198 Henry Clifton Sorhy, LL.D., F.E.S., F.G.S., etc., 



a paper written in 1856, states, " The method of preparing fossil woods 

 and other inorganic substances for examination under the microscope 

 had its origin in this city" (Edinburgh). " But as the claims of two 

 or three eiuinent individuals (all deserving praise) are mingled in this 

 improvement, I refrain from considering them." ^ As a matter of 

 fact, Brewster employed thin sections of minerals before 1816, and 

 many anatomists made transparent sections of bones and teeth at a 

 very early period. Sorby. as we have seen, tells us that Williamson,^ 

 who had learnt the lapidary's art as a boy, and was a pupil of 

 Sharpey in London, taught him, in 1849, how to make sections of 

 hard substances, and that he himself perceived the importance of 

 applying the method to the study of rocks. Bryson informs us that 

 he showed his own and Nicol's collections of sections to Sorby in 1856 ; 

 but after the latter had published his important paper in 1858 

 Bryson wrote to dispute his conclusions in a paper on the " Aqueous 

 Origin of Granite." * 



The manner in which Sorby was led from the study of limestones, 

 slates, and schists to that of the igneous rocks has been well described 

 by himself. After stating that the physical conditions under which, 

 certain kinds of rocks are formed at a great distance below the surface 

 of the earth had constantly engaged his attention, he says: "Their 

 microscopical structure had been most puzzling. The evidence of 

 igneous fusion and of the presence of liquid water were about equally 

 strong, and for some time it seemed difBcult to adopt any theoiy 

 which assumed either igneous or aqueous origin of such minerals and 

 rocks. All at once the correct expLanation flashed upon me. Both 

 igneous and aqueous action must have occurred more or less simul- 

 taneously, and the facts which I published have, as I believe, had no 

 small share in causing such a theory to be almost universally accepted 

 by geologists." ("Unencumbered Besearch," pp. 158-159.) 



Sorby's epoch-making memoir was read at the Geological Society on 

 December 16th, 1857, under the title " On some Peculiarities in the 

 Microscopical Structure of Crystals, applicable to the determination of 

 the Aqueous and Igneous Origin of Minerals and Bocks." ^ His 

 account of what took place on that occasion is very interesting. He 

 says: " My late good friend Leonard Horner was the chairman, . . . 

 after I had read this paper he said he had been a member of the 

 Geological Society ever since its foundation, and during the whole of 



1 Edinb. New Phil. Journ., iii (1856), pp. 297-308. 



- "William Crawford Williamson had almost as versatile a genius as Sorby himself. 

 At a very early age he originated, by his study of the Yorkshire cliff-sectious, the 

 zonal classification of strata by the aid of their fossils. At a subsequent date he led the 

 way in this country to the study of the Foramiuifera and the microscopical characters 

 of their shells. All the later years of his life were devoted to the study of coal-balls, 

 and to the important results of fossil botany that this study originated. Yorkshire 

 mav well be proud of having produced in a single generation two such men as 

 Williamson and Soi'by ! 



3 Edinb. New Phil. Journ., xv (1862), pp. 52-53. 



* The paper, Mhich was published in November, 1858, and was illustrated with 

 three plates of interesting drawmgs made by Sorby himself, appeared under the title 

 " On the ^Microscopical Structure of Crystals, indicating the Origin of Minerals and 

 Kocks " : Quart. Journ. Geol. Soc, vol. xiv, pp. 453-500. 



