Dr, Hunt on the Chemistry of the Earth, 203 



would contain in the state of chlorids and sulphates, not only al- 

 kalies, but also large portions of lime and magnesia. At a later 

 period, the decomposition of exposed portions of the silicated crust 

 under the influence of water and carbonic acid, would give rise, 

 on the one hand to clays, and on the other to carbonate of soda. 

 This latter, reacting upon the calcareous salts of the sea-water, 

 must produce chlorid of sodium and carbonate of lime. We have 

 here a theory of the source of the quartz, the carbonate of lime, 

 and the argillaceous matters of the earth's crust, explaining at the 

 same time the origin of the chlorid of sodium of the sea, and the 

 fixation of the carbonic acid of the atmosphere in the form of 

 carbonate of lime. In this is seen a great and harmonious series 

 of chemical processes, which have operated, and which continue 

 to operate at the surface of the globe. These notions of the chem- 

 istry of the earth has been taught in my public lectures for the 

 last four years, and will also be found in a paper read before the 

 Geological Society of London on the 5th of January, 1859, and 

 published in the Quarterly Journal of the same Society for that 

 year, p. 488. In support of these views will be found the results 

 of a series of investigations published in the Reports of the Geo- 

 logical Survey of Canada, and in the American Journal of Sci- 

 ence for 1859, upon the reactions of solutions of bicarbonate of 

 soda with sea-water, and upon the conditions required for the 

 precipitation of carbonate of magnesia and the formation of dolo- 

 mite. We have there also shown the mutual decomposition at 

 ordinary temperatures, of solutions of bicarbonate of lime and 

 sulphate of magnesia, resulting in the formation of gypsum, and 

 of a soluble bicarbonate of magnesia, which becomes the source of 

 dolomite or of sepiolite. A notice of the first part of these researches 

 will be found in the Comptes Eendus for May 23, 1859. In the 

 continuation of them, as cited above, it has been shown that the 

 association of magnesian and pure limestones, establishes the fact 

 that these rocks have both been deposited as sediments, and 

 that the hypothesis which explains the origin of dolomites by a 

 subsequent alteration of pure limestones is inadmissible. It was 

 also shown that great portions of limestone, even in fossiliferous 

 formations, have the characters of precipitates resulting from 

 ■ chemical reactions, and have never formed part of organised be- 

 ings ; which last, moreover, owe their carbonate of lime to similar 

 reactions. 



My views upon the composition of the primitive ocean were 



