Hektoen International

A Journal of Medical Humanities

Leonhard Thurneysser: scholar, alchemist, and miracle doctor

Portrait of Leonard Thurneysser.
Leonard Thurneysser. Via The National Library of Medicine.

A highly controversial figure even in his time, Leonhard Thurneysser remains to this very day for some a revered scientist and for others a resolute quack. Born 1531 in Basel, he was the son of a goldsmith and followed in his father’s profession. He also studied with a physician and alchemist but never attended any university. At age seventeen he was caught selling gold-covered lead as pure gold and was forced to flee Basel, leaving his young wife behind. After spending some time in Holland, France, and England, around 1552 he went to fight as a mercenary for the Margrave of Brandenburg. He was captured by the opposing army of Saxony and forced to work as a prisoner in their mines.1,2

On being released, Thurneysser went to work as a goldsmith in Nurenberg. From 1560 to 1570 he was in the service of the Archduke of Tyrol and was sent to various countries to learn metallurgical methods as well as medicine. He also wrote two books in verse on alchemy, and in 1751 published a book on mineral water analysis called Pison. This brought him to the attention of the Elector of Brandenburg, whose wife he cured of an allegedly serious illness. Despite his lack of any academic degree, he was made court physician.1

He established a factory in a Berlin monastery employing 300 people and producing various minerals as well as colored glass, drugs, essences, and even amulets. He had his own printing house, which published calendars and a variety of alchemical and medical works. These were beautifully illustrated with etchings in various typefaces and also with texts in some languages that he did not know and included what later were identified as common Hungarian swearwords. He became rich, owned a large library, collected pictures, and established a museum of natural history He sold drugs, cosmetics, and amulets to the rich in Germany, Poland, and Denmark. He even conducted a school of alchemy.1,2

In addition to his books on mineral water analysis, Thurneysser wrote on alchemical methods as well as a dictionary purporting to clarify the works of Paracelsus and included some passages he invented himself. According to a German 16th Century manuscript, it appears that he may have visited Lisbon in 1555 and described how black slaves were sold in its streets and speculated by using alchemy and astrology to account for the color of their skin.3 Nephrologists remember him as a practitioner of uroscopy who developed physicochemical methods of analysis, proposing that urine distillates and their residues should be burnt in order to define their composition from the color of the flame. These practices increased his income considerably and he is reported to have analyzed a specimen of the urine of Queen Elizabeth of England—sent to him in order to determine if there was a remedy for aging.5

When the plague broke out in Brandenburg, he left Berlin for Basel, where he purchased an estate and styled himself as a nobleman under the name of Thurneysser of Thurn. He took a third wife, with whom he had violent altercations, and when they divorced two years later, the city council confiscated all his assets and assigned them to her.1 Returning to Berlin, he tried unsuccessfully to transmute silver into gold. He then lived for some time in Italy, working for Ferdinand de Medici, Grand Duke of Tuscany. Ultimately, he returned to Germany and died in Cologne in 1594 or 1595.

Thurneysser has gone down in history as a polymath, living as he did at a time when one single person could practice metallurgy, publishing, pharmacology, botany, mathematics, astrology, and even medicine. A prolific author1 and successful entrepreneur,1 he made many enemies, some of whom thought he was a charlatan and imposter. Seen through the dark glass of medieval history, he has been considered even by modern scholars as a learned pathfinder and innovator—a description that may not be entirely accurate.



  1. Encyclopedia.com: Thurneysser Leonhard
  2. Berliner Lindenblatt: Komander G.H.M, Den Teufel in Kristallglase gefurt (The devil in crystal glass). Berliner Lindenblatt, November 2006 (in German)
  3. Jerosch, B, H: The Diary of the Swiss Leonhard Thurneysser and Black Africans in Renaissance Lisbon. Renaissance Studies; Oxford: Vol. 32, Iss. 3, (Jun 2018): 463.
  4. Hierholzer, K and Hierholzer, J: Leonhard Thurneysser and Hermann Senator. J Nephrol 2003: 16(5):760.
  5. Harrison, K: New York Times Book Review; New York (Feb 9, 2014)



GEORGE DUNEA, MD, Editor-in-Chief


Spring 2021  |  Sections  |  Science

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