Manchester Memoirs, Vol. IX. (No. 9). Plate II. 



Fig. I showing widening absorption 

 towards one side of spectrum on increased 

 exposure. 



I I 



mum m 



Fig. 2 showing absorption of dye 

 in three distinct bands. 



Fig. 3 showing absorption of blue- 

 green dye bleaching chiefly in its less 

 intense (violet) absorption band. 



