Incomplete letter, from Sir John Herschel to Charles Babbage, dated at St. John's College, Cambridge Autographed letter, incomplete. Gratitude for Charles Babbage's friendship. Chemical supplies and instruments. Describes synthesis of 'Sulphurane' [S2Cl2] and other experiments. Theories of combustion and acids. [Letter continued on 1813-9-21:] John Frederick William Herschel avidly studying law, against father's wishes. 20 September 1814