RAPIDITY OF NERVOUS CONDUCTION. 99 



animal, and, when there was evidently a conduction in both 

 directions, as evinced by pain and muscular action, failed to 

 detect the slightest evidence of an electric current with the 

 most delicate galvanometer that could be constructed. The 

 fact of the absence of a galvanic current in nerves during 

 their physiological action was even more strikingly illus- 

 trated by Matteucci, who demonstrated, in the electric eel, 

 that although the electric discharges from the peculiar or- 

 gans of this animal were under the control of the nervous 

 system, and could be excited by galvanic stimulation of the 

 proper nerves immediately after death, no galvanic current 

 existed in these nerves during their physiological action. 1 



AVhen we abandon the hypothesis of the identity of 

 nerve-force with electricity, we are compelled to admit that 

 the agent generated by the nerve-centres is sui generis, and 

 not to be compared with any force generated outside of liv- 

 ing organisms or artificially produced by direct stimulation 

 of the nerves ; but we admit, nevertheless, the fact that 

 electricity may be generated by animals, as the electric fish- 

 es, and that electric currents exist in different anatomical 

 elements of the living body, including the nerves, under cer- 

 tain conditions. Our study of the nerve-force, then, leaving 

 its essential nature unexplained, is mainly confined to a de- 

 scription of its attending phenomena. 



Rapidity of Nervous Conduction. Until within the last 

 few years, it has been assumed by many that the rapidity of 

 nervous conduction was one of those problems in human 

 physiology that could never be satisfactorily resolved ; and 

 those who have investigated the history of this question, 

 which dates from before the time of Haller, have often 

 quoted the words of Miiller, who says, in his great wo^k 

 on the " Elements of Physiology," that " we shall probably 

 never attain the power of measuring the velocity of nervous 

 action ; for we have not the opportunity of comparing its 



1 LONGET, Traite de physiologic, Paris, 1869, tome ill, p. 276, et seq. 



