Thursday, 20 May 2021

Agricola's De Re Metallica

I am grateful to Dr. Franklin White for the following review. Franklin is the author of the recently published biography of his father, Frank White, Miner with a Heart of Gold (posting of 21st September 2020) and of the historical review of De la Pirotechnia (posting of 17th November, 2020).

De Re Metallica: the treatise of Georgius Agricola
Foundations of Mineralogy and Industrial Hygiene

"To the… mighty Dukes of Saxony, Landgraves of Thuringia, Margraves of Meissen, Imperial Over- lords of Saxony, Burgraves of Altenberg and Magdeburg, Counts of Brena, Lords of Pleissnerland, To Maurice Grand Marshall and Elector of the Holy Roman Empire and to his brother Augustus... Most illustrious Princes, often have I considered the metallic arts as a whole… just as if I had been considering the whole of the human body; and… I became afraid that I might die before I should understand its full extent, much less before I could immortalize it in writing."

Georgius Agricola 1494-1555

Thus opens De Re Metallica, the most acclaimed treatise on technological chemistry, mining, geology and engineering of early modem times, as translated (1912) from the first Latin edition of 1556 by Herbert Clark Hoover, a mining engineer and 31st President of the United States (1929-33) and his wife Lou Henry Hoover. The Hoovers state:  

"that Agricola occupied a very considerable place in the great awakening of learning will be disputed by none except by those who place the development of science in rank far below religion, politics, literature and art.”  (1)

At a time when scholastic dogma reigned, he thought that:

"Those things which we see with our eyes and understand by means of our senses are more clearly to be demonstrated than if learned by means of reasoning."

Beyond his importance to mineralogy, on his role in scientific medicine, the Hoovers also state: 

"The wider interest of the members of the medical profession in the development of their science than that of geologists in theirs, has led to the aggrandizement of Paracelsus, a contemporary of Agricola, as the first in deductive science. Yet no comparative study of the unparalleled ravings of this half-genius, half-alchemist, with the sober logic and real research and observation of Agricola, can leave a moment’s doubt as to the incomparably greater position which should be attributed to the latter as the pioneer in building the foundation of science by deduction from observed phenomena."

A different perspective is offered by George Rosen in his introduction to the 1964 reprint of Wright’s 1940 translation of Bernadino Ramazzini’s famous De Morbis Artificum (Diseases of Workers) of 1713: 

"The first account of occupational ill-health among miners appeared in 1556 in the compendious treatise on mining by George Agricola (1494-1555). However, Agricola’s account is only incidental to his longer description of mining. Eleven years later, in 1567, the first monograph devoted exclusively to the occupational diseases of mine and smelter workers appeared at Dilingen, in Germany. The author was Theophrastus von Hohenheim (1493-1541), usually known as Paracelsus; the work was entitled "Von der Bergsucht oder Bergkrankheiten" (On the Miners’ Sickness and other Diseases of Miners). Paracelsus discussed etiology, pathogenesis, prevention, diagnosis, and therapy, and his work exerted a definite stimulating influence on occupational medicine… Agricola and Paracelsus placed the study of the occupational health problems of miners on a firm footing." (2)

Donald Hunter, author of "The Diseases of Occupations," a 20th century classic, helps to place the contributions of these two men in context: "It is striking...that (Paracelsus) refers to no" protective apparatus such as the veils to be worn by miners mentioned by Agricola. Nor does Paracelsus pay give ‘attention to dust as a causative factor in the diseases of miners... Although he makes correct clinical observations, he… turns to… alchemical theories to explain them..." (3)

Thus, Agricola seems unique in his era for recognizing the basic “importance of industrial hygiene, and the primacy of prevention in reducing the impact of miners’ diseases. Perhaps the most relevant acknowledgement comes from Ramazzini, "founder of occupational medicine," who credits Agricola as a primary source for his chapter on "Diseases to which Miners of Metals are Exposed." He makes no reference to Paracelsus. (2)

Agricola studied medicine, natural science and philosophy in Bologna and Padua, completing clinical studies in Venice. At the Aldine Press in Venice, he prepared an edition of the classical works of Galen (129 AD – c. 200/216) on medicine (published 1525). In 1526, he returned to Saxony, and from 1527 to 1530, he was town physician in Joachimsthal, in the 'richest metal mining district of Europe. He spent his spare time visiting mines and smelting plants, talking with the better-educated miners and reading books on mining. (Note: Biringuccio’s De la Pirotechnia published in 1540, is considered the first printed book on ore reduction processes and the applied metal arts, predating De Re Metallica by 16 years).  From 1530 onwards, he was appointed town physician at Chemnitz in Saxony, a position comparable to today’s medical officer of health. (4)

