Chemistry and Physics. 381 
vessel filled with water. But with mercury it always yields after 
a few days, even under a pressure of 40 atmospheres, Unfor- 
et 
reducing to absolute pressures woul y cury column, 
which, for the highest pressure would have to be over 1,200 feet 
igh. Recently, ho as suggested itself by 
T 
temperatures between 0° and 30° C., and agrees well with the 
results of the earlier measurements. The pressures are somewhat 
less than those given by Regnault, which were probably effected 
y the unavoidable pressure of air. 
he compressibility was carefully measured at temperatures of 
6°7°, 63°7° and 100°, the two latter temperatures being obtained 
by surrounding the apparatus with the vapor of methyl alcohol 
and water, and the pressure being carried to over 200 atmos- 
pheres. The results fully confirm those previously attained to 
the effect that its volume at high pressures and temperatures 
above the critical point is much less than that it should have if a 
A very large number of experiments were made on mixtures of 
carbonic acid and nitrogen, and the most important result was 
that the critical point is lowered by admixture with a non- 
Condensable gas, Thus a mixture of 3 parts by volume nl = 
. before 
and when mixed with air, which are not accounted for as has 
been alleged by the hygroscopic action of the containing vessel. 
—Vature, xii, 300. : RC. ch ; 
3. Magnets formed of Iron Filings.—M. Jamin has repeate 
the experiment + De Haldat, in which a brass tube was filled with 
‘ron filings and magnetized. The polarity was slight, not sensi- 
