In the year 1666 he was appointed public professor of medicine in the University of Mentz, and soon after chief physician to the elector. In that capacity he took up his residence in Munich, where he was furnished by the elector with an excellent laboratory: but he soon fell into difficulties, the nature of which does not appear, and was obliged to leave the place. He took refuge in Vienna, where, from his knowledge of finance, he was appointed chamberlain to Count Zinzendorf, and through him acquired so much importance in the eyes of the court, that he was named a member of the newly-erected College of Commerce, and obtained the title of imperial commercial counsellor and chamberlain. But here also he speedily raised up so many enemies against himself, that he found it necessary to leave Vienna, and to carry with him his wife and children. He repaired to Holland, and settled at Haerlem in 1678. Here he was likely to have been successful; but his enemies from Vienna followed him, and obliged him to leave Holland. In 1680 we find him in Great Britain, where he examined the Scottish lead-mines, and smelting-works; and in 1681, and 1682, he traversed Cornwall, and studied the mines and smelting-works of that great mining county; here he suggested several improvements and ameliorations. Soon after this an advantageous proposal was made to him by the Duke of Mecklenburg Gustrow, by means of Count Zinzendorf; but all his projects were arrested by his death, which took place in the year 1682. It is said that he died in London, but I have not been able to find any evidence of this. It would be a difficult task to particularize his various discoveries, which are scattered through a multiplicity of writings. He was undoubtedly the first discoverer of boracic acid, though the credit of the discovery has usually been given to Homberg.[179] But then he gives no account of boracic acid, nor does he seem to have attended to its qualities. The following is a list of Beccher’s writings: [179] In the sixth chemical thesis, in the second supplement to the Physica Subterranea (page 791, Stahl’s Edition. Lipsiæ, 1703), he says, “ubi etiam, continuato igne, ipsum sal volatile acquires, quod eadem methodo cum vitriolo seu spiritu aut oleo vitrioli, et oleo tartari, vel _borace_ succedit.” 1. Metallurgia, or the Natural Science of Metals. 2. Institutiones Chymicæ. 3. Parnassus Medicinalis illustrata. 4. Œdipus Chymicus seu Institutiones Chymicæ.