The scientific life of David Livingstone

On the 200^th anniversary of David Livingstone’s birth, Professor Michael Barrett described the man, his life, and his achievements as explorer, doctor and humanitarian – as well as an important figure in the Scottish tradition of tropical medicine.

David Livingstone was a remarkable Victorian – an explorer, doctor, scientist, naturalist and writer. He was, Professor Barrett said, one of the most astonishing figures in the history of humanity. In a lecture to mark the 200 ^th anniversary of Livingstone’s birth, Professor Barrett focused on the scientific achievements of the mill boy from Blantyre, in the context of his life more generally. In particular, he described Livingstone’s contribution to and understanding of tropical medicine.

David Livingstone was born in Blantyre in Lanarkshire, and lived with his parents and siblings in a small room in a tenement for mill workers. From the age of 10, he worked 14 hours a day in the mill, then attended school for two hours and read until midnight. He was keen to study science, being fascinated by fossils, flora and fauna, but his strictly evangelical father wouldn’t let him, believing that science and Christianity could not be reconciled. The young David, however, found a way forward: inspired by the writings of Thomas Dick, an eccentric scientist from Broughty Ferry, who wrote that science and religion were striving for the same truth, he persuaded his father that he could study medicine so that he could ‘save the heathen’ as a missionary.

Livingstone studied medicine in Glasgow, before applying to the London Missionary Society – where he was to meet the missionary Robert Moffatt, who was home from Kuruman, in South Africa. Livingstone had intended going to China, but the opium wars intervened, and he decided to follow Moffatt and go to southern Africa instead. Livingstone quickly made a reputation for hard work and derring-do – the famous episode where he fought off a lion, which left him with a broken arm, only enhanced his image. He married Moffatt’s daughter, Mary, who travelled with him across the Kalahari Desert.

It was here that Livingstone was to make one of his first significant discoveries in Lake Ngami; a large body of water so close to the Kalahari was important if his idea of opening up Africa to legitimate trade and agriculture was to succeed. Livingstone was keen to find a route into central Africa and walked many thousands of miles to try to find a way. Walking through Africa was tough – there were no roads, and there were threats from wildlife – not just the ‘big beasts’ we associate with Africa, but tiny creatures such as the mosquito. At the time, it wasn’t known that malaria was carried by mosquitoes, and Livingstone had repeated attacks of the disease; indeed, he nearly died. Meanwhile he was showing his scientific zeal and curiosity. When he first saw the Victoria Falls, for example (he was the first to bring this incredible landmark to the attention of Europeans), it wasn’t enough for him simply to wonder at their beauty and majesty: he immediately took his sextant and other scientific equipment and proceeded to measure it and record his observations. Deciding that the Zambezi river was the answer to finding a workable route, he went back to Britain and proceeded to raise the money for what was to be an ill-fated expedition.

Livingstone was feted as a hero back in the UK, and his ideas and writings were influential. He believed that the slave trade was the biggest impediment to development in Africa, for example, and this was a view that gained some momentum with his backing. Interestingly, another eminent Victorian, Charles Darwin, held similar views, and had a similar life pattern at this point (studying medicine in Scotland, theology in London, then travelling, although in Darwin’s case it was to South America). John Murray published Darwin’s Origin of the Species in 1858, the year after the same publisher brought out Livingstone’s Missionary Travels and Researches in South Africa.

Livingstone’s writings were remarkable for the beauty of his descriptions, but also for the observations of natural history. He discovered several new species – such as the honey guide, a bird which annoys and irritates humans and leads them to a bees’ nest, knowing that the humans will raid it for honey and the bird can feast on their leavings. Despite this skill as a naturalist, he disagreed with Darwin on evolution, saying he had witnessed no ‘struggle’ for life on the plains of Africa; but this avowal of a ‘stubborn Christian’, sticking to the idea of God as creator, was at odds with his writing, in which he described evolution in practice.

Livingstone’s observations contributed greatly to human understanding of medicine. For example, he observed the association between the bite of the tampan tick and relapsing fever, and probably gave the first description of an arthropod transmitting disease. His work was followed up by other great Scottish pioneers of tropical medicine, such as Patrick Manson, who established that mosquitoes acted as a vector for disease, and encouraged the amazing all-rounder and polymath Sir Ronald Ross to investigate the life cycle of the malaria parasite, and establish how it was transmitted by mosquitoes.

This discovery had huge significance; because mosquitoes were implicated, people could protect themselves by sleeping under mosquito nets and by draining swamps. Of course there were also drugs for malaria. Livingstone himself was assiduous about taking quinine to ‘cure’ himself of ‘African fever’, and worked out the correct dosage, which was to take it until it caused ‘ringing of the ears’. He also invented pills called ‘Livingstone Rousers’, in which the active ingredient was quinine.

Some of Livingstone’s ideas didn’t quite work in practice. For example, he noted that if domestic animals in Africa were bitten by the tsetse fly, they became emaciated and died, but wild animals didn’t. It would be too difficult to train wild animals – such as buffalo – in Africa to pull carts, so Livingstone imported Indian buffalo – which were already domesticated – thinking they too would be immune. They, however, weren’t resistant and died. “It was fruitless, but he was always trying,” said Professor Barrett. Livingstone won funding for his Zambezi expedition on the basis that it would open up mineral -rich central Africa for trade, and he also wished to ameliorate the lot of the African people, but he was thwarted by a number of circumstances. Perhaps the main barrier was the un -navigable rapids of the Zambezi, which he hadn’t previously noticed and which – despite the horror of his travel companions – he tried to conquer time and again. Other issues were famine, cholera and the growth of the slave trade, which all told against him. He did find a tributary, and did find what is now known as Lake Malawi, but that wasn’t what he had set out to do.

