Copy letter, from Sir John Herschel to William Henry Fox Talbot, dated at 32 Harley St. Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Agrees to William Henry Fox Talbot's use of name 'amphitype' [see William Henry Fox Talbot's 1851-5-6 or earlier]. 6 May 1851