The workmen of Höchst, in their turn, further divulged the secret. Bengraf, in 1750, carried the process to Fürstenberg, the factory under the patronage of the Duke of Brunswick. In 1744 an imperial china factory was established at St. Petersburg by the Empress Elizabeth Petrowna, who employed workmen from Meissen, and in 1765, under the patronage of the Empress Catherine II, the works were enlarged. There were two methods of obtaining the great secret of Meissen--by stealth and by experiment; most of the factories employed the former means. The attempts to arrive at the hard paste by experiment resulted in the establishment of many soft-paste factories. One remarkable instance of indefatigable industry is that of the chemist Pott, in the employ of the King of Prussia at Berlin, who endeavoured honestly to arrive at the nature of the composition of the Meissen body. He is credited with having made no fewer than thirty thousand experiments, and in so doing he contributed largely to the modern chemical knowledge of the effect of high temperatures on minerals.[3] [3] Roscoe and Schorlemmer, _Treatise on Chemistry_, vol. ii. p. 598. It is thus seen how great was the discovery of Böttger, of Meissen, and how far-reaching were the results of the manufacture of true porcelain in Saxony. A wild burst of enthusiasm followed which has been rarely equalled. Soldier-princes engaged in the wars which were waged in the German States turned aside to indulge in speculation concerning the new art. In 1717 about a hundred and fifty pieces of fine porcelain, many of them old Oriental, now at the Japanese Palace at Dresden, were acquired by Augustus the Strong of Saxony from the King of Prussia in exchange for a regiment of dragoons, without uniforms, horses, or arms. When the vigilant Frederick the Great commenced the Seven Years' War, and on a sudden filled the electorate of Saxony with sixty thousand Prussian troops, Dresden was taken. It was in vain that the Queen of Poland, daughter of an emperor and mother-in-law of a dauphin, placed the secret State documents in her bedroom to avoid seizure. They were too valuable to Frederick, who had them forcibly removed, and by publishing them proved that he was to be assailed at once by Austria, France, Russia, Sweden, Saxony, and the Germanic body. The factory of Meissen was depleted of material and models, and he transported artists and workmen to Berlin to found his factory there. Five hundred persons were engaged at this new factory, and in order to win commercial success he executed a master-stroke by framing a decree that all Jews in his kingdom must produce a voucher from the director of the factory that they had purchased a certain amount of the royal porcelain before permission would be granted to enable them to marry. [Illustration: VASE (ONE OF A PAIR).