A Method of obtaining pure Copper. 123. Dissolve the copper of commerce in muriatic acid, and precipitate it by a polished plate of iron; the precipitate will be pure copper. To make Brass, and other alloys of Copper. 124. Brass is made by fusing together lapis calaminaris (which is an ore of zinc) and copper. Tornbac is formed by melting together twelve parts of copper with three of zinc. Gun-metal consists of nine parts of copper and of tin. Bell-metal is copper alloyed with one-sixth of tin. A smaller proportion of tin is used in making church bells than clock bells, and a little zinc is added for the bells of repeating watches, and other small bells. Cock-metal is made with copper alloyed with zinc and lead. The gold coins of this country are composed of eleven parts of gold and one of copper. Standard silver contains fifteen parts of silver and one of copper. CHAPTER VI. THE PHILOSOPHY OF THE VEGETABLE KINGDOM. SECTION I. INTRODUCTION. 125. VEGETABLES are organized productions supported by air and food, endowed with life, and subject to death, like animals. They have, in some instances, spontaneous, not voluntary motion. They are sensible to the supply of nourishment, the action of the air, and light, and thrive or languish, according to the wholesome application of these stimulants. This is evident to all who have ever seen a plant growing in a situation, for which it is not suitable. Those who have gathered a rose, know 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 correct. The history of the vegetable kingdom is termed BOTANY, a science which includes the practical discrimination, the methodical arrangement, and the systematic nomenclature of vegetables. The external covering of plants, is commonly transparent and smooth; but sometimes it is downy; and sometimes so hard that flint has been detected in its composition. The Dutch rush serves as a file to polish wood, ivory, and even brass. Under the cuticle, is found the cellular integument of a pulpy texture, and the seat of colour. It is usually green in the leaves and stems, and is dependant for its hue on the action of light. When the cellular integument is removed, the bark presents itself; in plants and branches only one year old, the bark consists of a simple layer. In the branches and stems of trees it consists of as many layers as they are years old. The Peruvian bark affords a cooling draught to the fevered lip; that of the cinnamon yields a rich cordial; that which is stripped from the oak, is used for 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 other trees; and from these concentric circles, the age of the tree is determined. Within the centre of the wood is the medulla or pith, 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 new liber, or inner bark, every year, the undermost layer is transformed into cortex or outer bark, becoming the laburnam or soft wood of the next, and the laburnam becoming the lignum or hard wood. The chemical or elementary principles of vegetables, are carbon, water, and air; or hydrogen (15), and oxygen (85), for the constituent parts of (100) water; and azote and nitrogen (72), and oxygen (28), as the constituent parts of (100) atmospheric air; and carbon. 124. Vegetables generate, or give out oxygen or vital air, in the light or sunshine by a natural process of their own. The saccharine and oily productions of vegetables are parts of their sap or juices; but the turpentine, bitter, and acid principles, are effects of secretion. The green colour of vegetables arises from the oil they contain; the rays of the sun extract the oxygen from the outer surface, and leave the carbon and hydrogen the constituent parts of oil. Healthy vegetables, in general, perspire water by the under part of their leaves, equal to one-third of their weight, every twenty-four hours. Nor do they derive their substance in a principal degree from the matter of the soil in which they grow; but they are created as it were by a vital principle of their own, out of air and water, and of the imperceptible matters combined with air and water, from which they derive distinctions of smell, taste, and sub stance. SECTION II. OF ROOTS, BUDS, TRUNKS, LEAVES, PROPS, INFLORESCENCE, FRUCTIFICATION, AND CLASSIFICATION. 125. ROOTS are necessary to fix and hold plants, in the earth from 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 caudex or stump, which is the body or knot of the root, from which the trunk and branches ascend, and the fibrous roots branching from the caudex. Each tree, each plant, from all its branching roots, Which drink with thirsty mouths the vital juice, BLACKMORE. 126. Buds 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 unfold the embryo plant. 127. The trunk of a tree includes the stems or stalks. The stem as it advances in growth, either supports itself, or twines round other bodies. It is either simple, as in the lily: or branched, as in other plants. 128. Leaves are generally so formed as to present a large surface to the atmosphere. When of any other hue than green, they are said to be coloured. The internal surface of a leaf is vascular and pulpy, 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, and light also acts through this cuticle. 129. The effect of moisture must have been observed by every one. By absorption from the atmosphere, the leaves are refreshed; by evaporation, when separated from their stalks, they soon fade and wither. The nutritious juices, imbibed from the earth, become sap, and are carried by appropriate vessels into the substance of the leaves, and these juices are returned from each leaf into the bark. 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. The sap is carried into the leaves for the purpose of being acted upon by air and light, with the assistance of heat and moisture, and by all these agents, a most material change is wrought in the component parts of the sap, according to the nature of the secretions. The green colour of the leaves is owing to the action of light, but they are subject to a disease by which they become partially spotted or streaked, and in this state are variegated. The irritable nature of leaves is very extraordinary, for the sensitive plant, common in hot-houses, when touched by any extraneous body, folds up its leaves one after another, and the foot-stalks droop, as if dying. 130. Props or falera, are appendages to the truc leaves, or to their stalks. Your contemplation further yet pursue: BLACKMORE. 131. Inflorescence treats of the different kinds or modes of flowering. Sometimes the flowers surround the stem in a garland or ring, as in mint, deadnettle, &c. In other plants, a cluster, which bears several flowers, each on its own stalk, like a bunch of currants. In other plants, numerous crouded flowers are ranged along an upright, common stalk, expanding progressively, as in wheat and barley. Again we find a flat topped spike, as in the cabbage and wall flower. Who can paint Like Nature? can imagination boast, And can he mix them with that matchless skill, And lay them on so delicately fine, THOMSON. 132. Fructification is a term comprehending not only the parts of the fruit, but those also of the flower. The parts of fructification are described by many technical words, but include chiefly the flowercup, or external covering of the flower: the calyx, consisting in general of the coloured leaves of the |