438 CONSISTENCY OF GEOLOGY WITH SACRED HISTORY. 



Trap, porphyry, and pitchstone, have long been consigned over to 

 an igneous origin, and as there is no longer any difference of opinion 

 on this subject, it is not necessary here to enter into the discussion.* 

 Nor is it important to our argument, to adduce the proofs in favor 

 of the extension of the agency of fire, to the formation even of gran- 

 ite itself, with all its family of rocks. The igneous origin of granite 

 is now generally, although not universally, admitted. It is, however, 

 of no importance to this discussion, whether granite, as well as the 

 other unstratified rocks, is of aqueous or igneous origin, since the 

 proofs of geological succession, which is all that our argument re- 

 quires, are, in either case, sufficiently decisive. 



The intrusion of the rocks supposed to be of igneous origin, among 

 those that are superincumbent, producing dykes and veins, often 

 much ramified ; the elevation and disruption of the upper strata ; 

 the confusion often induced among them ; the chemical changes pro- 

 duced upon the contiguous masses, and the profuse and rich crystalli- 

 zation of many of the primitive rocks, both in the minerals proper to 

 their constitution, and in those foreign ones which they contain im- 

 bedded : all these afford decisive proofs of geological order, event, 

 succession, and time suflicient for the phenomena. 



Crystallization in Rocks. 



No person in the least acquainted with the subject, hesitates to ad- 

 mit that crystallization implies a previous state of corpuscular mobili- 

 ty either in fluid, in fusion, in vapor, or at least in a state of softness 

 and diminished cohesion. Although crystallization is not confined to 

 any one geological period, it is eminently conspicuous in the primi- 

 tive rocks. 



They present to the eye of one who has been accustomed to ex- 

 amine the results of chemical deposition, very decisive proofs that 

 their particles have been in that state of mobility, which leaves them 

 at liberty, to unite according to the laws of corpuscular attraction ; 

 the heterogeneous particles being connected by chemical, and the ho- 

 mogeneous by mechanical attraction. Thus in feldspar, (if we in- 

 clude both its necessary and occasional constituents) oxygen is an el- 

 ement in all the binary compounds that enter into its constitution ; 

 in the silex it is united to silicon; in the potassa to potassium; in 



* For a view of this subject, the reader is referred to Dr. Cooper's lecture, in the 

 fourth volume of the American Journal of Science, 



