36 THE ABSORPTION SPECTRA OF SOLUTIONS. 



that the bands at X 4270 and X 4295 are relatively stronger than usual. The 

 appearance of these two bands suggests that the precipitate is largely the 

 hydrate of neodymium chloride, the band X4270 being a water band, and 

 the band X4295 being an alcohol band. 



Neodymium Chloride in Propyl Alcohol. 



The only spectrogram of the absorption spectra of neodymium chloride 

 in propyl alcohol that is reproduced is that of A, plate 7. 



The a group is composed of the following bands : X 3445, a rather sharp 

 band about 4 Angstrom units in width; X 3460, about 10 Angstrom units in 

 width; X 3490 of about the same intensity and width as X 3460; X 3510 very 

 weak; X 3525 about 4 Angstrom units wide and quite strong; X 3540 quite 

 strong and narrow, this band almost running into the more diffuse band at 

 X 3560; a very weak band appears at about X 3580. The /3 group is quite 

 characteristic of the solvent, consisting of a very weak band at about X 4270, 

 a band at X 4285 about 10 Angstrom units wide, and a much wider and weak 

 band at about X 4330; a wide and weak band appears at X 4450. The y group 

 consists of a very weak and diffuse band at X 4600, and other bands at X 4700, 

 X4770, and X 4830. The <5 group consists of two wide and diffuse bands at 

 X 5130 and X 5180, the latter being very weak; and finer bands at X 5220, 

 X 5230, X 5250, X 5290 and a very weak band at X 5330. The e group consists 

 of the four bands X 5740, X 5780, X 5810, and X 5850, all being of about the 

 same width, the latter two being considerably the stronger. There are other 

 bands in the red region, but only X 6880 is at all strong. 



Neodymium Chloride in Isopropyl Alcohol. 



A, plate 6, gives the absorption spectrum of neodymium chloride in iso- 

 propyl alcohol. The finer structure of the different groups of bands is quite 

 different from that of the propyl alcohol spectrum. 



The a group of this alcohol is very simple, showing only three hazy bands, 

 at X 3460, X 3510, and X 3535, the middle band being much the weaker. Only 

 a single band of the 13 group shows, X 4265. Other bands appear at X 4420, 

 X4600 very diffuse, X4690 and X4730. 



The 8 group consists of X5100 and X5320. These bands are quite wide 

 and diffuse. On account of the plate not being properly developed the bands 

 do not show as much detail as they probably would under more favorable 

 conditions. Even this plate shows the finer bands slightly. 



The e group consists of a broad diffuse band at X 5720 and two much 

 stronger bands at X 5780 and X 5810. 



Neodymium Chloride in Butyl Alcohol. 



The absorption spectrum of neodymium chloride in butyl alcohol is given 

 in plate 5, A . Starting with the ultra-violet, we have X 3450 very sharp and 

 narrow; X 3460 weak; X 3492 somewhat diffuse; X 3535 very sharp and narrow; 

 X 3545, X 3560 very diffuse. The bands XX 4265, 4285, and 4300 are weak and 

 of approximately the same intensity, the band X 4265 being slightly narrower 

 than the other two. These bands differ not only in relative intensity from 

 the water bands but also in wave-length, band X 4265 being of shorter wave- 

 length and the band X 4300 of greater wave-length than the water bands. 



