Mineral and Mosaical Geologies. 125 



channelled out the beds of the rivers in which they now 

 flow. There is no reason for supposing^ the Rhine and the 

 Euphrates to be deeper or wider now than they were in the 

 days of Caesar and Cyrus ; but if their waters had originally 

 formed their own beds, since the action is continually going 

 on, they ought to be continually increasing in width and 

 depth. Valleys and mountains are obviously co-ordinate and 

 correlative — " a mountain signifies nothing but an elevation 

 above a valley, and a valley nothing but a depression below a 

 mouAtain," and the cause of these differences of elevation has 

 been already examined. '* The varied system of valleys, and 

 their intimate and direct relations both to mountains and 

 rivers," is referable only to the divine wisdom which ordained, 

 and gave to the mountains the very forms essentially necessary 

 for " separating the beds of those rivers from one another ; and 

 serving moreover, by means of their eternal snows, as reservoirs 

 for feeding the springs." The general system of rivers is to the 

 earth what the vascular circulating system is to the animal and 

 vegetable structure, the means by which the necessary fluids 

 are distributed from one extremity to the other, and rivers like 

 blood-vessels, are " so skilfully and equally distributed over 

 the whole surface, so artfully diverted in many places from the 

 nearest seas, and conducted through extensive inland regions," 

 that they incontestably argue supreme intelligence in their 

 designer. 



On the formation of coal our author touches with the judi- 

 cious caution which the obscurity of the subject demands. He 

 concludes with Mr. Halchett, to the probability of its vegetable 

 origin ; and from the failure of that celebrated chemist to pro- 

 duce bituminous coal, in his experiments on vegetable sub- 

 stances of land growth, and for other reasons, suggests that the 

 beds of natural coal " were perhaps immense accumulations of 

 fuci, &c., loaded with the various animal substances which 

 shelter among them, and which were overwhelmed by vast ag- 

 gregations of the loose soil of the sea, in the course of its re- 

 treat, and were left for decompositioai by the chemical action of 

 the marine fluid which they contained, and with which the en- 

 closing and compressing soils were saturated *." 



In the remaining portion of the work, our author ascribes the 

 covering of the new earth with vegetation after the second revo- 

 lution, to a fresh and immediate act of God ; and infers, from 

 the olive-leaf brought by the dove to Noah, that it was created 

 in full and perfect maturity. He supposes it probable, also, 

 that new animal species were at the same time created, to sup- 

 ply the place of those which it was the will of God to destroy 



" " There is evory reason to believe, that the agent employed by nature 

 in the (urination of co tl ;ii>d bitumen, has been either muriatic or sulphuric 

 acid."— Hatchett, I'hil. Trans. ISOC, p. 111.— K. 



