igop.] 



OF VARIOUS SALTS IN SOLUTION. 



203 



Angstrom units, yet their relative accuracy is probably correct to 

 within less than lo Angstrom units for the finer bands. 



The second spectrum strip from the top represents in the long 

 wave-length end of the spectrum the absorption of a 15 mm. solu- 

 tion of a 1. 125 normal solution of uranyl nitrate exposed i min, 

 to the Nernst glower. The a band appears, although not nearly 

 as intense as in the spectrum strip above. The region of shorter 

 wave-lengths beyond A 4300 represents the absorption of a 3 mm. 

 depth of layer of a 1.125 normal concentration exposed 5 min. to 

 the Nernst glower. A very faint transmission is shown in the 

 region A 3700. The ultra-violet line A 2478.8 is shown in the com- 

 parison spark spectra. The other spectrum strips were made in 

 a similar manner, using the concentrations given above. 



By this method of exposing two new bands were detected in the 

 ultra-violet. In aqueous solutions the intensities of the bands are 

 much the same. In other solVents however and for other uranyl 

 salts, the relative intensities of the bands change very greatly. In 

 uranyl nitrate crystals the bands are even more closely related to 

 each other than in aqueous solutions. The longer the wave-length 

 of the band the more intense and wider it is as a rule. The posi- 

 tion of the long wave-length bands in the orthorhombic uranyl 

 nitrate crystals U02(N03)26H20 is the same as the position of 

 the bands for an aqueous solution. The wave-lengths of the 

 bands are as follows : 



Water Sol. 

 Water Sol. 4870 

 Crystals 4870 



be d e f g 



4720 4540 4380 4290 4150 4020 Deussen. 



( Tones and 

 4705 4550 4390 4155 4030j-'g^^^^g 



4705 4500-4565 4405 4275 4170 4050 



h i j k I 



Water Sol. 3870 3790 3690 



Water Sol. 3905 3815 37io 3605 3515 



Crystals 3935 3830 (37-20?) 3600 



Deussen. 



Jones and 



Strong. 



In the original film from which A, Plate I, was made all these 

 bands except d could be very distinctly seen. The bands of longer 



