General Principles of Physiology . 261 



Art. III. J Review of some of the General Principles of 

 Physiology, with the practical Results to which they have 

 led*. By A. P. W. Philip, M. D., F. R. S. Edinb. 



[Continued from page 113.] 



We are now to direct our attention to the phenomena of the 

 nervous system. Under this term is generally included the 

 sensorial as well as nervous system, properly so called. From 

 a careful review of the functions of these systems, however, it 

 will appear, I think, that they do not difFer less from each 

 other than from the muscular system. 



M. le Gallois, as far as I know, is the only author who has 

 endeavoured by experiments to draw a line of distinction be- 

 tween them. It is unnecessary, however, to examine the opinion 

 he has advanced, as many of the facts which I shall have occa- 

 sion to state will be found incompatible with it. After review- 

 ing the phenomena of the nervous system, properly so called, 

 we shall be better prepared to enter on this question. 



The functions of the nervous are much more complicated 

 than those of the muscular system. The first we shall consider 

 is one on which I have already been necessarily led to make 

 some observations. We have seen that the influence of the 

 nervous system is the only stimulus of the muscles of volun- 

 tary motion, and that it is also capable of exciting those of 

 involuntary motion, although in their usual functions the latter 

 are excited by other means. Here the question arises, if the 

 nervous system be not concerned in the usual functions of these 

 muscles, why are they universally subjected to its influence ? 

 This question we are not prepared to consider till we have takea 

 a view of some of the other functions of the nervous system 5 



• Errata in the first part of this paper :— Page 97, 1. 22, for matter 

 r. them. Some infer from the evident dependence of the phenomena of 

 the vital principle on the due mechanism of the living body, that it is the 

 immediate result of that mechanism ; but this dependence would not be 

 less, were the vital principle something superadded to bodies, as electri- 

 city and magnetism are by many supposed to be. There is nothing in the 

 phenomena of tlie vital principle which can authorize either inference. 

 I'age llo, 1. 4, /»? produce r. produces. 



