172 



FLUORESCENCE OF THE URANYL SALTS. 



strong (s), medium (m), dim (d), very dim (vd), and very very dim (vvd) 

 respectively. No attempt is made in the diagram to indicate the width 

 of the bands. 



The spectrum of the single sulphate resembles those of the double 

 sulphates much more nearly than is the case with the single and double 

 salts of the other acids. 



Wave-lengths, frequencies, and relative intensities of the bands 

 observed in the fluorescence spectra of uranyl sulphate and the double 

 sulphates of ammonium, sodium, potassium, rubidium, and caesium 

 are given in tables 99 to 104. Similar measurements of the bands in 

 the absorption spectra are given in table 10. The determination of 

 wave-lengths were made by the visual and photographic methods de- 

 scribed in the foregoing chapters. 



TABLE 101. Uranyl sodium sulphate: Na z . UO 2 . (804)2 . 2H-f). Fluorescence at 185 C. 

 Prepared by crystallizing a solution containing the two component salts in the proportions of 

 the double salt. (See O. de Coninck, Chem. Centralblatt, ix, I, 919, 1905.) The preparation 

 consisted of crystalline grains about 0.5 mm. in diameter, with much mother liquor or deliques- 

 cence. The crystals are apparently monoclinic, with positive double refraction. 



