during Muscular Contraction. 197 



we have such control over our expermients as to afford us faci- 

 lities favourable for eliminating sources of error^ how easily may 

 we conceive that they would apply with far greater force to 

 physiological researches devoid of such facilities. The strong 

 prejudices which exist in reference to electro-physiological in- 

 quiries cannot therefore be a matter of much surprise^ but must 

 create a great difficulty to any individual who shall attempt the 

 elucidation of any electro-physiological problem experimentally ; 

 for not only has he to satisfy, from the mixed character of the 

 inquiry, the extreme views of the physicist on the one hand, and 

 those of the physiologist on the other, but they also afford the 

 indolent inquirer a ready means of apparent refutation, and a 

 powerful weapon to the controversialist. That these opinions are 

 not ill-founded we might easily prove*. Feeling the importance 

 of basing the conclusions in these inquiries upon strictly experi- 

 mental evidence, in discussing the different views that may be 

 entertained in regard to the evidence vipon which our experi- 

 ments justify us in concluding that some force is evolved during 

 muscular contraction, we shall confine our observations to the 

 experimental results obtained by IMatteucci and Du Bois-Rey- 

 mond, and endeavour to avoid everything of a purely controver- 

 sial character. 



Matteuccif has proved and shown by means of the galvano- 

 scopic frog, that during muscular contraction the muscles of the 

 galvanoscopic frog may be excited to contract, and that for this 

 purpose it is not necessary that the nerve should be brought into 

 contact with different portions of the muscular fibre. In repeat- 

 ing these experiments, we have been able to confirm the results 

 obtained by Matteucci. 



Matteucci J, in his endeavours to ascertain whether the mus- 

 cular current was increased during muscular contraction by form- 

 ing piles with muscular elements, failed to obtain any decisive 

 result. Du Bois-Reymond, by means of his galvanometer, has 

 satisfactorily shown that when the electrodes are so arranged 

 with a muscular element that the current (muscular) passes 

 through the instrument, that then, upon the contraction of the 

 muscle, the needle of the instrument recedes, and this he calls 

 " the negative variation " of the muscular current. This fact, 

 established by Du Bois-Keymond, and also the results obtained 



* Strange to say, it has been urged that the time has not yet arrived for 

 the ])rosecution of these experiments. This is the only tangible objection 

 that the author has yet had an opportunity of refuting. Tliat objections 

 may be started he is perfectly convinced ; but as the inquiry jirofesses to be 

 experimental, the objections must be supported by experimental evidence 

 before he can notice them. 



t Phil. Trans. 1850. Ninth Series. J Ibid. 1845. 



