110 Dr. A. P. W. Philip onthe 



stant, or constantly renewed action of stimuli over which the 

 will has no power ; while the sole stimulus of the muscles of 

 voluntary motion is wholly subjected to it. Besides, the action 

 of the former muscles produce no sensible effect. We will to 

 move a limb, not to excite a muscle ; we wish to handle, for 

 example, and on trial find that we can move the fingers, but 

 there is no act of volition which could be performed through the 

 medium of the heart and blood-vessels. If we had no wish to 

 handle, the muscles of the fingers, of course, could never have 

 become subject to the will. Few have any command over those 

 of the external ear ; and it deserves to be remarked, that the 

 will influences the rectum and bladder, the only internal organs 

 which can assist in accomplishing an end desired. It seems 

 unnecessary to add, after what has been said, that the ganglions 

 by no means intercept the influence of the brain and spinal 

 marrow in its course to the muscles of involuntary motion, as 

 some have supposed. 



From all that has been said, it follows that the muscular 

 power in every part of the body, depends on the constitution of 

 the muscle itself, but is also in every instance under the influ- 

 ence of the nervous system. Let us inquire whether, in other 

 parts of nature, any analogous power exists. It is, of course, 

 in animated nature alone that we can look for it. It might not 

 be difficult, perhaps, to prove that a power exists in the vege- 

 table world, in all essential respects analogous to that of the 

 muscular fibre, but this subject does not come within the scope 

 of the present paper. The analogy which the coagulation of 

 the blood bears to the contraction of that fibre, demands more 

 attention here. 



I shall only refer to the arguments of Mr. Hunter, for the vita- 

 lity of the blood, a position so clearly established by this great 

 physiologist *, that we may in our day safely assume it as 

 one requiring no additional proof, but I shall beg leave to 

 quote his observations on the analogy observed between mus- 

 cular contraction, and the coagulation of the blood. 



• Mr. Hunter's Treatise on Inflammation and Gun-shot ff'ounds,vo\. I. 



