THE CHEMICAL GAZETTE. No. CCCCI.—July 1, 1859. SCIENTIFIC AND MEDICINAL CHEMISTRY. On some Salts of Cerium and Lanthanium. By Dr. Holzmann. The author has prepared a series of double salts of protoxide of cerium. The material was purified by Bunsen’s method; the raw material was Swedish cerite. This was finely powdered, mixed with concentrated sulphuric acid into a thick paste, and evaporated to dryness in the sand-bath ; the dry mass was powdered, and extracted several times with boiling water, and finally with dilute nitric acid ; sulphuretted hydrogen was passed through the solution, the filtrate boiled and precipitated by oxalic acid after the addition of a large quantity of muriatic acid. The oxalates were washed by decanta tion with boiling water, then dried, and mixed with an equivalent proportion of calcined magnesia, stirred up with water, dried and exposed to a slight red heat with constant stirring in a porcelain capsule until the oxalic acid was decomposed, and the cerium entirely converted into oxide. This is known by the fact that a sample taken out dissolves in concentrated nitric acid. The calcined oxides are then dissolved in boiling nitric acid, and the solution heated until nearly all the free acid is expelled; the crystalline mass formed on cooling is dissolved in water. For this purpose each 100 grins, of the salt is triturated in a mortar with 100 cubic centims. of cold water, the solution is rapidly filtered, and put into two litres of boiling water previously mixed with 12 cubic centims. of concentrated sulphuric acid. By this means basic sul phate of cerium separates in a perfectly pure state ; it is washed by decantation with the same mixture of water and sulphuric acid. It is necessary to boil the fluid employed for washing previously to using it, and after the introduction of the precipitate to allow the whole mass to boil up for a short time, as the precipitate then settles more readily, and if this be not done, too large a quantity of it would be dissolved. Basic sulphate of cerium, indeed, exhibits a Chetn. Gaz. 1859. o