82 



ELECTRICAL CONDUCTIVITIES, ETC. 



The salts of calcium, strontium, barium, and magnesium have, in general, coeffi- 

 cients which do not differ widely from 2; although strontium nitrate has a value 

 of only 1.79. It might be mentioned that strontium nitrate crystallizes without 

 water. Zinc acetate also has a small coefficient, 1.59. This may be due to hydroly- 

 sis. Cadmium iodide, which crystallizes without water, has the large coefficient 

 2.27. Manganous sulphate has the rather small value 1.79, and copper sulphate has 

 the same value. Aluminium sulphate has the very low value 1.57, chromium sul- 

 phate 1.61, and uranyl sulphate only 1.29. 



Notwithstanding these apparent exceptions, there is unmistakably this general 

 relation, that the temperature coefficients for V = S and over this temperature 

 range, for a large number of very widely different compounds, are very nearly the 

 same and not widely removed from 2. 



If we examine the other columns of data corresponding to other dilutions and 

 other temperatures, we find relations similar to the above. Thus, for V = 1024, and 

 the temperature range 25 to 35, the average value of the coefficient is a round 2.1. 

 The average value of the coefficients for V = 8, between 50 and 05, is from 1.4 to 

 1.5, while the average value for F = 1024, between 50 and 65, is slightly greater. 



We thus see that change in volume, range of temperature being constant, has very 

 little effect on the temperature coefficients of conductivit}' expressed in per cent. 



The effect of rise in temperature is to decrease the magnitude of these coefficients. 



Temperature Coefficients in Per Cent. 



>-, 



_'o 



to 35 



Substances. 



v = S i y = 1024 



50 to 65 



v=8 



Lithium chloride 



Lithium bromide 



Lithium nitrate 



Lithium sulphate 



Sodium chloride 



Sodium bromide 



Sodium iodide 



Sodium nitrate 



Sodium chloride 



Sodium perchlorate 



Sodium sulphate 



Sodium carbonate 



Sodium ferrocyanide 



Sodium acetate 



Potassium chloride 



Potassium bromide 



Potassium iodide 



Potassium nitrate 



Potassium chlorate 



Potassium sulphate 



Potassium phosphate 



Potassium sodium sulphate. . . . 



Potassium nickel sulphate 



Potassium chromium sulphate . 



Potassium permanganate 



Potassium eliminate 



Potassium bichromate 



Potassium ferrocyanide 



Potassium aluminium sulphate. 



Potassium acetate 



Potassium sulphocyanate 



Ammonium chloride 



Ammonium bromide 



Ammonium nitrate 



2.13 



2.19 

 1.67 

 2.65 

 2.03 

 1.88 

 2.11 

 2.24 

 2.05 

 2.00 

 2.17 

 2.23 

 2.09 

 2.23 

 2.01 

 2.00 

 1.97 

 1.87 

 1.93 

 2.00 

 2.13 

 1.79 

 1.96 

 1.78 

 1.96 

 2.01 

 1.97 

 1.62 

 1.78 

 1.97 

 1.98 

 2.02 

 1.88 

 1.91 



2.15 

 2.13 

 1.98 

 2.24 

 2! 13 



2'l8' 



2.15 



2.13 



2.12 



2.19 



1.51 

 1.49 

 1.94 

 3.00 

 1.51 

 1.44 

 1.52 

 1.43 

 1.62 



?; = 1024 



1.62 



2.50 

 1.77 

 1.54 

 1.54 

 1.67 

 1.54 

 1.78 



2.37 



2.05 

 2.46 

 2.07 

 2.03 

 2.05 

 1.53 

 1.97 

 2.25 

 2.14 

 2.08 

 2.06 

 2.01 

 2.03 

 1.96 

 1.97 

 2.08 

 2.11 

 2.09 

 1.95 

 2.13 

 2.03 

 1.86 



1.58 

 1.59 

 1.42 

 1.61 

 1.37 

 1.35 

 1.46 

 1.40 

 1.40 

 1.35 

 1.61 

 1.44 

 1.25 

 1.33 

 1.44 

 1.35 

 1.37 

 1.36 

 1.06 



1.70 

 1.68 



1.47 

 1.46 



1.35 

 1.40 

 1.49 

 1.48 

 1.56 

 1.51 

 1.48 

 2.27 

 1.22 



1.56 



1.40 

 1.40 

 1.42 

 1.38 



