Published Letter from John Wilkinson to William Maclin (April 18, 1805)
“[The Jerks consist] in a sudden inclination, or reclining, of the shoulders, and is so quick, that the head appears to move too slow for the shoulders…. This is common to both sexes, but with this difference, that men seldom have more than one jerk…; whereas, a woman will frequently continue a repetition of that motion…for ten or fifteen minutes, reclining backwards as far as her feet, or some other obstacle will permit her, and bending so far forwards, as almost to touch the floor with her head….”