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LIX. The Absorption Spectra of certain Uranous and Uranyl 

 Compounds. By Hakry 0. Jones and W. W. Strong *. 



[This is part of an investigation that is being- carried out with the aid 

 of a Urant from the Carnegie Institution of Washington.] 



(Twenty-ninth Communication.) 



SEVERAL investigators have already studied the uranyl 

 bands, but only Deussen j" and the authors % have 

 noticed the marked changes in the frequencies of the uranyl 

 bands when the solvent in which the uranyl salt was dissolved 

 is changed. No one, so far as we know, has hitherto 

 observed the gradual change in the uranyl bands when one 

 uranyl or uranous salt is changed into another salt. Prac- 

 tically no work § has been done on the absorption spectra of 

 uranous salts, and very little upon "solvent" bands. Jones 

 and Anderson || have shown that neodymium possesses 

 "water"" and "alcohol" absorption bands when the salt is 

 dissolved in mixtures of water and alcohol. The " water " 

 bands gradually decrease in intensity as the amount of water 

 is decreased, while the " alcohol " bands increase in intensity. 

 The frequencies of the" water " and the "alcohol" bands 

 were found to remain constant and both sets of bands may 

 appear in the same solution. 



The purpose of the present investigation was to photograph 

 the absorption spectra of uranous and uranyl salts dissolved 

 in different pure solvents ; to find the relationship between 

 the uranous and the uranyl bands of the same salt in 

 different solvents by changing the solvent ; to find the 

 relationship between the uranous and uranyl bands of 

 different salts by changing the acid radical of the salt, and to 

 find the effect of the presence of acids and foreign salts upon 

 the bands. 



The general method of preparing the solutions of the 

 uranous salts was to add a little acid (corresponding to the 

 anion of the salt) and zinc to a solution of the uranyl salt. 

 The nascent hydrogen reduced the yellow uranyl salt to the 

 very green uranous salt. Mo^t of the uranous salts keep for 

 a very long time when not exposed to the air. Uranous 

 bromide and uranous chloride are stable in all the solvents 



* Communicated bv the Authors. 



t Wied. Ann. lxvi. p. 1128 (1898). 



X Phys. Ze.it. x. p. 499 (1909). 



§ Formanek, ' Die qualitative Spectralanalyse anorganischer Korper,' 

 Berlin, 1900. 



|| Phys. b'ev. xxvi. p. 520 (1908). Carnegie Institution of Washington, 

 Publication 110. 



