CONSISTENCY OF GEOLOGY WITH SACRED HISTORY. 431 



Still no one finds in the upper secondary rocks — much less in the 

 tertiary, the numerous and grand crystals that are common in the 

 primitive, and even to a degree in the transition and early secondary 

 formations, nor does any one look for those grand crystal cavities, 

 fours a cristaux, as they have been fancifully called,* except in the 

 ancient mountains, and in the veins and beds by which they are in- 

 tersected. 



No person who has been conversant with chemical effects can easily 

 confound them with those of mere mechanical deposition. Take a 

 piece of the most beautiful granite — its quartz is translucent if not 

 transparent — its feldspar is foliated in structure, presenting two regu- 

 lar cleavage planes, united at definite angles — its mica is perfectly fo- 

 liated, and splits into innumerable thin laminae, each of which, is per- 

 fectly transparent and has a high lustre, and this last property is com- 

 mon (sometimes in a less degree,) to the quartz and the feldspar. 

 Gneiss and mica slate and saccharoidal limestone are distinguished, in 

 a greater or less degree by similar characteristics. Now, translucen- 

 cy — transparency — lustre — cleavage-planes, and regular structure, 

 are known and established results of chemical deposition and are 

 never the efiect of mechanical aggregation. Compare the above 

 properties, with those found in a piece of clay, and no person, how- 

 ever unskilled in physical characteristics, can possibly attribute them 

 to a similar origin. The latter has as obviously sprung from me- 

 chanical as the former from chemical laws ; — mechanical suspension 

 must have preceded the one, and solution, fusion or sublimation the 

 other. 



Crystallization is the most exalted agency of the mineral kingdom 

 and it answers to organization in the animal and vegetable. It results 

 in the production of regular solids — often of beautiful figures, bound- 

 ed almost always, by plane faces, which constitute the outline of beau- 

 ty in the mineral kingdom, as the curve line does in the organized king- 

 doms. — Haily* 



Proximate Causes of Crystallization in the Earth. 



Of the original state of the materials of our planet, as first formed 

 by the Creator, we know nothing. It is, however, in the highest de- 

 gree improbable, that the innumerable crystals of so many different 

 substances and forms, which we find in the earth were originally crea- 



* Patrin's mineralogical travels. 



