In South Devon, in Shropshire--with its beautiful Wrekin, and Caradoc, and Lawley--in Wales, round Snowdon (where some of the soil is very rich), and, above all, in the Lowlands of Scotland, you see these red marks, showing the old lavas, which are always fertile, except the poor old granite, which is of little use save to cut into building stone, because it is too full of quartz--that is, flint.
Think of this the next time you go through Scotland in the railway, especially when you get near Edinburgh.

As you run through the Lothians, with their noble crops of corn, and roots, and grasses--and their great homesteads, each with its engine chimney, which makes steam do the work of men--you will see rising out of the plain, hills of dark rock, sometimes in single knobs, like Berwick Law or Stirling Crag--sometimes in noble ranges, like Arthur's Seat, or the Sidlaws, or the Ochils.

Think what these black bare lumps of whinstone are, and what they do.

Remember they are mines--not gold mines, but something richer still--food mines, which Madam How thrust into the inside of the earth, ages and ages since, as molten lava rock, and then cooled them and lifted them up, and pared them away with her ice-plough and her rain-spade, and spread the stuff of them over the wide carses round, to make in that bleak northern climate, which once carried nothing but fir-trees and heather, a soil fit to feed a great people; to cultivate in them industry, and science, and valiant self-dependence and self-help; and to gather round the Heart of Midlothian and the Castle Rock of Edinburgh the stoutest and the ablest little nation which Lady Why has made since she made the Greeks who fought at Salamis.
Of those Greeks you have read, or ought to read, in Mr.Cox's _Tales of the Persian War_.

Some day you will read of them in their own books, written in their grand old tongue.