166 ZOOCHEMICAL PROCESSES. 



ascertain the inner connection of their reciprocal effects, that a 

 great number of vital phenomena stand in the simplest relations 

 of dependence to well-known, so-called physical laws, or more 

 general propositions ; and that it is to the special mode of arrange- 

 ment of the individual elements of motion, and to a complication 

 of numerous conditions, that we must, at all events to a great 

 extent, refer the specific character which is impressed upon vital 

 phenomena. We certainly very often fail in solving the mystery 

 of the internal association of phenomena, or the connection of the 

 laws or forces by which they are controlled. Even in the case of a 

 purely mechanical or purely chemical effect, we very frequently 

 fail in comprehending the complication of circumstances which 

 has given rise to the peculiar results manifested. We must not, how- 

 ever, regard the various interruptions which present themselves to 

 our notice in the consideration of vital processes as a proof of the 

 development of forces pertaining exclusively to life. 



Molecular forces themselves, and the manifold complications 

 which they undergo in accordance with different circumstances and 

 relations of mass, are not yet sufficiently elucidated to enable us 

 to trace the causal connection of all the phenomena to which 

 they give rise even in the inorganic world. 



How numerous are the actions of affinity which we have 

 hitherto failed in referring to any general rules, or even to the 

 leading principles of chemistry ! We do not even know whether 

 chemical combination is the sole effect of chemical affinity. But 

 the simplest effects of cohesion and adhesion manifest themselves 

 under such numerous and various circumstances, that physicists 

 have been unable to elucidate the conditions on which they depend. 

 Who would have believed some years ago that the most strongly 

 developed chemical affinity might occasionally be destroyed by 

 simple diffusion ? or who would have ventured even a few months 

 back to plunge his hands into molten glass, or to immerse a living 

 child in melted copper? When experiments of this nature were 

 attempted in former ages, mere vital force was regarded as too 

 simple and inefficient to afford an explanation of this pheno- 

 menon ; no power but the All-Highest being capable, according to 

 the vulgar belief, of thus miraculously suspending the ordinary 

 laws of life ; yet this marvel, which still excites the wondering 

 admiration of the ordinary spectator, admits of being reduced to 

 very simple relations of cohesion. The effects of molecular forces 

 have never been so thoroughly examined in all their bearings and 

 modifications as to aid us in our consideration of the intricate 

 mechanism of the innumerable results manifested in the animal 



