The 1685 edition, in the original Latin, of two works on the medicinal qualities of mineral springs by Henri de Heer, published together. Henri de Heer (1570-ca. 1636), court physician in Cologne. It discusses the qualities of mineral waters at the famous springs in Spa. He published his Observationes medicae, with further observations on the same subject, in 1630 and the two were regularly issued together.
With a 1773 owner's inscription of Gustavus Guilielmus Henrici, who published a 1763 Ehrfurt medical thesis on fertile and unfertile eggs. Without the illustrated, engraved frontispiece present in some copies. Browned throughout and with a small stain on the title-page, but otherwise in very good condition. The binding is rubbed but structurally sound. One of the earliest studies of the medicinal qualities of mineral springs. BMN I, p. 435; Krivatsy 5383; STCN (7 copies); Wellcome III, p. 233; for Heer: G. Xhayet, Henri de Heer, médecin de cour et médecin de ville dans la Principauté de Liège.