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.
Two common uses of erbium today are in lasers and special kinds of optical fibers. Optical fibers are glass-like materials used to carry telephone messages. The correct chemical name for the rare earth elements is the lanthanides, which comes from the first element in the sixth row of the periodic table, lanthanum.