Discusses the power of land covered with snow to radiate heat.

Criticises CL’s discussion of slavery [in Travels in North America (1845)]. A review of CL’s book is in Gardeners’ Chronicle.

Mentions John Lindley’s views on carbonic acid gas and extinction;

refers to the discussion of multiple and single creations in Humboldt’s Kosmos.

The origin of volcanic craters of elevation.

There is a popular demand for a new edition of Principles.

Praises palaeobotanical work of C. J. F. Bunbury.

Encloses a testimonial letter for J. D. Hooker [see 907]. If WJH thinks the letter could be improved CD will alter it. Feels it a disgrace that a professor should be appointed by men "who never heard of Humboldt & Brown".

A letter in support of J. D. Hooker as a candidate for Edinburgh Chair in Botany. No one better qualified. Wishes him success.