394 BABCOCK. 



values of c,, at the specific volume 2.6593 ccs./gram, ha\'e been given 

 in Table II. over the temperature range 30° C. to 125° C. 



2. Keyes-Brownlee Data for Ammonia. 



To compute the numerical \alues of c^, and Csi from these values of 

 c„, by means of (26) and (27) the data of Keyes and Brownlee is used. 



For the heat of vaporization, Keyes/^ using 1 cal. : = 4.182 Joules, 

 gives 



logioL = 1.56817 - 2.822-10-=' (406.0 - T) 



+ 0.43387 logio (406.0 - 7') (30) 



where L is in calories per gram; and T is in degrees absolute on the 

 Centigrade scale. 



From this equation we obtain 



/^ _ ^) = L ] 6.49788-10- - -^^^^ - 1 1- (31) 



\dT TJ I 406.0 - r T) ^ ' 



In the following table are given the values of L and of ( ) for 



\T clT/ 



each 10°C. computed from equations (30) and (31). The first column 

 gives the temperature in degrees Centigrade; the units of column 

 two and three, are Joules per gram, and Joules per gram-degree, 

 respectively. 



17 Reference (3) p. 24. Eq. 34. 



