Cadmium, Car′bonate of. CdCO3. Syn. Cad′mii car′bonas, L. From a solution of sulphate or chloride of cadmium, and an alkaline carbonate; the precipitate being collected, washed, and dried by a gentle heat. A white powder.
Cadmium, Chlo′′ride of. CdCl2. Syn. Hydrochlo′′rate of cadmium, Mu′′riate of cadmium; Cad′mii chlori′dum, Cad′mii hydrochlo′′ras, L. Prep. 1. (Pure.) By dissolving carbonate or oxide of cadmium in hydrochloric acid, and crystallising by gentle
evaporation. Prismatic crystals; very soluble in water.
2. (Turner.) By exposing the product of the last process to heat. Amorphous.
3. From crude cadmium or its oxide, and hydrochloric acid, as last.
Cadmium, I′odide of. CdI2. Syn. Hydri′odate of cadmium; Cad′′mii iodi′dum, C. hydrio′das, L.
Prep. (Crookes.) Cadmium in filings 1 part, pure iodine 2 parts, are to be placed together in a capacious flask, with alcohol sufficient to cover them. Action commences at once, attended with considerable evolution of heat; when it ceases, heat the mixture till it is colourless; then filter from a few grains of cadmium which will remain undissolved, evaporate and crystallise.
Uses. In photography this salt has lately been employed with great success for iodizing collodion. Being very stable, it is not decomposed, and the collodion iodized with it preserves its sensitiveness undiminished during many months. (See Collodion.) In medicine it is used occasionally as a substitute for iodide of lead.
Cadmium, Ox′ide of. CdO. Syn. Protox′ide of cadmium; Cad′mii oxy′dum, L. Prep. 1. (Hydrated.) From sulphate or chloride of cadmium, and a solution of caustic alkali; observing to well wash and dry the precipitate. A white powder, freely soluble in acids.
2. (Anhydrous.) By igniting the hydrated oxide, or the carbonate or nitrate of cadmium. That from the first two has a pale brown colour; that from the nitrate has a dark brown tint and a semi-crystalline appearance. The former has been proposed to be used as a pigment.