country by hard dykes, or veins impermeable to water; to the farmer, the best places for finding lime-stone, marle, and clay; and to the architect, the most durable stones for buildings. The person who is attached to geological inquiries, can scarcely ever want objects of employment and of interest. The ground on which he treads-the country which surrounds him--and even the rocks and stones removed from their natural position by art, are all capable of affording some degree of amusement. Every new mine or quarry that is opened, every new surface of the earth that is laid bare, and every new country that is discovered, offers to him novel sources of information. In travelling, he is interested in a pursuit which must constantly preserve the mind awake to the scenes presented to it; and the beauty, the majesty, and the sublimity of the great forms of nature, must necessarily be enhanced by the contemplation of their order, their mutual dependence, and their connexion as a whole.

13. Oryctology, is the science which teaches the natural history of those animal and vegetable substances, which' are dug out of the earth in a mineralised state. By this science, we obtain not only a knowledge of the peculia beings which dwelt on this planet in its antediluvian state, but we also acquire a more correct knowledge of the structure of the globe itself. Among these we find the remains of several animals not known to exist: such as the BELEMNITE, part of a chambered shell, but formerly thought to be a thunderbolt; the ENCRINITE, an animal, formerly termed a stone lily; the CORNU AMMONIS, a shell, formerly considered as a petrified snake; the MAMMOTH, an animal resembling the elephant, but posses sing grinders much like to those of carnivorous animals, with numerous others yielding additional proofs of the wisdom and power of the great Creator of all things.

Select Books on the Mineral Kingdom.

Kirwan's Mineralogy, 8vo. Accum's Analytical Mineralogy, 2 vols. 12mo. Kirwan's Geological Essays, 8vo. Parkinson's Organic Remains of a former World, 3 vols. 4to. Martin on Fossils, svo. De Luc's Geological Travels, including England, a vols, svo. Trans actions of the Geological Society, 4to. Sowerby's Mineralogy, svo,

CHAP. II.—VEGETABLE KINGDOM.

1. VEGETABLES are organized, supported by air and

food, endowed with life, and subject to death, as well as animals. They have in some instances, spontaneous, though we know not that they have voluntary, motion, They are sensible to the action of nourishment, air, and light, and either thrive or languish, according to the wholesome or hurtful application of these stimulants. This is evident to all who have ever seen a plant growing in a climate, soil, or situation, not suitable to it. Those who have ever gathered a rose, know but too well how soon it withers; and the familiar application of its fate to that of human life and beauty, is not more striking to the imagination, than philosophically and literally true.

The history of the vegetable kingdom is termed BOTANY, a study which includes the practical discrimi❤ nation, methodical arrangement, and systematic nomenclature of vegetables.

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2. The external covering of plants, the epidermis or cuticle, is commonly transparent and smooth; sometimes it is hairy or downy; and sometimes of so hard a nature, that even flint has been detected in its composition. The equisetum hyemale or Dutch rush, serves as a file to polish wood, ivory, and even brass. Under the cuticle, is found The cellular integument which is analogous to the rete mucosum of animals; it is like that, of a pulpy texture, and the seat of colour. It is commonly green in the leaves and stems, and is dependent for its hue on the action of light. When the cellular integument is removed, the bark presents itself, which in plants and branches only one year old, consists of a simple layer. In the branches and stems of trees it consists of as many layers as they are years old. The uses of bark are familiar to us. The Peruvian bark affords a cooling draught to the fevered lip; while that of the cinnamon yields a rich cordial; and that which it stripped from the oak, is used for the purposes of tanning. Immediately under the bark is situated the wood, which forms the great bulk of trees and shrubs. This also consists of numerous layers, as may be observed in

the fir, and many other trees; and from these concentric circles, or rings, the age of a tree may be determined. Within the centre of the wood is the medulla® or pith, which is a cellular substance, juicy when young, extending from the roots to the summits of the branches. In some

plants, as in grasses, it is hollow, merely lining the stem. The trunk enlarges by the formation of the new liber, or inner bark, every year, the whole of the liber, excepting its outermost layer, which is transformed into corter or outer bark, becoming the alburnum or soft wood of the next, and the alburnum becoming the lignum or hard wood.

In describing the characters of plants, we shall treat of their roots, buds, trunk, leaves, props, inflorescence, fructi fication, and classification.

