E. W, Binney. 453 



colour to water ; that peat itself does not appear to contain any 

 bitumen, but that this latter substance in some of its modifications, 

 as asphaltum, mineral tar, oil, or naphtha, is generated by the slow 

 conversion and formation of the hydro-carbonaceous compound 

 under pressure, during which the complete separation of the 

 hydrogen from the carbon that takes place, and the consolidation 

 of the latter, is completed \ this, however, is a slow process, and a 

 lengthened time is necessary to complete it. That bituminised 

 wood, Surturbrand, Bovey coal, &c., as well as vegetables and 

 peat, contain hydrogen and carbon, and in greater proportion 

 according to the degree of closeness and pressure to which they 

 have been subjected under beds of soil, clay, &c. ; that a sufficient 

 length of time being allowed, mere pressure and exclusion from 

 the atmosphere are sufficient to convert bituminised peat and 

 lignite into coal ; and lastly, that the action of air and water on 

 vegetable substances is similar to that of fire, though much slower 

 and less complete.' 



Page 105. ^ My opinion is simply this. That the trees and 

 vegetables from which the beds of coal are derived, grew on the 

 identical spots the latter now occupy, when each bed was suc- 

 cessively the surface, and probably but Httle raised above the level 

 of the waters, either as detached islands or extensive plains or 

 savannahs ; that these surfaces, during the settling of the earth's 

 crust, were one after another submerged and covered with sedi- 

 ments from turbid waters, or with drifted clay, sand, and shells 

 which buried up the plants ; that these sedimentary deposits 

 gradually accumulated till they formed a new surface, which in 

 time produced another growth of plants and trees, and after a 

 second period of rest were in their turn submerged and covered 

 up by other deposits ; and that similar intervals of repose with 

 intermittent occasional subsidences, were repeated during the 

 entire period of the coal formation. As each vegetable surface 

 sunk beneath the waters, it gradually became converted into coal 

 by processes already explained, and the successive deposits of mud 

 and sand became consolidated into shales and sandstones.' 



Page 108. ' There is a peculiarity in the texture of coal which 

 has not received the attention it deserves. If it be closely ex- 

 amined, it will be found to consist of a series of parallel horizontal 



