The books and works of 10 of history's great naturalists are on display through July 20 at the George Peabody Library. Dating to the 1600s, the manuscripts are among the treasures of the natural history collections in the university's Sheridan Libraries. To accompany the exhibit, titled Animal, Vegetable and Mineral, an online presentation is available on the Web at http://naturalhistory.mse.jhu.edu. Robert Hooke (1655-1703) was a restless researcher who moved from one project to another; the illustrations of leaves, stones and insects in his Micrographia came from his study of life under the microscope. Abraham Trembley (1710-1784) became aware of hydra almost by accident, then concentrated on studying them in great detail. Carl von Linne, or Linnaeus, (1707-1778) had the same need for organization and applied it to creating a classification system of all three kingdoms of nature. Hooke, Trembley and the horticulturist William Curtis (1746- 1799) made their careers close to home, studying things that others considered ordinary or did not notice, while Maria Sibylla Merian (1647-1717), Mark Catesby (ca.1679-1749) and Alexander von Humboldt (1769-1859) traveled afar to study plants, animals and geology unknown in Europe. John Gould (1804-1881) was a taxidermist for the Zoological Society of London who taught himself to be an ornithologist. Charles Lucien Bonaparte (1803-1857) had a university education before becoming an outstanding zoologist. Merian, Catesby and Audubon (1785-1851) were artists, but the other naturalists depended on others to illustrate their books. Among the works are engravings, hand-colored in the earliest books, and lithographs by Audubon and Gould. To protect the works from the light levels in the Peabody Library, pages will be turned periodically during the run of the exhibit.