OF THE NERVE CUKKENT. 197 



as tlie sources of nervous power, wliile I consider that 

 the caudate nerve-cells are more probably concerned 

 in the radiation of the nerve-currents.* 



My views concerning the arrangement and pro- 

 bable mode of action of the two classes of cells will 

 be understood if the diagrams in plate IV, be re- 

 ferred to. The reader must suppose that the part of 

 the diagram x'epresenting the peripheiy is situated 

 at a great distance from the central cells, instead of 

 very close to them,, as indicated in the drawing. 

 The explanation under each fig-ure should be read 

 carefully. 



245. Of the nerve current. — The nature of the 

 nerve current is not known, but the general opinion 

 of physiologists is, that it is some mode of force, per- 

 haps, correlated with heat, electricity, &c., but not 

 exactly identical with any form or mode of energy 

 known or of which we have as yet any experience. The 

 arguments upon which this view is founded appear, 

 however, to me very inconclusive. In the first place, 

 I would ask, if it is reasonable for a scientific man to 

 assitme the existence of new modes or forms of force. 

 Secondly, much of the evidence we have unquestion- 

 ably favours the view that the nerve current is elec- 

 tricity, for many, indeed most, of the phenomena 

 familiar to us may be explained upon this view. 

 Lastly, some physiologists have sought to account for 

 the wonderful phenomena of the nervous system by 

 supposing that some force or power of a pecuhar and 

 exceptional kind is at work in nerve systems only. 

 Now, I shall endeavour to show that if electricity could 

 be made to travel in difierent directions, and the cur- 

 rents combined in various ways and made to traverse 

 series of condiicfcing cords very specially arranged, ac- 

 cording to design, the phenomena of nervous action 

 might be accounted for without resorting to the hypo- 



* See a paper by me in the " Microscopical Journal" for 

 AprH, 1869, and " The Mystery of Life." 



