On the wall of the sitting room in my small, Edwardian villa in the inner-London suburb of Stockwell (think Brixton, then walk back towards the center of town a little), I have hung a panorama of London. Drawn, then engraved and hand-colored, this handsome hybridization of a map and a prospect was produced as a giveaway with the Illustrated London News in the revolutionary year of 1848. It measures about a yard-and-a-half by a foot-and-a-half: a long strip of my natal city, as it appeared some years after my great-great-great-great-grandfather, Adolphus Self, arrived here — quite likely on foot — and established himself at Kennington Cross (about a half-mile from where I now live), in time for the 1831 census. 

In the autumn of 2022, aged 60, I was diagnosed with secondary myelofibrosis — a progressive and fatal blood cancer — which had evolved out of a myeloproliferative neoplasm with the rather …