270 On the Agency of Nerves. 



the connexion of the nervous system with the organic functions* 

 of the body are warranted by the facts that we possess; and, in 

 particular, to state t 1-i doubts that have occurred to me in regard 

 to the doctrine, that a constant agency of nerves is concerned 

 in the performance of these functions. If it shall appear, that 

 opinions have been prevalent on this subject, which are not only 

 not proved, but are rendered exceedingly improbable, by know- 

 ledge already in our possession, it must be admitted that it is 

 important, as a preliminary to farther investigation of the facts, 

 to have these opinions corrected. And on the other hand, if 

 the objections which I state are founded on erroneous or im- 

 perfect notions of the facts that have been observed, these facts 

 may be easily stated in such a way as to obviate the objections, 

 and to shew, beyond doubt, that the conclusions have been fairly 

 deduced from them. 



2. Dr. Philip thinks, that in asserting " that in the muscles 

 of involuntary motion, the nervous influence produces an altera- 

 tion in the vital power or tendency to contraction," I have 

 advanced an opinion altogether new, and untenable. Now I 

 object to the term nervous influence on this as on other occasions, 

 on account of its vagueness, and of its apparently implying a 

 , theory, the truth of which I very much doubt. But the state- 

 ment, which I made, that the vital power, or tendency to 

 contraction of muscular fibres, and particularly of the involuntary 

 muscles, may be altered or even destroyed, by impressions made 

 on the nervous system, is one, the correctness of which I apprehend 

 Dr. Philip could not have disputed, if he had not misappre- 

 hended my meaning in the above sentence ; because my intention 

 was, not to advance a speculative opinion, but to express a gene- 

 ral fact, the truth of which is no where better illustrated than in 

 his own works, although his mode of expressing it seems to me 

 objectionable. 



Dr. Philip (pp. 243, 244) refers to twelve experiments of his 



* By the term organic functions I mean those which take place in the 

 natural state, without the intervention or consciousness of the mind. 



