The Absorption Coefficient of Solution for Monochromatic Radiation. 33 



a colloid condition. They showed slightly a Tyndall cone in blue 

 light. An examination of these freshly filtered iso-butyl alcohol (and 

 also the iso-amyl alcohol) solutions with the ultra-microscope showed 

 that they were not colloidal in nature, but that they contained a 

 number of particles. Whether these particles were newly formed 

 precipitate or some impurity is unknown. 



. 1 1 33//# 

 734 



.194 



CoCI 2 in Iso-butyl alcohol 



800 900 1,000 1,100 1,200 1,300/4^ 



FIG. 9. The A-c and Absorption Curves for Cobalt Chloride in Iso-Butyl Alcohol. 



The A c curves for 734juju and 744/^u wave-lengths lying on the 

 edge of the yellow-red absorption band show again that A decreases 

 rapidly with dilution. For the wave-lengths 754juju and 764^ in the 

 region of transmission A is constant. The behavior of the edge of the 

 infra-red band is similar to the case of the propyl-alcohol solutions, for 

 A increases with dilution, as shown by the rise in the A c curves for 

 wave-lengths l,018;uju to 1,133/zji. 



COBALT CHLORIDE IN ISO-AMYL ALCOHOL. 



Six solutions were prepared varying hi concentration from c = 0.064 

 to c = 0.010. The solutions in the bottles were of a deep blue in the 

 higher concentrations, which changed to a greenish blue upon dilution. 



