Demystifying the unicorn, 1678, with frontispiece by Romeyn de Hooghe
Thomas Bartholin. De Unicornu Observationes Novae. Secunda editione auctiores & emendatiores editae à filio Casparo Bartholino.
Amsterdam, Henricus Wetstein, 1678. 12mo (14,5 x 9 cm). , 381,  pp. With etched frontispiece by Romeyn de Hooghe, 23 engraved illustrations, including one folding plate.
Contemporary vellum. Spine slightly soiled, otherwise in very good condition. Loosely inserted is the armorial engraved bookplate of N.F. de Douay du Prehedrez featuring three unicorns.
Second edition (the first illustrated) of Bartholin's influential treatise demystifying the unicorn, edited by Thomas's son Caspar.
In his treatise Bartholin, a Danish physician, shows that the many 'horns' displayed in cabinets of curiosities were in fact tusks of the narwhal. And he believed that the horse-like unicorns, allegedly sighted in Asia and Africa, too had their counterpart in the natural world.
Interestingly, he attributes many medicinal qualities to them and used the tusks to remedy a wide variety of ailments, developing what can be described as an early form of aspirin.
Bartholin's interpretation received a favourable reception, and most scientists readily accepted it. However, later research by Cornelis Stalpart van der Wiel among others falsified Bartholin's medical claims.
Krivatsy 822; Verkruijsse, Romeyn de Hooghe 1678.01; cf. Roling, 'Der Wal als Schauobjekt: Thomas Bartholin (1616–1680), die dänische Nation und das Ende der Einhörner', in: Zoology in Early Modern Culture (2014), pp. 172–196.