... the field of vision , its the same refractive index and optical glass increasing mirror altercation , so that a high ... cedar oil , a high degree of transparency , refractive index and glass approximate low acid value , the color is pale ... slightly viscous liquid , soluble in alcohol and ether , insoluble water.Refractive index (n20D) ...... 1.5148 ~ 1.5152Acid value ........................... < 60Use ...