William Schupbach explains how a portrait of an 18th-century Dorset farmer who carried out the first vaccinations found its way into Wellcome Library collections, via South Africa.

In 2005 an art dealer in Tyne and Wear wrote to the Wellcome Library about a portrait that she had been engaged to sell on behalf of a client. The oil painting showed Benjamin Jesty (1736-1816), a Dorsetshire farmer. One reason why she was offering it to us was that Jesty had a claim to be the first person to have practised vaccination against smallpox, in 1774, when the word vaccination did not exist.This was quite a claim: what is generally regarded as the first vaccination occurred in 1796, when Edward Jenner, a general practitioner in Berkeley, Gloucestershire, on his own initiative transferred or 'inoculated' cowpox (in Latin Variolae vaccinae, hence vaccine) from the hand of a milkmaid to the arm of a boy as a protection against smallpox. Jenner's achievement is commemorated in the many portraits of him collected by Henry S Wellcome and now in the Wellcome Library, whereas Jesty is today virtually unknown.

Jesty's earlier experiment with inoculation, 20 years before Jenner's, is however well documented. He had not only pondered the evidence that cowpox protected against smallpox, but had also followed through this idea by what must have seemed a bizarre and repulsive action: with a darning needle, he inserted pustular matter from an infected cow into the arms of his wife and two sons. The portrait was closely bound up with the evidence for Jesty's claim, for it was commissioned by the directors of the Original Vaccine Pock Institution, run by Dr George Pearson who had fallen out with Edward Jenner. In 1805 the Institution invited Jesty to London, interrogated him about his experiment, and had the portrait painted as a testimonial to him.

The verbal evidence of their examination was published in the Edinburgh Medical and Surgical Journal, while the ownership of the portrait passed to Jesty's descendents in Dorset and subsequently in South Africa. After a period in which it was stored in a barn in Dorset, it was recovered in the 1930s and taken to a farmhouse on a vast estate in Eastern Cape, South Africa.

There it remained, like most privately owned works unpublicised and inaccessible, until, by tenacious research, it was discovered by Patrick Pead, a microbiologist with a longstanding interest in the Jesty story, who also revealed the vivid early history of the portrait. Jesty arrived in London in August 1805, made his way to the Vaccine Pock Institution on the corner of Broadwick Street and Poland Street in Soho, and was examined by 12 medical officers of the institution. His family had tried to persuade him to dress in a more up-to-date fashion, but he refused saying that "he did not see why he should dress better in London than in the country". After his interrogation, Jesty was taken round to the studio of the portrait painter Michael William Sharp in nearby Great Marlborough Street. There, while Mrs Sharp played the piano, Michael Sharp captured in paint what was later described in Jesty's epitaph as the "Great Strength of Mind [with which he] made the Experiment from the Cow".

It is not surprising that the portrait, now acquired by the Wellcome Library, has suffered from its years in farm buildings. What is remarkable is that it has survived at all. When it has been stabilised and cleaned, it deserves to be displayed in an exhibition on Jesty and Jenner, which could raise the question why the idea of vaccination occurred to two people in two different counties in the West of England within 20 years of each other, and to nobody else. Or did it? When I gave a talk about the portrait to a recent symposium at the Wellcome Trust Centre for the History of Medicine at UCL, one of the scholars present mentioned that a very similar practice had been recorded in the 18th century on one of the Greek islands, but with goats instead of cows. Had this led anywhere, we might now be talking about goatpox instead of cowpox, and caprination instead of vaccination... but that story must await the exhibition of the cleaned and glowingly restored painting.