34 



Studies on Solution. 



The general character of the absorption curves is the same as that of the 

 ethyl-alcohol solutions. 



The iso-amyl alcohol solutions exhibited the same phenomenon of 

 precipitation upon dilution as has been described in the case of the iso- 

 butyl alcohol solutions. They also had the same appearance in the 

 cells and under the ultra-microscope. 



TABLE 10. Cobalt Chloride in Iso-Amyl Alcohol (Fig. Iff). 



A study was made of the precipitate which was thrown down in these 

 solutions, for the deposit in the case of the iso-amyl alcohol solutions 

 was more abundant than in the case of the deposits in the other cobalt- 

 chloride solutions. The solution was allowed to stand for two weeks 

 and the precipitate filtered off. This precipitate consisted of blue 

 needle crystals mixed with a flocculent scale-like residue. Analysis 

 showed that in this flocculent residue there was present 54 per cent 

 by weight of cobalt chloride ; if this precipitate was a compound of the 

 cobalt chloride and the alcohol, this percentage of the chloride would 

 indicate that the compound contained 2 molecules of the chloride to 

 3 of the alcohol. 



The A c curves for the edge of the yellow-red absorption band, 

 at 714juju and 724/z/z, show that A decreases with dilution. In the region 

 of transparency between the two bands, as shown by the A c curves 

 for 734/^u and 744//^t, the A c curves for the edge of the infra-red 

 band show that A increases very rapidly with dilution. 



