Trafalgar square in London is not a place for quiet contemplation, dominated as it is by tourists, grinding traffic and pigeons. This past summer there was an additional distraction on the “fourth plinth", a structure built in 1841 to house a statue that was never completed. In 1999, it began to be used for a rotating display of contemporary art works. From 6 July to 14 October, it housed Anthony Gormley’s “One and other”, an installation in which the plinth has been occupied by a different “plinther” every hour of the day for 100 days. “Plinthers” have included Godzilla, a bread sculptor, Morris dancers and even a man performing science experiments. Quite what these living sculptures mean is unclear but they have captured the imagination of many people. The three other plinths in the Square contain statues, one of George IV and two of men of war, Napier and Havelock. Nelson’s column towers over the scene as a celebration of his bloody naval success.

For four years in the mid 19th century, there was a fifth plinth in the square occupied by a statue of the Gloucestershire doctor, Edward Jenner, widely credited as the inventor of vaccination against smallpox. His achievements were honoured by the erection of a statue in this significant location, showing the esteem in which he was held. At the time, however, some felt that Trafalgar Square should be reserved for celebration of success in war, and that this was an inappropriate place for a statue of the non-military Jenner. Eventually this view prevailed and the statue was removed. The medical profession considered this an insult to Jenner, and the satirical magazine Punch summed this feeling up in the following way:

England’s ingratitude still blots
The escutcheon of the brave and free;
I saved you many million spots
And now you grudge one spot for me

The Jenner statue was relocated to the Italian Garden in Kensington Gardens within Hyde Park, a small walled area with ornate sculptures, ponds and fountains. It was designed at the express wish of Prince Albert and opened in 1861. The intertwined initials of Victoria and Albert adorn the walls and the sculptures on display show a classical influence. The large statue of Edward Jenner surveys the watery scene but it feels out of place and seems to intrude on the intimacy of Victoria and Albert. It has recently been proposed that the Jenner statue should be reinstated in Trafalgar Square, and a petition is circulating requesting this.

So, why is Jenner important and what did he do? Smallpox was a major killer in the 19th century, with about a third of those contracting the disease dying and those surviving having badly disfigured skin. Elizabeth I is said to have used large amounts of makeup to conceal her pocked skin. No cure existed, but a form of inoculation had been developed in Turkey whereby smallpox material was taken from infected people and rubbed in to a cut on the skin of someone to be inoculated. This technique had been brought to England by the prominent member of the bluestockings, Lady Mary Wortley Montagu, but the practice was hazardous and sometimes led to the inadvertent spread of smallpox.

It was well known at the time that cows contracted a related disease termed cowpox. Cowpox can be caught by humans but the disease is generally mild. Several farmers had noticed that milkmaids who contracted cowpox while exposed to infected cows did not suffer from smallpox. Indeed, milkmaids were known for their unblemished skin.

It is said that Jenner had the idea of deliberately infecting people with cowpox in order to protect against smallpox. In 1796, he transferred cowpox material from the young milkmaid, Sarah Nelmes, who was infected with the disease, into the arm of James Phipps, the son of a local farmer. The boy had some reaction to the cowpox but recovered well and six weeks later Jenner deliberately infected him with smallpox but he did not contract the disease.

It is not widely known, however, that several people had performed this experiment before Jenner. One of the first of these was Benjamin Jesty, a Dorset farmer. Jesty had contracted cowpox himself as a young man and had never suffered from smallpox despite being exposed to outbreaks. He realised that cowpox infection might lead to smallpox resistance and had the clever idea of deliberately infecting members of his family with cowpox in order to protect them. In 1774 he took material from a cowpox lesion on an infected cow and applied it to scratches on the arms of his wife, Elizabeth and their two sons. They contracted cowpox but eventually recovered well and never suffered from smallpox despite being exposed to the disease. Jesty was ridiculed for his experiment: “hooted at, reviled and pelted whenever he attended markets in the neighbourhood”. He vaccinated others but did not seek publicity for his innovative idea.

Several people petitioned on Jesty’s behalf for some recognition of his achievements, however, and in 1805 Jesty was invited to London to present his work to the Original Vaccine Pock Institution. During the visit he was presented with a pair of gold lancets and his picture was painted. This painting is now owned by the Wellcome Library and is currently on display in the County Museum in Dorchester. The painting is a fine tribute to this man who despite living in rural Dorset had a very original idea and was probably the first vaccinator.

So why do we remember Jenner and not Jesty? Jenner was not only an educated man and a doctor, but was already a part of the scientific establishment, having been made a Fellow of the Royal Society for his work on the natural history of cuckoos. Despite being ridiculed by some, Jenner followed his early test of vaccination with other trials to verify the principle that cowpox vaccination protected against smallpox. He published his data, he realised its importance and worked hard to promote vaccination. In his later life, he spent time supplying cowpox material to others around the world and discussing related matters. His work lead to the saving of countless lives and the eventual global eradication of smallpox. Despite having a very clever idea and testing it years before Jenner, Jesty had no scientific training and no idea how to promote and test the idea. So, it is really no surprise that Jenner is lauded and Jesty is largely forgotten.

This is an unusual case with great contrasts between the situations of the two men, but I wonder how often contributions made to great discoveries are ignored or forgotten. One of the more infamous examples of this concerns the “double helix” structure of DNA, a discovery forever associated with the names of Watson and Crick. When they were developing their model, Watson and Crick were in touch with a competing King’s College group including x-ray crystallographers Maurice Wilkins and Rosalind Franklin. Some of the important experimental data used for Watson and Crick’s model came from Franklin’s work and were shown to the Cambridge pair without her knowledge. There was a brief acknowledgment of Franklin’s contribution in Watson and Crick’s 1953 paper but Franklin sadly died very young at the age of 37 and has never been properly credited (although Quentin Blake recently produced a series of drawings entitled “Cambridge 800: an informal panorama” to mark the 800th anniversary of the University, and one is devoted to Franklin's contributions). Another case is the discovery of the rotating neutron stars termed pulsars for which Anthony Hewish received the Nobel Prize. The actual discovery was made by Jocelyn Bell Burnell, at that time a PhD student in Hewish’s lab in Cambridge. She was not included in the Nobel Prize but she has, however, subsequently received many honours. What these cases show is that it is not enough to have a brilliant idea or to obtain wonderful data: you also need to realise its importance, you need to promote it and you need to be in the right place at the right time.