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.
Lanthanum is usually found in combination with cerium and other rare earth elements, and it was first found by the Swedish chemist Carl Gustav Mosander in 1839 as an impurity in cerium nitrate â hence the name lanthanum, from the Greek Î»Î±Î½Î¸Î±Î½ÎµÎ¹Î½ (lanthanein), meaning to lie hidden.