Gesner, Konrad von (1516–1565)
Konrad von Gesner was a Swiss naturalist whose major work, Historia Animalium (4 volumes, 1551–58), an encyclopedic study of many varieties of animals, is considered the foundation stone of modern zoology. Unique to its time, the book included not only Greek and Biblical descriptions of animals, but also information Gesner had gained from dissection. Like many of his contemporaries, Gesner had some unusual beliefs. He thought that basilisks and dragons existed, and he catalogued their medicinal uses alongside those of their reptilian cousin, the snake. Gesner wrote, for instance, about the efficacy of dragon fat in treating "creeping ulcers" and that of viper's flesh in theriac, a supposed poison antidote and cure-all commonly used until the late 19th century.