1909] OF VARIOUS SALTS IN SOLUTION. 223 



aluminium chloride. The blue-violet and the yellow bands widen 

 unsymmetrically and the short wave-length edges of these bands 

 apparently moves towards the red at the higher temperatures. 



At 6° the ultra-violet band extends to A 2800, the blue-violet band 

 from A 4000 to A 4400 and the yellow band from A 5600 to A 6100. 

 At 64° the ultra-violet band extends to A 3100, the blue-violet band 

 from A 4000 to A 4600 and the yellow band from A 5650 to A 6300. 

 At 80° the ultra-violet band extends to A 3250, the blue-violet band 

 from A 3950 to A 5000 and the yellow band from A 5700 throughout 

 the red end of the spectrum as far as the film is sensitive. 



(d) Uranyl Chloride {A and B, Plate X.). 



A spectrogram (A, Plate X.) was made of the absorption 

 spectrum of a normal aqueous solution of uranyl chloride, the depth 

 of cell being 3 mm. Exposures were made to the Nernst glower for 

 90 sec, current 0.8 amperes and slit width 0.20 mm. The time of 

 exposure to the spark was 6 min. Starting from the comparison 

 spectrum the temperatures were 6°, 18°, 34°, 52°, 68° and 82°. 



At 8° the ultra-violet band extended to A 3550, the blue-violet 

 band from A 4000 to A 4450. The bands a, b and c appeared, but 

 the a band is very faint. The wave-lengths of the b and c bands 

 were AA4565 and 4725. 



At 82° the ultra-violet band extends to A 3700, and the blue- 

 violet band from A 3950 to A 4600. At this temperature only the b 

 band appears, — a being very weak and c being completely merged 

 into the blue-violet absorption band. The b band is located at 



^4755- 



A spectrogram, B, Plate X., was made of a uranyl chloride 

 water solution 0.0156 normal concentration and a depth of layer of 

 196 mm. Exposures were made to the Nernst gower for 30 sec, 

 current 0.8 amperes and slit width 0.20 mm. No exposures were 

 made to the spark except for comparison spectra. Starting with the 

 numbered scale the temperatures were 6°, 18°, 29°, 44°, 59°, 71° 

 and 79°. 



For this concentration there is a very slight temperature effect. 

 There is a very faint transmission band between the ultra-violet and 

 blue-violet bands. This is extremely faint and is practically un- 



