LIFE HISTOET OF COAL. 187 



the fourth, constituent, carbon, finds a place there. Other ele- 

 ments are there, and in past times in very different proportions 

 to those of to-day, but these particular four were always there, so 

 that truly every seam of Coal that the earth's crust now holds, 

 whatever its age, has first of all been overhead in our atmosphere. 

 And, but for life, there it must have remained. There is no other 

 known force which could fetch the constituents thence and make 

 them Coal. Living fingers had to stretch upwards and take the 

 Coal bit by bit through long centuries out of the air to clothe 

 the earth's surface, first as vegetation, in all its endless beauty of 

 form. All the Coal of the world has thus been rescued from the 

 air by vegetable life. 



Having adorned the surface, vegetation dies, gets buried, it 

 may be deeper and deeper, till now we find some seams of Coal 

 many, many fathoms deep in the crust. The history of every 

 seam of Coal is ; first, invisible in the atmosphere ; second, on 

 the earth's surface, in all the variety and beauty of root and 

 trunk and branch, of leaf and fiower and fruit ; and third, in the 

 earth's crust, a gleaming mass of black diamonds. Thus vege- 

 tation is and has been one great agency, by which the gases of 

 our earth take sold form in one group of combinations, the car- 

 bonaceous. In like manner, animal life is ever taking substances 

 in solution from the waters of the world and turning them into 

 solids of another group of combinations, the calcareous. 



These two forms of existing life, the vegetable and the animal, 

 are evidently branches from one stock, and as we come down to 

 the parent stem the dividing line becomes very difficult to trace, 

 so intricate is the dovetailing, so shadowy the line. They are and 

 have always been co-operative friends, mutually accommodating 

 each other, ever since the animal branch started budding. 



We, from man to mouse, from fish to fly, from animalcule to 

 whale, the whole animal world are manufacturers, from birth to 

 death, of carbonic acid gas. We take in carbon by our alimentary 

 canals, we take in oxygen by our respiratory organs, and within 

 ourselves they develope heat in bringing about the chemical union 

 of these two elements, and then we turn the manufactured article 

 out into the air "for the benefit of our relations the vegetable 



