80 ELECTHIC CONDITION OF THE OHAP. VIII. 



When the muscles and nerves had been placed in 

 strong concentrated solutions, so as to act chemically 

 upon the tissues, and different portions of them 

 were then formed into circuits, the effects upon the 

 needle were sometimes very powerful, sometimes 

 null ; the results, however, could never be predicated, 

 and were evidently due to the chemical actions set 

 up. 



If the muscle or nerve was placed in hot water at 

 the temperature of 180°, or in cold water at the 

 temperature of 33°, so as to freeze it, the muscle or 

 nerve current was seldom obtained. 



If the muscle or nerve was squeezed up into a 

 mass, so as to destroy its structure by mechanical 

 means, no effect at all analogous to that of the mus- 

 cular or nerve current was obtained ; effects upon 

 the needle were occasionally produced, but pre- 

 senting quite a different character. 



These results only tend to prove liie conclusions 

 already deduced by Matteucci and Du Bois Ret- 

 MOND, of the dependence of the muscular and nerve 

 current upon the normal or vitai condition of these 

 two tissues, and go far to shew, that these currents 

 cannot be entirely due to the heterogeneity of the parts 

 in the circuit, but that whatever destroys the normal 

 or healthy slate of the tissues, destroys also the 

 conditions upon which the muscular or nerve current 

 depends. 



If the existence of the muscular and nerve currents 

 be dependent entirely upon the changes which occur 



