568 Messrs. Jones and Strong on the Absorption 



Uranous chloride in acetone to which free hydrochloric 

 acid is added has absorption bands, each from 10 to 20 

 A. u. wide, at XX 5195, 5210, 5220, 5910, 5960, 6000, 6040, 

 6090, 6340, 6365, 6390, 6470, 6490, 6555, 6600, 6625, 6690 

 6740, 6780. These bands have been discovered in no other 

 spectrum and are as sharp as the erbium and neodymium 

 bands. Hitherto it has been found that by lowering the 

 temperature the uranyl bands are broken up into fine com- 

 ponents. In the case of uranyl chloride the resolution of the 

 bands is accomplished at ordinary temperatures. When no 

 free hydrochloric acid is present the groups of fine bands 

 consist simply of broad hazy bands. 



The absorption spectra of the various uranous salts in 

 methyl alcohol is very similar to that in ethyl alcohol. The 

 absorption of uranous chloride in methyl alcohol, for example, 

 is almost the same as in ethyl alcohol, and this is practically 

 the same as the absorption of uranous bromide in methyl 

 alcohol. The absorption consists of rather diffuse bands at 

 XX 4150, 4300, 4450, 4680 (very strong), 4950, 5100, 5250, 

 5500, 5650, 6250, and 6650. The relative intensities of the 

 uranyl bands are very considerably modified by the amount of 

 the reduction of the uranium salt present in solution. In several 

 cases the uranyl bands are broken up into several components, 

 and in other cases several uranyl bands may merge into a 

 single wide band. Uranous acetate in methyl alcohol possesses 

 a series of bands in the red that are very similar in character 

 to the uranyl series, except that it runs in the opposite 

 direction. Four such bands have been measured at XX 6700 

 6800, 6870, and 6920. The absorption spectrum of uranous 

 bromide in glycerol is almost identical with that in methyl 

 alcohol. 



The absorption bands of uranous salts in glycerol are very 

 wide and hazy. The presence of free acid does not in 

 general increase very greatly the sharpness of the bands. 

 Glycerol solutions of uranous bromide and chloride consist 

 of a strong band at X 6250, a hazy band at X 5300 and at 

 X 5000. The intensities of the uranyl bands depend largely 

 upon the extent of the reduction of the uranium salt. 

 Several uranyl bands of the partly reduced uranyl acetate are 

 broken up into two components. 



The absorption spectra of the various uranous salts in 

 water are very much the same. Uranous bromide and 

 chloride have bands at XX 6750, 6500, 6340, and 5500 ; and 

 uranous acetate at XX 6850, 6700, 5600, and 5550. In 

 aqueous solutions the uranous and uranyl bands are diffuse 

 and in many cases extremely weak. 



