only limited access of air, it becomes "stifled coke ;" and this consisting chiefly of solid carbon, is a form of fuel eminently calculated for the reduction of iron, and other metals from their ores; it burns with extreme steadiness, and great intensity of heat, and contains no sulphur, which "gas-coke" invariably does; hence the peculiar odor of burning brimstone emitted from ordinary coke fires, if the draught of the chimney be not powerful and rapid.

The mass of the globe hitherto explored, consists of the oxides of the metals, Aluminum, Silicium, Calcium, and Magnesium, and their combinations with each other, and with various acids, as mentioned at page 30. These are popularly called earths, and they do not admit of reduction to the metallic state by charcoal, coal, or coke. Accordingly, they are invaluable for the artificial construction of furnaces, for the reduction of the ores of ordinary metals, that are found naturally imbedded in

them.

Some of the metals either found upon or beneath the surface of the earth, are so nearly pure or elementary, as to admit of immediate application to useful and ornamental purposes;-Platinum, Gold, Silver, and Mercury, for example; whilst others, as Iron, Copper, Tin, and Lead, are found combined with non-metallic elements, and require chemical skill for their reduction before they admit of application to the purposes of life.

The former are called "native metals," the latter "metallic ores;" many of both were known at a very early period, for in the Book of Numbers is a passage remarkable for containing the names of the metals then in common use, viz:

Only the Gold and the Silver, the Brass, the Iron, the Tin, and the Lead."

And again, in the Book of Deuteronomy, it is writ

ten:

"A land whose stones are iron, and out of whose hills thou mayest dig Brass."

The opinion of the most learned commentators concerning this passage, is corroborated by science, viz., that the word "Brass" either means "Copper," or the most abundant ore of that metal, called "copper pyrites," or "sulphuret of copper," which is dug out of the earth, and is precisely similar to brass in its color and lustre.

Brass is not a metal, but an alloy, or compound of Copper and Zinc, and it has never been discovered in a native state; it was, and is artificially formed by melting Copper, or its ore, with that of Zinc; although this metal was not formerly known, pure and elementary as it is at present, its lapideous ore was well known, and used in metallurgical operations.

That much was ascertained regarding the art of working metals in the earliest ages, will be evident upon perusing the first Books of Holy Writ; mention is made of "the iron furnace," and of the metal itself, as employed for swords, knives, axes and tools for cutting stones, and the lavish employment of all the metals in the construction of the Tabernacle and the Temple.

Of late years, the nature and properties of the metals have been most attentively studied by the chemist, and he is enabled to obtain them pure, or extract them from their ores with great precision, and in vast abundance; and in consequence of the excellent conducting

power, even of some of the most common metals, they become invaluable for the construction of vessels in which water may be converted into vapor with extreme facility, to constitute the motive power of the steam engine.

Culinary utensils, of metal, enable us to prepare food more economically and perfectly than could be done in vessels of earthenware, or other imperfect conducting materials; and if it were not for the metals, we should be reduced to the condition of those Indian tribes who are yet unacquainted with them, who make rude vessels of the bark of trees, sewn together with thongs, to hold water, in which the food is placed, and then the water is heated to its boiling point by the successive immersion of red-hot stones.

In the earliest ages of the world, it is reasonable to conclude that man sought repose from his labor soon after sunset; but, in the course of his numerous operations upon matter, he would soon discover that the combustion of various organic productions might be employed, not only as sources of artificial heat, but of light.

It is impossible to determine how the wonderful phenomenon of combustion was originally displayed to man ; but one thing is certain, that he soon became aware of its power, and that it engaged his attention on account of its beauty and utility.

From this inquiry regarding the Chemistry of the Four Seasons, which is now drawing to its close, it is evident that the chemist is permitted to effect wondrous and strange changes upon the various forms of organic and inorganic substances that are presented in the vast laboratory of Nature; and although he may mix and

unmix, combine and decompose, gather and scatter, be it remembered that he can neither annihilate nor destroy. The power of annihilation and destruction is vested in the Hand of The God who created all things.

The phenomenon of combustion appears to contradict this assertion regarding the non-destruction of matter; for no expression is more common than that of "destruction by fire ;" yet, when accurately considered, this destruction is only found to be apparent, and not real.

Fire was anciently regarded as a peculiar, distinct principle or element, having a specific or inherent power of destruction; and in this sense it repeatedly occurs in many of the most sublime and forcible passages of Holy Writ; but science has been permitted to discover that Fire, so far from being an element, is the invariable result of intense chemical attraction between two or more substances.

During ordinary combustion, the elements of the combustible or inflammable substance exert affinity for the oxygen of the air, and produce compounds which, in the generality of cases, are gaseous or vaporous, and therefore elude observation; but they admit of detection by the chemist, and from them he can educe or draw forth elements, the sum total of which exactly equals the original weight of the combustible substance; therefore, when a substance is burned, or apparently destroyed by fire, its physical form alone is changed; but its elements are perfectly unchanged, or, in other words, the elements. of the combustible have been induced by elevation of temperature to relinquish their original affinities, and to assume new, but definite arrangements. These, in all ordinary cases, are carbonic acid and watery vapor.

Such compounds are ordained to travel throughout the Creation; and under the recondite powers of vitality, are decomposed, and their elements secreted into the form of woody fibre, and other organic matters, and thus again presented as fuel, which again produces the same compounds, and so on, perpetually traveling, and illustrating, at every change of their affinities, the indestructibility of matter, and the wisdom and power of the Creator.

All substances of organic origin are combustible, but all are not equally fitted for employment as sources of light and heat; the chemist, extending his researches regarding the oils expressed from seeds, or obtained from animals, discovers them to be precisely similar as to the number and nature of their elements, viz., Carbon, Oxygen, and Hydrogen, the latter element being in great excess or abundance, and conferring extreme inflammability upon their vapors; but they do not contain Nitrogen; if this element were present, in vegetable and animal oil or fat, these proximate principles could not be advantageously used as sources of artificial light, because during combustion, in addition to the production of carbonic acid and water, a considerable portion of Ammonia would be produced, and its odor would be as intolerable and fatal as that emitted by burning or putrefying flesh.

The organic matters used for artificial light, be they liquid as oil, or solid as fat, require to be raised into vapor, before they will burn; this is effected by the capillary attraction of the cotton wick of a lamp or candle, which raises the liquid oil, or melted fat, to its upper or red-hot portion, where it vaporizes, and then burns with a brilliant and useful flame.