Just watched Michael Johnson's documentary on C4 about the influence of slavery on genetic selection - in other words, why are black people faster runners? Short answer: no one knows. But it strikes me this would be a very good subject for research, if only to work out why the genes that produce superb sprinters also produce large numbers of people with diabetes.

Meanwhile, I think 'Joseph Knight' by James Robertson should be compulsory reading for all secondary school students - and their teachers, so that people in Scotland and the wider UK can understand better our role in the slavery business, the cruellest imaginable of trades. It would also make a splendid film.