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found it difficult to distinguish it, is not so hard, and, when fractured, generally breaks flat and smooth.
MATILDA. I think we have seen one specimen of Quartz, (Plate 2. Fig. 3.).
MRS. L. Yes, in six-sided pyramids closely aggregated, or crowded together. Here is a piece of Smoky Quartz, of a dark colour, but transparent. (Fig. 3.) Woodstone (Fig. 4.) has the appearance of wood--but is evidently formed by the surrounding particles of Silex filtering in, as the fibres of the wood decay, and assuming their form.
ANNE.-I feel much better acquainted with Quartz than before in some forms at least we shall know it when we see it. : MRS. L.-The next specimens are of Felspar“Felspar is a compound body, of which siliceous and argillaceous earths (Argil, clay) are predominant ingredients: it generally contains a little lime and potash, and is often coloured by minute portions of oxyde of iron iron and oxygen). Sometimes it is found crystalized, when it assumes the form of four or six-sided prisms, levelled at the extremities. Its usual colours are red, white, and grey. It is softer than Quartz, but harder than glass, and is characteristically marked by fusibility before the blow-pipe.
ANNE.What is a blow-pipe?
Mrs. L.-A small machine so constructed as by creating a current of Oxygen or pure air through a flame, so increases the intensity of the heat, that many substances are fused or melted by it, which resist the influence of ordinary fire. “Felspar is a very important ingredient in many kinds of pottery; and the suba stance used by the Chinese, under the name of petuntz, is probably of a similar nature. The decomposing Felspar of Cornwall is abundantly employed in the English porcelain manufactories, and as it contains no iron, it retains its perfect whiteness. There are some beautiful
varieties of Felspar employed in ornamental jewellery, such as the green and blue of Siberia and America, the foliated, pearly, or resplendent Felspar, called Adularia and Moonstone; and the Felspar of the island of St. Paul upon the coast of Labrador, (Labrador Spar,) distinguished by the property of reflecting very beautiful colours when the light falls upon it in certain directions. Felspar is an important component part of several other rocks besides Granite.
MAT.—What do you mean by the decomposing Felspar?
Mrs. L.–A body is decomposed, when the ingredients of which it is compounded are separated-when we speak of a body as decomposing, we mean inclined to dissolve and separate its own parts: Felspar will sometimes do this; when it assumes the form of Clay. When fractured, Felspar has a flat, shining, foliated surface, as if it would separate in thin leaves, or laminæ, but this it will not do: by the appearance of the fracture you may always distinguish it from the Quartz, which breaks rough. Fig. 5. is the common Felspar-Fig. 6. the Labrador Felspar; but it is impossible here to convey the beauty of the reflective tints.
ANNE.-The next substance is Mica, I suppose.
MRS. L.—"Mica is a well marked compound mineral, consisting principally of argillaceous and siliceous earths, with a little magnesia and oxyde of iron. Its texture is lamellar, and it is easily split into thin, flexible, elastic, and transparent plates. It is so soft as readily to yield to the nail : it is sometimes met with crystalized in four and six-sided plates and prisms. Its usual colours are shades of brown and grey; sometimes it is red, and sometimes black. In some parts of Siberia, Mica is copiously quarried, and is employed as a substitute for glass in windows and lanterns, whence it is called Muscovy glass. It has been thus used in Russian ships of war, where it has the advantage of not being shattered,
like glass, by the discharge of artillery. The extreme tenuity of the plates into which it may be divided, and their elasticity, render it very useful for the enclosure of objects to be submitted to microscopic inspection." Mica has a tendency in all its crystalizations to assume an hexagonal form. Here is a piece, transparent, and as thin'as paper--you would suppose it artificially cutbut this is its natural shape. Fig. 7.
ANNE.—But what is this pretty pink substance classed with it-it does not look like Mica.
MRS. L. Because it is in a mass—but if you rub it between your fingers, you will find it crumble into bright, scaly particles, resembling minute flakes of Mica. This is called Lepidolite. Fig. 8.
