Scientific Intelligence. 399 
Cortampert: Cours de Géographie. . 2d edition; 1857.—Mr. Cor- 
tam rt is eminent in France, as an instructor in Geography ; dnd bis 
works have corresponding success. The first edition appeared two years 
1858; 
Paris.—The printing of this work began in 1854, and the last volume 
in Auvergne, — 
ESS RES 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHYSICS. 
| 1. On telescopes of silvered glass and mirrors with ellipsoidal and par- 
aboloidal surfaces——Foucavtt has communicated to the Academy of 
Sciences a memoir on the substitution of silvered glass for metallic alloys 
in the construction of reflecting telescopes, and on the possibility o 
surrounded by an aureole, the appearance of which indicates 
The author remedies these defects by retouching the mirror in 
focus; the image of course recedes in the opposite direction. By means 
of an appropriate polisher, the figure of the r is corrected for each 
| successive portion of the luminous point, until finally the aberration be- 
invisi A telescope constructed in this manner 
ndromedx 
into two distinct points. This result had hitherto been obtained only by 
Struve with the large Pulkowa instrument.— Comptes us, xlvii, 205, 
2. On the influence of temperature upon phosphorescence. 2 
has found that the color of the light emitted by phosphorescent, bodies 
ep upon the temperature. Thus sulphid of strontium obtained by 
the action of sulphur upon caustic strontia at 700° C. or 800° C. is lumin- 
ous with a violet light at ordinary temperatures, but changes its tints 
when rature varies, and returns again to its original tint when 
‘the original temperature is restored. In the case of sulphid of strontium 
the colors diminish in refrangibility as the temperature rises, but the re- 
