Chemistry and Physics. 407 
brought by the equatorial current in the upper regions of the 
long as the particles of water con- 
Stituting the cloud are at considerable distances from each other 
d 
charged with electricity opposite to that of the earth while the 
similar electricity escapes by the conductive vortex cloud into the 
higher regions, The author of this theory suggests that astro- 
nomical investigations may show from the perturbations of the 
paths of Mercury, the asteroids and the satellites, the existence or 
non-existence of a solar electric potential.— PAil. Mag., Sept. 1883, 
pp. 161-181. le 
9. Cause of anomalous double refraction in some isometric 
Salts.—The subject of the cause of the anomalous optical phe- 
nomena, observed in the case of many substances which appar- 
