Copy letter from Herbert Rix, to J B Bailey, Royal College of Surgeons, Lincolns Inn Field, W.C. 'Dear Sir, In answer to your note, we do not possess any copy at all of the tract you mention. We have only "Mémoires Académiques, Ou Nouvelles Découvertes Sur La Lumière". I do not know whether the tract you mention was ever presented to the Royal Society. Yours truly Herbert Rix Asst Sec RS [Assistant Secretary, Royal Society]'. 30 June 1891