The Absorption Coefficient of Solution for Monochromatic Radiation. 69 



and 783jUMi the region on the long wave-length edge of the green absorp- 

 tion band, show that A is a constant with respect to c for concentra- 

 tions greater than c = 0.05. The increase observed in A for solutions 

 of lower concentration than this is very probably due to the effect of 

 decomposition. 



TABLE 29. Potassium Permanganate in Water (Fig. 25}. 



CONCLUSION. 



The relation between A, the molecular light-absorption coefficient of 

 the solution, defined by formula 2, and c, the concentration of the 

 solution in gram-molecules of salt per liter of solution, has been deter- 

 mined. It has been found that in general A is not a constant. In 

 certain cases A decreases with dilution, in other cases A increases with 

 dilution, and still other cases as dilution proceeds A decreases to a 

 minimum, and then increases again. Another possible combination, 

 namely, that A should increase to a maximum and then decrease, was 

 not met with. The deviations from a constant value observed in A 

 were usually comparatively small, except at certain points in the 



