Some of the salts of cerium, a metal which exists in a few rare minerals, as cerite, have been made use of in medicine. The oxide and the oxalate of cerium have been most frequently used, and occasionally the nitrate has been given. The cerium salts have been chiefly employed to allay vomiting, especially that which occurs in pregnancy, also in the vomiting of phthisis; and in some cases of epilepsy accompanied with gastric disturbance. The dose of the preparations of cerium may be from 3 to 5 grs.