1. Roors are necessary to plants, to fix and hold them in the earth, froin which they imbibe nourishment. Roots are either annual, or living for one season, as in barley; biennial, which survive one winter and after perfecting their seed, perish at the end of the following summer, as wheat; or perennial, which remain and produce blossoms for an indefinite number of years, as those of trees and shrubs in general. The root consists of two parts, the eauder and the radicula. The cauder or stump is the body or knob of the root, from which the trunk and branches ascend, and the fibrous roots descend. The radicula is the fibrous part of the root branching from the caudex. Roots are: 1. Fibrous, or consisting entirely of fibres, as in many grasses and herbaceous plants. 2. Creeping, or having a subterraneous stem, spreading hori zontally in the ground, throwing out numerous fibres, as in mint and couch-grass. 3. Spindle-shaped, as in the radish and carrot, which produce numerous fibres for the absorption of nutriment. 4. Stumped, or apparently bitten off, as in the primrose. 5. Tuberous or knobbed, as in the potato, which consists of fleshy knobs, connected by common stalks or fibres. 6. Bulbous, as in the crocus. 7. Granulated, or having a cluster of little bulbs or scales connected by a common fibre, as in the saxifrage.'

II. BUDS. These are, in most instances, guarded by scales, and furnished with gum or woolliness, as an additional defence. Buds are various in their forms, but very

uniform in the same species, or even genus. They enfold the embryo plant.

III. TRUNK. The trunk of trees includes the stems or stalks, which are of seven kinds. The stem as it advances in growth, is either able to support itself, or twines round other bodies. It is either simple as in the lily; or branched as in other plants. The parts are: 1. Caulis, the stem which bears both leaves and flowers, as the trunks and branches of all trees and shrubs, as well as of many herbaceous plants. 2. Culmus, a straw or culm, the peculiar stem of grasses, rushes, and similar plants. 3. Scapus or stalk, springs immediately from, the root, bearing flowers and fruit but not leaves, as in the primrose or cowslip. 4. Pedunculus, the flower-stalk, springs from the stem or branches, bearing flowers and fruit, but not leaves. 5. Petiolus, the foot-stalk, is applied exclusively to the stalk of a leaf.

IV. LEAVES. These are generally so formed as to present a large surface to the atmosphere. When they are of any other hue than green, they are said, in botanical language, to be coloured. The internal surface of a leaf is highly vascular and pulpy, and is clothed with a cuticle very various in different plants; but its pores are always so constructed as to admit of the requisite evaporation or absorption of moisture, as well as to admit and give out air. Light also acts through this cuticle, in a different manner. The effect of moisture must have been observed by every one. By absorption from the atmosphere, the leaves are refreshed; but by evaporation, especially when separated from their stalks, they soon fade and wither.. The nutritious juices, imbibed from the earth and become sup, are carried by appropriate vessels into the substance of the leaves, and these juices are returned from each leaf, not into the wood again, but into the bark.* The sap is earried into the leaves for the purpose of being acted upon. by air and light, with the assistance of heat and moisture. By all these agents, a most material change is wrought in the component parts of the sap, according to the nature

* This is effected by a double set of vessels, analogous to the arteries and veins in animals, and is the circulation of the vegetable blood or sap.

of the secretions which are elaborated, whether resinous, oily, mucilaginous, saccharine, bitter, acrid, or alkaline. The green colour of the leaves is almost entirely owing to the action of light, as was before observed. Leaves are subject to a sort of disease by which they become partially spotted or streaked, as with white or yellow, and in this state are termed variegated. The irritable nature of leaves is very extraordinary. The mimosa pudica or sensitive plant, common in hot-houses, when touched by any extraneous body, folds up its leaves one after another, while the foot-stalks droop, as if dying.

V. Paops or fulcra. These are: 1. Stipula, a leafy appendage to the true leaves or to their stalks, for the most part in pairs. 2. Bractea, a leafy appendage to the flower or its stalk, very conspicuous in the lime-tree, 3. Spina, a thorn proceeding from the wood itself as in the wild pear-tree, which loses its thorns by cultivation. 4. Aculeus, a prickle, proceeding from the bark only as in the rose and bramble. 5. Cirrus, a tendril or clasper, is a support for weak stems, and enables them to climb rocks, or the trunks of lofty trees. 6. Glandula, a gland is a small tumour secreting a sweet, resinous, or fragrant liquor, as on the calyx or cup of the moss-rose, and the foot-stalks of passion-flowers. 7. Pilus, a hair, which includes all the various kinds of pubescence; bristles, wool, &c. some of which discharge a poison, as in the, nettle; causing great irritation whenever they are so touched, that their points may wound the skin,

VI. INFLORESCENCE, or the different kinds or modes' of flowering are, I. Verticillus, a whorl, in which the flowers surround the stem in a garland or ring, as in the mints, dead-nettle, &c. 2. Racemus, a cluster, bears several flowers each on its own stalk, like a bunch of currants. 3. Spica, a spike is composed of numerous crowded flowers, ranged along an upright, common stalk, expanding progressively, as in wheat and barley, 4. Corym bus, a corymb, is a flat-topped spike as in the cabbage and wall-flower. 5. Fasciculus, a close bundle of flowers, as in the sweet-william. 6. Capitulum, a head or tuft, as in the globe-amaranthus and thrift. 7. Umbella, an umbel, consists of several stalks, called rays, spreading like an umbrella, as in parsley, carrot, and hemlock, S.