A Manual of Photographic Chemistry, Including the Practice of the Collodion Process

by T. Frederick Hardwich

IODIDE OF SILVER. See [Silver, Iodide of].

IODOFORM.

The composition of this substance is analogous to that of Chloroform, Iodine being substituted for Chlorine. It is obtained on boiling together Iodine, Carbonate of Potash, and Alcohol.

Iodoform occurs in yellow nacrous crystals, which have a saffron-like odour. It is insoluble in water, but soluble in spirit.

IRON, PROTOSULPHATE OF.

Symbol, FeO SO₃ + 7 HO. Atomic weight, 139.

The properties of this salt, and of the two salifiable Oxides of Iron, are described at [page 29]. It dissolves in rather more than an equal weight of cold water, or in less of boiling water.

Aqueous solution of Sulphate of Iron absorbs the Binoxide of Nitrogen, acquiring a deep olive-brown colour: as this gaseous Binoxide is itself a reducing agent, the liquid so formed has been proposed as a more energetic developer than the Sulphate of Iron alone (?).

IRON, PROTONITRATE OF.

Symbol, FeO NO₃ + 7 HO. Atomic weight, 153.