Copy letter from Robert Frederick William Harrison, to the Clerk of the Salters Company, Salters Hall, E.C. 'With reference to your letter of the 23rd ult., I have the pleasure to inform you that I have received authority to issue an invitation for the Society's Soiree on the 19th inst., to Mr. De Barri Crawshay, in lieu of that sent to Mr. F. W. Clark, who the President [Lord Joseph Lister] learns with regret is prevented from attending. I enclose a card for Mr. Crawshay [not attached]. I am, Yours faithfully, Robt Harrison Asst. Sec. R. S. [Assistant Secretary, Royal Society]'. 1 May 1897