126 BLBCTEIC FOECE CHAP. X. §. I. 



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 : mine 

 has been to ascertain whether any force is evolved 

 during muscular contraction ; Dn Bois Retmond's, 

 whether the muscular current is affected dwring 

 muscular contraction. The importance of Du Bois 

 Reymond's researches cannot be denied ; but it 

 appears to be, and is, of extreme importance that 

 the two questions should be kept perfectly distinct, 

 although perhaps intimately connected with each 

 other. 



The results of my inquiries lead me 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. I am perfectly aware of the objections 

 that may be urged in reference to the fish being 

 provided with a special apparatus ; and in my first 

 endeavours to obtain some result with the galva- 

 nometer, in which I failed to obtain any evidence of 

 the existence of a force being evolved, I was then 

 led to the conclusion as to the improbability of any 

 force becoming free, as it were, during muscular 

 contraction ; that whatever force might be evolved 

 would be expended or converted during that act; 

 but I could never get over the difficulty which the 

 results of Mattexjcci, obtained by means of the frog, 

 presented for consideration, and which is doubly 

 increased by the results that have now been related 



