298 THE CANADIAN NATURALIST. [Aug. 



§ 81. I have in a previous section (§ 57) alluded to the con- 

 dition of the primeval ocean, and in this connection it may be well 

 to refer to a hypothesis which I some years since advanced 

 to explain the origin of its salts and the primeval sediments, 

 Starting from the notion " of a cooling globe, such as the igneous 

 theory supposes our earth to have been at an early period, and con- 

 sidering only the crust with which geology makes us acquainted, 

 and the liquid and gaseous elements which now surround it, I have 

 endeavored to show that we may attain to some notion of the 

 chemical conditions of the cooling mass by conceiving these 

 materials to again re-act upon each other under the influence of 

 an intense heat. The quartz, which is present in such a great 

 proportion in many rocks, would decompose the carbonates and 

 sulphates, and, aided by the presence of water, the chlorids both of 

 the rocky strata and of the sea ; while the organic matters and the 

 fossil carbon would be burned by the atmospheric oxygen. From 

 these re-actions would result a fused mass of silicates of alumina, 

 alkalies, lime, magnesia, iron-oxyd, etc. ; while all the carbon, 

 sulphur and chlorine, in the form of acid gases, mixed with watery 

 vapor, nitrogen, and a probable excess of oxygen, would form an 

 exceedingly dense atmosphere. When the cooling permitted con- 

 densation, an acid rain would fall upon the heated surface of the 

 earth, decomposing the silicates, and giving rise to chlorids and 

 sulphates of the various bases, while the separated silica might 

 take the form of crystalline quartz. In the next stage of the 

 process, the portions of the primitive crust not covered by the 

 ocean would undergo a decomposition under the influence of hot 

 moist atmosphere charged with carbonic acid, and the felspathic 

 silicates become converted into clay, with separation of the alkali. 

 This, absorbing carbonic acid from the atmosphere, would find its 

 way to the sea, where, having first precipitated from its highly 

 heated waters various metallic bases then held in solution, it would 

 decompose the chlorid of calcium, giving rise to chlorid of sodium 

 on the one hand, and to carbonate of lime on the other. In this 

 way we obtain a notion of the processes by which from a primitive 

 fused mass may be generated the silicious, calcareous and argillaceous 

 rocks which make up the greater part of the earth's crust ; and we 

 also understand the source of the salts of the ocean."* 



* Canadian Journal, May, 1859, 201, and Silliman's Journal [2], xxv, 

 102 ; also Comptes Rendus, June 9th, 1862, and Can. Naturalist, vii, 202. 



