1909.] OF VARIOUS SALTS IN SOLUllON. 229 



tensity with rise in temperature, and at present no shift has been 

 detected. When calcium chloride is added to the solution most of 

 the bands decrease in intensity with rise in temperature and several 

 are shifted towards the red at the same time. Several bands dis- 

 appear. Moreover, the band AA6800 to 6900, although it widens, 

 this widening is entirely on the red side, whereas for the pure 

 neodymium chloride solution this widening always takes place on 

 both sides of the band. 



A spectrogram (B, Plate XIII.) was made to show the effect of 

 change in temperature upon a 2.15 normal aqueous solution of 

 neodymium nitrate. The length of layer was 3 mm. The exposures 

 were for 40 sec. to the Nernst glower, current 0.8 amperes, slit 

 width .20 mm. The length of exposure to the spark was 6 mins. 

 Starting with the strip nearest the comparison spark the tempera- 

 tures were 4°, 17°, 29°, 43°, 58°, 71° and 84°. 



The changes in the spectrum due to this change in temperature 

 of 80° was very slight. The NO3 band extends to about A 3250 at 

 4°, and to about A 3280 at 84°. The bands at A 3500 became con- 

 siderably wider and their edges more diffuse at the higher tempera- 

 tures. At the lower temperatures fine bands appear at AA5210, 5225 

 and 5240. At 84° these bands all merge into a single band. The 

 red band extends from A 5705 to 5860 at 4°. The band at A 5820 is 

 very faint at the lower temperatures. At 84° it is unrecognizable, 

 At this temperature the red band extends from A 5700 to A 5880. 

 The widening of this band for the concentrated solution is somewhat 

 greater than for the dilute solution, but the effect of concentration 

 is very slight. This is to be expected since the effect of temperature 

 itself is so very minute. 



A spectrogram (A, Plate XIV.) was made of an aqueous solu- 

 tion of neodymium bromide 1.66 normal concentration and 54.6 mm. 

 depth of cell. The exposures were 3 mins. to the Nernst glower and 

 6 mins. to the spark. The current in the Nernst glower was 0.8 

 amperes and the slit width 0.20 mm. Starting with the strip nearest 

 the comparison scale the temperatures were 6°, 20°, 33°, 47°, 62°, 

 73° and 82°. 



The effect of rise in temperature upon the absorption spectra 

 of this salt was quite marked ; practically all of the bands broaden- 



