was very curious to find out all he could. He visited Bauduin and tried to draw from him the details of his process. But Bauduin was very shy of Kunckel, and the latter has left an amusing account of an evening he spent with his quarry. Kunckel tried to talk chemistry, but Bauduin would only take interest in music. At last, however, Kunckel induced Bauduin to go out of the room to fetch a concave mirror to see if with that the precious phosphorus (for Bauduin had already appropriated this name to the stuff) would absorb the light. While Bauduin was gone Kunckel managed to nip a morsel with his finger-nail. With this, aided by the fragments of information he had been able to steal from Bauduin's conversation, he commenced to experiment by treating chalk with nitric acid, and ultimately succeeded in producing the coveted luminous earth. He sent a little lump of it to Bauduin as an acknowledgment of the pleasant musical evening the latter had given him.
It was now 1669. Kunckel was visiting Hamburg, and there he showed to a scientific friend a piece of his "phosphorus." To his surprise the friend was not at all astonished at it, but told Kunckel that an old doctor in Hamburg had produced something much more wonderful. Brandt was the name of the local alchemist. He had been in business, had failed, and was now practising medicine enough to keep him, but was devoting his heart and soul and all his spare time to the discovery of the philosopher's stone. The two friends visited Brandt, who showed them the real "phosphor" which he had produced, to which, of course, the other substances compared as dip candles might to the electric light, but nothing would induce the old gentleman to disclose any details of his process. Kunckel wrote to a scientific
