132 A STUDY OF THE ABSORPTION SPECTRA. 



Uranous Acetate in Glycerol. 



Uranous acetate was obtained as already described. Some of the 

 solution in methyl alcohol and acetic acid was mixed with glycerol and 

 warmed so as to drive off as much alcohol and acid as possible. The 

 solution was filtered hot. The precipitate was green, the filtrate yellow; 

 indicating that the uranium in the glycerol was mostly in the uranyl 

 condition. 



The absorption spectra showed several of the uranyl bands. These 

 bands are not nearly so intense as the bands of uranous acetate in methyl 

 alcohol and acetic acid. The / band X 4220 appears to be double. The e 

 band consists of a band about 15 Angstrom units wide at X 4295, a band 

 at X 4340, and one at X 4390; the d band of two bands X 4480 and X 4530; 

 and the c band of X 4630 and X 4680, the latter being the weaker of the 

 two bands. 



Effect of Temperature on the Absorption Spectra of Uranous Chloride. 



A spectrogram was made to show the effect of change in temperature 

 on the absorption spectrum of an aqueous solution of uranous chloride. 

 To a normal solution of uranyl chloride in water was added a small amount 

 of zinc and hydrochloric acid. The hydrogen reduced the uranyl chloride 

 to uranous chloride a deep green solution which seemed quite stable. 

 The solution was then placed in the trough of the temperature apparatus 

 and an exposure made in the usual manner. The thickness of layer was 

 1 mm. The exposures were 50 minutes to the Nernst glower and 4 minutes 

 to the spark. The current through the glower was 0.8 ampere and the slit- 

 width 0.20 mm. Starting with the strip nearest the comparison scale the 

 temperatures were 8, 17, 33, 48, 62, and 73. An exposure was made 

 at 80 and will be described with the other exposures although it is not on 

 the spectrogram as printed. 



At 8 a slight mist formed on the prisms on account of their low tem- 

 perature and the humidity of the air. For this reason the strip is very much 

 underexposed and the bands apparently seem wider than at the higher 

 temperatures. At this temperature there is complete absorption to X 3650. 

 A blue-violet absorption runs from X 4050 to X 4450. Following this are 

 three strong bands of about equal intensity and each about 100 Angstrom 

 units wide. These bands are located approximately at XX 4590, 4760, and 

 4970. Then comes a band at about X 5510, a wide band from X 6400 to 

 X 6630, and a rather narrow band at X 6740. 



At 73 the spectrum is very similar to that at 8. The amount of 

 absorption has, however, increased quite considerably and all the bands 

 have widened. The ultra-violet band has widened to X 3800 and the blue- 

 violet band practically runs from X 4050 to X 5000; although there is some 

 transmission between the bands XX 4610, 4770, and 4980. It will also be 

 noticed that these bands have been slightly shifted towards the red. This 

 shift is quite small, and on account of the haziness of the bands is hard to 

 measure definitely. None of the other bands appear to be shifted. The 

 band at X 5500 has become about twice as wide as it was at the lower tern- 



