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they happen to like, has bad taste-every one who does not feel what happens to affect them, has no heartevery one who is not employed as they are, wastes their time every one who does not conform to their estimate of right, has no conscience-every one whose opinions are not like their own, or their mama's, or their governess's, is mistaken. If it ended here, we might live very happily in our self-esteem; and society, if not in unanimity, might remain in peace. But it does not we are never content in our fancied superiority-offence is taken where it is not given, or given where it is not provoked-kindness is coldly withheld, or rudely repulsed, or ungratefully repayed with ridicule-pain is inflicted unnecessarily where all have of necessity enough -innocent feelings are mortified and innocent enjoyments marred-instead of being as we ought to be, the variously wrought parts of one providential whole, to support, to counterbalance, to assist each other, to communicate to others what we hold in pre-eminence, to avail ourselves in others of what in us is deficient, it seems to be the very essence of our existence to depreciate and despise others, while our minds become at once narrowed and inflated by admiration of our own supposed advantage ground.
CONVERSATIONS ON GEOLOGY.
Quartz-Felspar-Mica-Hornblende-Origin of Granite Rocks. MRS. L. Now I hope you recollect the fundamental constituents of the Granite Rock, as I enumerated them in the last conversation.
ANNE. I think they were Quartz, Felspar, Mica, and Hornblende, some of which were always present,
but not necessarily all of them; and occasionally they were intermixed with Schort, Garnet, and other substances, not considered as the usual base of the Granite.
MRS. L.-You are quite correct and I now propose to show you these substances separately, and explain their qualities. This is rather the province of Mineralogy than of Geology; but as I have said before, I prefer clearness to regularity, and it is vain to go on talking about Quartz, Felspar, &c. without knowing the meaning of the terms, or having an idea of the substances they stand for. "QUARTZ is the substance commonly called Rock Crystal: it consists of pure siliceous earth, (Silex, flint,) aud is abundantly found in more or less regular sixsided prisms, terminated by six-sized pyramids. Fig. 1. It occurs of various colours, such as a rose, brown, yellow, and purple, metallic bodies generally giving these
and sometimes these varieties are transparent, and when properly cut, constitute beautiful articles of jewellery:" such are the Amythist, Cairne-Gorum, Cats-eye, &c. "It is so hard as not to be scratched by a knife, and it cuts or scratches glass. Quartz is sometimes met with in mountain masses, which usually present a conical appearance. The Quartz has then the appearance of Fig. 2. The sugar-loaf mountains near Dublin; the pass of the Jura, in the Western Isles of Scotland, and some of the mountains of Sutherland and Caithness present instances of this formation." Siliceous earth is an important substance in some arts, and is an essential ingredient in glass, earthenware, and porcelain. There is Silex, or Siliceous earth in almost every earth; but in its pure state, it is more particularly called Quartz. "There are tracts of country, exhibiting strata of some thousand feet in thickness consisting solely of Quartz Rock of the appearance of Fig. 2. The Fracture of this piece you will obseve to be uneven, of no determinate form-try the edge on glass, and you find it will scratch it, though your sharpest pen-knife fails to scratch the Quartz. The Felspar, from which you
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 substance used by the Chinese, under the name of petuntz, is probably of a similar nature. The decomposing Fel spar 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 crystals— it 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 Granitethe 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 taska 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 dissolvedfor 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