Sec eee 
Physics, 21: 
on the relation between the capacity of the condenser and the 
thickness of the insulating layer and plates were verified even 
when there were several insulating plates instead of one. 
ese experiments were made both with a mom 
a continuous charge; both cases gave nearly equal capacities. 
rom this we 
produced quite rapidly. 
Th r found as probable values of the constant of dielec- 
tricity the numbers for sulphur, 3°86 ; hardened caoutchoue, 3°15; 
resin, 2°55 ; paraffine, 2°32. 
Maxwell arrived at the conclusion that the square root of the 
constant of dielectricity ought to equal the index of refraction. 
The following table shows that this law holds true quite within 
the limits of probable error: 
VD. Index of refraction. 
Sulphur, 1960 2°060 
esin, 1597 1°563 
523 1°536—1°516 
202. Be OP: 
. Flow of Saline Solutions through Capillary Tubes.—M. T. 
Hisener finds that the velocity of flow of solutions in capillary 
sented two marks, and with a seconds-watch the time which was 
required for the level of the liquid to fall from one of these marks 
to the other, was accurately measured. eo e 
“ Operating in this way upon solutions of chloride, bromide and 
lodide of potassium, chloride of sodium and ammonium, with a 
“3 
alloid, e variations presented by the velocity from one body 
to another are as much more mark i as the tube is more capillary 
and as the concentration of the solution is greate: ei 
r. 
comparing two solutions, of chloride of sodium and 
ts 
re} 
B 
g 
E 
i 
B 
g 
w 
2 
z 
0B 
cS 
chlorides of the alkaline-carth metals barium, strontium, ma ) 
sium, M. Htibener thinks it nay be concluded generally, with a 
high degree of probability, that the velocities of flow of these. 
