Prof. Schinbein on the Allotropic Modifications of Oxygen 19 
Nitrate of Cadmium, 64 8 H,.—This salt melts at 139° F. It 
has been cooled to 91° before beginning to crystallize. It boils 
at about 270°. On continued boiling it continues clear and thin 
till nearly three equivalents of water are gone. When all the 
water has passed off, a small portion of the remaining dry mass 
is insoluble. 
as ten equivalents. It is se possible then that nitrate of bis- 
muth may be a combination o 
and have for its true formula Bik, H, + Bi, H, 
€, In water, and does not melt clear. At 1634° F., it 
resolves itself into a clear liquid and one olid. The 
mixture has been cooled to 155°, but on stirring it solidified 
again while the temperature rose to 1634°. me of the liquid 
part decanted clear, formed on cooling a mass of crystals quite 
wet with acid and having altogether a composition not far from 
Bi, Ris H,,=3 Bik, H,, ,+2NH,. 
Arr. IV.—Further Observations on the Allotropie Modifications of 
en, and on the Compound Nature of Chlorine, Bromine, dc. ; 
by Professor ScHONBEIN.* 
THESE last six months I have been rather busily working on 
oxygen, and flatter myself not to have quite in vain maltreated 
my favorite; for I think I can now prove the correctness of that 
old idea of mine, according to which there are two kinds or 
allotropic modifications of active oxygen, standing to each other 
in the relation of + to —, 7. ¢, that there is a positively-active 
and a negatively-active oxygen,—an‘ ozone and an ant-ozone, 
which on being brought together neutralize each other into 
to some general statements, which I hope, however, will give a 
doings. A paper will 
* Addressed as a letter to Prof. Faraday, and communicated by him to the L., E. 
and D. Phil. Mag., xvi, 178, : 
