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.
Discovered by: Carl Mosander of Sweden. Description: Named from the Greek word meaning to lie hidden, lanthanum is a very soft, silvery-white metal--soft enough to cut with a knife. It is very reactive, tarnishing quickly in air and reacting with water to form hydrogen gas.escription: Named from the Greek word meaning to lie hidden, lanthanum is a very soft, silvery-white metal--soft enough to cut with a knife.