Copy letter from Robert William Frederick Harrison to Professor G [Gosta] Mittag-Leffler, Foreign Member of the Royal Society 'Dear Sir, With reference to your letter of February 26th, asking to be supplied with Proceedings Nos. B537-543, it appears that, in answer to a postcard request from you, received here November 23, 1908, we sent you Proceedings Nos B537-542. No. B543 is sent herewith, and perhaps you will be good enough to make search for our previous despatch.' 13 March 1909