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Section C— Geology. 

 President of the Sectioit.— J. J. H. Teall, M.A., F.E.S., F.G.S. 



I 



THURSDAY, SEPTEMBER 14. 



The President delivered the following Address: — 



It is a striking and remarkable fact that, although enormous progress has been 

 made in petrographical science during the last hundred years, there has been com- 

 paratively little advance so far as broad, general theories relating to the origin of 

 rocks are concerned. In Hutton's ' Theory of the Earth,' the outlines of which 

 were published in 1788, the following operations are clearly recognised: — The 

 degradation of the earth's surface by aqueous and atmospheric agencies; the 

 deposition of the debris beneath the waters of the ocean ; the consolidation and 

 metamorphosis of the sedimentary deposits by the internal heat and by the injec- 

 tion of molten mineral matter; the disturbance and upheaval of the oceanic 

 deposits ; and, lastly, the formation of rocks by the consolidation of molten 

 material both at the surface and in the interior of the earth. 



Hutton regarded these operations as efficient causes ordained for the purpose of 

 producing an earth adapted to sustain animal and vegetable life. His writings 

 are saturated with the teleological philosophy of the age to which they belong, and 

 some of his arguments strike us, therefore, as strange and inconclusive ; moreover, 

 the imperfect state of the sciences of chemistry and physics occasionally led him 

 into serious error. Notwithstanding these imperfections, we are compelled to 

 admit, when viewing his work in the light of modern knowledge, that we can find 

 the traces, and sometimes far more than the traces, of those broad general theories 

 relating to dynamical geology which are current at the present day. 



If Hutton had contented himself with proving the reality of the agencies to 

 which reference has been made, it is probable that his views would have been 

 generally accepted. But he went much further than this, and boldly maintained 

 that one or other of these agencies, or several combined, would account for all the 

 phenomena with which the geologist has to deal. It was this that gave rise to the 

 controversial fire which blazed up with such fury during the early years of this 

 century, and whose dying embers have not yet been extinguished. 



The views of Hutton were in strong contrast to those of Werner, the celebrated 

 professor of mineralogy at Freiberg, to whom science owes a debt of gratitude as 

 great as that due to the Scottish physician. The value of a man's work must not 

 simply be judged by the truth of the theory which he holds. I consider that the 

 Wernerian theory — by which I understand a reference to the early stages of 

 planetary evolution for the purpose of explaining certain geological facts — has 

 been on the wane from the time it was propounded down to the present day ; but 

 I claim to be second to none in my admiration for the knowledge, genius, and 

 enthusiasm of the illustrious Saxon professor. The uniformitarian doctrines of 

 Hutton gave a very decided character to the theoretical views of British geologists 

 during the middle of the century, in consequence of the eloquent support of 



