Agricola did not confine his interest entirely to medicine and mining, for during this period he composed a pamphlet upon the Turks, urging their extermination by the European powers. This work was no doubt inspired by the Turkish siege of Vienna in 1529. It appeared first in German in 1531, and in Latin in which it was originally written in 1538, and passed through many subsequent editions.
At this time, too, he became interested in the God's Gift mine at Albertham, which was discovered in 1530. Writing in 1545, he says[1]:
"We, as a shareholder, through the goodness of God, have enjoyed the proceeds of this God's Gift since the very time when the mine began first to bestow such riches."
Agricola seems to have resigned his position at Joachimsthal in about 1530, and to have devoted the next two or three years to travel and study among the mines. About 1533 he became city physician of Chemnitz, in Saxony, and here he resided until his death in 1555. There is but little record of his activities during the first eight or nine years of his residence in this city. He must have been engaged upon the study of his subjects and the preparation of his books, for they came on with great rapidity soon after. He was frequently consulted on matters of mining engineering, as, for instance, we learn, from a letter written by a certain Johannes Hordeborch[2], that Duke Henry of Brunswick applied to him with regard to the method for working mines in the Upper Harz.
In 1543 he married Anna, widow of Matthias Meyner, a petty tithe official; there is some reason to believe from a letter published by Schmid,[3] that Anna was his second wife, and that he was married the first time at Joachimsthal. He seems to have had several children, for he commends his young children to the care of the Town Council during his absence at the war in 1547. In addition to these, we know that a son, Theodor, was born in 1550; a daughter, Anna, in 1552; another daughter, Irene, was buried at Chemnitz in 1555; and in 1580 his widow and three children Anna, Valerius, and Lucretia—were still living.
In 1544 began the publication of the series of books to which Agricola owes his position. The first volume comprised five works and was finally issued in 1546; it was subsequently considerably revised, and re-issued in 1558. These works were: De Ortu et Causis Subterraneorum, in five "books," the first work on physical geology; De Natura Eorum quae Effluunt ex Terra, in four "books," on subterranean waters and gases; De Natura Fossilium, in ten "books," the first systematic mineralogy; De Veteribus et Novis Metallis, in two "books," devoted largely to the history of metals and topographical mineralogy; a new edition of Bermannus was included; and finally Rerum Metallicarum Interpretatio, a glossary of Latin and German mineralogical and metallurgical terms. Another work, De Animantibus Subterraneis, usually published with De Re Metallica, is dated 1548 in the preface. It
