The date is established by the relationship between this letter and the letter from E. S. Galton, 12 November 1879 (Correspondence vol. 27). The fragment is an autograph from an album with some text on the reverse; it is accompanied by a letter from Wheler explaining that she had been looking over some letters sent to her by CD when he was working on Erasmus Darwin and was sending her correspondent an autograph from one of them.