METALLOGRAPHY;

OR

THE SCIENCE OF THE METALS.

CHAPTER I.

DERIVATION AND MEANING OF "METALLOGRAPHY.' THE NAMES OF THE METALS.-DERIVATION OF NAMES.SYMBOLS.-EQUIVALENTS.-SPECIFIC GRAVITIES.-DATES OF DISCOVERIES.-NAMES OF ELIMINATORS.-EXPLANATION OF THE TERMS, METALLIC LUSTRE, SPECIFIC GRAVITY, FUSIBILITY, AND CRYSTALLIZATION.

THE word METALLOGRAPHY is derived from two Greek words, metallon, a metal, and graphé, a writing or description, and has been applied to that science which describes and treats of the properties of that very large class of simple or elementary substances called Metals. Of these substances there are no fewer than fifty-five.

Several of them are very rare, and at present of no practical use; nevertheless, the advance of knowledge will probably elicit valuable properties.

Their names, arranged alphabetically, are as follows:

These substances are distinguished as a class from all other bodies by their peculiar brilliancy, which has been termed by metallographers metallic lustre; and it arises out of their opacity and reflective power. But there are other properties besides this by which we may distinguish these useful bodies-such as their weight or specific gravity, fusibility, ductility, and malleability. When we speak of the specific gravity of a metal, we mean its weight as compared with that of water, which, as a standard of comparison, is called one. Thus, for instance, the specific gravity of platinum is marked 21:53 in the foregoing table; that is, it is rather more than 21 times as heavy as water. Lithium, on the other hand, which is one of the lightest of the metals, is only 59 as heavy as water; or, in other words, water is nearly twice as heavy as lithium, which, on this account, will float.

Again, all the metals are fusible (i.e., capable of being poured out from the Latin fundo, I pour out), but the degree in which they possess this quality is considerably diversified. Platinum, for example, requiring to be melted by the oxy-hydrogen blow-pipe, whilst mercury or quicksilver, is not only fluid at the ordinary temperature of our atmosphere, but continues so even in a degree far beyond that at which water becomes solid; it actually requires a cold of 72 degrees below the freezing point of Fahrenheit's thermometer an intensity of cold not known in our climate-in order to solidify. If, when in a state of fusion, the metals be allowed to cool slowly and quietly, they all crystallize, most of them assuming the form of the octohedron. The word crystallization is derived from the Greek krustallos, ice or crystal, and has been applied to the oper ation in nature as well as art, in which various earths, salts, and metallic substances, passing from a fluid to a solid state, assume certain geometrical forms. Pure carbon is capable of crystallization, though not by art, in which state it is called diamond.

Amidst the great variety of departments which this science embraces, the changes which the metals undergo by their absorption of oxygen from the atmosphere are perhaps more eminently calculated than any other to give a relish for chemical experiments, and to engage the minds of the young in the unremitted examination of the works of the Great Creator of the Universe.

"The philosophic youth

To Nature's voice attends from month to month,
And day to day, through the revolving year;
Admiring, sees her in her every shape,
Feels all her sweet emotions at his heart;
While Truth, divinely breaking on his mind,
Elates his being, and unfolds his powers."

The youth who possesses an intelligent and well-educated mind, is nearly always delighted in discovering the origin, studying the properties, or tracing the past history of any natural object, as revealed in its structure and growth; and the study of the various sections of the animal, vegetable, and mineral kingdoms cannot fail to occupy and charm such an one. The more we, as human beings, inquire and search into the economy of Nature, as displayed in the numberless different objects by which we are surrounded, so far from finding any imperfection, we shall obtain more and more convincing proofs that not only every animal and vegetable, but also every mineral and metal is equally well adapted for the purpose for which it was intended by God. And it is a remarkable fact that the more we magnify the works of Nature, with the assistance of the microscope, the more strikingly do their regularity and beauty show themselves. But this is not the case with the works of man. Take, for instance, a drawing, painting, or engraving; although it may have been executed with the most delicate care that the most clever artist can bestow upon it, yet when placed under the microscope, we are indeed astonished at its appearing so harsh, so rough, so uncomely. It was the study of the works of nature which led the Psalmist to exclaim, "O Lord, how manifold are thy works, in wisdom thou hast made them all; the earth is full of thy riches!"

Then

"Canst thou renounce the boundless store

Of charms which Nature to her votary yields?
The warbling woodlands, the resounding shore,
The pomp of groves, and garniture of fields;
All that the genial ray of morning yields,
And all that echoes to the song of even',

And all that the mountains' sheltering bosom yields,
And all the dread magnificence of Heaven?
Canst thou renounce, and hope to be forgiven ?”