284 JONES AND ANDERSON— ABSORPTION SPECTRA OF [April 25, 



A 4290, about 10 A. U. wide and only moderately intense. At A 4325 

 a band somewhat wider and fainter. At X 4460, a rather wide hazy 

 band with a faint hazy companion towards the violet. This is the 

 band which is perhaps due to praseodymium. The much greater 

 concentration of the alcoholic solutions of praseodymium chloride 

 studied in this work, makes it impossible to verify this by seeing 

 whether the praseodymium band in dilute solution really has this 

 general character. 



There are bands at A 4700, A 4780 and A 4825, all of about the 

 same intensity ; the one at A 4770 being, however, much narrower 

 than the other two, of which A 4825 is somewhat the wider. Both 

 A 4700 and A 4780 have faint companions to the violet. 



The group in the green is made up of six bands as follows: 

 A 5125 hazy and rather wide, moderately intense; A 5180, also hazy 

 but much fainter ; A 5220 moderately intense and narrow ; A 5245 

 intense and with faint companion towards the red ; A 5290 narrow 

 and moderately intense. Shading as far as A 5330 with indications 

 of faint band at A 5315. 



The yellow group is made up of seven bands having the fol- 

 lowing characteristics : A 5725 moderately intense with hazy edges ; 

 A 5765 narrower, but not quite as intense as A 5725 ; A 5800 fairly 

 narrow, strong ; A 5835 very intense ; A 5860 hazy and moderately 

 intense ; not clearly separated from A 5835 shading to A 5970, with 

 two faint bands superposed on it, one at A 5895 and the other at 



A 5925- 



No trace of bands is to be seen in the orange, but in the red 

 there is a fairly narrow but faint band at A 6860. The spectrum 

 ends at A 7355 in a deep, rather narrow band. It is evident that 

 the spectrum of neodymium chloride when dissolved in methyl alco- 

 hol is quite different from its spectrum in aqueous solution. 



Neodymium Chix)ride in Mixtures of Methyl Alcohol and 

 Water. (See plates 3 and 4.) 

 Since, as we have just seen, the absorption spectrum of neody- 

 mium chloride in aqueous solution is so different from that of the 

 alcoholic solutions, it was thought to be of some interest to see how 

 the change from one to the other would take place if one of the 



