FARADAY, Michael (1791-1867). Eleven autograph letters signed to various correspondents including Thomas Winkworth (2), William Pepys (3), William Upcott (1), R. Barclay (1), Dr. Buckland (1), Mrs. Buckland (2) and Lieutenant Earle (1), Royal Institution, 23 October 1817 - 1 April 1860, referring to the Institution and arrangements for lectures and equipment, one on 'the philosophy and practice of Chemical Manipulation', declaring that he is 'not in the habit of preparing my Lecture table in a slovenly way or of leaving much to chance' and demanding that everything should be ready, commenting on scientific projects including the preparation of a black dye and Earle's proposed experiment with a tube of fog, recommending a promising student and writing in appreciation of some strongly scented flowers, 13 pages, 8° and 7 pages, 4°, one autograph envelope, address panels, seals (letter to Barclay pasted onto second leaf of letter to Upcott, small tears without loss of words, traces of tape on verso of 2 letters, one letter repaired at seal tear), and a letter by Mrs. Faraday to the widow of Sir Humphrey Davy. ARAGO, François (1786-1853). Autograph letter signed to Faraday, Paris, 5 December 1831, acknowledging on behalf of the French Royal Academy of Science a memorandum, one page,4°. Faraday writes to Lt. Earle, at Cambridge, 'If a tube were so full of fog that you could not see through it I do not expect that a current of electricity would convert the fog into water'. The letter to Dr. Buckland (Professor of Geology at Oxford) includes an unexpected analysis of some fragments of resin, apparently forming a ball 'made to burn tow mixed with shell lac of combustible resins... It is not unusual on Guy Faux (sic) night to make such balls. I have seen them used as blazing footballs. Can this have been intended for such a purpose? The 5th Novr has not long passed by'. (13)