This paper presents a historical approach about the double refraction of light, especially the ideas of Isaac Newton. Initially, I discuss the studies of Erasmus Bartholinus, who discovered and described the phenomenon in 1669, and also the studies of Christiaan Huygens, who developed an explanatory model based on a vibration conception of light in his Treatise of Light (1690). Next, I analyze the concept of sides of light elaborated by Newton to explain the phenomenon and described in the "Queries" of the Opticks (1704). Through this analysis, 1 intend to outline other elements of Newtonian optics not yet known by scholars and educators.
Newton; optics; double refraction; polarization; history of science
