Copy letter, from Sir John Herschel to D. C. E. van Monckhoven, dated at Collingwood Copy of a letter. Is honored by DM's letter and proposal to dedicate his book [Traite general de photographie] to John Frederick William Herschel. Points out some errors of attribution he would like incorporated if not too late. Pass on his good wishes to J. A. F. Plateau. 2 January 1863