Changes in Dielectric Constants and in Volumes. 75 



The probable errors for single determinations and for the 

 mean determination are respectively 



f72 = 48 and fl2 = 8. 



At first inspection these figures are discouraging, but when 

 we find the mean error of a single determination to be 72 

 and then find that this mean error will more than bring 

 29 out of the 35 determinations into the mean of the whole, 

 namely 96, and that 5 of the 6 exceptions have experimental 

 errors of their own more than sufiicient to bring them also 

 into the mean, and that the other one has an unknown experi- 

 mental error, the final result is not so bad and there is nothing 

 to disprove the correctness of equation 4 and the constancy of 

 the quotient e/Q,. In other words, that the heat of a change 

 comes from a change in the field surrounding us and that this 

 change is measured by the dielectric constants of the compo- 

 nents of the system, is an assumption in agreement with the 

 foregoing experiments. 



Eutgers College, New Brunswick, N. J. 

 February, 1903. 



