Phil. Mag. S. 5. Vol. 10. PL V 



Theoretical 

 limit of pris- 

 matic spec- 

 trum. 



Plate showing reversing actions of Iodides, Bromides, and oxidizing 

 agents on Agl. 



N.B. — The curves below the line show the reversals or positive images ; 

 the curves above the line show the ordinary action, or negative images ; 

 the ordinates approximately represent the amount of action. 



