Summary

Thanks for MS observations on expression. Discusses hair standing on end in terror and rage. Asks JC-B to observe contraction of platysma myoides. "Your description of the grinning and exposure of the canine teeth under furious rage is excellent. I presume that you would not object to my quoting it." Asks about contraction of "grief muscles". Comments on blushing. Offers to send book by G. B. A. Duchenne [Mécanisme de la physionomie humaine (1862)].