and the absorption spectra, of various permanganates. 249 



The other bands were too faint to make any exact observations of 



them, 



I. 



tSolutions of the permanganates of barium and potassium 



were made and allowed to stand for two days in the full glare 



of a well lighted room. They were then examined; and the 



5 solutions showed the well known permanganate tint ; whilst the 



154 solutions were pink, and the 310 solutions were yellowish 



brown. 



A. Barium permanganate l ,r-^ i 4.- 

 ■p, , . ' ] ° ^154 solutions, 



rotassium do. J 



do. do. 5 solutions. 



Band 1 was narrower in the 154 solutions than in the 

 5 solutions ; band 2 was also narrower, and the differences were 

 well marked ; band 3 was also narrower but the difference was 

 not so marked as in band 2, whilst bands 4 and 5 were a little 

 wider in the 154 solutions than in the 5 solutions. Also the 

 general absoi-ption was much greater in the 154 solutions; and the 

 position of the bands in the 5 solutions was more towards the red 

 end of the spectrum than in the 154 solutions. 



Barium permanganate "1 o,^ , ,. 



Potassium do. J ' 



do. do. 5 solutions. 



Bands 1, 2 and 3 were narrower in the 310 solutions, and 

 these differences were more marked than in the corresponding 

 bands of the 154 solutions ; and the bands 4 and 5 were also much 

 wider than the corresponding bands of the 5 and 154 solutions. 

 Also the general absorption had greatly increased, and it was 

 greater in the 310 solutions than in the 154 solutions. The 

 position of the bands in the 5 solutions was also more towards 

 the red end of the spectrum : the difference in this respect was 

 more marked when compared with the 810 solutions than with the 

 154 solutions. 



B. The solutions were allowed to stand two days longer 

 and they were again examined. In the 154 solutions the general 

 phenomena were very like those observed before, except that 

 the general absorption had slightly increased. In the 310 

 solutions the general absorption had also slightly increased, and 

 the differences in the width of the bands 2 and 3 were much more 

 marked. 



C. The solutions then stood for three weeks and they were 

 again examined. The 154 s(jlution of barium permanganate was 

 a reddish brown colour ; the bands 1, 2 and 3 were much narrower 

 than the corresponding bands in the 5 solution, and the bands 



17—2 



