Erasmus Darwin: Sex, Science and Serendipity, by Patricia Fara

Forty years before the birth, in 1809, of his more famous grandson Charles, Dr Erasmus Darwin was a force to be reckoned with. A successful and respected country doctor, first in Staffordshire and then Derbyshire, he played, according to Patricia Fara, a "crucial role in British science, politics and literature". That is something of an overstatement perhaps, but Erasmus Darwin certainly helped to further Enlightenment thinking in 18th-century Britain, and is much more than a cultural footnote.

Fascinated by the work of the Swedish botanist Carl Linnaeus, he wrote lengthy erotic poems in which he explored the reproductive mechanisms of plants, related them to politics, and pondered the mysteries of creation. (Like many of his contemporaries, he knew that the natural world must have evolved over time; grandson Charles simply worked out the mechanism.)

Instead of writing a biography, Fara uses Darwin's three major poetical works – The Loves of the Plants, The Economy of Vegetation and The Temple of Nature – as a framework to examine his life, ideas, and achievements. The verse is spectacularly overblown, easy to parody and – a sure sign that it was taken seriously – was widely satirised, especially by the anti-Jacobin movement in The Loves of the Triangles. So sexually suggestive is some of the work, with its breathy references to "loose desires", "sighing florets" and a "quivering pinion" that it was generally considered unsuitable for ladies.

Darwin co-founded the Lunar Society, whose 14 members included James Watt, Josiah Wedgwood and Joseph Priestly. They were interested in social reform as well as science and technology, and Fara's format allows her to explore Darwin's liberal condemnations of slavery, the treatment of prisoners, the status of women and much more. Even in his private life he was unorthodox, fathering 12 children, whom he treated equally, with two wives and his children's governess.

Fara is no dry academic and her pleasing book is, in part, an entertaining account of her research journey in the Rare Books Department of Cambridge University Library and elsewhere. Some of her discoveries are engagingly serendipitous – an important, but sometimes understated, feature of serious research.