CONDUCTIVITY OF SODIUM HYDROXIDE IN AQUEOUS SOLUTION. 



TABLE III. 



J71 



In no case does the difference exceed 0'00002, though the absolute values for the 

 density are liable at 18 per cent. NaOH to an error of '00004 on account of the fact 

 that the concentration is only known to 1 part in 5000. 



Comparison with the Results of other Observers. With the help of the temperature 

 coefficients deduced in Part III. of the paper, it is possible without any loss of 

 accuracy to calculate the values for the density at 1 5 C. and so to make a comparison 

 of our results with those of other investigators. This has been done in Table VI. of 

 the paper, in which the densities at 18 C. and 15 C. are given for each exact 

 percentage from to 50. On account both of errors of titration and impurities in 

 the solutions the earlier values are in almost every case higher than those given in 

 Table VI., and the errors extend in some cases even into the second place of 

 decimala* The deviations from our determination at five typical concentrations are 

 as follows : 



TABLE IV. 



We had expected that, when corrected for the error due to titration, PICKERING'S 

 values would have shown a close agreement with our own, or, in other words, that 

 the differences between the two series of observations would have been proportional 



* See footnote post, p. 287. 



t 39 per cent, value. 



{ Calculated by means of an interpolation formula from the observations of DALTON and TtJNNERMANN. 



