MR W. R. BOUSFIELD AND DR. T. M. LOWRY ON THE ELECTRICAL 



EXPERIMENTAL METHODS. 



(1.) The Glass Vessels. In measuring the temperature coefficients of conductivity 

 the two chief difficulties were (1) the exact regulation of the temperature in the 

 higher ranges, and (2) the fouling of the solutions by the action of the glass of the 

 condxictivity vessels. The earlier observations were made in glass vessels of the form 

 shown in fig. 7 ; the resistance capacity, which was dependent upon the length and 

 diameter of the U-tube between the electrodes, was measured with the help of the 



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Fig. 7. Fig. 8. Fig. 9. 



standard solutions recommended by KOHLRAUSCH, HOLBORN and DIESSELHORST 

 (' Wied. Ann.,' vol. 64, pp. 440 and 451, 1898); the capacities of the vessels used 

 were as follows : L 2 , 2'156 cm.- 1 ; L 4 , 4'125 cm." 1 ; L 18 , 13'36 cm.- 1 ; L M , 5473 cm.- 1 ; 

 L 162 , 162'62 cm."" 1 . For the lower capacities the U-vessel was modified, as shown in 

 fig. 8 ; a vessel of this type was used for the more dilute solutions and had the 

 capacity N . 1( 0-1236 cm." 1 . 



(2.) Adjustment of Temperature. These glass vessels were placed in a large 

 water bath, holding about 100 Ibs. of water, and the conductivity was measured at 



