None, however, in the seventeenth century, understood better the use and preparation of gold-purple than John Kunkel, who, after being ennobled by Charles XI., king of Sweden, assumed the name of Löwenstiern. He himself tells us, that he made artificial rubies in great abundance, and sold them by weight, at a high price. He says, he made for the elector of Cologne a cup of ruby-glass, weighing not less than twenty-four pounds, which was a full inch in thickness, and of an equally beautiful colour throughout. He employed himself most on this art after he engaged in the service of Frederic William, elector of Brandenburg, in the year 1679. At that time he was inspector of the glass-houses at Potsdam; and, in order that the art of making ruby-glass might be brought to perfection, the elector expended 1600 ducats. A cup with a cover, of this manufacture, is still preserved at Berlin. Kunkel, however, has nowhere given a full account of this art. He has only left in his works a few scattered remarks, which Lewis has collected[327]. In the year 1684, earlier than Cassius, John Christian Orschal wrote his well-known work, Sol sine veste[328], in which he treats, more intelligibly than any one before him, of the manner of making ruby-glass. He, however, confesses that Cassius first taught him to precipitate gold by means of tin; that Cassius traded in glass coloured with this precipitate, and that a good deal of coloured glass was then made at Freysingen, but that the art was kept very secret. As Orschal deserves that his fate should be better known, I shall here mention the following few particulars respecting him. About the year 1682 he was at Dresden, in the service of John Henry Rudolf, from whom he learnt many chemical processes, and particularly amalgamation, by which he gained money afterwards in Bohemia. After this he was employed at the mines in Hesse; but he brought great trouble upon himself by polygamy and other irregularities, and died in a monastery in Poland. Christopher Grummet, who was Kunkel’s assistant, wrote, in opposition to Orschal, his known treatise, Sol non sine veste, which was printed at Rothenburg, in 1685[329]. In like manner, an anonymous author printed against Orschal, at Cologne, in 1684, another work, in duodecimo, entitled Apelles post tabulam observans maculas in Sole sine veste. The dispute, however, was not so much concerning the use of gold-purple, as the cause of the red colour, and the vitrification of gold. It is worthy of remark, that Kunkel affirms he could give to glass a perfect ruby-red colour without gold; which Orschal and most chemists have however doubted. It is nevertheless said, that Krüger, who was inspector of the glass-houses at Potsdam, under Frederic William king of Prussia, discovered earlier the art of making ruby-glass without gold, and that a cup and cover of cut glass made in this manner is still preserved at Berlin.