Georgius Agricola's De Re Metallica

Georgius Agricola's De Re Metallica

Knowledge of mining, minerology, and metallurgy was reserved to a small group of professionals and handed down orally from one generation to another across the Middle Ages. A small, cosmopolitan elite was responsible for the construction of great cathedrals and exploring the mysteries of alchemy. This began to change with the Renaissance culture of learning, aided by the invention of the printing press. De Re Metallica is a masterpiece by Georg Bauer (1494-1555), known by the Latinized version of his name: Georgius Agricola. He dedicated the twenty most fruitful years of his life to writing the treatise, and his knowledge of the classics and his status as physician and apothecary ennobled the study of geology and mining. 227 detailed woodcuts by Basilius Weffring, to which he dedicated three years of his life, make the work an artistic treasure as well. Its content – clear, precise and novel in many aspects – has helped geologists, miners, and smelters for centuries. The first edition is presented here and was published in 1556, one year after the author’s death. An authoritative translation into English, upon which numerous subsequent translations were based, was completed in 1912 by the mining engineer and later President of the United States Herbert Hoover (1874-1964) and his wife Lou Henry Hoover (1874-1944), a geologist and Latinist. The translation includes explanations for Agricola's invention of several hundred Latin expressions to cover medieval German mining and milling terms that were unknown to classical Latin.

“The Father of Minerology”

Agricola was gifted with a wonderful intellect and received the equivalent of a modern primary and secondary education in several schools in Glauchau, Zwickau, and Magdeburg. After his studies at the University of Leipzig, he obtained a Bachelor of Arts degree and began his professional activity teaching Greek and Latin. In 1523 he began his medical studies at the University of Leipzig to continue in Bologna and Venice. He was chosen as town physician at Joachimsthal in modern Czechia, a center of mining and smelting works. Agricola returned to Chemnitz, another center of mining, in 1530 after being appointed historiographer by Prince Maurice of Saxony (1521-53). There he held important positions related to politics and administration: mayor, counselor of the Court of Saxony and mediator in the Reformation, between local authorities and Emperor Charles V. The Catholic Agricola was forced to resign as mayor by the Protestant population of Chemnitz, allowing him to retire to private life and focus entirely on his scholarly pursuits. The great humanist Erasmus of Rotterdam (1466-1536) was a fervent admirer of the innovative works of Agricola. Erasmus, as we can read in Bermannus sive de re metallica dialogus, proclaims the uniqueness of Agricola's writings: "such a lucid mind cannot produce anything mediocre."

A Masterpiece in 12 Books

De Re Metallica is divided into twelve books. In them he tells us:
1. The reasons why the study of geology, mining and metallurgy is interesting.
2. The qualities that a miner must possess. The rod to locate those singular points of the earth where the minerals are concentrated.
3. The veins and deposits.
4. The officers of the mines and working conditions.
5. Surveying, fixing, construction of galleries and the search for minerals.
6. The tools, pumps, drains, machinery and diseases of the miners.
7. Methods of assay of minerals in wood and bone ash cups. The muffle furnaces. The process includes the scorification of the pyrite ores, the use of the touchstone and the needles for tests built with the gold, silver and copper alloy.
8. The preparation of minerals: selection, crushing, milling, washing, roasting, and the amalgamation process for gold.
9. It deals with melting furnaces and the preparation of mercury by descent.
10. It describes the separation of gold and silver by cementation, fusion with sulfur or antimony, and the dissolution of silver in nitric acid.
11. Describes the separation of silver from copper and the construction of furnaces. He also talks about the methods used for the rolling of metals and for the manufacture of parts. End this chapter with the procedures to separate iron from silver.
12. Obtaining common salt from both natural solutions and seawater. Obtaining alkaline substances from the ashes of plants. Methods of extraction and purification of saltpeter, alum and vitriol. The manufacture of glass objects.