Nitroglycerine refractive index

Nitroglycerin and the Nitroglycerin-Nitro-Dolyglycerin mixture Determination of the refractive index of a sample should give at least a qualitative indication of the presence of the glycol compounds... 

Dinitrodiglycol exists in two crystalline forms—a stable form melting at a temperature of +2°C and a labile one whose melting point is —10.9°C (thus resembling nitroglycerine). At 20°C it is an oily liquid of density 1.385 g/cm3, boiling and simultaneously decomposing at 160°C. Its refractive index is 1.4517 (at 20°C). 

If the nitroglycerine it suspected to contain compounds such as dinitrochlorhydrin, it may be examined by specific gravity, nit en content, chlorine content, refractive index, Nitrosugan increase the viscosity and lower the nitrogen content. Hoffman and Hawse give a polarimetric method for nitrosugars. 

Nitroglycol is a colorless liquid, only slightly more viscous than water, specific gravity (x /15 ) 1.5176 at 0 , 1.5033 at 10 , and 1.4890 at 20 . It freezes at about —22.3 . Rinkenbach reports the index of refraction of nitroglycol for white light to be 1.4452 at 22.3 , and that of a commercial sample of nitroglycerin under the same conditions to be 1.4713. The same author reports the vapor pressure of nitroglycol to be 0.(X)7 mm. of mercury at 0 and 0.0565 mm. at 22 , and points out that its vapor pressure... 

---