URANIUM SALTS. 131 



spectra of the anhydrous salt. Uranous acetate in water (Plate 96, B) 

 gives a lot of weak diffuse bands. The bands are located at c, X 4600; 

 d, X 4460; e, 4330; /, X 4200; and g, X 4090. Besides these are broad bands 

 at XX 5050, 5600, 6700, and 6850. 



Absorption Spectrum of Dry Uranous Acetate. 



The green precipitate that is formed when a solution of uranous ace- 

 tate in methyl alcohol stands for several hours was illuminated by light 

 from the Nernst glower; the illuminated salt being over the slit of the 

 spectroscope. The green salt changed to a dark color probably due to 

 oxidation. 



The absorption spectra showed weak diffuse bands at XX 4240, 4350, 

 4500, 4650, and a wide band running from X 4900 to X 5200. If these bands 

 are to be identified as the/ (X 4240), e (X 4350), d (X 4500) and the c (X 4650) 

 bands; and their relative intensities are about the same as that of the 

 bands of uranous acetate in methyl alcohol; then the bands are slightly 

 shifted towards the red, this shift being about 50 Angstrom units. 



Uranous Acetate in Methyl Alcohol and Acetic Acid. 



To a solution of uranyl acetate in methyl alcohol was added glacial 

 acetic acid and some metallic zinc. The solution becomes green in color 

 after standing a few minutes. In an hour or more a greenish precipitate 

 is formed, and after standing several hours the solution shows only the 

 uranyl bands. The plate represents the absorption spectra of the green 

 uranous acetate. The only variation here is the depth of cell. For the 

 three strips nearest the top the depth of cell was the same. 



Starting in the ultra-violet the spectrogram shows a general absorp- 

 tion which extends into the blue for the greater depth of layer. No indica- 

 tion of the blue-violet uranyl band is to be noticed. Several fine bands 

 appear in the blue-violet region. As these coincide very closely in position 

 with the uranyl acetate bands they will be so considered. Of these the 

 a, b, c, d, e, f, and g bands appear. The g band (X 4070) is very faint 

 The / band (X 4200) is stronger and is about 30 Angstrom units wide. The 

 c, d, e, and / bands appear quite strong; the e band being the strongest. 

 It appears to be complex, being composed of a fuzzy band at X 4285 about 

 10 Angstrom units wide; a fine sharp band at X 4310 about 3 Angstrom 

 units wide, and a band extending roughly from {* ^1} to X 4340. The 

 d and c bands (XX 4470 and 4610) are about 30 Angstrom units wide and of 

 about equal intensity. The a and b bands are very weak (XX 4910, 4740) 

 and only appear on the original negative. 



The a band with two other very diffuse bands XX 5000, 5100 form the 

 wide absorption band in this region and practically merge into each other. 

 A similar band extends from X 5550 to X 5650. In the red there are quite 

 a number of fine bands very similar to the uranyl group in the blue and 

 violet. These are very faint; the widest and strongest appearing at X 6450; 

 this band being about 40 Angstrom units wide. The other bands are about 

 20 Angstrom units wide and are located approximately at XX 6600, 6700, 

 6800, 6870, and 6920. 



