224 JONES-STRONG— THE ABSORPTION SPECTRA [April 24. 



affected by temperature. The blue-violet band widened slightly 

 with rise in temperature. The uranyl bands in the concentrated 

 solution were much stronger and wider than in the dilute solution. 



(e) Neodymium Salts. 



A spectrogram (A, Plate XL) of the absorption spectrum as 

 affected by change of temperature was made of neodymium chloride 

 solution in water, the concentration being 3.4 normal and the depth 

 of layer 12 mm. The length of exposure was 2 min. to the Nernst 

 glower, current 0.8 amperes ; slit width .20 mm. The time of ex- 

 posure to the spark was 6 min. Starting with the strip nearest the 

 numbered scale the temperatures were 11°, 22°, 33°, 45°, 59°, 73° 

 and 85°. 



An absorption band appears at about X 2970 for the 11° tempera- 

 ture, a very strong band from X3250 to A 3285 and an adjacent 

 band from A 3285 to A 3310. At 11° a very narrow and feeble 

 transmission band separates these two bands. At 85° the trans- 

 mission band has weakened very much. At 11° a very strong 

 band lies between A 3490 and A 3580. The band A 4274 is about 8 

 Angstrom units wide. An extremely narrow band appears at A 4297, 

 A 4306 and A 4324. At A 4234 is a wider and rather diffuse band, it 

 being about 12 Angstrom units wide. Bands at 11° lie between 

 AA4415 and 4470, AA4580 and 4650, AA4665 and 4710, AA4740 and 

 4775, AA4815 and 4835, and the very wide bands AA5010 and 5300 

 and AA5665 and 5935. Weak bands are located at A 4645, A 4800, 

 A 5320, A 6235, A 6255, A 6280, A 6305 and A 6380. Rather diffuse 

 bands appear at AA6780 and 6840, at A 6850 and from A 6870 to 

 A 6920. 



The effect of rise of temperature from 11° to 85° is quite 

 noticeable, although it is not great. In the ultra-violet there is a 

 slight increase in the general absorption. The band AA3285 and 

 3310 widens slightly. The band AA 3490-3580 at 11° has widened 

 so that at 85° it extends from A 3450 to A 3600. The band at AA4415 

 and 4470 has widened but little. The group of bands from A 4600 

 to A 4800 have also widened but little. The faint diffuse bands 

 AA4645 and 4800 have practically disappeared. The bands AA5010 

 and 5300 and AA5665 and 5935 at 11° have widened at 85° to 



