§ 6. But however this may be, there is one lesson evidently intended to be taught by the different characters of these rocks, which we must not allow to escape us. We have to observe, first, the state of perfect powerlessness, and loss of all beauty, exhibited in those beds of earth in which the separated pieces or particles are entirely independent of each other, more especially in the gravel whose pebbles have all been rolled into one shape: secondly, the greater degree of permanence, power, and beauty possessed by the rocks whose component atoms have some affection and attraction for each other, though all of one kind; and lastly, the utmost form and highest beauty of the rocks in which the several atoms have all different shapes, characters, and offices; but are inseparably united by some fiery process which has purified them all.
It can hardly be necessary to point out how these natural ordinances seem intended to teach us the great truths which are the basis of all political science; how the polishing friction which separates, the affection which binds, and the affliction that fuses and confirms, are accurately symbolized by the processes to which the several ranks of hills appear to owe their present aspect; and how, even if the knowledge of those processes be denied to us, that present aspect may in itself seem no imperfect image of the various states of mankind: first, that which is powerless through total disorganization; secondly, that which, though united, and in some degree powerful, is yet incapable of great effort or result, owing to the too great similarity and confusion of offices, both in ranks and individuals; and finally, the perfect state of brotherhood and strength in which each character is clearly distinguished, separately perfected, and employed in its proper place and office.
§ 7. I shall not, however, so oppose myself to the views of our leading geologists as to retain here the names of Primary, Secondary, and Tertiary rocks. But as I wish the reader to keep the ideas of the three classes clearly in his mind, I will ask his leave to give them names which involve no theory, and can be liable, therefore, to no great objections. We will call the hard, and (generally) central, masses Crystalline Rocks, because they almost always present an appearance of crystallization. The less hard substances, which appear compact and homogeneous, we will call Coherent Rocks, and for the scattered débris we will use the general term Diluvium.
§ 8. All these substances agree in one character, that of being more or less soft and destructible. One material, indeed, which enters largely into the composition of most of them, flint, is harder than iron; but even this, their chief source of strength, is easily broken by a sudden blow; and it is so combined in the large rocks with softer substances, that time and the violence of the weather invariably produce certain destructive effects on their masses. Some of them become soft, and moulder away; others break, little by little, into angular fragments or slaty sheets; but all yield in some way or other; and the problem to be solved in every mountain range appears to be, that under these conditions of decay, the cliffs and peaks may be raised as high, and thrown into as noble forms, as is possible, consistently with an effective, though not perfect permanence, and a general, though not absolute security.
§ 9. Perfect permanence and absolute security were evidently in nowise intended.[42] It would have been as easy for the Creator to have made mountains of steel as of granite, of adamant as of lime; but this was clearly no part of the Divine counsels: mountains were to be destructible and frail; to melt under the soft lambency of the streamlet; to shiver before the subtle wedge of the frost; to wither with untraceable decay in their own substance; and yet, under all these conditions of destruction, to be maintained in magnificent eminence before the eyes of men.
Nor is it in any wise difficult for us to perceive the beneficent reasons for this appointed frailness of the mountains. They appear to be threefold: the first, and the most important, that successive soils might be supplied to the plains, in the manner explained in the last chapter, and that men might be furnished with a material for their works of architecture and sculpture, at once soft enough to be subdued, and hard enough to be preserved; the second, that some sense of danger might always be connected with the most precipitous forms, and thus increase their sublimity; and the third, that a subject of perpetual interest might be opened to the human mind in observing the changes of form brought about by time on these monuments of creation.
In order, therefore, to understand the method in which these various substances break, so as to produce the forms which are of chief importance in landscape, as well as the exquisite adaptation of all their qualities to the service of men, it will be well that I should take some note of them in their order; not with any mineralogical accuracy, but with care enough to enable me hereafter to explain, without obscurity, any phenomena dependent upon such peculiarities of substance.
§ 10. 1st. Crystalline Rocks.—In saying, above, that 1. Crystalline Rocks. the hardest rocks generally presented an appearance of "crystallization," I meant a glittering or granulated look, somewhat like that of a coarse piece of freshly broken loaf sugar.
But this appearance may also exist in rocks of uniform and softer substance, such as statuary marble, of which freshly broken pieces, put into a sugar-basin, cannot be distinguished by Are always Compound. the eye from the real sugar. Such rocks are truly crystalline in structure; but the group to which I wish to limit the term "crystalline," is not only thus granulated and glittering, but is always composed of at least two, usually three or four, substances, intimately mingled with each other in the form of small grains or crystals, and giving the rock a more or less speckled or mottled look, according to the size of the crystals and their variety of color. It is a law of nature, that whenever rocks are to be employed on hard service, and for great purposes, they shall be thus composed. And there appear to be two distinct providential reasons for this.
§ 11. The first, that these crystalline rocks being, as we saw above, generally the oldest and highest, it is from them that other soils of various kinds must be derived; and they were therefore made a kind of storehouse, from which, wherever they were found, all kinds of treasures could be developed necessary for the service of man and other living creatures. Thus the granite of Mont Blanc is a crystalline rock composed of four substances; and in these four substances are contained the elements of nearly all kinds of sandstone and clay, together with potash, magnesia, and the metals of iron and manganese. Wherever the smallest portion of this rock occurs, a certain quantity of each of these substances may be derived from it, and the plants and animals which require them sustained in health.