VEGETABLE REMAINS. 59 



Besides this coal, many strata of the carboniferous order 

 contain subordinate beds of a rich argillacious iron ore, 

 which the near position of the coal renders easy of reduc- 

 tion to a metallic state ; and this reduction is farther facili- 

 tated by the proximity of limestone, which is requisite as a 

 tiux to separate the metal from the ore, and usually abounds 

 in the lower regions of the carboniferous strata. 



A formation that is at once the vehicle of two such valu- 

 able mineral productions as coal and iron, assumes a place 

 of the first importance among the sources of benefit to man- 

 kind ; and this benefit is the direct result of physical changes 

 which affected the earth at those remote periods of time, 

 when the first forms of vegetable life appeared upon its sur- 

 face. 



The important uses of coal and iron in administering to 

 the supply of our daily wants, give to every individual 

 amongst us, in almost every moment of our lives, a personal 

 concern, of which but few are conscious, in the geological 

 events of these very distant eras. We are all brought into 

 immediate connexion with the vegetation that clothed the 

 ancient earth before one-half of its actual surface had yet 

 been formed. The trees of the primeval forests have not, 

 like modern trees, undergone decay, yielding back their ele- 

 ments to the soil and atmosphere by which they had been nou- 

 rished; but treasured up in subterranean store-houses, have 

 been transformed into enduring beds of coal, which in these 

 latter ages have become to man the sources of heat, and 

 light, and wealth. My fire now burns with fuel, and my 

 lamp is shining with the light of gas, derived from coal that 

 has been buried for countless ages in the deep and dark re- 

 cesses of the earth. We prepare our food, and maintain 

 our forges and furnaces, and the power of our steam-en- 

 gines, with the remains of plants of ancient forms and ex- 



V'ol. iii. Book iii. Ch. xv. and Prof. Phillips's Article Geoloj^y in Enclyclo- 

 pxdia Metropolitana, Pt. 37, pag^e 596. 



