GEOLOGY. 133 



of the mineral system ; they are the characters of orders ; 

 there is thus properly no order of silex but of quartz, none 

 of clay but of feldspar, none of talc but of mica, at least 

 according to their signification. 



594. The points of origin for this division of the 

 mineral system or that formed by the fundamental earths 

 are the three fundamental crystallizations, and upon these 

 everything that does not belong to the calcareous earth 

 must and does naturally arrange itself. The mineral 

 system is only the developed and separated granite. The 

 fact cannot rest unobserved, that mica has only one 

 laminar cleavage, feldspar two, quartz three, this being for 

 the first time a perfect crystal, a double tetrahedron with 

 one column. 



595. With granite and with it alone the solidity, the 

 body and form of the earth has been given ; it is the 

 homogeneous fundamental mass of the planet, and is 

 therefore crystallized throughout to the finest degree in 

 its three constituent forms. 



GNEISS AND MICA-SCHIST. 



596. If, in addition to granite, several formations are 

 displayed which bear traces of the same mode of origin, 

 of the same component parts and the same aggregation, 

 it may be inferred that they are only metamorphoses of 

 the same precipitate. Granite is the basis of geogeny. 



597. Granite is a totality for the earth, it is a represen- 

 tation of the three terrestrial elements under the form of 

 identical earth ; it is the earth represented in silex, water 

 in clay, and air in talc; it is an universe represented 

 individually in the earth-elements. 



598. The granite can undergo metamorphosis in only 

 three ways ; for its essence is indeed only trinity. No- 

 thing can individualize itself from granite but quartz, 

 feldspar, and mica. All the formations of this period are 

 thus quartz, feldspar, or mica formations. The granite 

 appears under a threefold form as quartz, feldspar, and 

 mica-granite. 



599. The first quartz formation is properly the granite 



