WORK OF II. R. KREIDER. 



97 



tration at t han at 25. In a few cases the maxima occur at the same concentration 

 at both temperatures. In nearly every case where there is a maximum there is a 

 slight decrease in conductivity, then a rapid increase as dilution increases, thus 

 giving an inflection in the curve. 



Conductivity of potassium iodide in mixtures 

 of ethyl alcohol and water at 0. 



25 50 75 



Per cent, of ethyl alcohol 



Figs. 33 to 36 give the curves for the conductivities of potassium iodide in mixtures 

 of methyl alcohol and water and of ethyl alcohol and water. The abscissse represent 

 the percentage of alcohol and the ordinates the conductivity. In fig. 33 there is a 

 marked minimum with 50 per cent methyl alcohol. Fig. 34 shows a minimum with 

 75 per cent methyl alcohol. Fig. 35 for potassium iodide in methyl alcohol-water 

 mixtures shows the same characteristics. Fig. 36 shows a minimum for only three 

 concentrations; these are with 75 per cent ethyl alcohol. 



Figs. 37 to 40 are the curves for the conductivity of cobalt chloride in methyl alcohol- 

 water mixtures and ethyl alcohol-water mixtures at both and 25. Fig. 37 shows 

 a minimum with 50 per cent methyl alcohol. Fig. 38 shows minima in the curves 

 with 75 per cent ethyl alcohol. In figs. 39 and 40 there is no minimum. 



Tables 67 and 68 represent the values for the conductivities of potassium iodide 

 and cobalt chloride in mixed solvents, arranged according to temperature. The pro- 

 portions in which the solvents are mixed and the concentrations vary. A study of 

 the maxima of conductivity in these tables is interesting. The more probable values 

 for jUoo are indicated by an asterisk (*). By means of these values we have calculated 



