and the absorption spectra of various permangoAiates. 251 



The change in colour was accompanied by some changes in 

 the appearance of the absorption bands. There appeared to be 

 little or no change in the band 1 ; band 2 was not so wide in the 

 dilute solutions ; and similarly in band 3, although the difference 

 was not so well marked as in band 2 ; whilst in bands 4 and 5 

 there was little or no difference in the solutions. Besides 

 alterations in the bands, there was much more general absorption 

 in the 154 solutions. 



E. Barium permanganate "I ^i q i ^• 

 Potassium do. / 



do. do. 5 solutions. 



Band 1 in the 310 solutions was a shade narrower than the 

 corresponding band in the stronger solutions: the width of band 2 

 was much less in the 310 solutions (cf. the 154 solutions): band 3 

 had also decreased in width but the difference was not so marked 

 as in band 2 ; band 4 was also very slightly decreased in width : 

 whilst band 5 did not appear to have decreased, although there 

 was a slight difference in the intensity. 



Also, there was much more general absorption in the 310 

 solutions. Besides these changes, the position of the bands 1 

 and 2, and in a less degree, band 3, is not so far towards the 

 red end as in the 5 solution, and the same remark applies to 

 bands 4 and 5 although the difference is not so marked. 



The above solutions stood two days longer in the dark, and 

 they were again examined. 



The colours of the 154 solutions were of a rose red tint — they 

 were not so brown as the solutions made two days earlier and 

 kept in the light ; whilst the 310 solutions were yellow brown. 



G. Barium permanganate | ^^^ ^^^^^.^^^ 

 rotassium do. J 



do. do. 5 solutions. 



There appeared to be little or no change in band 1 in all the 

 solutions; band 2 was much narrower in the 154 solutions; 

 band 3 in the 154 solutions was also narrower than in the 

 5 solution, but the difference was not so marked as in band 2 ; 

 bands 4 and 5 did not show a marked difference, although they 

 appeared to be a shade wider in the 154 solutions. 



There was more general absorption in the 154 solutions, and it 

 had increased a little since the observations of two days ago. 



H. Barium permanganate 1 q^ ^ , ,. 

 Potassium do. J 



do. do. 5 solutions. 



Band 1 was not quite so wide in the 310 solutions as in the 



