Page:Collected Physical Papers.djvu/50

30 The following are the readings in degrees for the first six sets of observations with P (a, b) or Q (c. d).

From the results given above it would appear that the index of refraction of sulphur is very near 1.734.

The method is also well suited for liquids; no large quantity of material is required; and the results possess a high degree of accuracy.

The determination of the indices of other solids and liquids are in progress. An account of these will be given in a future communication. (Proc. Roy. Soc., Oct. 1895.)