ON COAL. 131 



According to this method of estimation, Great Britain is superior to 

 all other countries in actual material civilization. But if the con- 

 sumption of coal is a measure of the actuau civilization of a country, 

 the amount of coal area represents its 2yotential civilization. How far 

 are we superior to all other countries in this respect ! What a glorious 

 destiny awaits us in the future — a destiny already predetermined in 

 the earliest geological history of the earth. 



One more remark and I am done. It is certain that, as manu- 

 facturing and productive industry take root and flourish almost ex- 

 clusively in cjol and temperate climates, so also in them do the coal 

 formations prevail in the greatest abundance. Oar scientific maps 

 and investigations confirm the one, and national statistics the other. 

 Almost all the true coal of the world is found in the north temperate 

 zone. Thus the climates which are most congenial to laborious occu- 

 pations, the latitudes best adapted to the vigorous growth of industrial 

 civilization, are precisely those where, fortunately, have been placed 

 the materials of labor, the aliment of industry. Fortunately did I 

 say? No; this has not been the result of blind chance, but oi 

 deliberate providential design. We have here a sublime illustration 

 of that all-comprehensive foreknowledge which foresees and designs 

 the end from the beginning ; of that immutability which changes not, 

 but only unfolds its eternal plans ; of that unity in the system of 

 time-worlds of which I have already spoken, our own epoch being the 

 sun and centre. 



THEORIES OF THE COAL. 



There is no point connected with the coal which has been the 

 subject of so much discussion as the manner of its accumulation. At 

 first view, existing nature seems to offer no analogy to guide us in 

 our attempts to account for such enormous accumulations of carbona- 

 ceous matter. It is admitted, however, I believe, on all hands, that 

 the deposit must have taken place in water. The perfect preservation 

 of the carbon of the plants, and often of their external forms and 

 structure, which must have suffered complete oxydation and disinte- 

 gration if exposed to the air, the fact that the plants were most or all 

 of them swamp plants, and, more than all, the alternation of coal 

 seams with sedimentary deposits of clay and sand, all seem to point 

 unmistakably to water as the preserving agent. There is still 

 another evidence which I think has generally been overlooked. In 

 the midst of the more structureless bituminous matter of the coal are 

 often found imbedded wedge-shaped masses of vascular tissue called 

 native carbon. No one who attentively examines these wedges can 

 fail to perceive that they are the wooden wedges of exogens separated 

 by the decomposition of the softer cellular tissue of the intervening 

 medullary rays, while they floated as logs upon the water and finally 

 became imbedded in the carbonaceous mud below. 



Thus far I believe all theorists agree. But from this point opinions 

 diverge ; some geologists holding that the coal was deposited on the 

 spot where the plants grew, others that the plants were drifted in the 



