Читать книгу A History of Inventions, Discoveries, and Origins - Johann Beckmann - Страница 13

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It is well known that quicksilver unites very readily with almost all metals, and when added in a considerable quantity forms with them a paste which can be kneaded, and which is called amalgam. On the other hand, as it does not unite with the earths, being a metallic substance, it furnishes an excellent medium for separating gold and silver from the substances with which they are found. The amalgam is squeezed through a piece of leather, in which these precious metals remain with a certain portion of the quicksilver; and the former are freed from the latter by means of fire, which volatilizes the mercury. This amalgam made with gold serves also for gilding metals (water-gilding)28, if it be rubbed over them, and afterwards heated till the quicksilver be driven off.

The first use of quicksilver is commonly reckoned a Spanish invention, discovered about the middle of the sixteenth century; but it appears from Pliny, that the ancients were acquainted with amalgam and its use, not only for separating gold and silver from earthy particles, but also for gilding29. Vitruvius describes the manner of recovering gold from cloth in which it has been interwoven. The cloth, he says, is to be put into an earthen vessel, and placed over the fire, in order that it may be burnt. The ashes are to be thrown into water, and quicksilver added to them. The latter attracts the particles of the gold, and unites with them. The water is then to be poured off, and the residue put into a piece of cloth; which being squeezed with the hands, the quicksilver, on account of its fluidity, oozes through the pores, and the gold is left pure in a compressed mass30. Isidore of Seville says also, that quicksilver is best preserved in vessels of glass, as it penetrates all other substances; and that without it neither silver nor brass can be gilded31. Modern mineralogists however have this advantage over the ancient, that they know how to separate the quicksilver from gold and silver without losing it. Instead of exposing the amalgam to an open fire, as formerly, and driving off the volatile metal, it is now put into a retort, and the quicksilver is collected in a receiver for further use.

Those also who wash gold from the sand found near rivers, use quicksilver before their work is completed; and I am strongly inclined to believe that this method prevailed in Germany long before the discovery of the mines in America. In the year 1582, John Michael Heberer described the washing of gold as he saw it practised at Selz, not far from Strasburg; and at that time quicksilver had been long employed for that purpose. In Treitlinger’s Dissertation, also, concerning the collecting of gold, and particularly in the Rhine, there is a description of the manner in which gold sand is washed by means of quicksilver, but no date is mentioned32.

The history of employing mercury in procuring the American silver is, as far as I know, most fully given by the Jesuit Acosta33, whose relation of the Indies abounds with curious and useful information. The quicksilver mines of Peru are situated in an extensive ridge of mountains near Guamanga, on the south side of Lima, and at no great distance from it. They are called Guancabelica, or Guancavilia. The mines were discovered about the year 1566 or 1567, when Castro was viceroy of Peru, by Henry Garces, or Graces, as he is called by the Portuguese. This man was a native of Porto, went to Peru in the Spanish service, and after the death of his wife became canon of the cathedral of Mexico. He translated the Lusiad of Camoens from the Portuguese into Spanish, and this has procured him a place in Professor Dieze’s translation of Velasquez’s History of Spanish Poetry. He caused a law to be enacted that no silver bullion should be suffered to circulate in Peru; but his greatest service was the discovery of the quicksilver mines. As he was one day examining the red earth, which the Indians use for paint, and call limpi, he observed that it was native cinnabar; and as he knew that quicksilver was extracted from it in Europe, he went to the place where it was dug up, made some experiments, and thus laid a foundation for the most important works. No one however thought of employing this metal in the silver mines till the year 1571, when Francis de Toledo being viceroy, one Pero Fernandes de Velasco came to Peru, and offered to refine the silver by mercury, as he had learnt at the smelting-houses in Mexico. His proposal being accepted, and his attempts proving successful, the old methods were abandoned, and that of amalgamation was adopted in its stead34. From this account it appears that Garces was not the inventor of amalgamation, that it was introduced into Peru in the year 1571, and that it had been long before practised in Mexico; but at what period it was first used there I have not been able to learn. The abbé Raynal says, that quicksilver was a free article of trade till the year 1571, when it was declared to belong exclusively to the crown; and this regulation was made in consequence of its being employed in refining. Robertson, in his History of America, tells us that the mines of Guanacabelica were discovered in 1563, and that amalgamation was introduced in 1574.

