Caesium history

This has led to such cases in the history of chemistry that spectroscopic signals have been unidentified till newly discovered elements was found (e.g. rubidium, caesium, indium, helium, rhenium) or new species (highly ionized atoms, e.g. in northern lights [aura borealis], luminous phenomena in cosmic space and sun aura, such as nebulium , coronium , geocoronium , asterium , which was characterized at first to be new elements see Bowen [1927] Grotrian [1928] Rabinowitsch [1928]). 

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