Geological Socieiy. 505 



there would be thus produced, simultaneously, any greater effects 

 than those which are known to have occurred from the falling in 

 of unsupported mines ; and these have never approached in their 

 scale to any except the smallest earthquakes. 



While geologists are thus looking in all directions for causes M'hich 

 may produce the phenomena which they study, it is natural that the 

 powerful, but as yet mysterious influences of electricity should draw 

 their attention. Mr. flobert Were Fox has endeavoured to show, 

 that by voltaic agency, a laminated structure, and deposits of metal 

 in cracks, resembling metallic veins, may be produced in masses of 

 clay. The experiments are of an interesting kind, and it can hardly 

 be doubted that voltaic agency had some influence in such cases 

 as those described by Mr. Fox; although Mr.Henwood and Mr. Stur- 

 geon have failed in attempting to reproduce his results, and although 

 results much resembling these occur in cases where no electrical ac- 

 tion is suspected. But we may remark that the conditions under 

 which such voltaic effects are produced have not yet been attempted 

 to be defined with any accuracy ; and that till this is done, the reality 

 of such agency can neither be verified nor applied to geological 

 speculations. 



A reflection which naturally offers itself upon this review of our 

 recent career, is this : — that different portions of the science of geo- 

 logy advance with very different rapidity. Descriptive Geology is con- 

 stantly and actively progressive : facts are accumulated by obsei'vers 

 in every land ; and though facts are, in truth, of no value, at least 

 for any purpose of science, except so far as they are reduced to some 

 classification, yet on the other hand, sound classifications are perpe- 

 tually, almost necessarily, suggested, when observation is vigilant 

 and persevering. Even if we at first express our facts in terms of a 

 false classification, we find afterwards the means of translating them 

 into the language of a true one. And the spirit of geological ob- 

 servation is so widely diffused, and so thoroughly roused, that I 

 trust we need not anticipate any pause or retardation in the career 

 of Descriptive Geology. I confess, indeed, for my own part, I do 

 not look to see the exertions of the present race of geologists sur- 

 passed by any who may succeed them. The great geological theo- 

 rizers of the past belong to the Fabulous Period of the science ; but 

 I consider the eminent men hy whom I am surrounded as the Heroic 

 Age of geology. They have slain its monsters, and cleared its wil- 

 dernesses, and founded here and there a great metroiiolis, the queen 

 of future empires. They have exerted combinations of talents Mhich 

 we cannot hope to see often again exhibited, es])ccialiy when tlic 

 condition of tlie science which jjroduced them is changed. I consith'r 

 that it is now the destiny of geology to pass from tiie heroic to the 

 Uistoricul Period. Siie can no longer look ior supernatural suc- 

 cesses, but she is entering ujion a career, I trust a long and j)rosi)er- 

 ous one, in whicli she must carry lu'r vigilance into every province 

 of her territory, and extend her (hmiiinon over the eartii, till it 

 becomes, far more truly than any belore, an universal empire. 



