Copy letter from Robert William Frederick Harrison to Dr J D Thomson, Lister Institute, Chelsea Bridge Road, SW 'Dear Sir, I enclose a cheque for £25 (twenty-five pounds) being the final instalment of the honorarium for Sleeping Sickness Investigation work, which you conducted in colla boration with Mr Plimmer to the end of November 1907. Kind return the accompanying form of receipt.' 11 April 1908