Detrital Theory of Geology. 307 



when it would have appeared as insoluble gypsum a rock 

 found here and there in the sedimentary series, especially in 

 the triassic and tertiary systems, but nowhere to any great 

 extent. On the other hand, if it be imagined that heat has 

 expelled the chlorine, and so a large sediment of lime has 

 been precipitated, still, setting aside every difficulty as to 

 where the chlorine went, and how it was again taken up to 

 form a chloride of sodium, etc., it may be briefly stated that 

 such a process would only assist to explain the formation 

 of ONE STRATUM or layer, and would leave the rest to 

 chance. 



Hence the conclusion of Bischof may be adopted without 

 hesitation, that " The assumption that sea water contained 

 a larger quantity of carbonate of lime at the period of the 

 formation of the great limestone strata from the transition 

 limestone to the chalk, and that the increase of limestone 

 formations during this period was a consequence of the 

 decrease of this carbonate in sea water, is contradicted by 

 the circumstance that it would then have been impossible 

 that a solution should have been left which is so far from 

 saturation as the sea water of the present time ; for all pre- 

 cipitations which result from evaporation of solutions leave a, 

 saturated mother liquor. 



" It is, therefore, evident that in every point of view the 

 assumption that our great limestone strata, from the 

 grauwacke limestone to the chalk, have resulted from the 

 evaporation of sea water, is altogether unfounded."* 



It being granted that the LIME in granite, superadded to 

 that of the lime in sea water, is insufficient to account for 

 the amount found in the sedimentary rocks, as now known, 

 the important point still remains to be answered Whether 

 the calcareous casts or exuviae of the universally diffused 



* "Chemical and Physical Geology," by Gustav. Bischof. Vol.1., 

 page 178. 



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