This 1916 first edition (or circa 1916 printing) of Winfield Scott Hall’s Sexual Knowledge: The Knowledge of Self and Sex in Simple Language is a rare early sex-education/physiology text aimed at young people, husbands and wives, parents, teachers and nurses. It contains illustrative diagrams and covers social ethics, hygiene, reproduction, and the “best time to impart sexual knowledge” according to the era. A striking antique reference for collectors of early sex-education literature or medical/social-history publications.