metallic oxides are soluble in alkaline oxides; further, cyanogen, like oxygen, is capable of assuming an allotropic condition.
Following up analogies here, I would class cyanogen and sulphur together, and so I would their hydrides. HS, like cyanogen, is not strongly acid, indeed probably not acid at all, for as in the case of hydrocyanic acid HS exhibits a great tendency to oxidize when in contact with water and to form oxyacids, so that in testing this gas for acidity we are liable to obtain reactions not due to the gas itself.
Our new nomenclature, by doubling the equivalents of oxygen and sulphur, has disturbed the uniformity which before this existed between their common hydrides and that of cyanogen; thus one point of resemblance has been removed, but I think this has been done somewhat arbitrarily in regard to cyanogen. Certainly when the equivalent of cyanogen is retained, its hydride then being Cy H (hydrocyanic acid), comparing with that of chlorine, the supposed similarity of these substances is maintained; and this by the way may have been one of the reasons for which the doubling process described was broken off at cyanogen. However, if I am correct in assuming that this compound is analogous with oxygen rather than with chlorine, its equivalent will also require doubling. If you now agree with me, or at least will contemplate the possibility that cyanogen is not analogous to chlorine and its isomorphs, but rather to oxygen, you will be in a position to perceive certain interesting relations which it bears to oxygen, and which could not well have presented themselves had the assumption I have here attempted to disprove remained unassailed.
Thus ferro- and ferri-cyanogen become upon this view ferri-oxides in which oxygen is replaced by its isomer cyanogen, and the same being true for the rest of the metallic cyanides, these substances should be, I think, viewed as comparing with the oxides of sulphur and chromium as they exist in the sulphates or chromates; further, sulphocyanogen and selenocyanogen, the only compounds containing cyanogen (or at least its elements), which do compare with the simple halogens, are not at all analogous with cyanogen. The cyanides thus viewed are not salts at all any more than the oxides are; sulphocyanides on the other hand are true salts, comparing exactly with the corresponding salts of the halogens.
Further, in regard to the question often raised as to the nature of certain of our elements, whether compound or not, it seems interesting that in this compound, cyanogen, we have a substance very similar to the element oxygen, one which at least only varies from it within the limits we are compelled to allow for variation in the members of certain well defined natural groups of our elements. We are thus, as far as is allowable from such apparent resemblances, justified in entertaining the supposition that oxygen itself is
