TULP, Nicolaas (1593-1674). Observationes medicae, Amsterdam: Ludovic Elzevir, 1652, small 8°, engraved title, 18 engraved full-page illustrations (lacking the final blank, title lightly spotted, light damp marks to inner margin of some leaves, occasional light spotting, modern illustration laid down at end), later calf, lettering-piece (lower rear joints cracked but holding, rubbed along joints, corners bumped). [GM 3737: Tulp was among the first "to describe the ileo-caecal valve ('Tulp's valve')"; Waller 9716; Willems 1155]