to the Agency of (he Nei-ves. 121 



system upon the function of secretion, but an occasional and 

 controlling agency. 



3. But what appears to me to remove all doubt upon this 

 subject is the class of facts (very candidly acknowledged, but 

 I think not duly weighed, by Dr. Philip, — Experimental Inquiry, 

 S(c., p. 240,) in regard to secretion and nutrition taking place 

 where nervous influence cannot be supposed to operate ; in 

 vegetables, in the animals in which no nervous system has been 

 discovered, in the chick in ovo before any vestige of the brain 

 and spinal marrow can be traced, in the early part of the exis- 

 tence of the human foetus when the brain and nerves appear in- 

 capable of performing their functions, — but most of all, in the 

 cases, which are reported on unquestionable authority, of fcetuses 

 born alive without either brain or spinal marrow. 



Dr. Philip gets over this difficulty by supposing that there 

 may be some other apparatus, in all these cases, by which gal- 

 vanism may be applied to the blood, and which may therefore 

 supply the place of the nervous system. But this is obviously 

 supporting one hypothesis by means of another and a much 

 bolder one. That galvanism is at all concerned in secretion or 

 nutrition is a hypothesis which rests fundamentally upon two 

 suppositions, that galvanism is identical with nervous influence, 

 and that nervous influence is essential to secretion. If we put 

 nervous influence out of the question, we have no better evi- 

 dence of galvanism being at all concerned in secretion than 

 merely this, that it produces chemical effects on the blood, and 

 in particular coagulates its albumen, effects which are equally 

 produced by caloric and various other chemical agents, and 

 which never can be considered as amounting to a proof of se- 

 cretion depending upon galvanism. When, therefore, we ad- 

 duce even a single instance of secretion taking place indepen- 

 dently of any influence that can be derived from the nervous 

 system, we cut away at once the very foundation of the hypo- 

 thesis which attributes secretion to galvanism ; and although 

 the hypothetical explanation of such instances, by galvanism 

 supposed to be drawn from another source, given by Dr. Philip, 

 may possibly, in the progress of knowledge, turn out to be 



