Chemistry and Physics. 121 
SCIENTIFIC INTELLIGENCE. — 
I. CuEemistry AND Puysics. 
1. On the polarization of light by refraction through a metal.—Biot 
found that two gold leaves are sufficient to polarize direct solar rays 
completely. Rollmann has examined the subject anew, and has em- 
ployed the gold leaves both as a polarizing and as an analyzing arrange- 
m When the light is very intense, only a single leaf can be em- 
ployed, as otherwise the field of view appears too dark. hen used 
€ green in order to transmit the light well. Brewster’s discovery of 
the elliptic polarization by metallic reflection is thus extended and com- 
pleted.—Pogg. Ann., xc, 188. 
dditional experiments on the internal dispersion of light.—In a 
lecture delivered before the Royal Institution in London, Prof. Stokes 
has communicated some new observations on internal dispersion, which 
are of much interest. In accordance with an observation of Fara ay, 
he spectrum to a small fraction of its original length, 
the highly refrangible portion being entirely absorbed. The discharge 
Srconp Sznies, Vol. XVI, No. 49—Jan, 1854, 
