112 Scientific Intelligence. 
that which it has at 0° C. At this pct phd ae ha total quantity ~ 
of vis-viva of the shen darth is very nearly 12 
y combining two molecules so that i> ibe a as one, Babinet 
proves that their vis-viva will be doubled; or if the final temperature is 
to be the original temperature, the combination m ust lose a vis-viva equa 
i that originally possessed by each of the molecules, or 1200 dynamic 
calories 
The acess of the law of a. and Petit is favorable to thé 
peculiar views of Babinet; but w await further developments be 
fore we can form an intelligent Spina oasaiag the other asin 7 his 
paper. 
15. Action of heat on the optical properties of crystals, —DasCuae 
been found related to other optical properties. DesCloizeaux found 
bic erystals— 
Displacement. Dispersion. 
19 showed great, great. 
10 * feeble, considerable. 
4 = insensible, considerable. 
10 be considerable, 
12 - feeble, 
ve sm. 
17 “- insensible or uncertain, very feeble or nearly zero. : : 
Aragonite and the micas show exceedingly small variation. Celestine : 
{increase of 6° 41’ between 10° and 105° C. = and leadhillite (dimin | 
tion of 16° 50’ between 15° and 180°) are among the more variable. i 
_ While in the ortho rhombic forms the median line @ of He op | 
most m 
Des found that 11 
a a feeble or fs sano, 5 showed hardly any change in the : & 
es The five triclinic minerals investigated albite, ambl nite, sx z E 
3 pace sce or tho plans of ie ad 175° C. C. hardly. a 
stitul, 1866, pp. 199-141 oe ma 
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