144 Scientific Intelligence. 
reflected by a prism of crown glass, the third the amount reflected 
according to Fresnel’s formula, and the fourth and fifth the ob- 
served and computed reflections for a similar prism of flint glass. 
The incident beam is in all cases taken as 100. 
Crown glass. Flint glass. 
Obs. Calc. Obs. Calc. 
30° 5°5 59 7°0 : 
40 7°2 73 8°4 9°3 
50 10°4 11°4 12°0 13°3 
55 13°3 14°1 16°1 16°2 
60 17°4 17°9 20°3 20°3 
65 23°1 22°9 25°4 25°7 
70 29°3 30°2 32°7 33°0 
The indices of refraction were found from the angle of total polar 
zation, since eck has shown that the density and, therefore, 
fer in some cases as much as four per cent from one another.— 
Monats. Acad., Berlin, 1874, p. 511; Phil. Mag., x\viii, 475. 
E. € 
18. Electrical Polarization.—M. G. QuincxE describes in detail 
a great number of experiments on the electrical currents accom 
panying the non-simultaneous immersion of two mercury elec- 
trodes in various liquids, and has arrived at the following col 
clusions : 
tween the electrodes is increased. e electromotive force var 
with the nature of the liquid and increases as the concentratio? 
diminishes, in some cases amounting to 0°6 of a Volt. The le 
however, reaches a maximum, especially in the 
e aus iy 
near the surface of contact after the wetting. Similar effects a7 
obtained with solid metals, as with mercury. Thecu 
with acids are due chiefly to chemical action, and are, t! 
secondary phenomena. The surface tension may be either 1 
creased or diminished and may change its sign with the directio? 
and duration of the current. The disturbances in capillarity : 
not be accounted for by electrolysis.—Pogg. Annal., cliii, 161-203; 
Phil. Mag., xlviii, 479. Ez. 
