COBALT CHLORIDE. 



139 



Tables 69 and 70 (figs. 60 and 61), for lithium bromide in mixtures of 

 acetone and ethyl alcohol, show the same characteristics as were observed 

 in the tables for this salt in mixtures of acetone and methyl alcohol. The 

 values for //, in acetone are greater than the corresponding values in the pure 

 ethyl alcohol at practically all dilutions. 



CONDUCTIVITY AND VISCOSITY OF CERTAIN SALTS. 



The temperature coefficients increase slightly with the increase in dilution. 

 The values are highest in ethyl alcohol, from which there is a regular grada- 

 tion to the values of pure acetone. 



100* 



Percentage of Acetone 



FIG. 58. CONDUCTIVITY OF LITHIUM: BROMIDE IN MIXTURES 

 OF ACETONE AND METHYL ALCOHOL AT 0. 



COBALT CHLORIDE. 



The cobalt chloride used in this work was obtained from Kahlbaum. No 

 appreciable impurity could be detected. This salt can not be dehydrated in 

 contact with the air, and special precautions must be taken to prevent the 

 formation of the oxychloride. The salt containing 6 molecules of water 

 was first placed over concentrated sulphuric acid, in a vacuum desiccator, for 

 several days. It was thus deprived of part of its water of crystallization. It 

 was then placed in an air-bath and dried at 140 to 150, in a stream of dry 

 hydrochloric acid gas. The salt was subsequently kept in a vacuum desic- 

 cator over sulphuric acid and potassium hydroxide. It gave no test for free 

 hydrochloric acid, and possessed a pale, sky-blue color. 



