528 Geological Society. 



he says, " may be formed in the stratifications of a mountain, as 

 well as in a chemist's laboratory." 



His treatise ends with two chapters on the probable effects of the 

 decomposition of different classes of rocks on the nature and ferti- 

 lity of soils ; being an attempt to apply geology to agriculture. He 

 is the father of American, much more than Smith is of English, 

 geology ; and American geology is especially important, because in 

 America and in Russia we have two of the largest classes of forma- 

 tions, the Silurian and Carboniferous, developed at the distance of 

 half an hemisphere. We may, with good cause, congratulate our- 

 selves that this comparison will shortly be consummated by the 

 distinguished author of the ' Silurian System,' whom we have this day 

 elected to be our President for the ensuing year. 



In 1822 Mr. Maclure published some speculative conjectures on 

 the probable changes that may have taken place in the geology of 

 the Continent of North Amei-ica east of the Stony Mountains (Sil- 

 liman's Journal, vol. vi. p. 98), in which he considers that a very 

 extensive lacustrine condition of the upper country prevailed before 

 these waters wei-e discharged by the gorges that give exit to the 

 present great rivers, and observes, that " the large masses of granite, 

 some of them weighing tons, which are scattered over the second- 

 ary strata between Lake Erie and the Ohio, while there is not an 

 atom of granite in place nearer than the north side of the Lake, 

 would seem to point at the only mode by which they could probably 

 be transported — viz. by supposing the Lake extended thus far, and 

 that large pieces of floating ice from the north side might have car- 

 ried those blocks with them, and dropped them as the ice melted 

 in going south ; the fact of few or no blocks being found south of 

 the Ohio, shows that the southern sun melted the ice before it got 

 so far." (Silliman's Journal, 1823, vol. vi. p. 102.) 



It must be no less gratifying to the family of Mr. Maclure than 

 it is to the great scientific family of the investigators of nature 

 throughout the world, to learn that the Academy of Natural Sci- 

 ences of Philadelphia has appointed a member of their body to de- 

 liver a discourse in commemoration of their venerable and respected 

 President and benefactor ; to whom, " as the pioneer of American 

 geology, the whole country owes a debt of gratitude, and in his 

 death will acknowledge the loss of one of the most efllicient friends 

 of science and the arts ;" and who, " as the patron of men of science, 

 even more than for his personal researches, deserves the lasting re- 

 gard of mankind*." 



Mr. William Maclure died, 23rd March 1840, at San Angel, near 

 the city of Mexico, where, during some years, his declining health 

 had obliged him to seek a more genial climate than the United States, 

 and he has left a large property to the Academy of Natural Sciences 

 at Philadelphia, of which he was President f. 



* Silliraan's Journal, vol. xxxix. July 1840, p. 212. 



+ Besides the works above mentioned he published an " Essay on the 

 Formation of Rocks," and a work in three volumes, entitled " Maclure's 

 Opinions." 



