Zinc is one of those metals which were not known to the Greeks[82], Romans, or Arabians. This we have reason to conjecture, because it has not been distinguished by a chemical character like the rest; but it is fully proved, by our not finding in the works of the ancients any information that appears even to allude to it. I know but of one instance where it is supposed to have been found among remains of antiquity. Grignon pretends that something like it was discovered in the ruins of the ancient Roman city in Champagne[83]. Such an unexpected discovery deserved to have been investigated with the utmost minuteness; but it seems to have been examined only in a very superficial manner; and as that was the case, it is impossible to guess what kind of a metal or metallic mixture this author considered as zinc.
It is not surprising that this metal should have remained so long unknown, for it has never yet been found in the metallic state. Its ores are often and in a great degree mixed with foreign ingredients; and when they are melted, it sublimes in a metallic form, and is found adhering above to the cool sides of the furnace; but a particular apparatus is necessary, else the reduced metal partly evaporates, and is partly oxidized, by which means it appears like an earth, and exhibits to the eye no traces of metal.
That mixture of zinc and copper called at present brass, tomback, pinchbeck, princes-metal, &c., and which was first discovered by ores, abundant in zinc, yielding when melted not pure copper, but brass, was certainly known to the ancients. Mines that contained ores, from which this gold-coloured metal was produced, were held in the highest estimation; when exhausted, the loss of them was regretted; and it was supposed that the metal would never be again found. In the course of time it was remarked, no one knows by what accident, that an ore, which must have been calamine, when added to copper while melting, gave it a yellow colour. This ore was therefore used, though it was not known what metal it contained, in the same manner as oxide of cobalt was employed in colouring glass before mineralogists were acquainted with that metal itself. Aristotle and Strabo speak of an earth of that kind, the use of which in making brass has been retained through every century. Ambrosius, bishop of Milan, in the fourth century; Primasius, bishop of Adrumetum in Africa, in the sixth; and Isidore, bishop of Seville, in the seventh, mention an addition by which copper acquired a gold colour, and which undoubtedly must have been calamine. When in course of time more calamine was discovered, the ancient method of procuring brass from copper-ore that contained zinc was abandoned; and it was found more convenient first to extract from it pure copper, and then to convert it into brass by the addition of calamine.
Those desirous of inquiring further into the knowledge which the ancients had of this metal must examine the meaning of the word cadmia, which seems to have had various significations. This task I have ventured to undertake; and though I cannot clear up everything that occurs respecting it, I shall lay before my readers what information I have been able to obtain on the subject, because perhaps it may amount to somewhat more than is to be found in the works of old commentators. Cadmia signified, then, in the first place, a mineral abounding in zinc, as well as any ore combined with it, and also that zinc-earth which we call calamine. Those who should understand under it only the latter, would not be able to explain the greater part of the passages in the ancients where it is mentioned. It is probable that ore containing zinc acquired this name, because it first produced brass[84]. When it was afterwards remarked that calamine gave to copper a yellow colour, the same name was conferred on it also. It appears, however, that it was seldom found by the ancients[85]; and we must consider cadmia in general as signifying ore that contained zinc. Gold-coloured copper or brass was long preferred to pure or common copper, and thought to be more beautiful the nearer it approached to the best aurichalcum. Brass therefore was supposed to be a more valuable kind of copper; and on this account Pliny says that cadmia was necessary for procuring copper, that is brass. Copper, as well as brass, was for a great length of time called æs, and it was not till a late period that mineralogists, in order to distinguish them, gave the name of cuprum to the former[86]. Pliny says that it was good when a large quantity of cadmia had been added to it, because it not only rendered the colour more beautiful, but increased the weight. In the like manner a quintal of copper in Hungary produces a hundred and fifty pounds of brass. The same author remarks also that the cadmia (fossilis) was not used in medicine: this however is to be understood only of the raw ore, for some physicians prepared oxide of zinc from ore that contained zinc, as he afterwards tells us; and Galen extols the calamine found in Cyprus on account of its superior effects, because, perhaps, the oxide could be obtained from it much purer.
In the second place, cadmia, among the ancients, was what we call (ofenbruch) furnace-calamine, or what in melting ore that contains zinc, or in making brass, falls to the bottom of the furnace, and which consists of more or less calcined zinc. As this furnace-calamine assumes various appearances, according to the manner of melting, and according to many other circumstances that in part cannot be defined, and as the ancients comprehend all its varieties under the general name of cadmia, and give to each variety, according to its form, consistence and colour, a particular name also, a confusion of names has hence arisen which cannot now be cleared up, especially as it is not thought worth while to distinguish all its incidental variations. Our physicians esteem only the pure oxide of zinc; and as they know how to obtain it, they are not under the necessity of using impure furnace-calamine. In our melting-houses it is employed, without much nicety in the choice, for making zinc or brass[87].
