Mentions Miss Buckley’s information on roosting in trees [see Variation 1: 181 n.].

Refers to Duke [of Argyll] and his Lamarckian view of change.

Roosting habits and behaviour of pigeons in Egypt.

Criticises Herbert Spencer’s works.

Has finished Elements; comments on Laurentian stages.

Remarks on his health

and forthcoming work [Variation].

Took JH's box of specimens and had a discussion with William Logan, A. C. Ramsay, and some young surveyors, one of whom had examined JH's neighborhood. Similar rhomboids to the Irish ones have been located in Wales. Hopes to have a discussion on this subject later. Can JH give, or refer him to data, the temperature of celestial space without the sun? Returns the drawings with many thanks.

Comments on why JH gave 239 degrees F as the temperature of space. Geological specimens may be given to the Geological Society or to the Jermyn Street Museum.