with Chemhtrij and the Xattiral Sciences. 319 



emanates from the brain ; and that the perception of pain, on 

 the other hand, ascends to it from the origin of the nerves. 



Physicians, then, who mean to employ electricity in the heal- 

 ing art, should pay attention to two especial circumstances in 

 transmitting the current along the course of the nerve. The 

 first refers to its direction, and the second to its continuance. 

 Respecting the former the effects vary according to the direc- 

 tion ; and, regarding the latter, the excitability becomes exhaust- 

 ed in the ratio of the time. 



In the living animal there exists a power which, by degrees, 

 repairs the injury produced on the organs of motion by the ac- 

 tion of the current, and which begins to exercise its restorative 

 agency so soon as the current is interrupted. This repairing 

 principle does not cease to operate, even with life. For a time 

 and in a certain extent, it manifests itself, even after death. 



Phenomena of a different kind also supply us with informa- 

 tion concerning the agency which electricity may play in the 

 phenomena of life. We here allude to the powers possessed 

 by electrical fishes, and which we have studied, along with M. 

 Breschet, upon the shores of the Adriatic. We have determined, 

 by the help of all the means which science puts at our disposal, 

 that the effects produced were assuredly owing to electricity ; 

 and that the shock of the torpedo was the result of a discharge 

 analogous to that of a Leyden jar, arranged in such a way, that 

 the upper surface of the electric organ is the site of positive elec- 

 tricity, and the lower surface that of negative electricity. In 

 suitably arranging the apparatus, we have since seen the spark 

 which accompanies this discharge. The torpedo, then, is a true 

 living electrical machine. 



In collecting together all the observations which have hitherto 

 been made respecting the physiological action of electricity and 

 the powers of electrical fishes, we have succeeded in establishing 

 a theory concerning the contractions which may satisfy the im- 

 mediate requirements of science. We conceive the organic par- 

 ticles of the muscles and the nerves during life, and for a short 

 time after death, as being in a state of unstable equilibrium, but 

 which the slightest causes disturb with the greatest facility. This 

 instability appears to be one of the attributes of life, for it ceases 



