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Art. III.-1. Fresenius' Instructions in Chemical Analyses. London:

Churchill. 2. Galloway's Manual of Qualitative Analyses. London : Churchill. 3. Abel and Bloxam's Handbook of Chemistry. London : Churchill. 4. Faraday's Lectures. London: Longmans.

IN

our days, and in those of the generation that is now

passing away, the science of chemistry has grown up from a puny stature into gigantic proportions, and with its giant's size has attained to a gigantic strength. Still with its colossal power and might it has, when this has been needed, refined upon its original delicacy. Ever in operation chemistry sometimes astonishes us with the tremendousness of its results, while at other times we are forced to admire the extreme minuteness of its proceedings. Chemistry can make explosive compounds that may destroy a city, and yet can detect in, and separate the hundredth part of a grain of arsenic from, the stomach of a poisoned man, or the one four hundred and fiftieth thousandth of a grain of iodine in a wine-glass full of mineral water. Chemistry directs the metallurgist in the management of his huge furnaces, and also the manufacturer of a pin ; it penetrates into the cook's kitchen, and yet the highest refinements of luxury, as far as material things can be, are dependent upon it for their properties. Without the assistance at least of chemistry, the powerful steamengine would scarcely do its mission, and yet without it the soldering of a tin kettle cannot be rightly performed. If chemistry sometimes wields its power for the purposes of destroying life, by its means more food is produced, and from its stores medicine draws some of her most useful remedies. Yet all these powers, and much more, have been mainly acquired by chemistry in less than a century, and from the hour when Cavendish analyzed water to the other day, its onward course has been uniformly continuous. But even Jupiter nods, and for a moment as it were chemistry is reposing. Perhaps its slumbers are disturbed by vague dreams of allotropism, and like hypotheses, that are destined it may be to dim its hitherto unclouded escutcheon, and give another proof that everything in this world, even science itself, is subject to error, and doomed too often to receive wounds from those who should be its guardians and protectors. Be this as it may, this present resting-time seems suitable enougḥ for considering the history and present state of chemical science.

At first sight it would appear that the best plan of narrating the history of chemistry is, to detail the labours of the chemists of each succeeding age, but this is not so. As, when only some few hundreds of plants were known, the botanist could arrange them according to any artificial system that he pleased, but found it necessary, when the genera multiplied upon him, to arrange them into different natural families and orders, so it is with chemistry. It is indeed so extensive a science, or rather a series of sciences, that in narrating its career it is necessary, unless done on a very extended scale, often to merge individuals, and regard merely the rise and progress of great epochs. Even in doing this, it is sometimes necessary to sink chronology, for often we can trace the seed of a great principle that lies dormant for ages ere it is vivified into an existence. Perhaps the history of chemistry is naturally divided into that of 1st, the origin and progress of chemistry, among the ancient Semitic nations; 2nd. of the chemistry of the Arabians, and the alchemists, the latter being the first great outburst of methodic chemistry ; 3rd. of Paracelsus, and his school, or of the first avowed school of empirical chemistry ; 4th. of Van Helmont, and the new methodical school of iatro-chemistry ; 5th. of the commencement of the re-establishment of the rational dogmatical school; 6th. of Black and the pneumatics; 7th. of Lavoisier and the French school; 8th. of Davy and the electrical school; and 9, of Liebig and the organic chemists.

Chemistry is essentially a science of the Semitic race, no nations not belonging to this great division of mankind having ever cultivated it with success. Indeed, its very name, xquia, is probably derived from our great ancestor Shem of the Vulgate, and Chem of the Egyptians. Farther, it appears almost certain that post-diluvian chemistry had its origin, certainly a humble one, in Egypt. History, tradition, and archæology, in fact combine to tell us that it was in this country that science of all kinds sprang up. The scientific inquirer, who considers the physical geography and the geology of the country around Thebes, cannot fail to be struck with the suitableness of such a locality for the birth-place of chemistry. The first chemistry was unquestionably practical metallurgy, i. e. the extraction and management of the metals. If, then, we regard the geology around Thebes, we see that on the western side of the Nile there occurs to the north, limestone, then sandstone, and that both are intersected with primitive mountains of quartz, and long stretches of graywacke, or transition rocks. The eastern ridge of the Nile, also, pretty near to the Delta, has limestone formations, but as we go southward we find an immense quantity of granite, and when we arrive at Syene we come upon the worked quarries of that variety of it, called, from this circumstance, syenite. Between the Nile and the Red Sea the mountains are all primitive, and in about 28° of latitude we find in these primitive mountains the remains of what have been extensively-worked copper-mines. The valleys in this district, however, contain small formations of sandstone and primitive limestone.

