as good
enough to deal with Britain as we have dealt with New Zealand, the
primaeval Briton, blue with cold and woad, may have known that the
strange black stone, of which he found lumps here and there in his
wanderings, would burn, and so help to warm his body and cook his
food. Saxon, Dane, and Norman swarmed into the land. The English
people grew into a powerful nation, and Nature still waited for a full
return of the capital she had invested in the ancient club-mosses. The
eighteenth century arrived, and with it James Watt. The brain of that
man was the spore out of which was developed the steam-engine, and all
the prodigious trees and branches of modern industry which have grown
out of this. But coal is as much an essential condition of this growth
and development as carbonic acid is for that of a club-moss. Wanting
coal, we could not have smelted the iron needed to make our engines,
nor have worked our engines when we had got them. But take away the
engines, and the great towns of Yorkshire and Lancashire vanish like a
dream. Manufactures give place to agriculture and pasture, and not ten
men can live where now ten thousand are amply supported.

Thus, all this abundant wealth of money and of vivid life is Nature's
interest upon her investment in club-mosses, and the like, so long
ago. But what becomes of the coal which is burnt in yielding this
interest? Heat comes out of it, light comes out of it, and if we could
gather together all that goes up the chimney; and all that remains in
the grate of a thoroughly-burnt coal-fire, we should find ourselves in
possession of a quantity of carbonic acid, water, ammonia, and mineral
matters, exactly equal in weight to the coal. But these are the very
matters with which Nature supplied the club-mosses which made the
coal. She is paid back principal and interest at the same time; and
she straightway invests the carbonic acid, the water, and the ammonia
in new forms of life, feeding with them the plants that now live.
Thrifty Nature! Surely no prodigal, but most notable of housekeepers!

VI.

ON CORAL AND CORAL REEFS.

The marine productions which are commonly known by the names of
"Corals" and "Corallines," were thought by the ancients to be
sea-weeds, which had the singular property of becoming hard and
solid, when they were fished up from their native depths and came into
contact with the air.

"Sic et curalium, quo primum contigit auras Tempore durescit: