32 



Studies on Solution. 



curve (and the A c curves for 1,056/j/* and 1,095/jju) have been plotted 

 on a scale of ordinates one-tenth as great as the other A c curves. 

 For wave-lengths in the region of low absorption, 764juju to 842/jju, A is 

 approximately constant, although in this region the values of a are so 

 small that the values of A are liable to considerable inaccuracy. The 

 A c curves for wave-lengths 920/1/1 to 1,095/zju, on the edge of the 

 infra-red band, show that A increases rapidly with dilution. 



COBALT CHLORIDE IN ISO-BUTYL ALCOHOL. 



Four solutions were prepared varying in concentration from c = 0.194 

 to c = 0.05. The absorption curves have the same character as those 

 for the ethyl-alcohol solutions and the color of the solutions in the 

 bottles was the same, being a deep blue which changed to a greenish 



TABLE 9. Cobalt Chloride in Iso-butyl Alcohol (Fig. 9). 



blue upon dilution. In preparing the solutions the usual procedure 

 was followed, namely, to make the dilutions by adding pure alcohol 

 to the saturated mother solution. It was found that a precipitate 

 appeared immediately upon dilution. The solutions were then 

 filtered and the concentrations were measured by a determination of 

 the density. The value of the concentration determined in this way 

 was found to agree within the error of experiment with the concentra- 

 tion calculated from the known amount of dilution. This showed that 

 the loss by precipitation was either negligible or that the precipitate 

 contained nearly equal parts of cobalt chloride and iso-butyl alcohol. 

 The filtered solutions appeared quite free from any visible particles. 

 In the cells they had a somewhat cloudy appearance, suggestive of 



