But the science of language, when wisely conducted, not only presents an interesting analogy to geological stratification; it sometimes goes further, and bears direct witness to important geological changes as conclusive as any evidence derived from the existing conformation of the earth’s crust. How this comes to pass may easily be shown by a few familiar examples. The words _wold_ and _weald_ originally meant _wood_ and _forest_, as the Anglo-Saxon Dictionary and the living use of the German language--_wald_--alike declare; but the wolds at present known in Yorkshire, Gloucestershire, and other parts of England, are generally bare and treeless, and in bad weather very cheerless places indeed. If, then, “there is nothing arbitrary in language,” and all local names tell an historical tale, it is certain that, at the time when those names were imposed, these same sites were part of an immense forest. The geologist, when, in the far-stretching bogs east of Glencoe, and near Kinloch Ewe, and in many other places of Scotland, he calls attention to the fact of layers of gigantic trees lying now deeply embedded under the peat, adduces an argument with regard to the primitive vegetation of our part of the world not a whit more convincing. The same fact of a lost vegetation is revealed in not a few places of England which end in the old word _hurst_, signifying a forest. Again, there is a large family of places in and about the Harz Mountains, in Germany, ending in _ode_, as OSTERODE, HASSELRODE, WERNINGERODE, and so forth. Now most of these places, as specially HASSELRODE, are now remarkably free from those leagues of leafy luxuriance that give such a marked character to the scenery of that mountain district. It is certain, however, that they were at one time in the centre of an immense forest; for the word _rode_, radically the same as our _rid_, and perhaps the Welsh _rhydd_, Gaelic _reidh_, simply means “to make clear” or “clean,” and teaches that the forest in that part had been cleared for human habitation.