The Atmosphere of Heaven, By Mike Jay

Mention Beddoes and most think of the macabre Romantic poet, Thomas. He scarcely knew his father, another Thomas Beddoes, who died, aged 48, at Christmas 1808. Beddoes was six, with scant idea of the man who had also brought into existence a Pneumatic Institute in Bristol. This not only treated the ailing with compounds which evolved into laughing gas but encouraged an apprentice, Humphry Davy.

Described by Lytton Strachey as "a remarkable man, endowed with high and varied intellectual capacities and a rare independence of character", Dr Beddoes senior could have found a place in his later, more satirical writings. Of portly physique, he had a thirst for knowledge as obsessive as it was omnivorous, but lacking that humour which could have alleviated it.

He often appears a stray from his contemporary Thomas Love Peacock's fiction; indeed, among those who filled Beddoes's house was Peacock's bete noire Coleridge. Another discovery was young Roget, he of the thesaurus.

The place was a hive of experiment and revolutionary sympathies, which Beddoes had imbibed since his 1760 birth. He was grandson of a Shropshire tanner whose scientific ways elevated the family before a fall from a horse brought emphysema.

Its hopeless treatment was watched by the nine-year-old Beddoes who, becoming friendly with the doctor, found the course of his life established. Oxford, where he taught himself languages, was followed by medical studies in London and Edinburgh. On returning as a lecturer to Oxford in 1788, he also wrote verse akin to Erasmus Darwin's botanical epics. As his revolutionary sympathies survived 1789's troubled aftermath, a move from Oxford was prudent. He settled in riot-prone Bristol and founded the Institute in 1798 with the "Lunar Men" Tom Wedgwood and Gregory Watt, who put him in touch with their Penzance landlady's teenage prodigy, Davy. Meanwhile, surprisingly, Beddoes married Anna, vivacious sister of novelist Maria Edgeworth.

As Mike Jay suggests in this measured, detailed biography, she may not have satisfied. "I would rather be mistress to the man I love than wife, but since this is contrary to all custom, and cannot be, I must be contended with being wife in the usual way." So she told another man in a letter found by Jay.

Beddoes was a prolific writer but best known for his creation of laughing gas, which made one patient declare "I feel like the sound of a harp". However, he did not deduce its being a harbinger of anaesthesia, but was distracted by another air. So convinced was he that cow's breath is beneficial that he set up a stall beside a ward whose occupants remarked more upon the animals' other end than anything from the nostrils. For all Beddoes' achievements, that image is indelible.