THE NITRATES AND PHOSPHATES. 



143 



(5) One molecule of phosphoric acid to 1 molecule of uranyl phosphate 

 and 2 molecules of sodium phosphate. When dried, this contained much 

 free sodium phosphate. 



(6) Two molecules of phosphoric acid to 1 molecule of uranyl phosphate and 

 1 molecule of sodium phosphate. This specimen did not dry, but remained 

 syrupy at room temperature and appeared to be vitreous at 180. 



(7) A solution of uranyl phosphate in a considerable excess of syrupy 

 phosphoric acid. This gave a glass-like mass even at +20. 



The fluorescence spectra of these 7 substances are plotted to the 

 usual frequency scale in figure 81 . 



Table 53 gives the location of the narrow bands, and approximately 

 of the crests of the broad, unresolved groups; also the frequencies and 

 frequency intervals. 



It will be seen that the spectra of 1, 2, and 3 consist of recurring 

 groups of narrow bands and that homologous members of these groups 



TABLE 53. Wave-lengths and frequencies of the line series of the fluorescence of the sodium 



uranyl phosphates. 



* Series B' is found in spectrum No. 5 only. 



