CHAP. Xr. CONCLUDING BBMAEKS. 151 



To suppose that the conditions may exist in the 

 one case and not in the other, and that the two 

 forces may still be the same, cannot be deemed 

 satisfactory to any experimentalist. If nerve force 

 be electric force, we have a right to ask for some 

 proof of it. The circuit form of the arrangement 

 exists in the transverse direction of a nerve, and we 

 can detect the necessary current, the so-called nerve 

 current. The effects here, however, are analogous 

 to those of a charged Leyden jar rather than to a 

 voltaic circle, as I have endeavoured to shew in 

 previous chapters, and to which I have already 

 referred. The very circumstance of our being able 

 to shew this state in the transverse direction, would 

 lead us to expect that we ought to be able to prove 

 its existence in the longitudinal direction, if it 

 existed. 



The subject under consideration involves, how- 

 ever, three distinct questions. Is*, Is nerve force 

 nothing more than the electric force which exists in 

 the nerve, and put into motion during nerve action ? 

 or, ^ndly, Is this electric force in the nerve converted, 

 as it is called, into nerve force during nerve action ? 

 or, Srdly, Is this electric condition of the tissue 

 merely a condition, and perhaps a necessary con- 

 dition, for the manifestation of nerve action ? 



In reply to the ifirst question, it may be observed, 

 that my experiments have failed to give the necessary 

 proof in favour of this supposition. 



In regard to the second question, if we could 



