AMERICAN GEOLOGY EATONIAN ERA, 1820-1829. 293 



diateh' beDeath, what fills the void? he asked. If it is arched over 

 from side to side, what security is there that subterranean tires will 

 not melt down the abutments and undermine the continent? But, 

 whether the mountains were raised from below, left prominent by the 

 subsidence of the contiguous regions, or were reared by accumulation, 

 he regarded as immaterial for his present purpose. "It is agreed on 

 all hands that they existed before the subsidence of the early ocean, 

 whose retreat must of course have first exposed their summits." 



Among the rocks belonging to the transition period he included the 

 crystalline limestones — marbles — of Bennington, Middlebury, and 

 Swanton in Vermont; the graywackes of the Chaudiere Falls in Lower 

 Canada, of Rhode Island, and of the Catskill Mountains; the breccia 

 marble of Point of Rocks, Maryland; and the conglomerates of Dor- 

 chester and other locatities in Massachusetts. These, as is well known, 

 are now relegated to various widely separated horizons, extending 

 from the Cambrian in the case of the Swanton marbles to the Triassic 

 in the case of that of Point of Rocks. 



The manner in which the fossil organisms were conceived to have 

 become imbedded in their various matrices is interesting: 



We can not doubt that the animals received their existence and lived and died in 

 an ocean full of carbonate of lime, in solution, or in mechanical suspension, or both. 

 When they died they of course subsided to the bottom and were surrounded, as they 

 lay, by the concreting calcareous matter; * * * the interstices were filled by the 

 calcareous deposit, and this being more or less chemically dissolved, produced a 

 firm, subcrystalline mass, a section of which shows the animals sawn through. 



Concerning the value of such remains, he was fully cognizant: 

 "Fossil organic bodies contained in rocks are now considered as good 

 indicia of the geological age and character of the strata in which they 

 occur.' 1 



As with others of his time, Silliman was a believer in the Noachian 

 deluge. Indeed, in point of detail, he outdid all others in his attempts 

 at harmonizing apparently conflicting statements and ideas and wrote, 

 as Huxley has aptly expressed it, "with one eye on fact and the other 

 on Genesis." 1 "There is decisive evidence that not further back than 

 a few thousand years an universal deluge swept the surface of the 

 globe." This deluge, it should be remarked, was considered quite dis- 

 tinct from the original, primeval ocean, and to have been brought 

 about through direct intervention of the Creator for the purpose of 

 punishing and partially exterminating the race. It was sudden in its 

 occurrence, short in duration, and violent in its effects. In order to 

 account for the biblical expression, "the fountains of the great deep were 

 broken up, 11 Silliman offered the suggestion that, contemporaneous 

 with the fort}' da} T s and nights of rain, a deluge of water burst forth 

 from the bowels of the earth, whence it was forced by the sudden dis- 

 engagement of gases, the presence of the subterranean water he having 



