186 LIFE HISTOEY OF COAL. 



X. — Life History of Coal. By the Eev. Aethue Watts, F.Gr.S. 

 Eead at a Joint Evening Meeting of the Natural History Society 

 and the Tyneside ]!^at. Field Club, held on Jan. 31st, 1895. 



Supposing the province of a Natural History Society to be as 

 wide as nature itself, we may consider Coal a fair subject for a 

 paper, and the more so as this particular rock belongs to the 

 class of organic rocks ; rocks that are the product of organized 

 beings, animal or vegetable ; in this case vegetable. Many sili- 

 ceous rocks being diatomaceous are also of vegetable origin, 

 though others are of animal origin, being formed by Sponges or 

 by Radiolarians. Many, nay even most calcareous rocks fall 

 into the same group, being of animal origin, the product of 

 Foraminiferae, Mollusca or Zoophytes; whilst there is strong 

 reason for believing that some, at least, of the ferruginous rocks 

 are of animal origin. 



"We do not propose, to-night, to deal with all the Carbonaceous 

 rocks which are of organic origin, but with those only which, 

 from their economic value to man, are known as Coal; and, 

 indeed, with only one phase of that substance, the phase covered 

 by the words ^^Life-history.'''' We would justify the title of 

 this paper, "Life-history of Coal," on double grounds, — first, 

 because Coal is the gift of Life, and of nothing else ; and second, 

 because it has truly a life of its own. 



That Coal is the gift of life, it is scarcely necessary for me to 

 prove to you, many of whom are as familiar with the vegetable 

 fossils as with the chemical composition of Coal. You will all 

 doubtless at once grant there was a time when no Coal existed 

 on the earth. Its constituent parts, carbon, oxygen, hydrogen, 

 and nitrogen did, but not Coal. These constituents were in the 

 air then as now. The air itself consists of two of them, oxygen 

 and nitrogen. No natural air is dry, and the aqueous vapour 

 thereof supplies another factor in hydrogen, besides increasing 

 the oxygen. And as all air holds some carbonic acid gas (CO2), 



