Dissertatio epistolaris . . . de observationibus nuperis circa curationem variolarum confluentium nec non de affectione hysterica.

"Sydenham so precisely describes the symptoms of hysteria that even today little can be added to what he said. He maintained that is was the most common chronic disease, and he recognized that in spite of the fact that hysteria refers to the uterus (Greek, hysteron, uterus), males suffer form this disease also... Sydenham recognized for the first time that hysterical symptoms may simulate almost all forms of organic diseases" (Alexander & Selesnick, History of psychiatry, pp. 94-95).