On Dalton's cat: The history of the cervical sympathetic syndrome

The priority of the description of the syndrome resulting from disconnection of the cervical sympathetic has been wrongly ascribed to Johan Friedrich Horner. During the American Civil War William Williams Keen, a military surgeon from Philadelphia, recognized the syndrome six years before Horner in a soldier wounded in the neck, and correctly attributed it to a lesion of the cervical sympathetic. Many characteristics of the syndrome were already known from animal experimentation. In 1727 Francois Pourfour du Petit, also a military surgeon, had noticed the changes in the eyes of dogs as result of cutting the sympathetic in the neck. These two authors deserve acknowledgment for their important contributions.