Letter, from Henry Warburton to Sir John Herschel, dated at 45 Cadogan Place Autograph letter signed by sender. Coefficients of differences of odd powers of zero observe same law as those of even powers. Example of table of coefficients of differences of 015. Table took 15 minutes to compute by Henry Warburton's process of summation. Notes error in table for 012 sent earlier. 26 May 1856