Page:The fairy tales of science.djvu/320

276 cannel coal. It is always compact, and does not soil the fingers. It varies much in appearance, from a dull earthy to a lustrous wax-like substance. The bright shining varieties often burn away like wood, leaving scarcely any cinders and only a little white ash, while the duller kinds leave white masses of ash, almost equal in size and shape to the original lumps of coal. Jet, of which you make necklaces and bracelets, is merely an extreme variety of cannel coal.

"Brown coal, or lignite, is a substance of comparatively recent formation, and it sometimes exhibits the structure of the plants from which it is derived, the trunks and branches being plainly perceptible. This brown coal is only had recourse to where there are no older beds beneath, or where they are too far down to be reached by the miner.

"Although you mortals are constantly consuming vast quantities of coal in your stoves, fire-places, and engine-furnaces, I give you my word that there is quite enough in the earth's crust to supply all your wants for thousands of years to come. Many of the great coal-fields are as yet untouched, for until the wood of a new country is used, and civilization has made some progress, man never dreams of looking for his fuel in Gnome-land."

Where have we been? To Gnome-land, or to dream-land? The cavern and all its weird inhabitants have vanished. We are sitting at our desk, with a text-book of mineralogy open before us, the source from which our fairy tale proceeded.