Asks JT to distribute some circulars about the work of Gustavus Hinrichs of Iowa, whom CD wishes to help.

Admires JT’s Norwich address [to Mathematics and Physics Section, BAAS meeting, Rep. BAAS 38: 1–6] and his Fortnightly Review paper on scientific discovery [7 (1867): 645–60].

Gustavus Hinrichs is also a [not highly regarded] correspondent of JT’s; he will put GH’s papers on the table at Royal Institution to ease CD’s conscience.

Dined with the Asa Grays at Hooker’s. Told Mrs Gray that CD’s ill health was a benefit because it caused him to ponder a great deal.

Invites JT to come to Down with the Asa Grays and Hookers.