BECHER, Johann Joachim, a celebrated chemist, born at Spire in 1635. His father, a Lutheran clergyman, died while he was very young, and the boy was compelled to support himself by teaching. He was a diligent student, and acquired a very extensive acquaintance with chemistry and allied sciences. In 1666, after having travelled through some parts of Europe, he was made professor of medicine at Mentz. He then removed to Munich, where he superintended the magnificent laboratory. His somewhat turbulent and unbending disposition obliged him to leave Bavaria, and he proceeded to Vienna, where he gained the friendship of Zinzendorf. He was made member of the council of commerce, and proposed various commercial schemes to the Austrian Government. He soon quarrelled with Zinzendorf; and about 1678 we find him at Haarlem. After a short time he visited England and »Scotland, inspecting their mines. He died in 1682, it is said at London. He wrote many works, the principal of which are —(l) j Physica Subterranea, which was printed at Leipsic in 1703 and 1739, in 8vo, with a small treatise by E. Stahl, entitled Specimen Becherianum; (2), Experimentum chymicum novum, 8vo; {?>),Character pro Notitia Linguarum universali; (4), Institutiones Chymicoe, seu Manuductio ad Philosophiam Hermeticam, 4to; (5), Institutiones Chymicoe, seu Oedipus Chemicus, 12mo; (6), Experimentum novum ac curiosum de Miniaria arenaria perpetua, &c. In some respects he anticipated Stahl, whose phlogistic theory is an extension of what he says. He was also the discoverer of boracic acid.