Mat.-The remaining specimen I conclude is the Hornblende.
Mrs. L. It is so: of a dirty black or green-a rough, crumbling, gritty substance---sparkling a little, but not flaky, or transparent like the Mica. Hornblende, (Fig. 9.,) sometimes forms prismatic crystalsit yields easily to the knife: it contains siliceous and argillaceous earths, magnesia and a large quantity of iron. You now, I trust, feel yourselves in some degree acquainted with all the component parts of Granite the first and most abundant of the Primitive Rocks.
ANNE.--I think so. And you promised further to explain to us the supposed manner and period of the formation of the Granite Rock.
Mrs. L.- This is the most difficult part of my task a secret upon which we may innocently form conjectures, but which the Creator has probably determined never to disclose. Granite and the other Primitive Rocks, are crystalized substances, which lead to conclude that they must some time have been dissolved for all we understand of crystalization, is by the previous solution of the body, which, as it becomes solid again, assumes a crystaline appearance. Again, it seems to us impossible that these substances could be dissolved in water the strongest fire we can create is alone sufficient for the purpose-wherefore it has been concluded, that all these substances have been some time liquefied in fire. Another doubt is respecting the form and situation of these Rocks, whether they are as they were first deposited, or whether their shape and place have been subsequently changed. There is ample reason to believe the latter. “ On the origin of Granite, geologists widely differ. As it constitutes the basis upon which all other rocks appear to lie, Werner has regarded it as the first formation of that chaotic, rock-depositing fluid in which he imagines the earth once to have been enveloped. But many peculiarities of Granite have been deduced by Dr. Hutton as contrary to such an opinion. If we examine a granitic district in nature, we shall observe in regard to it, two leading phænomena. The one is, that veins of Granite frequently shoot from the great mass, into the superincumbent strata. The other--that the bodies lying upon Granite, especially if they be stratified, either bear evidence of having been broken up, dislocated, and penetrated by the Granite whilst in a fluid state, or they seem as if gradually elevated by some power which has thrown the Granite up from below. So that upon this view of the subject, the date of Granite, as far as concerns its present position, is posterior to that of the strata that rest upon it. They were first deposited, and the Granite then erupted from beneath, and elevated the other strata, throwing them out of the horizontal, and giving them various inclinations to the horizon, and sometimes a vertical position.”
ANNE. I believe I do not quite understand this question.
Mrs. L.-It is simply this—whether the strata, that now lie above the Primitive Rocks, were once flat, and were broken and forced into their present form by the throwing up of the Granite from under themor Whether the Granite having its present form before these were deposited upon it, they gradually assumed the shape of the mould on which they fell. This is a question we cannot answer.
Certain it is, that every thing wears the appearance of violence and change. As we proceed, we shall see ample reason to believe that the ocean has changed its bed—that the now dry land has been some time covered with water, and that more than once.
MAT.-But if more than one such flood had taken place, would it not have been recorded.
MRS. L. Most likely, if it had occurred since the race of man became the inhabitants of earth.
MAT.-But were not the earth and man created at the same time? When then could these things happen?
MRS. L.—Moses, the historian of divine truth, has told us that in the beginning God made the earth, and it was without form and void. The earth, therefore, existed before it assumed its present form at the successive commands of the divine word. Moses does not tell us what was the condition of the earth while the darkness was upon it, nor how long it remained in that condition, nor what changes it underwent before the Almighty commanded the light to shine upon it. Whatever was the condition of the earth before the six days' work of creation began, Moses, who did not mean to teach us Geology, or any thing but the history of our race, thought it enough to tell us that God had made it. If, therefore, Geology could prove that the earth has subsisted millions of years, instead of the thousands that our present race has dwelt upon it, it could not invalidate the truth of the Mosaic Scriptures. In the beginning, whenever that beginning was, God created it-and when it pleased him he made it what it is: and in the manner that he himself relates, prepared it for the reception of the beings he intended to place upon it.
any thing we discover in nature seems inconsistent with this relation, we may be assured it is our mistaken VOL. V.