210 JONES-STRONG— THE ABSORPTION SPECTRA [April 24, 



characteristics, but when proper concentrations are used so as to 

 bring out the fine bands it is found that the two spectra are entirely 

 different. For example,- the aqueous solution shows a very fine 

 band at A 4274. In the glycerol there is a band that on first sight 

 appears exactly identical with this 4274 band. However, its wave- 

 length is about A 4287, and it has two extremely fine components on 

 each side, one at A 4273 and one at about A 4300. The same is true 

 throughout the spectrum. 



In general, in mixtures of water and glycerol the appearances 

 indicate that there are " glycerol " bands and " water " bands and 

 as the amount of one solvent is increased, so are the bands cor- 

 responding to this solvent increased in intensity. Herein lies a very 

 large field for investigation and considerably more work is being 

 carried on here along these lines. The above described spectrum 

 of the glycerol solution of neodymium indicates that glycerol has a 

 a very great influence upon the vibrations of the electrons within 

 the neodymium atom — and that this is due to a kind of "atmos- 

 phere " of glycerol about the neodymium atom. Jones and Ander- 

 son showed that alcohol has a similar effect, and that the " alcohol " 

 bands were much less persistent than the water bands. Further 

 work is being done upon the relative persistence of " water," " alco- 

 hol " and "glycerol" bands; also on the effects of foreign sub- 

 stances and rise of temperature upon these bands, both in the pure 

 solvent and for mixtures of solvents. 



VI. Absorption Spectrum of Uranyl Chloride. 



The absorption spectrum of uranyl chloride was mapped for an 



aqueous solution, a methyl alcohol solution, an ethyl alcohol solution, 



a mixture of methyl alcohol and water, a mixture of methyl alcohol 



and calcium chloride, and a mixture of water and aluminium chloride. 



(o) The Absorption Spectrum of Uranyl Chloride in Water. 



The absorption spectrum of uranyl chloride in water was found 

 to be very similar in general to that of the other uranyl salts. The 

 uranyl bands were less sharp than the bands of the nitrate and sul- 

 phate in water. The wave-lengths of a few of the bands are as 

 follows : 



