Nouvelles Observations et Conjectures sur l'Iris

Paris: Pierre Rocolet, 1650. 4to. (9 1/4 x 7 inches). [6], 340, [6]pp. Engraved printer's device on title-page, engraved head-piece and initial on the dedication leaf, 26 engraved illustrations (including one full-page). Contemporary mottled calf, expertly rebacked to style, spine gilt with raised bands, red morocco lettering piece

First edition of an important work of optics and the musical nature of the refraction of color.

La Chambre, a protege of Cardinal de Richelieu, served as physician to Chancelier Seguier and Louis XIII, and entered the Academie Royale in 1666. The present work was instrumental in the development of French mathematician Pierre de Fermat's eponymous principle, as well as the experiments by Newton which led to his publication of Opticks in 1704. Following Aristotle in deriving a link between the color specturm and musical theory, La Chambre theorized all colors being encompasses within white light and arranged colors over two octaves (with the seven colors of Aristotle at successive fourths, fifths and octaves). Thus arranged symmetrically, the "scale" could be read in either direction, both up and down, with white as the highest or lowest notes. La Chambre hoped to establish a universal theory of color and musical harmony; i.e. if a musical interval was dissonant, the colors it represented would similarly clash. In Newton's Opticks, this parallel between the color spectrum and a musical scale was further refined. A second edition of this work would be published in 1662; the first edition is scarce.

Krivatsy 3017; Brunet III 726; Grasse IV 62; Cioranescu 22651.