MAPPING ABSORPTION SPECTRA OF VARIOUS SALTS. 39 



appear at X 4420, X 4690, X 4730, and X 4820. The other bands are at X 5090, 

 X 5220, X 5710, X 5800, and X 5930. 



The absorption spectrum of neodymium nitrate in butyl alcohol resembles 

 very closely the spectrum in isopropyl alcohol, but is quite different from 

 the spectrum in isobutyl alcohol. 



Neodymium Nitrate in Isobutyl Alcohol. 



The absorption spectrum of neodymium nitrate in isobutyl alcohol is 

 similar to that of the chloride in the same alcohol. The bands in some cases 

 are not so wide, but they are all quite weak when they first appear in the spec- 

 trum. The ultra-violet absorption was so great that in the plate taken the 

 a group does not appear at all. At X 4285 appears a weak double band about 

 15 Angstrom units wide. These bands are so close to one another that it 

 is difficult to be certain that they are separate bands. There are also very 

 weak bands at X 4305 and X 4325. The /5 group of the chloride in isobutyl 

 alcohol is very different in its structure from that of the /3 group of the 

 nitrate. A very weak band appears at X 4450 and X 4600, which is about 80 

 Angstrom units wide. The y group consists of weak bands, each about 20 

 Angstrom units in width at XX 4715, 4750, 4770, and 4850. The 8 group con- 

 sists of the wide and very hazy band at X 5120, two comparatively weak bands 

 at X5215 and X5230, and three strong bands that practically merge into each 

 other at X 5245, X 5255, and X 5275. The e group forms a single wide band 

 extending from X 5730 to X 5900. Very hazy and weak bands appear at 

 X 6000, X 6050, and about X 6800. 



The composition of the various groups of the nitrate isobutyl bands is 

 quite different from the chloride bands. This is a general phenomenon, the 

 nitrate bands, in general, being quite different from the chloride and bromide 

 bands in the same solvent. 



Neodymium Nitrate in Acetone. 



The absorption spectrum of neodymium nitrate in acetone also consists 



of wide, diffuse, and weak bands. The ultra-violet absorption is large. 



The following bands appear: X 4285 very weak, X 5130, X 5250, X 5750 



and X 5840. 



Neodymium Nitrate in Ethyl Ester. 



The absorption spectrum of neodymium nitrate in ethyl ester is given 

 in A and B, plate 12, and B, plate 10. The absorption bands of this spectrum 

 are in general quite diffuse. The a group consists of three hazy bands, the 

 middle one being much the weakest at XX 3455, 3500, and 3540. The /3 group 

 consists of a single band about 15 or 20 Angstrom units wide at about X 4270. 

 The bands at X 4440 and X 4600 are very broad and weak. The y group is 

 quite different from the y group of other solvents, in that the bands are not 

 even approximately of the same intensity or at equal distances from each 

 other, being at about X 4710, X 4730, and X 4830. The 8 group consisted of 

 X 5120, X 5210, X 5240, and X 5260. The e group consists of XX 5700, 5750, 

 5780, and 5810. These bands are very diffuse, about 20 Angstrom units wide, 

 and the latter two are much the stronger. A band also appears at X 5980. 



The absorption spectrum of neodymium nitrate in methyl ester is identical 

 with that in ethyl ester. 



