PROF. T. RtrPERT JONES ON COAL. 91 



As -will subsequently appear, successive jungles grew and died 

 in their place, accumulating dead wood, leaves, and fruitage (cones 

 and spores), under different conditions of chemical eliange, until 

 beds of coals, each several feet in thickness, remained in evidence 

 of past centuries upon centuries.* 



A Eatrachian, something like a newt, has been found in the 

 hollow trunks of fossil trees in jS^ova Scotia, for, in some of the coal 

 beds, stumps, rotted down to a certain level, are still standing, 

 having survived the changes of the forest, and the shale having 

 been formed round them. There are also some marine animals 

 found in the coal-measures here and there ; and these show that 

 sea-water came in to a certain extent. 



Of course these great forests depended for their life upon the 

 sun ; and therein is the poetry of the matter ; for it shows that 

 the sun gave light and heat the same as now. Light, heat, 

 fragrance, and colour, all come from coal ; what more could the 

 sun himself do for us ? AYe have the solar rays absorbed by the 

 jungles of the past preserved to us in our coal-fields, and in very 

 many ways we use their heat, light, and colour again. 



4. The Varieties of Coal. — Tables have been prepared of the 

 fossil fuels that Have carbon in them in greater or less proportion, 

 mostly combined with hydrogen and oxygen. Pure carbon is found 

 in the diamond, in graphite (commonly called black lead), and in 

 anthracite. Then comes steam-coal. And there are the following 

 kinds of so-called " bituminous " coal : — caking coal, coking coal, 

 cherry coal, splint coal, and eannel coal. 



Cannel coal, or Parrot coal, has much hydrogen in it, and will 

 go off into gas when burned ; it is therefore very valuable for 

 makins: household sas. Boshead coal is of the same kind. 



&^' 



The following is a general classification of the coals : — 



rTorbanite, cannel-coal, ] Vegetable matter much 

 Hiarhly Bitu- 1 ri i_ ( parrot-coal J altered. 



minous 



1 Gas coals \ Parrot-coal / altered. 



. f 1 Tasmanite, better-bed 1 c i 



^ I coal, &c. I Spore-coals. 



p T)-(. \ r Caking and coking coal, ~j Laminre of charcoal 



' [-Householdcoals-! cherry coal, splint V (mother - coal) and 



J y coal, and other coals. J hydrocarbon. 



Semi-bitumi- f Free - burning f 1. Charcoal deposited abundantly at first, 

 nous I steam coals \ 2. Hydrocarbon partially lost by change. 



Anthracitic .. j j" ^f" .^ ^™° ^"j I Hydrocarbon nearly all lost by change. 



Anthracite Smokeless coal All the hydrocarbon lost by heat under pressure. 



Coke j ,-,■ VV'i'^'^ ] \ Hydrocarbon lost by heat without pressure. 



Jet is fossilized wood which has undergone certain changes and 

 become a hydro-carbon, instead of remaining in that peculiar 

 combination of carbon, hydrogen, and oxygen of which wood is 

 composed. Peat also is decomposed woody material, and under 



* 



Prof. Jones here explained how these seams were formed, and showed 

 diagrams of various animals and plants wliich occurred in them. 



