Lead, Chloride of. PbCl2. Syn. Chloride lead; Plumbi chloridum (Ph. L. 1836). Prep. (Ph. L. 1836). Dissolve acetate of lead, 19 oz., in boiling water, 3 pints; next dissolve chloride of sodium, 6 oz., in boiling water, 1 pint; mix the two solutions, and when cold wash and dry the precipitate. A white, crystalline powder.
Dissolve finely powdered litharge in boiling
dilute hydrochloric acid, and set aside the filtered solution to cool. Brilliant colourless needles.
Prop. Soluble in 135 parts of cold and in 22 parts of boiling water; it melts when heated, and solidifies on cooling, forming a horn-like substance (horn lead; plumbi corneum).
Uses, &c. In the Ph. L. 1836, chloride of lead was ordered to be employed in the preparation of ‘hydrochlorate of morphia.’ Mr Tuson highly recommends it in cancerous affections, to allay pain and restrain morbid action, either in the form of a lotion or ointment.
Various mixtures of lead chlorides and oxide are employed as a white pigment under the name of ‘Pattison’s white.’ It is prepared by rapidly mixing a boiling solution of lead chloride with an equal volume of lime water. Another similar compound is called ‘patent yellow’ or ‘Turner’s yellow.’
Lead, Chromate of. PbCrO4. Syn. Lemon yellow, Leipsig yellow, Paris yellow. Prep. By adding a filtered solution of acetate or nitrate of lead to a like solution of chromate of potassium, as long as the precipitate forms, which is collected, washed with water, and dried. For information respecting the manufacture of this substance on the large scale, as a colouring substance (chrome yellow), see Yellow pigments.
Lead, Dichromate of. Syn. Chrome orange, Chrome red. PbCrO4.PbO. Prep. By adding to a solution of nitrate or acetate of lead a solution of chromate of potassium, to which an equivalent of potassa has been added. This compound is of a splendid scarlet colour. See Red pigments.
Lead, Cy′anide of. PbCy2. Syn. Plumbi cyanidum, L. Prep. By adding hydrocyanic acid to a solution of acetate of lead, as long as a precipitate forms, which, after being washed with distilled water, is dried by a very gentle heat, and preserved from the light and air. Sometimes used as a source of medicinal hydrocyanic acid.
Lead, Iodide of. PbI2. Syn. Lead iodide; Plumbi iodidum (B. P., Ph. L. E. D.). Prep. (B. P.) Nitrate of lead, 4; iodide of potassium, 4; distilled water, a sufficiency. Dissolve with the aid of heat the nitrate of lead in 30 of water, and the iodide of potassium in 10 of water, mix, collect the precipitate, wash, and dry at a gentle heat.