CHEMICAL THEORY OF THE NERVE CURRENT. 199 



while he explains further that the matter of the nerve 

 cell is the seat " of destructive molecular changes 

 and disenffa^ement of motion !" 



248. Clieiuical theory of the nerve current. — A 



chemical theory was long held concerning the nature 

 of muscular action, but it was at last admitted, as 

 was, indeed, apparent from the very first, that muscles 

 would have to be destroyed and reformed at a far 

 more rapid rate than it was on other grounds reason- 

 able to suppose possible, if the great amount of energy 

 manifested during their action was really due to 

 chemical decomposition of the tissue of the muscle 

 itself. There was, in fact, no evidence whatever, ex- 

 cept that which was distilled from the imagination of 

 the chemist, for the conclusion that muscular tissue 

 did undergo rapid disintegration and reconstruction. 

 From my own investigations of muscular fibres in 

 various animals, I felt quite sure at the very time when 

 these chemical doctrines were in high favour, that 

 the conclusions were thoroughly erroneous. Prom 

 the study of muscular tissue at difi"erent periods of 

 development, and the consideration of various cir- 

 cumstances connected with the growth of muscle and 

 its relation to other textures in a variety of animals, 

 particularly in the class of insects, I was convinced 

 that muscle was a sloidy growing tissue, and that the 

 work it performed was certainly not due to the 

 chemical decomposition of its material particles. 

 ^Nevertheless the fact of the change in the reaction of 

 muscle from alkaline to acid is still urged in favoiir 

 of the doctrine, and some have af&rmed that a similar 

 change occurs in nerve. In spite of the statements 

 of Liebreich, Heidenhain, and other observers to 

 the direct contraiy, the view that nerve energy 

 is stored up in chemical compounds which undergo 

 chemical change during nerve action is still taught. 

 That such an idea should be stated at all betrays igno- 

 rance of the character of the axis cylinder of the nerve 



