198 On the Force evolved during Mtiscular Contraction. 



by ]\Iatteucci, have beeu confirmed by some of oui- own experi- 

 ments. But we cannot help thinking with Matteucci*, that the 

 falhng or the receding of the needle in Du Bois-Reymond's 

 experiment may be attributed in a great measure to the variation 

 in the contacts between the surfaces of the muscle and the elec- 

 trodes during the act of contraction. We are not aware that 

 the existence of the muscular current is disputed by anyone ; it 

 has been attributed to niitritive actions by Matteuccif, and some 

 experiments of our own J tended to confirm the views of Mat- 

 teucci. We now have two distinct questions before us : — 1st, Is 

 there, or is there not, any force evolved during muscular con- 

 traction ? Sndly, Is the muscular current affected during muscular 

 contraction ? and this brings us to speak of the results we have 

 obtained in the present paper. 



Du Bois-lleymond's results lead him to consider that in the 

 frog the current is direct, and in man inverse, as shown by the 

 galvanometer. Our experiments lead us to believe that the 

 current is dii-ect in both instances. Upon carefully looking over 

 Du Bois Reymond'si^ last paper, it appears to us that he fre- 

 quently obtains the direct ciuTcnt ; but laying so much stress, 

 as he does, upon the necessity of a current (muscular) circulating 

 through the instrument prior to contraction before he can con- 

 clude that the resulting action upon the needle is what he calls 

 "the negative oscillation" of the muscular cm-rent, that his object 

 was to ascertain whether the muscular current in the human 

 subject was not aflfected during muscular contraction, as in the 

 frog. We may be mistaken in our opinion. As we have not 

 been able to obtain this inverse current, and if Du Bois-Reymond 

 has been endeavouring to obtain this inverse current to prove 

 " the negative variation " of the muscular current in the human 

 subject, then the object that each of us has had in view differs : 

 om's has been to ascertain whether any force is evolved during 

 muscular contraction ; Du Bois-Reymond's, whether the mus- 

 cular current is affected during muscular contraction. The 

 importance of Du Bois-Reymond's researches we do not deny ; 

 but it appears to us to be of extreme importance that the two 

 questions should be kept perfectly distinct, although perhaps 

 intimately connected with each other. 



The results of our inquiries lead us to believe, that during 

 muscular contraction a force is evolved, as in the fish, but that 

 it is only during extraordinary muscular exertion that it can 

 become manifest to the galvanometer. We are pei'fectly aware 



* Phil. Trans. 1850. Ninth Series. 



t Ibid. 1845, p. 301. 



X Proceedings of the Royal Society, Nov. 25, 1852. 



§ Bibliotheque Universelle de Geneve, Juin 1853. 



