Philippus Theophrastus Aureolus Bombastus von Hohenheim (1493-1541), better known as Paracelsus, is considered one of the most important mystics and physicians of all times. Some myths even claim he got his medical knowledge from the devil himself; in fact he studied the subterranean realm of earth to understand its effects on human health - one of the earliest examples of medical geology.

Born in the Swiss village of Einsiedel, he studied medicine in Ferrara, soon extending his studies to astrology, botany and alchemy. Alchemy included at the time also metallurgy and Paracelsus became quickly interested also in mining. To acquire the necessary knowledge he travelled a lot, visiting the countries of Salzburg, Carinthia, Tyrol, Saxony, Bohemia and Moravia, all important mining districts at the time. In his work "Chronica und Ursprung dises lants Kernten" (1538), a history of Carinthia, he describes the laboratories associated to the local mines there. As the content and quality of the ores can vary, it is necessary to test samples before starting with the proper process to extract the metal from the rock. As physician, Paracelsus noted how fumes, dust and ash, found both in the mines and produced during the melting process of the ores, affected the health of miners and workers.

Fig.1. Testing the quality of the ore, image from "De re metallica" (1556). Curiously the author, German mining engineer Georgius Agricola, suggest in the caption of this image to eat a piece of butter to be protected from the poisonous exhalations! (image in public domain)

Unfortunately his observations on medical geology were published only after his death in two heavily edited versions in 1567 and 1589-91. Paracelsus dedicated his three-part study "on the mountain-consumption and -sickness" to the "miners, smelters, samplers, moneyers, goldsmiths and alchemist". All people coming necessary into contact with the "poisonous air", found inside earth or emanating from earthly products like ores, and therefore interested in this "Safety at Work" textbook.

He subdivided his study in three chapters - the health risks found in the underground, the health risks found on the surface (when working and processing the ores) and the health risks coming from mercury poisoning (mercury was considered in the alchemistic arts an elemental compound of all matter, therefore it´s importance and an entire chapter dedicated only to its effects). He describes the mountain-consumption as "a lung disease, a swelling of the body, an upset stomach, such sick are those consumed by the mountain". What Paracelsus describes are real mining-related respiratory diseases, like pulmonary tuberculosis and lung cancer (known also as Schneeberger-Disease, named after an important Saxonian mining district). Miners are prone to these diseases due the inhalation and accumulation in the lungs of microscopic particles of dust over the years, also toxic or radioactive minerals can contribute to lung diseases. Paracelsus couldn´t know of the toxicity of certain elements found in the earth, however he didn´t explain the observed diseases only with the "bad influence of the stars" (he was after all also an astrologist) as many physician at the time would do. He correctly argued that the bad quality of the air in the mines was the greatest risk to the workers' health.

Fig.2. Refreshing "the heavy air" in a tunnel by "ventilating by the constant shaking of linen cloths", from "De re metallica" (image in public domain).

However he assumes incorrectly that this bad quality found underground derives from the saturation of the air with a chaotic combination of mercury, sulfur and saltpeter (the three principal elements in alchemy). He then suggests to study the local mines, as every mine shows another unbalanced combination of these three alchemistic elements in the air (doing so Paracelsus indirectly emphasizes the variability of geology in different mining districts). A successful cure must bring back the harmony in the combination of the three elements both in the air as in the body (he was after all an alchemist).

Paracelsus realizes the high toll that earth´s riches demand. Asking himself why people sacrifice their health and lives in the mines, he concludes:

"a very good thing, worth to be acquired, has first to be separated from the bad. The art is such, that nothing good can be acquired without a price… to get what you want, you must face also that you don´t want."

Words still true today…

Bibliography:

FRANZ, I. (2007): Paracelsus - Naturkundiger Unter und Über Tage. Mit einem Brückenschlag zu Franz von Baader. Geo.Alp, Sonderband 1: 33-43