ANNIVERSARY ADDRESS OP THE PRESIDENT. 161 



rolled sand, they afford positive proof of the pre-existence of land 

 and water, and atmospheric destructive agency to supply the ma- 

 terials of these strata, and the bed of a sea to receive them. Is 

 it not highly improbable that this sea was untenanted? There 

 must doubtless be a lowest sedimentary stratum, the materials of 

 which must have been derived from land composed of non-sedi- 

 mentary rocks. By "non-sedimentary" I mean a rock the for- 

 mation of which may with the greatest probability be ascribed to ig- 

 neous action. Whether it was granite, or any other form of igneous 

 rock with which we are acquainted, we cannot tell ; because of the 

 great uncertainty as to how far the lowest sedimentary deposits have 

 undergone changes by metamorphic action ; but that silica and clay 

 and very little lime entered into its composition is evident from the 

 predominance of the two former earths in all the oldest strata, and 

 the comparative rarity of lime. 



But animal and vegetable life may have existed while the land 

 that afforded the materials for the first sedimentary deposits was 

 wholly composed of unstratified rocks. Nor is it necessary to have 

 recourse to the obliteration by metamorphic action in all cases 

 where there are no traces of organic remains. We have learned 

 from the valuable report by Professor Edward Forbes of his re- 

 searches in the JEgesm Sea, that ther^ are profound depths in which 

 no animals and no vegetables seem capable of living ; and thus, as 

 there may be now, and probably are, deposits of vast thickness pro- 

 duced without organic bodies having ever lived in or upon them, in 

 the profound depths of the Atlantic and Pacific Oceans, so is the 

 absence of such remains in any stratum no proof, that when it was 

 deposited there might not have existed above it a sea teeming with 

 life. I cannot support this view better than by quoting what Pro- 

 fessor Forbes says on the subject : " As in the sea there is a zero of 

 vegetable life, so, we may fairly infer, is there one of animal life. 

 AU deposits formed below that zero will be void, or almost void, of 

 organic contents. The greater part of the sea is far deeper than 

 the point zero ; consequently the greater part of deposits forming 

 will be void of organic remains. Hence we have no right to infer 

 that any sedimentary formation, in which we find few or no traces 

 of animal life, was formed either before animals were created, or at 

 a time when the sea was less prolific in life than it now is : it might 

 have been formed in a very deep sea*." 



The muddy waters of the Amazon stretch 300 miles into the 

 Atlantic Ocean, and their sediment must be deposited in depths far 

 below the zero of animal and vegetable life. Unless therefore por- 

 tions of dead organisms be transported down steep slopes by sub- 

 marine currents, from a shallower sea to those depths, and be mingled 

 with the sediment, rocks must now be forming over the bottom of 

 the Atlantic Ocean, which, when upraised in future ages, will exhibit 

 as few traces of living bodies having existed when their component 



* On the light thrown on Geology by submarine researches. Edin. Phil. Journ. 

 April 1844. 



VOL. II. — PART I. M 



