THE SULPHATES. 



171 



If the above groups are aligned by bringing band F into vertical 

 registration, as in figure 89, it will be seen that the apparent dissimi- 

 larity in the composition of the group in the various salts is due rather 

 to the occurrence of various weak bands than to the arrangement of 

 the stronger bands, which, while not identical, approximates to identity 

 almost as closely as in the acetates or the nitrates. As in previous 

 diagrams (see the chapters dealing with the spectra of the chlorides, 

 nitrates, and acetates), the vertical lines indicate the position of the 

 crests of the bands and, qualitatively only, their relative intensities. 

 They are estimated in making observations merely as very strong (vs), 



- U0 2 . (SOt)i.8HiO. 



TABLE 100. Uranyl ammonium sulphate: 



Fluorescence at 185 C. 



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

 double salt. The composition has been determined by Rimbach (Ber. d. d. Chem. Ges., 37, 479 

 (1904) ; the crystallization by de la Provastaye (Ann. Chem. Phys. (3), 5, 51 (1842), who described 

 it as being monoclinic. The preparation consisted of square and rounded plates of diameter 

 from 0.025 to 0.050 mm. The needle-like crystals showed distinct pleochroism from colorless 

 to yellow, the greatest absorption being in the direction of greatest index. 



