In 1666 he was appointed teacher of medicine at Mainz and body-physician to the archbishop-elector; and the same year he was made councillor of commerce (Commerzienrat) at Vienna, where he had gained the powerful support of Albrecht, Count Zinzendorf, prime minister and grand chamberlain of the emperor Leopold I Sent by the emperor on a mission to Holland, he there wrote in ten days his Methodus Didactica, which was followed by the Regeln der Christlichen Bundesgenossenschaft and the Politischer Discurs von den eigentlichen Ursachen des Auf- und Abnehmens der Städte, Länder und Republiken. In 1669 he published his Physica subterranea, and the same year was engaged with the count of Hanau in a scheme for settling a large territory between the Orinoco and the Amazon.
Meanwhile he had been appointed physician to the elector of Bavaria; but in 1670 he was again in Vienna advising on the establishment of a silk factory and propounding schemes for a great company to trade with the Low Countries and for a canal to unite the Rhine and Danube.
1678 he crossed to England, whence he visited the mines of Scotland at the request of Prince Rupert. He afterwards went for the same purpose to Cornwall, where he spent a year. At the beginning of 1680 he presented a paper to the Royal Society in which he attempted to deprive Huygens of the honour of applying the pendulum to the measurement of time. In 1682 he returned to London, where he wrote the Chymischer Glücks-Hafen, Oder Grosse Chymische Concordantz Und Collection, Von funffzehen hundert Chymischen Processen and died in October of the same year.
Becher was the father of the phlogiston theory. When a substance was burnt he supposed that the terra pinguis was liberated, and this conception is the basis on which G. E. Stahl founded his doctrine of "phlogiston".
This entry was originally from the 1911 Encyclopedia Britannica.