Copy letter from Herbert Rix, to Professor Dr Emil Du Bois Reymond, Foreign Member of the Royal Society 'Dear Sir, Mr Ludwig Mond, an eminent chemist of this country who is at present staying at 64 Via Sistina, Rome, has sent to our President, Sir William Thomson, a cheque for £25 (twenty five pounds), being his donation to the Helmholtz Memorial. I have pleasure in handing you that cheque herewith, and beg that you will advise me of its safe receipt. I am, Dear Sir, Your obedient servant, Herbert Rix Asst Sec RS [Assistant Secretary, Royal Society]'. 18 April 1891