“It has just occurred to me that the brain may digest certain portions of food, say the ethereal part, as well as the stomach – perhaps dandruff is the excreta of the mind – the quantity of this material being directly proportional to the amount of reading one indulges in. A book on German metaphysics would easily ruin a dress suit . . .”

– Thomas Edison, July 12, 1885

(From The New York Diaries, ed Teresa Carpenter)