It is a rare metal.

Its salts are supposed to resemble those of bismuth and silver in their action.

Cerii Oxalas. Oxalate of Cerium, B. and U.S.P. CeC2O4.3H2O, B.P.; Ce(C2O4)3.9H2O, U.S.P

Characters. - It is a white granular powder, insoluble in water.

Preparation. - Is prepared by precipitating a soluble salt of cerium with oxalate of ammonium.

Reactions. - At a red heat it is decomposed into a reddish-brown powder, which dissolves completely in boiling hydrochloric acid without effervescence (oxide). The resulting solution gives a white crystalline precipitate of double sulphate of potassium and cerium when a saturated solution of sulphate of potassium is added to it.

Impurities. - Aluminium, carbonates, and metals.

Test. - When the salt is boiled with caustic potash and filtered, the filtrate is not affected by chloride of ammonium, showing that no aluminium is present: but when supersaturated with acetic acid it gives with calcium chloride a white precipitate of oxalate of calcium. The absence of carbonates and metals is ascertained by the usual tests.

Dose. - 1 to 10 grains. Large doses may succeed when small ones fail.

Uses. - It was introduced by the late Sir James Simpson as a remedy to check the vomiting of pregnancy, and for this purpose is sometimes useful. It has also been employed in cases of chronic bronchitis and dyspnoea, and has been used also in nervous cough and nervous palpitation. It has been given, but with doubtful utility, in chorea and epilepsy.

1 United States Dispensatory, 15th ed. p. 167.