DOMAIN V. CALCAREOUS. 



Infiltrations of quartz are also found in these bri- 

 cias. This rock is cut by frequent fissures, per- 

 pendicular to the planes of the beds. It is palpa- 

 bly seen, that these clefts have been formed by the 

 unequal subsidence of the beds, and not by a 

 spontaneous retreat : for the pieces, or foreign 

 fragments, are all divided, and distinctly cut by 

 these fissures ; while in the natural divisions of the 

 beds, these same fragments are entire, and pro- 

 jecting from the surface. The nodules of quartz, 

 and the several crystals which schisti contain, 

 present the same phenomenon ; and the same con- 

 sequence may be drawn from it ; they are divided 

 in the clefts, and whole in the separations of the 

 layers. 



" Although these flattened fragments, as I have 

 said, afford, at first sight, the idea of compression, 

 yet I cannot admit it; no other vestige of this 

 compression being observable : I should rather 

 imagine that these fragments have belonged to 

 very thin layers, which have been rounded under 

 the waters, by rolling and friction ; that afterwards, 

 when they have been successively carried down 

 and lodged by the waters, they have taken the 

 horizontal position that their weight imposed on 

 them ; and that afterwards the elements of the 

 calcareous stone which forms the base of the 



