From W. E. Darwin [7 April 1868]1
My dear Father,
We have decided that I shall go to London and talk the difficulty over with Hacon your lawyer, who I believe you consider a sensible safe man; if he wants a barrister’s opinion he could get it without difficulty2
I have seen Langstaff; he has watched carefully the faces of two adults and two babies; in all four he is perfectly certain that the first movement is the contraction of the “depressores”: in the adults as the suffering did not reach crying pitch there was no other contraction visible, but in the two babies (both of which he watched while he was vaccinating them) directly there was a sign of whimpering or beginning of crying, the little Zygomatics contracted, and slightly drew up the corners of the mouth which were depressed & then the mouth assumed an oblong oval which agrees with what Sanford said.3 he is going to watch for platysma & blushing.4
I see there is a review in the popular Science, Intellectual Observer, & G H. Lewes again in the April Fortnightly.5
I will write when I know anything; I am afraid the madness will be a sticker, as he will not stand I fear any clause on such a subject, but we must try him.
Luckily we have the clause in our partnership deeds.
Your affect son | W E Darwin
Describes the action of facial muscles at the onset of crying as observed by Langstaff.