Anderson says, in his History of Commerce35, that in the second volume of Hakluyt there is a letter which shows the use of quicksilver to have been a new invention in the year 1572. This letter I found, not in the second, but in the third and last volume of the Voyages collected by Hakluyt36. It was written in the above year by a merchant named Henry Hawks, and contains only the following information: “A good owner of mines must have much quicksilver; and as for this charge of quicksilver, it is a new invention, which they find more profitable than to fine their ore with lead.”

Gobet, in a work entitled The Ancient Mineralogists of France, accuses Alphonso Barba of asserting that he found out amalgamation in the year 1609. To examine this charge, it will be necessary to give some account of the metallurgic works of that Spaniard, which, perhaps, may not prove unacceptable to those who are fond of metallurgy and mineralogy. Alvaro Alphonso Barba was born at Lepe, a small town in Andalusia, and officiated many years as clergyman of the church of St. Bernard, at Potosi. The first edition of this work was printed in quarto, at Madrid, in 1640, in the Spanish language, and illustrated with cuts. This book the Spaniards for a long time concealed, because they considered it as containing all their metallurgic secrets; though at that time there were much better works of the kind in Germany, and though amalgamation had been long known and practised. Edward earl of Sandwich, being ambassador to Spain, found however an opportunity of procuring a copy of it, as a great rarity; and he began a translation of it into English, but translated only the first two books. This translation was published at London in octavo, in 1674, after the earl’s death, and entitled The First Book of the Art of Metals, in which is declared the manner of their generation, and the concomitants of them. Written in Spanish by Albaro Alonso Barba, translated by the earl of Sandwich. From this English edition several German translations have been made, of which I am acquainted with the following: two at Hamburg, one printed in 1676, and the other in 1696; and two at Frankfort, one in 1726, and another in 1739. In the year 1749 a new edition appeared at Vienna. This edition, which is very different from any of the former, was translated from the French by one Godar, who was not a German, and who on that account apologises in the preface for the badness of his style. All these editions however are imperfect; for the original contains five books, as we learn from Leibnitz, who caused them to be transcribed. In the year 1751 a new translation came out at Paris, entitled Metallurgy, or the art of extracting and purifying metals, translated from the Spanish of Alphonso Barba, by M. Gosfort, with the most curious dissertations on mines and metallic operations; of this translation the celebrated abbé Lenglet de Fresnoy is said to have been the editor37.

To judge by two of the German editions, Gobet has done Barba an injustice. In that of 1676, I find Barba expressly says he does not believe the ancients were acquainted with the art of extracting silver from pounded ore by the means of quicksilver. This certainly does not indicate that he laid claim to the invention; besides, he everywhere speaks of amalgamation as an art long used in America, but complains of the negligence with which it was practised. In a passage however in the Vienna edition, and which has probably been added by Gobet, we are told that in the year 1609, Barba attempted to fix quicksilver, and with that view bethought himself of mixing it with finely pounded silver ore; that he at first imagined, with surprise, that he had obtained a mass of silver, but that he soon perceived that the mercury was not changed into silver, but had only attracted the particles of that metal. “I was,” adds Barba, “highly pleased with my new discovery of managing ore, of extracting its contents, and of refining it; and this method I continued to practise.” I imagine that Barba was still in Europe in 1609, and made that experiment before he was acquainted with the smelting-works in America. I am however of opinion, that one will see by the original that Barba did not wish to claim the invention of amalgamation as practised in the mines of America.