CHAP. IX. MnSCDLAR AND NERVOUS TISSUES. 101 



end of the nerve, in order to arouse muscular con- 

 toaction. It need scarcely be added, that the mus- 

 cular and nerve currents may, however, be obtained 

 under these circumstances between the separated 

 portions. 



The results of these investigations lead to the con- 

 clusion, that the muscular and the nervous tissues 

 are both, during life, in a polarized state or condition, 

 and from our inability to increase this state by any 

 artificial means, it being produced and maintained 

 by nutrition, would almost stamp it as being peculiar 

 to the organic kingdom. All the experiments tend, 

 moreover, to shew, that it must be by acting upon 

 and employing the means by which it is produced 

 and maintained, viz. through the act of nutrition, 

 that we can hope to succeed ; and it is reasonable 

 to suppose, that whatever would increase this act 

 would also iiicrease this condition, as shewn by an 

 increase in the muscular and nerve currents under 

 these circumstances. That tetanic contractions may 

 be produced by means of the electric current upon 

 the nerve, might perhaps be adduced as an argument 

 ,,in favour of the supposition that an increased action 

 of the nerve is produced, and, consequently, aa 

 increase in the polarized condition ; but how far the 

 peculiar state of the nerve which produces tetanic 

 constritctions under these circumstances is due to an 

 increase of the normal polarized condition is question- 

 able, as I shall endeavour to point out. 



When an electric current from a voltaic circle or 



