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ADDRESS. 2 1 



Starting witli tlie Laurentian rocks, I liave shown tliat the phe- 

 nomena of metamorphism of strata have been continued from that date 

 all through the later formations, or groups of formations, down to and 

 including part of the Eocene strata in some parts of the world. 



In like manner I have shown that ordinary volcanic rocks have been 

 ejected in Silurian, Devonian, Carboniferous, Jurassic, Cretaceo-oolitic, 

 Cretaceous, Eocene, Miocene, and Pliocene times, and from all that I 

 have seen or read of these ancient volcanoes, I have no reason to believe 

 that volcanic forces played a more important part in any period of geo- 

 logical time than they do in this our modern epoch. 



So, also, mountain chains existed before the deposition of the Silurian 

 rocks, others of later date before the Old Red Sandstone strata were 

 formed, and the chain of the Ural before the deposition of the Permian 

 beds. The last great upheaval of the Alleghany Mountains took place 

 between the close of the formation of the Carboniferous strata of that 

 region and the deposition of the New Red Sandstone. 



According to Darwin, after various oscillations of level, the Cordillera 

 underwent its chief upheaval after the Cretaceous epoch, and all geologists 

 know that the Alps, the Pyrenees, the Carpathians, the Himalayas, and 

 other mountain-chains (which I have named) underwent what seems to 

 have been their chief gi'eat upheaval after the deposition of the Eocene 

 strata, while some of them were again lifted up several thousands of 

 feet after the close of the Miocene epoch. 



The deposition of salts from aqueous solutions in inland lakes and 

 lagoons appears to have taken place through all time — through Silurian, 

 Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Eocene, 

 Miocene, and Pliocene epochs — and it is going on now. 



In like manner fresh- water and estuarine conditions are found now in 

 one region, now in another, throughout all the formations or groups of 

 formations possibly from Silurian times onward ; and glacial phenomena, 

 so far from being confined to what was and is generally still termed the 

 Glacial Epoch, are now boldly declared, by independent witnesses of 

 known high reputation, to begin with the Cambrian epoch, and to have 

 occurred somewhere, at intervals, in various formations, from almost the 

 earliest Pateozoic times down to our last post-Pliocene ' Glacial Epoch.' 



If the nebalar hypothesis of astronomers be true (and I know of no 

 reason why it should be doubted), the earth was at one time in a purely 

 gaseous state, and afterwards in a fluid condition, attended by intense 

 heat. By-and-by consolidatioD, due to partial cooling, took place on the 

 surface, and as radiation of heat went on, the outer shell thickened. 

 Radiation still going on, the interior fluid matter decreased in bulk, and, 

 by force of gravitation, the outer shell being drawn towards the interior, 

 gave way, and, in parts, got crinkled up, and this, according to cos- 

 mogonists, was the origin of the earliest mountain-chains. I make no 

 objection to the hypothesis, which, to say the least, seems to be the best 

 that can be offered and looks highly probable. But, assuming that 



