Page:Popular Science Monthly Volume 84.djvu/71

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not only ingots of gold and silver, but also from time to time a mineral in the form of little white metallic grains, infusible and very heavy. The miners found it associated with gold and with diamonds (?) and called it platina, from its similarity to silver (plata in Spanish).

The government had no use for the platina and, fearing it might be used to debase the coinage, ordered (ineffectually) that it should be buried when extracted from the ore. Meanwhile in 1741, an Englishman named Wood gave the knowledge of platina to Europe; in 1750 Watson announced that it contained a metal hitherto unknown; in 1752 Scheffer, director of the Stockholm mint, and in 1754 Lewis in London, dispelled all doubt regarding the fact that a new metal actually existed. Baron von Sickingen proposed a method for its extraction from the ore.

The new metal, platinum, thus obtained was in the form of a powder or sponge, which resisted fusion, even in the most powerful furnace, and was thus wholly useless in the arts. Chabaneau undertook the difficult task of obtaining platinum in metallic ingots, in spite of its infusibility. He recognized that this very infusibility would give great value to objects made of this new metal.

Several other chemists of the time had busied themselves with this same problem. The only hope of success appeared to be in alloying platinum with other metals, but this seemed to present insurmountable difficulties, owing in part to the impurity of the platinum ore, and also to the large amount of other metals necessary for its solution. It was early observed (von Sickingen says by Scheffer, who wrote in 1751) that a small amount of metallic arsenic caused platinum to fuse easily, but the ingot thus obtained was exceedingly brittle. Achard (1779) found that by heating this alloy for a long time at a high temperature the arsenic was gradually volatilized, leaving a mass of platinum in a malleable condition. While his communication to the Berlin Academy is entitled "Leichte Methode, Gefässe aus Platina zu bereiten," it was nearly ten years before practical application seems to have been made of the method, and though a letter appears in Krells Annalen in 1790 stating that platinum vessels can be bought cheaply of Jeanty in Paris, they were actually very rare and possibly never practically used until after the close of the century. Achard's method seems, however, to have been used industrially by Jeanty as late as 1820, though the method of Chabaneau, rediscovered by Knight and possibly independently by Cock also, came into general use in the first decade of the nineteenth century. The vessels made by Achard's method could never have been satisfactory, especially owing to the difficulty of completely removing the arsenic from the platinum.

Among the nobility who had interested themselves in the founding of the college at Bergara was the Marquess of Aranda. This man (minister of state and general, in 1787 ambassador to Paris) was distinguished among all the nobles for his devotion to science. He held Chabaneau in high esteem and encouraged him strongly in his projected work upon platinum. He had the government turn over its whole supply of platinum ore to Chabaneau, and furnished him everything in his power for the laborious undertaking, Laborious indeed,