Now gold occurs in the primary and transition rocks,* (whence it is generally washed away in grains by means of water,) copper in the same rocks and in sandstones; lead in the early limestone and sandstones, and also in the primitive; tin in the granite and transition rocks, and hematite or iron oxide in the primitive. That is, the Egyptian monarchy, of which Thebes was the capital, was surrounded abundantly by gold, and by, ores of copper, tin, lead, and iron. It also contained a river, the banks of which varied much at different times of the year, and which would probably have in its mud a good deal of the gold that had been washed down from the primitive rocks, and the veins of quartz in the graywacke.

But the knowledge of metals was probably long antecedent to any familiarity with metallurgy. We know from archæology that there was a time when mankind was unacquainted with any metal that would form weapons or tools, and was consequently obliged to employ stone for the purpose, and yet was aware of the existence of gold and silver. We know farther, that in the very earliest

* Many parts of Egypt, and probably of the great desert on the opposite side of the Red Sea, likely contain much gold.

records these metals are spoken of as being quite familiar, and physical science points out to us that they are found in the beds of rivers that flow from primitive and metamorphic rocks. No doubt but that the early inhabitants of Thebes discovered these metals, and probably used them as ornaments. In order, however, to do this, no chemical knowledge whatever is necessary. But this is not the case with the two metals that we know mankind next discovered and employed. For we not only have the researches of the archæologists, but those likewise of ordinary antiquarians prove, that before the discovery of iron ; copper, and, (but perhaps a little subsequently, tin were known and used.* The alloy formed by these two metals constitutes bronze, and the metallic weapons and utensils of mankind were for a long time made of this compound. The tombs of the men of this bronze period never contain iron, and indeed, even Homer describes the weapons of his heroes as composed of copper, and although they were acquainted with iron, they are described as so unfamiliar with it, that Achilles offered an iron ball as one of his most valuable prizes at the games celebrated in honour of Patroclus.

The copper ore from which the Egyptians most probably extracted their copper, was the copper pyrites, or sulphuret of that metal. To obtain copper from this ore several processes of a chemical nature must have been gone through. The usual ore of tin is an oxide, and the details of the process followed to extract it would not be the same as in the case of copper, and the variation of the two processes and the necessity for the constancy of this variation imply a certain extended amount of practical chemical skill, and so also would the admixture of the two to constitute bronze.

Long after the bronze age had begun, and doubtless flourished after its own fashion, the art of extracting iron from its ores, and of the manufacture of that metal were discovered and understood. † The iron ore that the Egyptian metallurgists operated upon was almost certainly a hematite, and the mode of reducing the metal from it

*

Perhaps the most interesting English work on this subject is Dr. Daniel Wilson's - Archæology of Scotland."

+ See again Dr. Daniel Wilson's work as quoted above.

must have been different from the plan followed in the reduction of copper ore, and also most probably in that of the tin. Chemistry, even did it consist in traditional practices merely, had by this time not only commenced, but progressed.

The whole of the Egyptian chemistry was probably not communicated to the Greeks, and by them transmitted to the Romans. Nevertheless, among these two people chemistry continued in its own way to acquire at any rate new facts, and many of these undoubted ones. By the time of Constantine, and with regard to most of the substances for long before,) the chemists of the empire knew, and could obtain all the pure metals as they are called, save one-platinum, and they likewise possessed zinc, although they confounded it with tin. Of the other, now ranked as elementary substances, they only knew sulphur. Their one acid was the acetic, but they had carbonate of soda, (which they called nitre), and potash. They were acquainted also with some metallic salts, and with alum, common salt, (marine salt), and ammoniacal salt, or our hydrochlorate of ammonia. Their knowledge of the earths and minerals was tolerable, and they were familiar with a good many oils, both fixed and essential. What was perhaps of still greater importance, they knew how to perform several chemical processes, such as crystallization, distillation, sublimation, expression, fusion, and many others. Their applications of chemistry, too, to the arts, were pretty numerous.

It is almost impossible, from our very imperfect evidence to decide as to how far the human intellect had gone in endeavouring to extract from the known facts of chemistry one or more general chemical principles. Something that had possibly been done in this way by the Egyptians was probably lost, and, moreover, the genius of the Greeks did not incline to what in our day is called mixed physical science, and the Romans were essentially an unscientific people. Still, we know that some little hypothesis was indulged in. The Greeks reduced all the forms of matter to the four elements of fire, air, earth, and water, but it would not appear that they understood the expression, element, in the same sense that modern chemists do, (viz., a substance that cannot, by any means that we possess, be resolved into two,) but under the name of the four elements they seem to have expounded a theory,

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