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146 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I. PHysics AND CHEMISTRY. - 
1. On the General Law of Solidification of Solvents.—Raouit 
has studied the effect which is.produced upon the point of solid- 
ification of a solvent by dissolving solid, liquid or gaseous sub- 
stances init. If A represent the coefficient of depression, that is the 
amount by which the temperature of solidification is lowered 
when one gram of the substance is dissolved in 100 grams of the 
solvent; M the molecular weight of the anhydrous substances 
and T the molecular depression of the freezing point (that is, the 
depression corresponding to the solution of one molecule of the 
dissolved substance in 100 grams of the solvent) then MA=T. 
The solutions employed were very dilute, containing less than one 
molecule (in grams) of the solid to two kilograms of the solvent. 
solvents used were water, benzene, nitrobenzene, ethylene 
dibromide, formic acid and acetic acid, whose saper yp 
solid, liquid or gaseous, when dissolved in a definite compound 
nitrobenzene 72 and 36, for benzene 49 and 
, for formic acid 28 and 14 and 
185. The greater of these two values, wh 
the normal depression, is much the more f: t 
the case of water. Since, with the same solvent, the subs 
rm 
of in fixing the molecular weig 1 salts of the alkalies 
for example, when dissolved in water, 
depression of about 37; hen mong many 
as for example, when they are in the state of vapor, so t 
physical molecule contains only a single chemical molecule, the 
stig a3 a) 
