Imperator Crassus. Julius Caesar arrives at the House of Crassus and after a brief tussle with Crassus' guards, is welcomed by the man himself. Crassus strikes an alliance with Caesar in order to bring an end to Spartacus' rebellion. He orders Caesar to remain unshaven and the purpose of this is not revealed.
1 Lanthanum oxide additive to tungsten is used in gas tungsten arc welding electrodes, as a substitute for radioactive thorium. 2  Various compounds of lanthanum and other rare-earth elements (oxides, chlorides, etc.) are components of various catalysis, such as petroleum cracking catalysts.
History and Uses: Lanthanum was discovered by Carl Gustaf Mosander, a Swedish chemist, in 1839. Mosander was searching for impurities he believed existed within samples of cerium. He treated cerium nitrate (Ce(NO 3) 3) with dilute nitric acid (HNO 3) and found a new substance he named lanthana (La 2 O 3).Roughly 0.0018% of the earth's crust is composed of lanthanum.anthanum also makes up about 25% of Misch metal, a material that is used to make flints for lighters. Lanthana (La 2 O 3) is used to make the glass used in camera lenses and in other special glasses.