On the 30th of January I attended the opening of the current exhibition at the Royal College of Physicians, ‘A Cabinet of Rarities’: the Curious Collections of Sir Thomas Browne. This included an ‘in-conversation’ between Prof. Claire Preston, editor of the soon to be published ‘The Complete Works of Sir Thomas Browne’, and Dr Gavin Francis, physician and author.

Their discussion touched upon the chapter ‘Of Unicorns Horn’ in Thomas Browne’s  ‘Pseudodoxia Epidemica,  or Enquiries into very many Received Tenants, and Commonly Perceived Truths’, which he penned in 1646. The ‘commonly perceived truth’ which Browne was exploring in this chapter was whether unicorn horn had the medicinal properties claimed for it in his day.

A fortnight later I had the opportunity to visit the Rare Books room of Cambridge University Library and decided to take the chance to read the chapter in full for myself. I was already familiar with the writing of a contemporary of Browne, Monsieur Pomet, and his take on unicorns as set out in ‘A Compleat History of Druggs’.  “The unicorn is an animal which our naturalists describe under the figure of a horse, having in the middle of his head a spiral horn, of two or three foot long; but as we know not the real truth of this matter to this day (my italics), I shall only say, that what we sell under the name of the Unicorn’s horn, is the horn of a certain fish, by the Islanders call’d Narvual.” I will return to the subject of the sale of Narwhal horn, but it is clear from this passage that as far as Pomet was concerned the jury was still out over whether the unicorn was a real or mythical beast. Thomas Browne, however, had no doubt. “Some conceive there is no such animal [but] we know that there are several kinds.” (Here Browne is using the ‘royal we’.) It was not the existence of unicorns that Browne was questioning but “whether those vertues pretended do properly belong unto it.”

The chief of these virtues, or medicinal qualities, was that it was considered an antidote to poisoning second to none. 

Browne says that the origins of this belief lie in ancient writings. This was reinforced by the ‘Physiologus’. Written in Greek some time between the 2nd and 4th centuries AD, it became popular throughout Europe in the Middle Ages. It consists of descriptions of animals, birds and fantastical creatures, and the description of each creature is followed by anecdotes which draw out its moral and symbolic qualities. The chapter on the unicorn tells us of a snake which polluted with its venom a lake from which all the animals wanted to drink. The unicorn destroyed the poison by dipping its horn in the water and making the sign of the cross with its point.

Browne’s verdict was that unicorn horn was effective as an antidote to poisoning, but he does qualify this. Although he was satisfied that a cordial made from unicorn horn counteracts ‘proper venoms’ he suggests that in cases of poisonings caused by corrosives such as arsenic, the patient would be better treated with more common-sense remedies based on fat or oil.

Although Browne’s certainty in the existence of unicorns was at variance with Pomet’s statement quoted above, he did allow that some horns venerated as those of true unicorns were in fact the centrally placed, spiralled tooth of the Narwhal and that these could be identified by their great size, some being big enough and strong enough “to penetrate the ribs of ships”.  He states that it had been confirmed by Ole Worm that “that those long horns preserved as pretious rarities in many places, are but the teeth of Narhwhales”.  The Royal College of Physian’s exhibition includes a copy of Ole Worm’s Museum Wormianum with its wonderful frontispiece illustration of Worm’s Cabinet of Curiosity, (cabinet in the sense of small room) which includes a narwhal skull and tooth propped up in the window to the left of the scene.

Apothecaries who deceived their customers by selling them Narwhal tooth under the guise of unicorn horn were relieving them of considerable sums of money. Pomet tells us that a unicorn horn was valued at its weight in gold.

There is no reference to the apothecary of St Thomas’ Hospital using ‘unicorn horn’ as a medicinal ingredient but it is highly probable that he was making use of harts horn and this will be the subject of a future blog.


Browne, Thomas (Sir). 2001. Pseudoxia Epidemica, or Enquiries into very many Received Tenents, and Commonly Presumed TruthsLondon.

Worm, Ole. 1655. Museum Wormianum. Leiden.

Teleska, Werner. 2001. Wisdom of Nature: The Healing Powers and Symbolism of Plants and Animals in the Middle Ages. Munich, London, Prestel.

To cite this post : Julie Wakefield, “Unicorns and Disingenuous Apothecaries”, From the Herb Garret (blog on oldoperatingtheatre.com), February 28th, 2017.

 [On line] https://oldoperatingtheatre.com/unicorns-and-disingenuous-apothecaries/

Julie Wakefield began specialising in herbalism at the Museum of the Royal Pharmaceutical Society. As a former staff member at the Old Operating Theatre she delivered talks on past uses of plants both in the Herb Garret and Southwark Cathedral. 

Unicorns and Disingenuous Apothecaries
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