What here appears to me most singular is, that the ancients should have given the same names to furnace-calamine as they gave to ores that contained zinc. The affinity of these substances they could conjecture only from their effects, or perhaps they were induced to do so from observing that furnace-calamine was not produced but when the different kinds of cadmia, as they were called, were melted; that is, when yellow and not red copper was obtained. Ofenbruch got the name of furnace-calamine at Rammelsberg, when it was observed that it could be employed instead of native calamine for making brass[88]. Were the ancients then in any measure acquainted with this use of it? Galen and Dioscorides speak only of its use in medicine, and say nothing of its being employed in the preparation of brass. The Arabian writers, particularly the translators of the Greek physicians, speak in a much clearer manner of the preparation of brass; but the appellations which they employ are so indeterminate in their signification, that an answer to the above question cannot be deduced from them. Climia, which some pronounce calimia and from which the modern Greeks made kelimia, and the Latins lapis calaminaris, seems to have entirely the same meaning as cadmia. Tutia, which occurs first in the eleventh century, in Avicenna, and which the Greeks write toutia, or perhaps more properly thouthia, signifies sometimes pompholyx; but in common it seems to express also minerals that contain zinc, and likewise furnace-calamine[89]. Could it be proved that the tutia of the Arabs and later Greeks was furnace-calamine, or the tutia of our druggists, the oldest account with which I am acquainted of furnace-calamine, employed in making brass, would occur in Zosimus, who, according to every appearance, lived in the fifth century[90]. This author tells us, that in order to make brass, Cyprus copper must be melted, and pounded tutia must be strewed over it. Salmasius suspects that Zosimus here means only calamine: but however this may be, his receipt has been retained till the present time in books on the arts; for these recommend not calamine, but tutia[91].
We can with more certainty affirm that this use of furnace-calamine, in making brass, was known to Albertus Magnus in the thirteenth century; for he says, first, that yellow copper was made by the addition of calamine, which he calls lapis calaminaris. He tells us afterwards, that Hermes taught how to give a gold colour to copper by throwing pounded tutia into the melted metal. Tutia, says he, which is used in the transmutation of metals, is not a native mineral, but an artificial mixture, produced in the furnace when copper-ore is melted; and he advises glass-gall to be strewed over the ore, otherwise calamine and tutia will lose their force in the fire[92]. It would appear that the last-mentioned name, in the thirteenth century, signified only furnace-calamine, and that its use for making brass was at that period known.
For many centuries, however, the ofenbruch (furnace-calamine), with which, as we are told, the furnaces at Rammelsberg overflowed, was thrown aside as useless, till at length, in the middle of the sixteenth century, Erasmus Ebener first showed that it might be used instead of native calamine for making brass. This Ebener, descended from the noble family of that name at Nuremberg, was a man of great learning, and an able statesman. He was employed by his native city, and by foreign princes, on occasions of the highest importance. In 1569 he was privy-counsellor to Julius duke of Brunswick, and died in 1577, at Helmstadt, where he was buried. I regret much that I can give no further account of this important discovery; the time even when it was made is not known with certainty. Lœhneyss says that it was sixty years before the period when he wrote. But at what period did he write? The oldest edition, with which I am acquainted, of his treatise on mines, is of the year 1617, so that this discovery would fall about the year 1557[93]. Calvör caused to be printed an old account of the Rammelsberg mines, which was said to have been published in 1565. According to that work, Ebener made the above-mentioned observation at Nuremberg, about seventeen years before, that is, about the year 1548. Schluter assigns as the period about 1550, and Honemann about 1559. We may therefore very safely place it in the middle of the sixteenth century, and probably the discovery happened in 1553, at which time Ebener was sent to duke Henry, with whom he continued a long time, as we are expressly told by Doppelmayer. This use of calamine refuse induced the managers of the profitable brass-works in the Harz forest to pick up carefully that which before had been thrown aside. Duke Julius, who endeavoured to improve every branch of manufacture, and particularly what related to metallurgy, and who, agreeably to the then prevailing mode of princes, suffered himself to be duped with the hopes of making gold, improved the brass-works at Buntheim, below Harzburg, and by these means brought a great revenue to the electoral treasury.
Another production of zinc, artificial white vitriol, was also long prepared, used and employed in commerce before it was known that it was procured from this metal. That it was not known before the middle of the sixteenth century, and that it was first made at Rammelsberg, may with confidence be affirmed. Schluter ascribes the invention of it to duke Julius, and places it in the year 1570: but it must be somewhat older than the above-quoted account of Rammelsberg; for the author, who wrote about 1565[94], relates, that in his time one citizen only, whom he calls Henni Balder, boiled white vitriol; and it appears that this person kept the process a secret. That the invention was not then new, is evident from his adding, that what its effects might be in medicine had not been examined; but that its use in making eye-water had been known almost as early as the time when it was discovered. This agrees with another account, according to which the method of boiling white vitriol was found out at the time when Christopher Sander, whose service to the Harz is well-known, was tithe-gatherer. Honemann says that Sander was tithe-gatherer at the mines of the Upper Harz before the year 1564, but that in this year he was principal tithe-gatherer and director of the mines and melting-houses at Goslar. Sander himself, in a paper dated August 3, 1575, seems to ascribe the invention of white vitriol to duke Julius[95].
At first this salt was called Erzalaun, a name occasioned by its likeness to alum, but afterwards it was more frequently known by those of Gallitzenstein, Golitzenstein, and Calitzenstein. The latter names however appear to be older than white vitriol itself; as we find that green vitriol, even before the year 1565, was called green Gallitzenstein. May not the word be derived from gallæ; because it is probable that vitriol and galls were for a long time the principal articles used for making ink and in dyeing? I am of opinion that the white vitriol, which is produced in the mines of Rammelsberg in the form of icicles, gave rise to the discovery and manufacture of this salt. The former, so early as the year 1565, was called white native vitriol, or white Gogkelgut, and was packed up in casks, and in that manner transported for sale[96]. I shall not here enter into the old conjectures respecting the origin and component parts of this vitriol; but it deserves to be remarked, that Henkel and Neumann[97] observed in it a mixture of zinc, by which Brandt, a member of the Swedish council of mines, was led to prove, that, when pure, it consists of vitriolic acid and oxide of zinc; and this was afterwards confirmed by Hellot[98].