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Donkey milk knowledge archive · Historical source
Hildegard of Bingen, Physica: she-ass’s milk in a medieval leprosy ointment
In her work on nature from the mid-twelfth century, Hildegard of Bingen has a root curdled in she-ass’s milk and cooked with pork lard into an ointment against fresh leprosy. An older printed version also names ass’s milk as a drink for lepers.
- Author
- Hildegard of Bingen (1098–1179), abbess of the Rupertsberg
- Work
- Physica (Liber subtilitatum diversarum naturarum creaturarum), edition in Migne, Patrologia Latina vol. 197, Paris 1855
- Passage
- Book I “De plantis”, chap. 118 “De swertula”, col. 1178; book VII “De animalibus”, chap. 9 “De asino”, cols. 1319–1320 with note 11
- Time & place
- c. 1150–1160; edition Paris 1855 · Rupertsberg near Bingen
- Type of source
- Natural history and medicine (monastic literature)
In the original words
What the original says
Contra recentem quoque lepram radicem ejusdem swerteln tunde, et sic in lac asinæ pone, ut simul gerynn, et mox sagimen porci in patellam funde, et tunsam radicem cum asinæ lacte ad sagimen illud in patellam pone, et fortiter simul commiscendo coque
Against fresh leprosy, pound [according to Hildegard] the root of the same sword-lily and put it into she-ass’s milk so that they curdle together; then pour pork lard into a pan, add the pounded root with the she-ass’s milk to the lard in the pan and cook it, stirring vigorously.
Lac autem de asino procedens leproso homini prodest, si illud frequenter bibit.
The milk that comes from the she-ass benefits [according to this version] a leprous person if he drinks it often.
English rendering: our own translation by the DON DONKEY’S editorial team, following the sense of the text.
A look at the original
What the passage looks like
Patrologia Latina, vol. 197 (Paris 1855), cols. 1177–1178: Hildegard’s chapter “De swertula”; the recipe with she-ass’s milk is in the right-hand column.
The page comes from a freely accessible digitised copy. Click to open the passage at the library.
Internet Archive, Digitalisat der Migne-Ausgabe von 1855; gemeinfrei
Background
Who, when, what kind of text
From about 1150 Hildegard of Bingen led the convent she had founded on the Rupertsberg near Bingen. Besides her visionary writings, two works on nature and medicine are attributed to her, the Physica and the Causae et curae. The Physica describes in nine books plants, elements, trees, stones, fish, birds, animals, reptiles and metals, each with its nature and its use for humans. Latin sentences with German words mixed in are typical.
The transmission is difficult: no manuscript from Hildegard’s lifetime survives. According to its preface, the edition in volume 197 of the Patrologia Latina (1855) follows a fifteenth-century paper manuscript in Paris and records in its notes the variants of the first Strasbourg print, published by Johann Schott in 1533. The two versions differ markedly in the chapter on the ass in particular.
Content
What the source reports about donkey milk
The most detailed passage is in the book of plants, under the sword-lily (swertula), which the editors identify as Gladiolus. Against fresh leprosy, the pounded root is to be placed in she-ass’s milk until both curdle, then cooked with pork lard in a pan and strained through a cloth. Before anointing, the patient is to wash the affected areas with a lye made from alder ash.
In the book of animals Hildegard describes the ass as rather warm, foolish and drawn to humans; its meat, she says, is not fit to eat. The manuscript of the edition then recommends a ritual for the paralysed and the moonstruck. The Strasbourg print of 1533 instead has a sentence on the milk: ass’s milk benefits lepers if drunk often and holds back scrofula, “because the unclean drives out the unclean”.
At a glance
Figures & facts from the source
Timeline
Where this source stands in the history of donkey milk
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Fact check
Recorded or just told?
Hildegard of Bingen recommended donkey milk as a general remedy.
In the Physica she-ass’s milk appears mainly as an ingredient in an ointment against fresh leprosy. The advice to drink ass’s milk is found only in the printed version of 1533 and is missing from the manuscript followed by the 1855 edition.
Critical assessment
How reliable is this source?
Source value
The 1855 edition can be checked column by column and makes the differences between manuscript and first print visible. Whether every sentence goes back to Hildegard herself remains open because of the late transmission; scholars assume later reworking.
Recipe rather than dietetics
Unlike the Arabic dietetic writers, Hildegard does not classify ass’s milk by thickness or warmth. She uses it as a curdling base for an ointment. The reasoning in the 1533 print follows a logic of likeness, not humoral theory.
Today’s assessment
Leprosy is a bacterial infection that is treated with antibiotics today. Hildegard’s recipes are documents of medieval monastic medicine and are to be understood neither as treatment nor as skin-care advice.
Our assessment
Hildegard is often linked with donkey milk today, usually without evidence. We are interested in what the Physica actually says: an ointment recipe against leprosy and a drinking recommendation known to only one of the two versions of the text.
References
Sources to check
- Primary sourceHildegard of Bingen, Physica, book I “De plantis”, chap. 118 “De swertula”, in: J.-P. Migne (ed.), Patrologia Latina, vol. 197, Paris 1855, col. 1178 (archive.org)
https://archive.org/details/patrologiaecursu0197mign/page/n594/mode/1up - Further passageSame edition, book VII “De animalibus”, chap. 9 “De asino”, cols. 1319–1320; note 11 gives the reading of the Strasbourg edition of 1533 on ass’s milk
https://archive.org/details/patrologiaecursu0197mign/page/n665/mode/1up
More sources and studies in the research archive. Summarised by the DON DONKEY’S editorial team, as of November 2026.