The editors are grateful to:

Richard Doll, University of Oxford, for drawing attention to this record;

Jon Pollock for the photograph of his father, Martin Pollock;

and to the Archive Department of the Royal London Hospital for the portrait of Clifford Wilson.

Elsevier Ltd. for making a pdf of this article available (letter to Iain Chalmers from Laura Pritchard, 14 May 2014). For conditions of further reproduction, see here.