METALS. MALLEABILITY OF GOLD.

THE SOLID MATERIALS OF THIS GLOBE.

METALS are simple bodies, characterized by their absolute opacity, great degree of gravity, peculiar brilliancy, and insolubility in water. Some of them possess a considerable degree of ductility, but this property is not common to them all. Almost all the metals seem to be capable of impressing the. organs with a peculiar taste and smell. Professor Davy mentions thirty-eight different sorts already known. All of these have different degrees of importance and usefulness in the grand economy. The uses of the more common metals are well known. They contribute to domestic convenience, agricultural improvement, and a variety of important purposes in the different arts of civilized society. Metals enter into the constitution of almost all other bodies; they are found in plants, stones, and even floating along the arteries and veins of many animals.

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Of all the metals, gold is the most susceptible of malleability and ductility; and on these accounts, together with its not being liable to corrosion from

b Parkinson.

A small proportion of iron is found in the blood of some animals, and is supposed to be the cause of its red colour.

SOILS AFFORD FOOD TO PLANTS.

the action of the atmosphere, it is applicable to a variety of most important purposes. It has been calculated that it would take fourteen millions of films of gold, such as cover some fine gilt wire, to make up the thickness of one inch; whereas fourteen million leaves of common printing paper make up almost three quarters of a mile; and that one ounce of it is sufficient to gild a silver wire more than thirteen hundred miles in length.

The EARTHS which are known, are nine in number; of different qualities, characteristics, and uses. Their essential properties, like the essential properties of all other substances of our globe, are but little known. It is from them principally that vegetables derive their stamina, and their grand support. By being mixed together in different proportions, under different circumstances, a great variety of earths is produced, forming soils suited to the almost unbounded variety of vegetables which cover the surface of this globe, and which derive their respective nutriment from them. Each class of vegetables requires a composition of these earths, in some respects different from all others, that it may grow with vigour, and subserve the purposes of its original formation. Some vegetables require a soil of a more loose, others of a more compact consistence; and this variety of compositions is found upon the face of the globe, most exactly adapted to the necessities. of vegetation.

THE LOADSTONE.

Those masses of matter which we call STONES, are composed principally of the nine earths mixed together in different proportions and numbers. Some stones are nearly simple, formed by a concretion of one earth to the exclusion of almost all the rest; others are compounded of two, three, or all the earths, embracing also metals, salts, shells, and a number of other substances, constituting stones of different textures, solidity, and variety, almost innumerable. Their uses in society are too well known to need description.

There is one of these substances, which, on account of its singular properties, and peculiar importance to mankind, deserves to be mentioned;-it is the LOADSTONE. Though its application to the purposes of navigation is comparatively of recent date, Providence seems to have conferred on it exclusive properties, with an original regard to its ulterior appropriation. The fluid, or peculiar property of this stone, be it what it may, (for it has hitherto completely baffled the skill of the most acute philosopher to say what it is,) is capable of being communicated to a metallic needle, which, when balanced upon a pivot, directs one of its ends to the north pole. Aided by the magnetic needle, ships are navigated from one country to another the most remote, with an exactness and certainty which was thought impossible before this great discovery was made. The destruction of this fluid, or its sus

THE MATERIALS AND SOLIDITY OF THE EARTH DISCOVER WISDOM.

pension, would occasion an almost entire interruption of that intercourse which is carried on by the nations of the earth, so necessary to their mutual advantage.

A variety of other substances might be mentioned under the class of solids, such as salts, sulphurs, and alkalies; but the design of this work forbids enlargement on this part of our subject. And though, when we look upon these objects, they appear rude, shapeless, and uncouth; yet, when we analyse their parts, and develop their physical properties, we see that they possess the finest and most important qualities, -food for the most fragrant flowers, and the most delicious fruits. What foresight is here manifest on the part of the Deity, in regarding the necessities of plants and animals! and what wisdom appears in the formation of these objects, so suitable to their respective ends!-Animals require vegetables, possessed of certain properties, for their nutriment;-these vegetables demand also their support from the soils in which they grow,-and these soils are endowed with all the requisite qualities. How evident the wisdom of that Being, who is wonderful in counsel, and mighty in executing!

These various materials, blended and brought into contiguity, form the dry land, which is destined to support animals and vegetables. The surface of the earth is so tempered with a due proportion of water, as to be neither so soft as to yield under the incum

MEANS OF THE EARTH'S DUE TEMPERATURE.

bent pressure, nor so hard as to forbid the roots of plants from penetrating into its pores; and by this means at the same time acquiring firmness, and obtaining their food.

The same unerring skill is apparent in the preservation of the earth in a temperature suited to vegetation. Were the earth subject to as great a degree of cold as the atmosphere by which it is invested, the vegetable creation would be destroyed by its intensity. But a most wise and merciful provision is made by the Creator against this, and to continue the earth in nearly the same temperature in even the coldest regions. When the atmosphere is reduced to thirty-two degrees, the water which is contained in it is congealed, descends in snow, and covers the earth. Snow being a bad conductor of heat, it refuses to carry off that which the earth contains; so that the parts covered by the snow are but rarely reduced below the above temperature of thirty-two degrees, which most vegetables can bear without being destroyed.

THE FLUIDS WHICH BELONG TO THIS GLOBE.

WATER is the first of those fluid bodies I shall mention. It occupies nearly two-thirds of the surface of the globe, in oceans, seas, rivers, and lakes.