1.3 Overwork, Illness and Marriage
While developing this intensive study of transmutation, Darwin became involved in more work. Still rewriting his Journal, he took on editing and publishing the expert reports on his collections, and with Henslow’s help obtained a Treasury grant of £1,000 to sponsor this multi-volume Zoology of the Voyage of H.M.S. Beagle. He agreed to unrealistic dates for this and for a book on South American Geology supporting Lyell’s ideas. Darwin finished writing his Journal around 20 June 1837 just as Queen Victoria came to the throne.
Darwin’s health suffered from the pressure. On 20 September he had “an uncomfortable palpitation of the heart”, so his doctors urged him to reduce his work schedule and live in the country for a few weeks. After visiting Shrewsbury he joined his Wedgwood relatives at Maer Hall, Staffordshire. His charming, intelligent, and cultured cousin Emma Wedgwood, nine months older than Darwin, was nursing his invalid aunt. His uncle Jos pointed out an area of ground where cinders had disappeared under loam and suggested that this might have been the work of earthworms, inspiring “a new and important theory” on their role in soil formation which Darwin presented at the Geological Society on 1 November.
William Whewell asked Darwin to take on the duties of Secretary of the Geological Society. After initially declining the work, he accepted the post in March 1838. Darwin made remarkable progress on transmutation, taking every opportunity to question expert naturalists and, unconventionally, people with practical experience such as farmers and pigeon fanciers. Over time his research drew on information from his relatives and children, the family butler, neighbours, colonists and former shipmates. Seeing an orang-utan in the zoo on 28 March 1838 noted its child-like behaviour.
By June he was suffering with stomach problems, headaches and heart symptoms. For the rest of his life, he suffered of stomach pains, vomiting, severe boils, palpitations, trembling and other symptoms, particularly during times of stress such as attending meetings or making social visits. The cause of Darwin’s illness remained unknown, and attempts at treatment had little success.
Being cured, he returned to Shrewsbury in July. Continuing his research in London, Darwin read the sixth edition of Malthus’s “An Essay on the Principle of Population”. In October 1838 he wrote “fifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population; it at once struck me that under circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species.” He now had a theory on to work…”
Malthus asserted that unless human population is kept in check, it increases in a geometrical progression and soon exceeds food supply. Darwin saw that this also applied to de Candolle’s “warring of the species” of plants and the struggle for existence among wildlife, explaining how numbers of a species kept roughly stable. As species always breed beyond available resources, favourable variations would make organisms better at surviving and passing the variations on to their offspring, while unfavourable variations would be lost. This would result in the formation of new species. By mid December he saw a similarity between farmers picking the best breeding stock and a Malthusian Nature selecting from chance variants so that “every part of newly acquired structure is fully practical and perfected.
On 11 November, he returned to Maer and proposed to Emma. She accepted, and then in exchanges of loving letters she showed how she valued his openness in sharing their differences, also expressing her strong Unitarian beliefs. While he was house-hunting in London, bouts of illness continued and Emma wrote urging him to get some rest. He found what they called “Macaw Cottage” in Gower Street, and then moved his “museum” in over Christmas. On 24 January 1839 Darwin was elected a Fellow of the Royal Society.
On 29 January Darwin and Emma Wedgwood were married at Maer in an Anglican ceremony arranged to suit the Unitarians, then immediately caught the train to London and their new home.