476 Scientific Intelligence. 
of combustion of the two siaaely i ha 8 a ae pe 
and thus keeping the oxygen away, the 
nosity is equally well ec when the: cscs o shies ases is 
prevented by a large sheet o n having a hole in it, through 
which the tube of the burner pase air-tight 
rom these observations it may be Sonainded that the non- 
luminosity of a gas-flame is not caused by a dilution of the a, 
this dilution being in fact increased by heating the mixture. 
only cause is a cooling of the interior of the flame. This is further 
proved by the fact that it is most difficult to get a non-luminous 
flame from a mixture of coal-gas and oxygen, showing that neither 
rapid oxidation nor dilution produces the non-luminosity. — Deut. 
Chem. Ges. Ber., viii, 226; Jour. Chem. Soc., xiii, 6038. 
11. Rotatory Polarization of Quartz —MM. J. L. Sanne ne Ez 
Sarazin have repeated the experiments of Broch and Stefan extend- 
ing them to the more Hee poe sige of the diner? e light 
gpa eg bt ith the fluorescent eye-piece of M. Soret. " For the rays 
and a, a bie of cobalt glass was jiitetponsd to cut off the adja- 
cent fright light. 
@ A 
A 760°0 12°68 +0°10 
a 718°5 14°33 00 
B 686°7 15°75 00 
C 656°2 17°35 00 
D 588°9 21°79 —"05 
E 526°9 27°61 ~ °06 
F 486°07 32°85 —°O7 
G 430°72 49°63 +06 
h 410°] 47°52 —"05 
H 396°8 51°22 00 
L 381°9 55°88 — 08 
M 372°7 59°03 —°06 
_— 372°0 59°24 0 
N 358°5 64°41 +03 
The formula p = A +73 wi in which gis the angle of rotation — 
and A the wave-length ee well with observations betwee? tt 
and 7, but is inexact if used between more extended limits. — 
has eae the po Ga = + e + 2 + pe ae 
two terms only, and computing B and ( for the lines @ io 
710533, "151227 well with 
ie — eee ha — ‘ 
