The Absorption Coefficient of Solution for Monochromatic Radiation. 47 



.OIOO_ 



.5 1.0 1.5 C 2.0 



FIG. 15. The A-c Curves for Cobalt Sulphate in Water. 



NICKEL CHLORIDE IN WATER. 



Nineteen solutions were prepared, varying in concentration from 

 c = 3.945 to c = 0.05. The absorption curves cover the region from 

 550/jju to 1,150/z/z. In this region the water solutions of nickel chloride 

 have an absorption band in the red with its maximum at 744/z^u, a region 

 of transmission with minimum absorption at about 880/z/i, and absorp- 

 tion again beyond this. 



The A c curves show that the values of A undergo changes with c 

 depending upon the wave-length. For wave-lengths 565/iju and 605^/z, 

 which lie nearly in the region of green transmission, A is a constant for 

 all concentrations. For wave-lengths 645/^u and 684^, which are on 

 the short-wave side of the red absorption band, A increases with dilu- 

 tion. At the top of the band, at 724/J./J,, A is again constant. For 

 wave-lengths 803/zjit to 920^, which lie on the long-wave side, the red 

 absorption band decreases with dilution. The result of these changes 

 is to shift the band as a whole towards the blue with dilution. The 



