14 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



have been better to have a hollow cover also with provision for changing 

 its temperature ; this further improvement has since been successfully tried. 

 The apparatus is outlined in Figure 3, a glance at which, in connec- 

 tion with the foregoing description, will suffice to explain it. 



A 



i 



^ 



c 



3 



do 



2T_ 



QO 



CO 



CO 



Q 



Figure 3. 



With it, two series of determinations were made, — one, in which the 

 temperature of the outside bath was kept constant at a temperature 

 somewhere between the initial and final temperatures ; and a second, in 

 which the temperature of the bath was made to run parallel with the 

 temperature of the quantitative mixture. 



The first of these series is recorded in the table on the opposite page, 

 the corrected rise of temperature being determined by the Regnault- 

 Pfaundler formula, 



