ee 
Miscellaneous Intelligence. 433 
sg being passed through a solution of sulphate of quinine or other'sebsi-« 
tive medium, affords peculiar advantages for the study of those rays ; 
the fixed lines of the invisible part of the solar spectrum may now be 
exhibited to our view at pleasure. The constancy with which a partic- 
ralizati 
Mr. Joule’s researches with reference to heat are briefly alluded to, 
ion is then made of some experiments in progress under the 
covery by rendering it but the first step in a still more extensive gene- 
on 9 
and men 
_ direction of Mr. Hopkins, for determining the influence of pressure on 
] n 
sented to the British Association, to have an important bearing on the 
questions of the original and present state of the interior of the earth. 
~ It is-well known that the temperature of the earth increases as we de- 
considerable increase in the temperature of fusion occasioned by pres- 
eighty or one hundred miles in thickness enveloping a fluid nucleus. 
Mr. Hopkins considers this state to be inconsistent with the observed 
amount of the precession of the equinoxes, 
perature of fusion be not increased considerably by pressure, the hy- 
pothesis of internal high temperature being due to primitive heat can- 
not be correct; whilst, on the other hand, if the temperature of fusion 
