186 Influence of sounds on Anumals. 
subjected many chronometers to pressures, from half au - 
inch of mercury to 75 inches; and in all cases has found, 
that in all instances if a time-keeper gained by increasing the 
density, it lost by diminishing it, and vice versa. A difference 
of density denoted by an inch of quicksilver, is sufficient to 
produce in many chronometers, a visible alteration of rate. 
Mr. H. has drawn from it several important conclusions : 
for instance, that a chronometer constructed in London, 
nearly on the level of the sea, would undergo an alteration 
éf rate, from difference of atmospheric pressure alone, if 
transported to Geneva, to Madrid, to Mexico, or any other 
place, situated much above the level of the place where it is 
constructed. 
The whole of the results are about to be laid before the 
Royal Society. Lend. Phil. Mag. Vol. 63, p. 311. 
23. Sordawalite, a new mtineral_—This name has been 
given by M. G. Nordenskiold, Esq. to a mineral from Sor- 
dawala in Finland. 
The mineral is somewhat like coal in appearance. It oc- 
curs massive and without any traces of cleavage. The co- 
lour is greenish, or grayish black It is as hard as glass. It 
occurs in a thin bed, and breaks readily in a direction at 
right angles to the direction of the bed. The fracture is 
conchoidal ; and the lustre vitreous, inclining to semi-metal- 
lic Opaque. Brittle. Spec. grav. 2,530. It becomes red- 
dish on long exposure to the atmosphere. 
Its chemical composition is found to be as follows : 
Silica, 49.40 Magnesia, 10.67 
Alumine, 13.80 | Phosphoric acid, 2.68 
Peroxide of Iron, 18.17 Water, 4.38 
99.10 
24. Influence of sounds on the Elephant and Lion.—In the 
human ear the fibres of the circular tympanum radiate from 
its centre to its circumference, and are of equal length, but 
Sir E, Home has found that in the elephant where the tym- 
panum is oval they are of different lengths, like the radii from 
the focus of an ellipse. He considers that the human ear 
is adapted for musical sounds by the equality of the radii, and 
We is of opinion that the long fibres in the tympanum of the cl- 
