The element cerium (named by Berzelius, 1803, after asteriod Ceres, then just discovered, 1801) occurs sparingly in nature, chiefly in cerite, also in gadolinite, allanite, and orthite. Monzanite sand, N. Ca., contains cerite, also silicates or oxides or phosphates of other earthy metals, as zirconium, erbium, thorium. The oxide of thorium gives a bright white light at comparatively low temperature, on which account it is employed in the mantle of the Welsbach incandescent burner. Cerium resembles aluminum in chemical behavior, but its salts act medicinally like those of bismuth and silver. The metal itself is chocolate-brown, burning more easily than magnesium, oxidizing readily in moist atmosphere, and forms two oxides - cerous, Ce2O3, and cerie, CeO2. We have only one official salt.
Tests for Cerium Salts: 1. If to a colorless cerous salt sodium hypochlorite be added, we get a red precipitate, which is soluble in warm HC1 with evolution of chlorine. 2. Any residue, after heating a cerium salt, dissolved in H2SO4 and strychnine crystal added, gives a deep blue, changing to purple, then red.
Cerii Oxalas. Cerium Oxalate, Ce2(C2O4)3.9H2O +. - (Syn., Cerii Oxal., Cerous Oxalate, Oxalas Cericus; Fr. Oxalate de Cerium; Ger. Cerium Oxalicum, Oxalsaures Ceroxydul, Ceroxalat.)
Manufacture: This salt consists chiefly of a mixture of the oxalates of cereum, didymium, lanthanum, and other associated elements, and is obtained by digesting cerite (native silicate) with sulphuric acid, dissolving dried mass in diluted nitric acid and passing into the solution hydrogen sulphide, to remove copper and other metals; to filtered solution add hydrochloric acid, to retain calcium salt, and oxalic acid to precipitate the cerite metals as oxalates, mix with magnesium carbonate, calcine to decompose oxalates, dissolve residue in nitric acid, and pour into water (large quantity) containing .5 p. c. of sulphuric acid to precipitate yellow cerie sulphate, lanthanum, didymium, and magnesium remaining in solution, dissolve cerie sulphate in sulphuric acid, reduce to cerous sulphate by sodium thiosul-phate, and precipitate cerous oxalate with oxalic acid, dry. It is a fine white, slightly pink, powder, odorless, tasteless, permanent, insoluble in water, alcohol, ether, solutions of potassium or sodium hydroxide, insoluble in cold but soluble in hot diluted sulphuric or hydrochloric acid; heated to redness decomposes leaving 47 p. c. of the salt - reddish brown residue. Tests: 1. Boil with potassium hydroxide T. S. - insoluble precipitate (white hydroxides); supersaturate filtrate with acetic acid, + calcium chloride T. S. - white precipitate, insoluble in acetic acid, but soluble in hydrochloric acid. 2. Dissolve in diluted hydrochloric or sulphuric acid, + potassium hydroxide T. S. - precipitate (white hydroxides) insoluble in large excess of reagent but yellowish on exposure, -+- ammonium carbonate T. S. - white precipitate
Properties and Uses. - Nervous and gastric sedative, similar to bismuth subnitrate; nausea, vomiting of pregnancy, sea-sickness, asthma, uterine disorders, hysteria, dyspepsia, pyrosis, cough of phthisis, bronchitis, chorea.