RICHARDS. CALOMEL ELECTRODE. 



17 



COMPARISON OF THEORETICAL AND ACTUAL TEMPERATURE 



COEFFICIENTS. 



Centinormal Solutions. 



The examination of this table shows that the slight differences in the 

 degree of dissociation of the various chlorides should produce no es.sential 

 difference in the temperature coefficients, except in the case of cadmium, 

 where the theoretical value corresponds exactly with that actually found. 

 The theoretical values for cadmium, zinc, and magnesium agree suffi- 

 ciently well with the experimental values, but those for barium, stron- 

 tium, and calcium are too high, while that for lithium is too low. The 

 potassium and sodium are of course the standards. 



It becomes now a matter of great interest to apply this formula to the 

 more concentrated solutions, using the value of P = 550, which has thus 

 been computed from the relations of centinormal potassic and sodic 

 chlorides. Such an application furnishes us with the best possible test 

 of the legitimacy of our hypotheses. In the same terms as before the 

 formula for decinormal solutions becomes 



^" 0.000198 ^^2JU2, 



dT 



VOL. XXXIII. 



