Frater, ave atque vale

As his obituaries pointed out, my brother David made a name for himself with his unrideable bicycle; his ‘perpetual motion’ machine — a bicycle wheel still rotating in a frame on our mantelpiece (it attracted 1.1 million hits on a German website); and his theory that the arsenic found in Napoleon’s hair and fingernails was down to his wallpaper.

The papers naturally got all this wrong (‘Napoleon killed by wallpaper’ they intoned, as did Andrew Roberts), and the image of the potty prof emerged. In fact, his purpose was serious. He was equally serious about our children — after a failed marriage, he had none of his own, to his great regret — and at lunch every Sunday the idiosyncratic scientist and dedicated uncle came together.

David brought liquid nitrogen so the children could freeze flowers and make instant golden syrup ice lollies. He put a reversed vacuum cleaner in the bath together with Fairy liquid to fill the room with bubbles.