the Appearance of Man on the Earth, 45 



pi'ovince had formerly possessed the same extent of surface as 

 at present, we would feel completely at a loss to account iot 

 the fact, that the coal strata are so irregularly distributed over 

 the country. 



The same causes which, in the vicinity of Saarbrucken, of 

 Eshweiler and of Aachen, gave rise to a luxuriant vegetation, 

 and which influenced the formation of such extensive beds of 

 coal, must have been in operation all over the other dis- 

 tricts of the Rhine province. Instead of this, the coal has 

 been deposited in isolated basins, analogous to the manner in 

 which islands are grouped together. Some of these coal-beds 

 are, however, of considerable dimensions ; witness, for instance, 

 the enormous coal-beds in England and Scotland, which prove 

 such a blessing to these two countries, and which lead us to 

 infer, that, during the period of luxuriant vegetation. Great 

 Britain had nearly attained to its present size. 



Another component element of our atmosphere, viz., car- 

 bonic acid gas, formerly in large quantities, and which con- 

 stitutes a chief portion of the nourishment of plants, in con- 

 junction with heat and moisture, acted a prominent part in 

 the production of a vegetation remarkable for its luxuriance. 



On examining more closely, we cannot but perceive the ad- 

 mirable order displayed, in all the arrangements of nature. 

 This very element of our atmosphere, the carbonic acid, so 

 indispensable to the growth of plants, is prejudicial to animal 

 life ; for an atmosphere containing more than 8 per cent, of 

 this gas proves fatal to every animal, our own species not 

 excepted. It kills, because it arrests the process of breathing. 

 Nevertheless, the elements of which it is composed are neces- 

 sary to the sustenance of human life. Not a single animal 

 has been gifted by nature with the faculty of digesting these 

 elements when presented under this particular form. Vegeta- 

 tion was destined to inter-mediate between unorganized na- 

 ture and the animal world. An unorganized world issued 

 from the hand of the Creator ; immense quantities of carbonic 

 acid gas were disengaged from its bowels. This gas was de- 

 composed by plants, the second wonder of the creation ; and 

 food was thus provided for animals, the third wonder of the 

 creation. 



