254 Epitome of the Progress of Natural Science. 



the agreement of trap rocks with volcanic products. Werner, 

 therefore, who could not be ignorant of these facts, availing him- 

 self of his influence, preferred, as it would seem, to sustain an 

 hypothesis based upon his own inventive imagination, to the truths 

 which nature taught, and which had been very ably brought 

 forward. This substitution of his hypothesis had for a long pe- 

 riod, the effect of suppressing the truth, and of retarding the ad- 

 vancement of geological knowledge. 



Whilst in Europe the influence of Werner's geological theory 

 has entirely passed away, it is due to the memory of that great 

 mineralogist to say, that the progress in mineralogical knowledge is 

 to be attributed to the school he formed ; and that the very awa- 

 kening which geological science has received, arose from the 

 boldness of his hypothesis, the enthusiasm with which it was 

 maintained by him and his disciples, and the inquiries it provoked. 

 Those who obstinately explained all phenomena by the doc- 

 trine of aqueous precipitates, soon received the designation oiKep- 

 tunists, in opposition to that of Vulcanists, which was given to the 

 other side, and of whom Hutton, the cotemporary of Werner, was 

 the most conspicuous member. He was a man of unwearied ac- 

 tivity and application, who examined for himself, and who sought 

 to account for all geological phenomena by the reasonable action 

 of known natural agents. In 1788, he published his " Theory of 

 the Earth." He presents the earth to us as a pure self-acting 

 machine, operating eternal degradations and renewals. Conti- 

 nents worn down by external circumstances, their ruins carried 

 by streams into the oceans, there consolidated by subterranean 

 heat and pressure, to be again raised up by subterranean 

 power. Satisfied that trap rocks were of igneous origin, and 

 finding that the phenomena of veins and dykes belonging to it, 

 were common to the granite, he came to the conclusion, that the 

 primary rocks were not formed from aqueous deposites, but from 

 mineral matter in a state of igneous fusion. To this opinion, the 

 geological theory has been for some time steadily tending : but 

 that part of his doctrine which implies that all the changes 

 which have taken place in the globe, have been the result of 

 causes co-eflicient with all time, and that the energy of subter- 

 ranean power, as far as the whole globe is concerned, has at all 

 times been uniform, is deemed insufficient by the greater portion 

 of accredited geologists ; who neither admit the inconceivable 



