Remarkable Spectra of Compounds of Zirconia and Uranium

Abstract

THOUGH the spectra of different salts of bases which show well-marked absorption bands often differ in detail, yet they generally resemble one another so much that there is no difficulty in recognising each element. Judging from facts hitherto known, it was more probable that spectra of the new type described in my former paper^* were due to a new element than that they were merely due to a combination of zirconium with uranium, and that there seemed to be no reason for suspecting a few special compounds of uranium would give spectra with bands unlike all others. Uranic salts, when in a state of moderately fine powder, give a spectrum not only showing absorption-bands, but also those which depend on fluorescence, and are characteristic of light reflected from the powder.† These two kinds of bands can be easily distinguished by means of a plate of deep blue cobalt glass, which proves that the abnormal bands seen in the spectra of the compounds of zirconia with the oxides of uranium are due to genuine absorption and not to fluorescence.