Treatise on Light was published in 1690 and is probably the largest scientific volume on light published before Newton's Opticks. The book explains how light travels (i.e., that it has a certain velocity), and what happens when it hits a surface (refraction and reflection). A large portion of the book is devoted to the double refraction occurring in Iceland chrystal, and all drawn conclusions are proved geometrically. Christiaan Huygens (1629 - 1695) was a prominent physicist and astronomer. His main discoveries are the centrifugal force, collision laws for bodies and the argument that light consists of waves. He was a contemporary of Galilei and Descartes, and a member of the French Royal Society since 1663.

Latest episodes of the podcast Treatise on Light by Christiaan Huygens

• Preface and Note by the Translator
• I: On Rays Propagated in Straight Lines, Part 1
• I: On Rays Propagated in Straight Lines, Part 2
• II: On Reflexion
• III: On Refraction, Part 1
• III: On Refraction, Part 2
• IV: On the Refraction of the Air
• V: On the Strange Refraction of Iceland Chrystal, Part 1
• V: On the Strange Refraction of Iceland Chrystal, Part 2
• V: On the Strange Refraction of Iceland Chrystal, Part 3
• V: On the Strange Refraction of Iceland Chrystal, Part 4
• VI: On the Figures of the Transparent Bodies, Part 1
• VI: On the Figures of the Transparent Bodies, Part 2