cence, a permanent alteration, and a delineation of figure or pattern, such as dotted, spotted, clouded, flamed, striped, veined, &c. With respect to the second grand generic distinction: cohesion of particles; metals are divided into 1, Solid, or such as have their parts coherent, and not easily moveable: 2, Friable, or that state of aggregation in which the particles may be overcome by simple pressure of the finger; and 3, Fluids, or such as consist of particles which alter their place in regard to each other by their own weight. After the external aspect, the fracture forms no inconsiderable character in minerals. Its lustre may be determined as in the external lustre; but the fracture itself admits of great varieties. It may be compact, splintary, uneven, earthy, &c. If the fracture is fibrous, we are to consider the thickness of the fibres, if coarse or allicate; the direction of the fibres, if straight or curved; and the position of the fibres, if parallel or diverging. The external characters of metals from the senses are as follows. Those from the touch are eight in number, as already enumerated. The different characters which occur in the mineral kingdom from the sound, are a ringing sound, as in native arsenic, and their splinters of horn or stone; a grating-sound, as in fresh burnt clay; a creaking-sound, as that of natural amalgam. Those from the smell may be spontaneously emitted, and described, as bituminous, faintly sulphurous, or faintly bitter; or they may be produced by breathing on, and yield a clay-like smell; or they may be excited by friction, and smell urinous, sulphureous, garlic-like, or empyreumatic. The external character from the taste prevails chiefly in the saline class, and it contains the following varieties: a sweetish taste, sweetish astringent, styptic, saltly bitter, saltly cooling, alkaline, or urinous. Having thus given a very brief synoptical view of the external characters of minerals, I refer the student to the important and luminously arranged propositions of our author in the following lessons. LESSON THE FIRST. MINERALS. 2. Mineralogy is a science, the object of which is to describe and arrange inorganic bodies; that is, all bodies which belong to our globe, except animal and vegetable substances. 2. Minerals constitute the external covering of our globe, their number is very great, and their character almost infinitely diversified. 3. The business of mineralogy consists in describing the different appearances and characters of minerals; and in arranging and classifying them according to their most obvious relations. 4. All mineral productions are comprehended in four classes: viz. the earthy, or stones; the saline, or salts: the inflammable, as sulphur, &c.; and metals, or metallic ores. 5. The earthy minerals contain all such as derive their qualities from the earths, (described in Lesson 5. Chemistry) these are divided into families, or genera, according to the particular earth which predominates in each. Example. (1.) The silicious, or flint genus, contains all those earthy minerals in which silex or flint predominates, as the garnet, ruby, quartz, common flint, &c. (2.) The clay genus includes common clay, slates, and all those substances that contain a predominant quantity of alumina. 6. The saline class of minerals contains all the combinations of the acids with alkalies which exist in the mineral kingdom; such are saltpetre, or nitrate of potash; common rock salt, or muriate of soda; and salammoniac, or the muriate of ammonia. 7. The third, or inflammable class, comprehends all combustible bodies, except metals, and the diamond; and it includes sulphur, resins, bitumens, and graphite. Examples.-(1.) The resin includes amber, and a substance called retinasphaltum, which seems to connect resins with bitumens. (2.) Bitumens contain petroleum, mineral pitch, and various kinds of coal. (3.) Graphites are true carburets of iron, of which plumbago, or black lead, used for pencils, is one. 8. The fourth class comprehends all mineral bodies, composed either entirely of metals, or of those bodies of which metals constitute the most considerable part. 9. The genera of minerals are divided into species, and these again into sub-species and varieties, according to their agreement, or difference in external qualities, as shape, colour, fracture, hardness, &c. 10. From minerals of the fourth class all metals are extracted, hence they have obtained the name of ores. 11. Metals exist in ores either in a metallic state: combined with sulphur: in the state of oxides: or combined with acids. Hence the four genera, alloys, sulphurets, oxides, and salts. QUESTIONS FOR EXAMINATION. 1. What is mineralogy? 2. What constitutes the covering of the earth? 3. Of what does the business of mineralogy consist? 4. Into how many classes are mineral productions divided? 6. What does the saline class of minerals contain? 7. What does the inflammable class comprehend? Give the examples. 8. What does the fourth class of minerals comprehend? 9. How are the genera of minerals divided? 10. Whence are all metals extracted 11. In what do metals exist? LESSON THE SECOND. ROCKS. 1. The stony masses of which the earth, as far as it has been explored, is composed, are either simple, (such as have been described in the last lesson) or compound. 2. Stony masses, or rocks, are very numerous, and they are found in the earth, laid one above another; so that a rock of one kind is covered by another species of rock, and this by a third, and so on. 3. This arrangement is not arbitrary, but every species of rock occupies a determinate place, so that they follow each other in regular order, from the deepest part of the earth's crust to the surface. Example.-Lime stone is found no where under granite, but always above it. 4. Rocks are divided into five classes. The first class of rocks are covered by all the rest, but never themselves lie over any other. The others lie in order over each other. 5. These classes are denominated formations: hence we have PRIMITIVE; TRANSITION; FLOETZ; ALLUVIAL; and VOLCANIC formations, according to the period in which, and the mode by which, they have been formed. 6. The primitive formations are the lowest of all, and the alluvial constitute the very surface of the earth; for the volcanic formations are confined to particular points. 7. Primitive rocks are supposed to have been chemical precipitations, formed in the early chaotic state of the earth; because they never bear any trace of organized beings; these are chiefly composed of siliceous and argillaceous earths, as granite, gneiss, slate, &c. 8. Transition rocks were formed during the transition of the earth into a habitable state: they differ from the primitive in the variety of their colour, and by containing the remains of marine animals. 9. The floetz rocks are disposed in fiat, horizontal strata: they contain the remains of animals and vegetables, and must have been formed after the creation of these. 10. Alluvial formations consist of the component parts of previously existing rocks, separated by the influence of the air, &c. and deposited in beds. 11. Alluvial formations are compounded, (1.) Of sand, gravel: and (2.) of alluvial deposit; as loam, clay, sand, turf, and calcturf. This last contains plants, roots, moss, bones, &c. which it has encrusted. The clay often contains petrified wood, and skeletons of quadrupeds. 12. Volcanic formations are of two kinds, namely, the pseudo-volcanic, and the true-volcanic: the first are minerals altered in consequence of the burning of beds of coal situated in their neighbourhood: the second are those which have been actually thrown out of the crater of a volcano. 13. Volcanic productions consist of pumice-stones, lava, and basaltes. Pumice-stone is a kind of glass, but on account of its pores it is often lighter than water: lava is a semi-vitrified substance; and basaltes may, by heat, be converted into glass of a beautiful black colour. QUESTIONS FOR EXAMINATION. 1. How are the stony masses of the earth distinguished? 2. How are rocks found in nature? 3. Is the arrangement of rocks arbitrary? Give the example. 4. How are rocks divided? 5. How are the classes of rocks denominated, and what is the result? 6. What is meant by primitive formations? 7. How are primitive rocks supposed to have been formed, and of what are they composed? 8. How have transition rocks been formed, and how do they differ from primitive rocks? 9. How are floetz rocks disposed? 10. Of what do alluvial formations consist? 11. Of what are alluvial formations compounded? 12. How are volcanic formations distinguished? 13. Of what do volcanic productions consist? BOTANY. THE EMPLOYMENT IT SUPPLIES. "At once array'd In all the colours of the flushing year By nature's swift and secret-working hand, BOTANY is a term derived from the Greek, for an herb or plant and it formerly implied a knowledge of the nature, |