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PROCEEDINGS OF THE AMERICAN ACADEMY. 



a pressure range of 3000 kgm. This equation would predict a con- 

 tinuous diminution in the specific heat up to infinite pressures, the 

 limiting value being very approximately 0.5. It was shown in the 

 preceding paper that there is some new eflfect introduced at the high 

 pressures which does not make itself felt at the low pressures, with the 



23456789 10 U12 

 Pressure, kgm. / cm.^ x 10' 



Figure 11. The specific heat at constant pressure of water as a function 

 of the pressure. 



result that an extrapolation to infinite pressures from the behavior 

 for the first 3000 kgm. is not safe. This was shown in that paper by 

 the behavior of the volume, which tended to decrease more rapidly at 

 the high pressures than was predicted by the formula. The present 

 data also show that there is a new effect at the high pressures, and 

 indicate that the effect, whatever it is, is such as to have a much 

 greater influence on the specific heats than on the volume itself. 

 The specific heat at constant volume may be found from the specific 



fd^ 



heat at constant pressure by means of the formula, Cn — Cu=—T -y—-' 



dp 



This quantity, so calculated, is shown in Figure 12. The same ab- 

 normalities are shown at 0° and 20° as were shown in the curves for 

 Cp. The curves for 40° and 60° decrease for nearly their entire 

 lengths, although they are just beginning to rise at the very highest 

 pressures, but the curve for 80° shows the same sharp turning point 

 and the same rise through the greater part of its length as the curve 



