1. The refractive index of 23 samples of wool grease from different sources
of raw wool has been determined over a temperature range from 25° C. to 50°C.
2. Curves plotted from the data show a definite form of considerable
3. It is recommended that 50°C. should be adopted as the temperature at
which the refractive index of wool grease should be determined.
4. Compared with other fats and oils the refractive index of wool grease
varies considerably. The average value obtained is 1•4752 at 50° C.
5. From the shape of the curves the refractive index at temperatures outside
the melting range can be calculated with a fair degree of accuracy.