NATURAL HISTORY OF CREATION. 43 



observation, wo readily detect in it a regulavity and 

 order from which much instruction in the history of our 

 globe is to be derived. 



The deposition of the aqueous rocks, and tlie projec- 

 tion of the volcanic, have unquestionably taken place 

 since the settlement of the earth in its present form. 

 They are indeed of an order of events which we see 

 going on, under the agency of more or less intelligible 

 causes, even down to the present day. We may tliei-e- 

 fore consider them generally as comparatively recent 

 transactions. Abstracting them from the investigations 

 before us, we arrive at the idea of the earth in its first 

 condition as a globe of its present size — namely, as a 

 mass, externally at least, consisting of the crystalline 

 kind of rock, with the waters of the present seas and the 

 present atmosphere around it, though these were pro- 

 bably in considerably different conditions, both as to 

 temperature and their constituent materials, from what 

 they now are. We are thus to presume that that 

 crystalline texture of rock ^^•hich we see exemplified in 

 granite is the condition into which the great bulk of the 

 solids of our earth were agglomerated directly from the 

 nebulous or vaporiform state. It is a condition emi- 

 nently of combination, for such rock is invariably com- 

 posed of two or more of four substances — silica, mica, 

 quartz, and hornblende — which associate in it in the 

 form of grains or crystals, and which are themselves 

 each composed of a group of the simple or elementary 

 substances. 



Judging from the results and from still remaining 

 conditions, we must suppose that the heat retained in 

 the interior of the globe was more intense, or had 

 greater freedom to act, in some places than in others. 

 These became the scenes of volcanic operations, and in 



