Copy letter, from Sir John Herschel to D. C. E. van Monckhoven, dated at Collingwood Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. 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