De Re Metallica consists of 12 “books”. The first addresses the philosophical content of mining and metallurgical arts. The second describes the miner. The third deals with veins and seams in rocks. The fourth depicts the functions of mining officials. The fifth describes the digging of ore and the surveyor’s art. The sixth describes tools and machines. The seventh describes assaying the ore. The eighth contains rules for roasting, crushing and washing the ore. The ninth explains smelting. The 10th instructs on the separation of silver from gold, and lead from gold and silver. The 11th shows ways of separating silver from copper. The 12th gives rules for manufacturing salt, soda, alum, vitriol, sulphur, bitumen, and glass. The work is illustrated by 289 beautiful woodcuts, faithfully reproduced in the Hoovers’ translation. (1)

Early stamp mills

In the first book, Agricola states: 

"There are many arts and sciences of which a miner should not be ignorant..." and then addresses philosophy, medicine, astronomy, surveying, arithmetical science, architecture, drawing and law.

On the relevance of medicine, he explains: 

"… to look after.. diggers and other workmen, that they do not meet with those diseases to which they are more liable than workmen in other occupations, or if they do meet with them, that he himself may be able to heal them or may see that the doctors do so.”

In reference to the use of protective timbers, he notes:

"The lagging on the sides of the shaft confine the vein, so as to prevent fragments of it which have become loosened by water from dropping into the shaft and terrifying, or injuring, or knocking off the miners and other workmen who are going up or down the ladders from one part of the mine to another." 

On alleviating the miners' exposure to dust and gas, he explains:

"If a shaft is very deep and no tunnel reaches to it, or no drift from another shaft connects with it, or when a tunnel is of great length and no shaft reaches to it, then the air does not replenish itself… it weighs heavily on the miners, causing them to breathe with difficulty, and sometimes they are even suffocated, and burning lamps are also extinguished. There is, therefore, a necessity for machines...which enable the miners to breathe easily and carry on their work.” 

On the breaking of ores, he records:

"... legs of the workmen...are protected with coverings resembling leggings, and their hands are protected with long gloves, to prevent them from being injured by the chips which fly away from the fragments." 

Thus, the fundamentals of mining, metallurgy, occupational health and safety, were documented by Agricola almost 500 years ago.

Concluding Comments:

Although it is said that Agricola was born of obscure parentage (3), the Hoovers conclude that:

"Agricola’s education was the most thorough that his times afforded in the classics, philosophy, medicine and sciences generally."

That he wrote in Latin (sine qua non of scholarship in his time, and a reflection of social status), and revealed an exhaustive knowledge of classical literature, and of obscure manuscripts buried in European public libraries, all reveals that his learning was of a high order. This is reflected in correspondence among other scholars of his era: Erasmus, Melanchthon, Meurer, and Fabricius.

It seems likely therefore, that he came from a family that not only valued scholarship but, judging from his Preface addressing the “most illustrious Princes”, was well attuned to the social order of the times, and likely enjoyed the favour of persons in those seats of political power. 

The text of De Re Metallica was completed in 1550, but publication delayed by preparation of the woodcuts of Agricola’s illustrations. In 1553, the completed book was sent to Froben Press; but it was March 1556 before it appeared in print. Meanwhile, Agricola had died on November 21, 1555. (4)

1. Agricola G. De Re Metallica (1556). In: Hoover HC, Hoover LH, trans. London: The Mining Magazine, 1912. Republished by Dover Publications, Inc. New York, 1950.
2. Ramazzini, Bernadino. De Morbis Artificum (1713). Wright WC, trans. (1940). The New York Academy of Medicine. Hafner, New York 1964.
3. Hunter D. The diseases of occupations. The English Universities Press, London 1955.
4. White F.  De Re Metallica: treatise of Georgius Agricola Revisited. Annals of the Royal College of Physicians and Surgeons of Canada 1994, 27: 163-6.


  1. Sir
    Brilliant. Thanks for a comprehensive report of review by Dr Franklin White on review of Treatise of revered Agricola.

  2. Dr.Franklin White, son of Prof. F.T.M. white, writing such a review really gave me pride and pleasure.  What T.C.  today is all due to the generous offer of Prof.White to take me to U.Q which shaped my professional career--I mentioned many times.
    Franklin, what a narration of "mining in that era".It shows that people with vision and passion to explore, irrespective of so many hazards, entered this profession  Minerals have been the main drivers of growth and so I salute them all.
    All I can comment on this is " masterpiece elevating our profession to newer heights".Thank you, Franklin.

  3. Agricola said: look for gold where there is red earth.
    In 12 of his books there is a description of modern technology for the biooxidation of sulfide ores.


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