Nevertheless he reported that the area was ripe for conversion by missionaries, and a number arrived – only to die very quickly from malaria. His wife, Mary, also died.

Livingstone felt very guilty and responsible for the missionaries’ deaths, because he had assumed they would take quinine, but hadn’t advised them to do so. The enterprise was considered a fiasco, and Livingstone was profoundly embarrassed, returning to Britain this time as a villain, rather than a hero.

By this time African exploration was all the rage, and Livingstone joined the latest great debate, which was over the source of the Nile. Explorers such as Richard Burton and John Speke were competing over it – and Livingstone, still wanting to find ways into Africa, thought he’d look for it too. It was harder this time to raise the money, but Livingstone travelled back to Africa, to Zanzibar, and spent his time tracing rivers to try to find the source. He became very ill, and lost his medicine chest; he was dependent on Arab traders, and eventually travelled to Lake Tanganyika, where his supplies were stolen. He was in a parlous state, and rumours of his death were already circulating in Britain.

It was at Lake Tanganyika that the famous meeting was to take place between Livingstone and the journalist Henry Morton Stanley, who had been sent to find him by the New York Herald newspaper – and who probably didn’t actually say ‘Dr Livingstone, I presume’. Stanley brought him new life, supplies and medicines, and tried to persuade him to go back to Britain. This Livingstone refused to do, and he continued to try to find the source of the Nile, but had lost his scientific instruments. He didn’t know where he was as he traversed inhospitable swamps and, in fact, was out of his way by miles.

Livingstone died on 1 May 1873. He was eviscerated and his heart buried in Africa, then his body was dried and transported on foot for over a thousand miles by his attendants, before being returned to Britain, where he was buried in State in Westminster Abbey.

Although the cause of death is generally given as malaria and internal bleeding caused by dysentery, Professor Barrett believes that Schistosomiasis, or bilharzia, an infection caused by parasitical tropical worms found in water, is a likely candidate – based partly on the knowledge that Livingstone had terrible bleeding haemorrhoids, for which he refused an operation on the grounds that it would be ‘embarrassing’.

It is likely, then, that Livingstone fell victim to one of the tropical diseases that still kill people today, despite his contribution to our understanding of parasitology. Professor Barrett finished by outlining the current state of malaria, and neglected tropical diseases, saying that efforts were underway to continue the work of Livingstone, and other great Scottish pioneers of tropical medicine, in making such conditions a thing of the past.

But who is today’s Livingstone? Professor Barrett could only describe a composite: as a naturalist, David Attenborough, whose television programmes are engaging and fascinating, much like Livingstone’s books; as an explorer, astronaut Neil Armstrong, and as a preacher and human rights activist, Martin Luther King. “It takes a collection of people – an extraordinary achievement for a mill boy from Blantyre whose 200^th birthday we celebrate today.”

Questions

An historian asked whether a recent television characterisation of Livingstone as a ‘liar’ over the prospects of the ill-fated Zambezi expedition was harsh. Professor Barrett said that he felt Livingstone had exaggerated the ease and the benefits, but that this was for reasonable reasons. His preliminary exploration had missed the rapids – which obviously scuppered the attempt – but he couldn’t have been expected to know about the spread of cholera and famine, and the increase in slavery. “He messed up, he exaggerated, but that doesn’t mean he was a liar.” He said that Livingstone was manic depressive, and that in his optimistic moments, he thought he could pull anything off. “I think he generally believed that colonisation was plausible, and he was profoundly disappointed when it didn’t happen.”

Another historian pointed out that Livingstone deserved credit for not subscribing to the view of the anthropologists and ethnographers of the time – who have been called pseudoscientific racists – that there were different ‘species’ of human. Richard Burton, on the other hand, believed there were. The historian added that he felt that part of the failure of the Zambezi expedition was down to Livingstone’s lack of political flair. Professor Barrett agreed, saying that Darwin had also been outraged by ethnographers and others using measuring sticks to try to define differences. Burton’s portrait is on prominent display in the ‘Victorian explorers’ section of the National Portrait Gallery, while Livingstone’s is not. “It’s outrageous that his isn’t the biggest portrait in the Victorian gallery,” he added, urging everyone to write to the Gallery to make that point.

Sir John Arbuthnott asked how Livingstone kept in touch with the latest scientific thinking when on very long journeys to inaccessible places. Professor Barrett said that Livingstone received copies of The Lancet and the British Medical Journal – sometimes a year out of date – and that he also received letters. Indeed, he was a prodigious letter writer, sometimes penning 20 per day. Great sacks of mail used to arrive by sea, then be transported to towns and villages by anyone who happened to be going that way, including Arab traders. His own mail went the reverse route.

Asked why malaria wasn’t on the list of neglected tropical diseases on the point of being controlled or eradicated, Professor Barrett said that unfortunately it is so widespread that it isn’t considered ‘neglected’. Microsoft billionaire and philanthropist Bill Gates has dared to express the ambition of the eradication of malaria, and there are positive initiatives taking place – such as product development partnerships. The good news is that incidence of malaria has fallen dramatically, he said.