﻿740 Prof. H. (J. Jones on Absorption Spectra 



If we compare carefully the spectra of neodymium chloride 

 in butyl and isobutyl alcohols, we find that the bands are weak 

 and diffuse in isobutyl alcohol, and have different relative in- 

 tensities from what they have in the butyl alcohol. The bands 

 in butyl alcohol are very much finer and sharper than they 

 are in isobutyl alcohol. Further, the bands of neodymium 

 chloiide in isobutyl alcohol have slightly greater wave-lengths 

 than in butyl alcohol. 



To eliminate the possibility of the effect of the solvent on 

 absorption spectra being due to anything inherent in the 

 nature of neodymium chloride, the nitrate of neodymium was 

 studied in the same way as the chloride. 



The absorption spectra of neodymium nitrate in water, in 

 methyl alcohol, in ethyl alcohol, in mixtures of these alcohols 

 and water, in propyl and isopropyl alcohols, in butyl and 

 isobutyl alcohols, in acetone and in mixtures of acetone 

 and water, in ethyl ester and in formamide, were carefully 

 photographed and studied. Results will be given in the case 

 of neodymium nitrate only for the a bands. 



ex. Bands. 



In water. Practically the same as the bands of neodymium 

 chloride, but the bands of the nitrate are broader and 

 hazier than those of the chloride. 



In methyl and ethyl alcohol. There are only two bands in 

 the a group, A, 3165 and X3545. 



In propyl alcohol. W 3455, 3500, and 3585. 



In isopropyl alcohol. Xk 3460, 3505, and 3535. 



In butyl alcohol. AX 3450, 3500, and 3540. 



In isobutyl alcohol. Ultra-violet absorption was so great that 

 on the plate taken the a group did not appear. The 

 absorption in general is the same as that of the chloride 

 in this alcohol. 



In acetone. \\ 3475 and 3555. 



In ethyl ester. W 3455, 3500, and 3540. 



The other groups of absorption bands of neodymium nitrate 

 in the different solvents show differences in the wave-lengths 

 comparable with the above; but these results suffice to show 

 the effect of the solvent on the power of neodymium nitrate 

 to absorb light. 



The above evidence that the solvent plays an important 

 part in the absorption of light by substances "dissolved in it is 

 strong. When we take into account the number of salts 

 studied and the number of solvents employed, the evidence 



