DESIDERATA, ETC. 
XX1I1 
Desiderata noticed in Sir David Brewster s Report. 
The determination of various constants —namely, 
1. The refractive indices of the two pencils in all crystallized 
bodies, measured in reference to definite points of the spectrum. 
2. The angles at which light is polarized by reflection from 
crystallized and uncrystallized surfaces. 
3. The inclination of the resultant axes of crystals having 
double refraction, for different rays of the spectrum. 
4. The dimensions of the ellipse which regulates the polariza¬ 
tion of metals and their alloys. 
5. The circularly polarizing forces of fluids and solutions. 
6. The refractive and dispersive powers of ordinary solid and 
fluid bodies, measured according to the method of Fraunhofer. 
7- Experimental determination of the effects of the absorption 
of light by gases upon the light of the fixed stars, (vol. i. p. 322.) 
Desiderata noticed in Professor Lloyd’s Report. 
1. Measurement of the refractive indices corresponding to the 
seven principal fixed lines of the spectrum in various singly re¬ 
fracting substances, according to the method of Fraunhofer. 
2. Similar determination of the principal refractive indices of 
crystals, in continuation of the researches of M. Rudberg. 
3. Experimental examination of Fresnel’s theory of double 
refraction, in biaxal crystals. 
4. Comparison of Fresnel’s formulae for the intensity of re¬ 
flected and refracted light, with observation. 
5. Theory of reflexion at the surfaces of crystallized media 
and metals, according to the principles of the wave theory. 
6. Explanation of the peculiar laws of double refraction and 
polarization in rock crystal, according to the same theory. 
7. Physical account of the phenomenon of circular polariza¬ 
tion in liquids. 
8. Physical theory of absorption. 
CHEMISTRY. 
Resolutions of the Committee. 
1. That Dr. Dalton and Dr. Prout be requested to institute 
experiments on the specific gravities of Oxygen, Hydrogen, and 
Carbonic Acid, and that a sum not exceeding 50/. be appropri¬ 
ated to defray the expense of any apparatus which may be re¬ 
quired. 
