A brief summary of the various color theories extant in the middle 1600's is followed by a translation into English of parts of Specimen Philosophiae Naturalis, written in 1692 by Caspar Thomeson Bartholin, Professor of Anatomy at the University of Copenhagen and physician to the King of Denmark. Bartholin's small book on natural philosophy exemplifles what the educated non-specialist understood about color at the time when Isaac Newton's papers were being published. -- AATA