ADVANTAGEOUS DISPOSITION OF METALS. 413 



The total quantity of all ^metals known to exist near the 

 surface of the Earth (excepting Iron,) being comparatively 

 small, and their value to mankind being of the highest order' 

 as the main instruments by the aid of which he emerges from 

 the savage state, it was of the utmost importance, that they 

 should be disposed in a manner that would render them ac- 

 cessible by his industry; and this object is admirably at- 

 tained through the machinery of metallic veins. 



Had large quantities of metals existed throughout Rocks 

 of all formations, they might have been noxious to vegeta- 

 tion ; had small quantities been disseminated through the 

 Body of the Strata, they M'^ould never have repaid the cost 

 of separation from the matrix. These inconveniences are 

 obviated by the actual arrangement, under which these rare 

 substances are occasionally collected together in the natural 

 Magazines afforded by metallic veins. 



In my Inaugural Lecture (page 12) I have spoken of the 

 evidences of design and benevolent contrivance, which are 

 apparent in the original formation and disposition of the 

 repositories of minerals ; in the relative quantities in which 

 they are distributed ; in the provisions that are made to ren- 

 der them accessible, at a certain expense of human skill and 

 industry, and at the same time secure from wanton destruc- 



otlier, the presence of a third body, wiiich is either a conductor of electrici- 

 ty, or in wliich capillary action supplies the place of conductibility, opens a 

 path to the electricity resulting from the chemical action, and a voltaic cur- 

 rent is formed wliich serves to augment tJie energy of the chemical action of 

 the two bodies. In ordinary cliemical actions, combinations are effected by 

 the direct reaction of bodies on each other, by which all their constituents 

 slmidtaneously concur to the general effect; but in the mode considered by 

 Becquerel the bodies in the nascent state, and excessively feeble forces, 

 are employed by which the molecules are produced, as it were, one by 

 one, and are disposed to assume regular forms, even when they are insolu^ 

 ble, because the number of the molecules cannot occasion any disturbance in 

 their arrangement. By the application of tiiese principles, that is, by the 

 long-continued action of very feeble electrical currents, this author has shown 

 that many crystallized bodies, hitherto found only in nature, may be artifi- 

 cially obtained." 



35* 



