212 Conductivity of Aqueous Solutions. Part VII. 



five experiments at 302 (see table 76, experiments 10 a -10 e) the con- 

 ductance-capacity had decreased by 0.65 per cent. A comparison Df the 

 initial data at 18 of these five experiments showed that three-fourths of 

 this change took place at the first heating to 302, which was made for 

 the purpose of steaming out the bomb. The remaining 0.2 per cent 

 change was therefore distributed equally over the five experiments. 



Just before March 2, 1906, the lower electrode was removed, replaced, 

 and replatinized, the conductance-capacity being thereby changed. The 

 succeeding determinations show that it remained constant at the new 

 value. The last two determinations of February 12, 1906, in table 73, 

 were made with only 60 c.cm. of solution in the bomb. The conductance- 

 capacity was increased 0.45 per cent by this change in the depth of the 

 solution; it was found independent of the depth when the volume of the 

 solution exceeded 85 c.cm. (See section 78). 



The electrode of bomb No. 3 was replatinized after the experiment 

 of June 20, 1906, and was removed, replaced, and replatinized before the 

 experiment of June 28, the conductance-capacity being changed slightly 

 each time. On July 3, the cylindrical electrode was removed, and a 

 quartz cup put in, for work with the stronger ammonium chloride and 

 sodium acetate solutions. 



82. THE CONDUCTIVITY DATA. 



In the following tables are recorded the data actually observed,* which 

 form the basis of subsequent theoretical calculations. For convenience 

 there are also included in these tables the corrections for impurities in the 

 water, and for the residual hydrolysis or for the added base or acid in 

 the case of ammonium chloride and sodium acetate, which corrections 

 were discussed in section 78. 



The first column gives the date of the experiment. The second gives 

 the number of the experiment ; the figure before the decimal point is the 

 number of the stock solution, that after the decimal point the number 

 of the dilute solution prepared from the stronger one; successive runs 

 with the same solution are designated by appending the letters a, b, etc. 

 In the next column or columns is given the concentration of the solute 

 or solutes in milli-equivalents (referred to the oxygen-equivalent as 

 8.000) per kilogram of solution. The column headed temperature (0 



*Ten experiments at 218, and fifteen at 306, were rejected on account of leakage 

 of solution out of the bomb. The initial 18 measurements on these solutions were 

 usually not affected, and have therefore been included among the data. Three other 

 experiments at 218, and one other at 306, were not used in deriving final values 

 on account of an abormal difference between the initial and final conductances at 

 18 ; but the data of these experiments are given for the sake of completeness. In 

 addition, several measurements with ammonium acetate at 218 have been omitted, 

 because a more complete and accurate series was made later. 



