However, one can't have everything, and Holmes certainly has a good eye for the entertaining incident. Davy met Byron in 1813, and the two men got on well; later Byron put Davy into Don Juan, and Davy and his rich wife Jane called on the poet in Ravenna (not Venice, as Holmes says). Byron explained to his mistress, Teresa Guiccioli, the nature of Davy's genius as a chemist. "What can he do?" asked she. "Almost anything," Byron replied. "Oh, then, mio caro, do pray beg him to give me something to dye my eyebrows black - I have tried a thousand things and the colours all come off & besides they don't grow - can't he invent something to make them grow?"

Holmes does not discuss the end of the close communion between the poetic and scientific imagination, though I think this too can be dated precisely, if only symbolically. It occurs at Lowther Castle in the Lake District in 1827 when Davy and Wordsworth met for the last time. The poet complained in a letter that it was no longer a meeting of kindred spirits. "His scientific pursuits had hurried his mind into a cause where I could not follow him, and had diverted it in proportion, from objects with which I was best acquainted."

This was the beginning of the bifurcation into the two cultures. It is true that Coleridge tried to keep them together. Holmes describes in detail how he attended the meeting of the new British Association for the Advancement of Sciences, held at Cambridge in 1833, spent three days there, and slept at Trinity, on a bed "as near as I can describe it to a couple of sacks of potatoes tied together... Truly, I lay down at night a man, and arose in the morning a bruise." Nevertheless, he took a full part in the debates, was in sparkling form, made a new friend in the young Michael Faraday, and was present at the session when William Whewell coined the term "scientist", on the analogy of "artist", to replace the old (more accurate) "natural philosopher". But a year later Coleridge was dead, and has never been replaced as a human bridge over the abyss between science and the arts. More's the pity, and that is why I find Holmes's suggestive book so poignant.