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Donkey milk knowledge archive · Historical source
Conrad Gessner, Historiae animalium (1551): donkey milk in the chapter “De Asino”
In 1551 the Zurich physician Conrad Gessner collected in the first volume of his “Historiae animalium” everything ancient and medieval authors had written about donkey milk. A single folio page ranges from Galen’s milk regimen to Poppaea’s bath.
- Author
- Conrad Gessner (1516–1565), physician and naturalist in Zurich
- Work
- Historiae animalium liber I: De quadrupedibus viviparis, Zurich: Christoph Froschauer 1551
- Passage
- Chapter “De Asino”, section on remedies, p. 10 of the first edition
- Time & place
- 1551 · Zurich (Swiss Confederacy)
- Type of source
- Natural history encyclopaedia
In the original words
What the original says
Asininum lac conferre aliquid candori in mulierum cute existimatur.
Ass’s milk is thought to contribute somewhat to the fairness of women’s skin.
Lac asininum melle mixtum Galenus iuveni, qui fere contabuerat, a balneo statim exhibuit.
Galen gave ass’s milk mixed with honey to a young man who had almost wasted away, immediately after the bath.
Asininum peculiariter collutos dentes gingivasque stabilit, Idem.
Ass’s milk in particular, used as a rinse, strengthens the teeth and gums, [says] the same [Dioscorides].
English rendering: our own translation by the DON DONKEY’S editorial team, following the sense of the text.
Background
Who, when, what kind of text
Conrad Gessner was town physician in Zurich, a botanist, bibliographer and linguist. With the “Historiae animalium” he set out to collect all knowledge about animals handed down by ancient, medieval and contemporary authors. The first volume, on viviparous quadrupeds, was published in 1551 by Christoph Froschauer in Zurich; volumes on oviparous quadrupeds, birds and aquatic animals followed until 1558.
Each animal chapter follows a fixed scheme of sections marked by letters: names, distribution, anatomy, behaviour, uses, remedies and finally philology. Gessner always cites his sources by name. This makes the work a reference book that gathers the tradition up to 1551 in one place. The linked copy of the first edition comes from the Dibner Library of the Smithsonian Institution.
Content
What the source reports about donkey milk
On page 10 of the chapter on the ass, in the section on remedies, Gessner lines up the statements on donkey milk, each with its origin: Marcellus on its laxative effect with honey, Dioscorides on the mouth rinse for teeth and gums, Pliny on numerous uses and on its use against poisons.
In the middle of this series stands the sentence that Galen gave donkey milk with honey to an almost wasted young man immediately after the bath – the same idea transmitted by Paul of Aegina in the 7th century. Gessner also quotes Pliny’s remark that donkey milk must be used fresh or only briefly warmed, because no milk loses its strength faster.
At the end of the section he turns to the skin: donkey milk is believed to contribute to the fairness of women’s skin. As evidence follows the story of Poppaea, who according to Pliny took 500 nursing she-asses with her and bathed in their milk.
At a glance
Figures & facts from the source
Critical assessment
How reliable is this source?
Source value
First edition of 1551, verifiable page by page as a digital copy. Gessner is a compiler: he gives no observations of his own on donkey milk but arranges and documents the statements of others. We have expanded abbreviations and the long s of the print in our rendering.
Bridge to the modern era
The work gathers ancient and medieval statements at precisely the time when donkey milk was becoming fashionable at European courts. Later authors such as Buffon and Krünitz could draw on this collection.
Today’s assessment
The therapeutic and beauty statements are tradition, not tested claims. They do not substantiate any effect and cannot be applied to today; donkey milk is a food.
Our assessment
Gessner’s page 10 reads like a table of contents of the earlier history of donkey milk: Dioscorides, Pliny, Galen and Marcellus stand side by side, each cited by name. For us it is therefore a helpful signpost to the original sources.
References
Sources to check
- Primary sourceFirst edition, Zurich: Christoph Froschauer 1551, p. 10 in the chapter “De Asino” (archive.org, copy Smithsonian Libraries, Dibner Library)
https://archive.org/details/ConradiGesnerimIGess/page/n53/mode/1up
More sources and studies in the research archive. Summarised by the DON DONKEY’S editorial team, as of November 2026.