Protoxide of Iron

The salts of protoxide of iron, for the most part, attract oxygen from the air and from other bodies, passing into salts of the peroxide. Hence they act in some cases as deoxidising agents. Gold is completely reduced from its solutions by protosulphate of iron. 

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The chemionl changes observed in the devitrification of iotlU-glasi consist, therefore,—1st. In-the loss of ft part or the whole of the -potassa. -2nd. In the passing of a part or the whole of the protoxide of iron and of manganese to the state of sesquioxides. 3rd. In the formation of one or mors definite and crystallized silicates, by means of tbe remaining products. 

Green may be produced either by protoxide of iron, protoxide of copper—Cn 0—or oxide of chromium— Cra Oj. Tho tint produced by the Erst of these substances has little brilliancy. The oxide of copper yields... 

Protoxide of iron,... Lime and noogneaia,. Oxide of manganese, Phoaphoria acid,. 

Carbonate of magnesia,. Protoxide of iron, Protoxide of nmneanese,... 

It ia very probable that several of these matters have been from the fuel. If the fuel contains much silica, the loss in iron, from this cause alone, will he considerable. In the shove analysis the silica and protoxide of iron appear as one to three. The combined weight of the iron tod cinder is always more than the1 weight of the pig-iron put in, Truran gives, as the result of Ills own experience, the following... 

With protoxide of iron, the Ted pruBsiate gives a dark-blue precipitete the yellow prussiate, a white precipitate, which almost immediately becomes blue when exposed to the air. 

A shorter exposure will then suffice, and the contrasts of whita and black are less violent, and half tones prevail to a greater extent The mode of treatment is the same as with pyrogallio acid. Nitrate of the protoxide of iron is sometimes substituted for the sulphate. 

Two equivalents of protosulphate of iron are decomposed into one equivalent of sesquioxide, one of sulphuric acid, and one of sulphurous acid one of the equivalents of sulphuric acid has parted with one of its equivalents of-oxygen, in order that the two equivalents of protoxide of iron might become sesquioxide. This equivalent of sulphurous acid is said to escape through the joints of the apparatus if so, and there does not appear to be any doubt of this boing the fact, inasmuch, as no other provision appears to have been made for its exit, one may naturally oonclude that sulphuric acid vapor must escape at the same time. 

Ferrous oxide 4 151 FeO Monoxide of iron protoxide of iron. 

Protoxide of Iron. Dry protoxide of iron is a black powdor in its hydrated state it is white, and when exposed to tho air rapidly absorbs oxygen, assuming first a grey-ish-groen color, and then a brownish-red, which is much brightened by exposure to a red heat, at tho same time that its solubility in acids is considerably lessened. The salts of protoxide of iron have a eenish color, but eld nearly colorless solutions, except when concentrated. The white hydrate is precipitated ii om solutions of tho protosalts of iron by the pure alkalies. Cooley )... 

Tests for Solutions of the Salts of Protoxide of Iron. When acidulated they are not precipitated by sulphuretted hydrogen even neutral solutions with wo aci< ore incompletely precipitated whilst alkaline solutions ore precipitated of a black color. 

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