Chemistry and Physics. 211 
in one direction. This will be true whether the isothermal 
couches be plane surfaces sibel os from a thinner to a thicker 
part of the mass, or whether they be curved surfaces arising 
from the mass reposing on a Uoeved bottom, and diverging in 
like manner. This explanation of the production of curve 
prisms, without the necessary ropereearen of external mechan- 
ical forces, having bent into s prisms originally formed 
straight, is, the author believes, pe ht the first time presented. 
e shows that great difficulties exist to the supposition that 
of ed prisms are ever the result of the bending of prisms 
qneinaly i by extraneous mechanical effort. The au- 
thor thus shown that all the salient phenomena pre- 
porate in ae by the forms, jointings, positions of the prisms, 
c., of columnar basalt are accounted for as consequences of 
contraction in cooling, submits that this solution given by him 
must be the true one. He, however, proceeds to examine at 
some length the different views of those who have imagined 
that prismatic and jointed basalt has resulted from the squeez- 
ing together by some wholly imaginary external force of sphe- 
roidal masses, more or less resembling those known as “ onion 
or concretionary spheroids, such as those imagined by 
Hee Gregory Watt. io author submits all points of the sub- 
t to a searching exami nation, and points out that, upon 
e as to the 
Bre 
pression could produce sa hiee at a ut must squeeze the 
spheroids instead into rhombic HAE i os cl 
SCIENTIFIC INTELLIGENCE. 
L CHEMISTRY AND Puysics. 
On Atmospheric Hydrogen Peroxide.—Between the first of 
dat and the first of December, 1874, ScHdNE examined one hun- 
dred and thirty specimens of rain, and twenty-nine specimens of 
snow, for hydrogen peroxide. These experiments were made in 
the ¥ vicinity of oscow. Of the whole number of specimens of 
established the fact, the author continued his oe wit 
reference to the pep arte 4 Form of occurrence of hy- 
in the fluid, or solid othe or ag ; (2) Relation to other meteoric 
a 
air; (5) Part played by it geologically and botanically; (6) 
tion upon the animal economy when breathed; and (7) iy cistlo 
