406 Scientific Intelligence. 
varies in its composition in different descriptions of steel similarly 
treated, though the experiments above given suggest that hard- 
ening diminishes the power of the carbide to resist the decompos- 
ing effect of the chromic solution.—/. Chem. Soc., xlili, 303, 
June, 1883. : G. F. B, 
7. A new fluid of great specific gravity, of large index of re 
fraction and of great dispersion—C. Roursacn describes the 
method of preparation of a solution of iodide of quicksilver and’ 
barium which possesses a great power of dispersion. At ordinary 
temperatures this solution is a clear fluid of a yellow color. The 
indices of refraction of various Fraunhofer lines were measured at 
the temperature of 23°C. by enclosing the liquid in a hollow Stein- 
heil prism of 60° (a) and afterwards in a similar prism of 10° (2) 
(H,, Na, H,). The results are compared with those obtained from 
other well-known liquids in the following table: 
: ng -h 
C D E F |nr-7c ger es 
ees 
Water, 18, 75°... 1°3320) 1°3336/| 1°3357| 1°3380| 0°0060 vee 
Bisulphide of carbon at 15, 65°_... | 1°6219| 1°6308| 1°6439| 1-6555} 0°0336 0-007 
Oil of cassia 979| 1-6073| 1°6207| 1°6358| 0°0379 0-0386 
Faraday’s heavy glass, G=4°728___| 1°7077| 1-7148] 1°7242| 1°7325| 0:0248 0-014 
Thoulet’s iodide of quicksilver : : : ; 0607| 0°0357 
and potash, G==3-112 t _-.| 1°7014} 1°7167| 1°7391| 1°7621) 0°0 
e same, G=3° SSC CULT SR Es Cou) fone eee 0-0369 
Iodide of quicksilver and barium a 17755] 1°7932| 1°8268| ---- | --2- | --70g 
564 b| 177521 1°7928| .... | 18448! 0-0736] 0°0409 
pp. 169, 174. 3 eed 
8. Assumption of a Solar Electric Potential. —Sir WiL14M 
SrzmeEns, in his memoir “On the Conservation of Solar Energy, 
makes the hypothesis that the sun possesses a high electric poten 
tial which possibly produces the phenomenon of the zodiacal light. 
in 
sun from space. erner Siemens in a recent article calls 
attention to his observations on the elect the a 
the Cheops pyramid by the whirling dust clouds of the desert, 4° 
illustrating his brother’s theory. “It is assumed that the body 
of the sun is conductive and is insulated by the sea of flame ¢D- 
veloping it. The photosphere retains one of the electricities 
