during the contraction and consolidation of the originally soft substances of the rocks themselves; and more frequently into fissures produced by the fracture and dislocation of the solid strata. Segregation of this kind may have taken place from electro-chemical agency, continued during long periods of time.*

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 accessible by his industry; and this object is admirably attained through the machinery of metallic veins.

The observations of Mr. Fox on the electro-magnetic properties of metalliferous veins in Cornwall, (Phil. Trans. 1830, &c.) seem to throw new light upon this obscure and difficult subject. And the experiments of M. Becquerel on the artificial production of crystallized insoluble compounds of Copper, Lead, Lime, &c. by the slow and long continued reaction and transportation of the elements of soluble compounds, (see Becquerel, Traité de l'Electricité, T. i. c. 7, page 547, 1834,) appear to explain many chemical changes that may have taken place under the influence of feeble electrical currents in the interior of the earth, and more especially in Veins.

I have been favoured by Professor Wheatstone with the following brief explanation of the experiments here quoted.

"When two bodies, one of which is liquid, react very feebly on each other, the presence of a third body, which is either a conductor of electricity, or in which capillary action supplies the

Had large quantities of metals existed throughout Rocks of all formations, they might have been noxious to vegetation; had small quantities been disseminated through the Body of the Strata, they would 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 render them accessible, at a certain expence

place of conductibility, opens a path to the electricity resulting from the chemical action, and a voltaic current is formed which serves to augment the energy of the chemical action of the two bodies. In ordinary chemical actions, combinations are effected by the direct reaction of bodies on each other, by which all their constituents simultaneously 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 insoluble, because the number of the molecules cannot occasion any disturbance in their arrangement. By the application of these principles, that is, by the long-continued action of very feeble electrical currents, this author has shewn that many crystallized bodies, hitherto found only in nature, may be artificially obtained."

of human skill and industry, and at the same time secure from wanton destruction, and from natural decay; in the more general dispersion of those metals which are most important, and the comparatively rare occurrence of others which are less so; and still further in affording the means whereby their compound ores may be reduced to a state of purity.*

The argument, however, which arises from the utility of these dispositions, does not depend on the establishment of any one or more of the explanations proposed to account for them. Whatever may have been the means whereby

I owe to my friend Mr. John Taylor the suggestion of another argument, arising from the phenomena of mines, which derives much value from being a result of the long experience of a practical man of science.

"There is one argument," says Mr. Taylor," which has always struck me with considerable force, as proving wise and beneficent design, to be drawn from the position of the metals. I should say that they are so placed as to be out of the reach of immediate and improvident exhaustion, exercising the utmost ingenuity of man, first to discover them, then to devise means of conquering the difficulties by which the pursuit of them is surrounded.

"Hence a continued supply through successive ages, and hence motives to industry and to the exercise of mental faculties, from which our greatest happiness is derived. The metals might have been so placed as to have been all easily taken away, causing a glut in some periods and a dearth in others, and they might have been accessible without thought, or ingenuity.

"As they are, there appears to me to be that accordance with the perfect arrangements of an allwise Creator, which it is so beautiful to observe and to contemplate."

mineral veins were charged with their precious contents; whether Segregation, or Sublimation, were the exclusive method by which the metals were accumulated; or, whether each of the supposed causes may have operated simultaneously or consecutively in their production; the existence of these veins remains a fact of the highest importance to the human race: and although the Disturbances, and other processes in which they originated, may have taken place at periods long antecedent to the creation of our species, we may reasonably infer, that a provision for the comfort and convenience of the last, and most perfect creatures He was about to place upon its surface, was in the providential contemplation of the Creator, in his primary disposal of the physical forces, which have caused some of the earliest, and most violent Perturbations of the globe.*

* That part of the History of Metals which relates to their various Properties and Uses, and their especial Adaptation to the Physical condition of Man, has been so ably and amply illustrated by two of my Associates in this Series of Treatises, that I have more satisfaction in referring my readers to the Chapters of Dr. Kidd and Dr. Prout upon these subjects than in attempting myself to follow the history of the productions of metallic veins, beyond the sources from which they are derived within the body of the Earth.

A summary of the all-important Uses of Metals to Mankind. is thus briefly given, by one of our earliest and most original writers on Physico-theology.

"As for Metals, they are so many ways useful to mankind, and those Uses so well known to all, that it would be lost labour

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CHAPTER XXII.

Adaptations of the Earth to afford supplies of water through the medium of Springs.

As the presence of water is essential both to animal and vegetable existence, the adjustment of the Earth's surface to supply this necessary fluid, in due proportion to the demand, affords one of the many proofs of Design, which arise out of the investigation of its actual condition, and of its relations to the organized beings which are placed upon it.

to say anything of them without the use of these we could have nothing of culture or civility: no Tillage or Agriculture; no Reaping or Mowing; no Ploughing or Digging; no Pruning or Loping; no Grafting or Insition; no mechanical Arts or Trades; no Vessels or Utensils of Household-stuff; no convenient Houses or Edifices; no Shipping or Navigation. What a kind of barbarous and sordid life we must necessarily have lived, the Indians in the Northern part of America are a clear demonstration. Only it is remarkable that those which are of most frequent and necessary use, as Iron, Brass and Lead, are the most common and plentiful: others that are more rare, may better be spared, yet are they thereby qualified to be made the common measure and standard of the value of all other commodities, and so to serve for Coin or Money, to which use they have been employed by all civil Nations in all Ages." Ray's Wisdom of God in the Creation. Pt. i. 5th ed. 1709, p. 110.