regulating Vital and Physical Plienomena. 339 



we can now readily explain. Would it have been thought 

 possible, for instance, by a chemist thirty years ago, that the 

 same substance should act the part of an acid in one case, and 

 a base in another ? — that water should be possessed of such 

 properties ? — or still more that hydrochloric acid in combina- 

 tion with chloride of platinum should act as the base or electro- 

 positive ingredient ? Yet such are the facts. These would 

 have appeared to a chemist at the commencement of the present 

 century, totally inconsistent with what he knew of chemical 

 action ; but they are now i-eadily comprehensible under laws 

 which include all the facts hitherto ascertained. Or, to take a 

 different illustration, would any electrician, twenty years ago, 

 have supposed it consistent with physical laws, that a mecha- 

 nical force, 50,000 times greater than that of gravity, may be 

 instantaneously generated by the action of galvanism on a 

 metallic alloy (as shewn by Sir J. Herschel), or that a feeble 

 current of electricity, issuing from a single pair of plates, may 

 generate (if properly applied) a magnetic force capable of sus- 

 taining many hundred pounds. The higher and more general 

 are the laws we attain, the more do we find that they include 

 facts, which at first sight appeared inconsistent with them ; and 

 unless a distinct set of laws could be established, regulating 

 vital affinities, which has not yet been accomplished or even 

 attempted, we are scarcely justified in assuming that these 

 laws may not be accordant with those which we recognise else- 

 where. 



And this leads us to remark, in the second place, that whilst 

 recent discoveries in inorganic chemistry have tended to widen 

 very much our notion of the play of chemical affinities, the ap- 

 plication of accurate and minute analysis to what have hitherto 

 been considered the proximate principles derived from the 

 organic world, has shewn that many, if not all of them, may 

 be considered as binary combinations of other substances much 

 simpler in their composition, and every fresh discovery is there- 

 fore tendmg to break down the barrier between the two classes 

 of organic and inorganic bodies, as far as regards their method 

 of chemical combination.* 



• Turner's Cheniistrj, p. 782, Prout's Bridgewater Treatise, p. 418, &c. 



