Sends 15 studies in expression, acted by his wife.

Describes David Ferrier’s experiments on electrical brain stimulation of animals; these show direct relation between convolutions of the brain and groups of muscles [West Riding Asylum Med. Rep. (July 1873)].

"Try only 1 or 2 drops of Formic A[cid]."

It is Huxley’s "duty to do what we wish him to do – his duty to his wife and children, his duty to us and to the world". Shares CD’s wish that Mrs [Henry] L[yell?] had not subscribed – it suggests the idea of an effort.