplectic sleep. 



" On the contrary, an injury to the spine leaves the 

 power of perception perfect, though the limbs are immove- 

 able ; but as life depends more on the functions of the 

 brain and of the lungs, than on the spinal marrow and its 

 dependent, locomotive muscles, the animal feels and lives 

 longer on its sustaining a given injury in the spinal marrow 

 than on a fracture or concussion of the head*. 



*^J. B. 



* That perception mav remain in the head, and respi'-ation be conti- 

 nued after the division of the medulla spinalis, will be evident to any one 

 who consults the anatomy of those parts. 



Jn the human subject, the par vagum, or eighth pair of nerves, ari'^ca 

 from the corpora olivaria of the medulla oblong;ita, and passes out of the 

 cranium tiirough the foramena laceia into the neck, thorax, and abdomen, 

 sending off branches to the tongue, larynx, pharynx, lungs, and abdomi- 

 nal viscera. 



Cuvier, in his Lemons iTAnaioniie compariic, after stating the course of 

 this nerve in the human subject, observes also, 



" Dans Ics mainmiferes. 



'« Cette distribution du ncrf vague etoit a-peu-pres !a mcmc dans quatre 

 ou cinq espcces do mammifctes sur Icsqucls nous avons fait <lcs rtchcrthi s 

 a cet cgard. Le 'veau seul nous a oftcrtunt panicularite que nous avons 

 indiquce a I'article du nerf facial ; mais Ics anastomoses avec le grand 

 sympathique, Ics ncrfs recurrcrs, les plexus cardiaques et pulmonaircs ne 



nous 



