860 PROCEEDINGS OP THE AMERICAN ACADEMY. 



TABLE XXXVI. 



y ■= S c.c Trichloraceticester ; x = c.c. Water ; z = c c. Alcohol. 

 Formula x yO-« / z i-« = C; log C - 1.336. 



X. 



Tables XIX.-XXXI. fwrnish a striking confirmation of the way in 

 which the Mass Law applies to this class of phenomena ; while some of 

 the results are not as satisfactory, perhaps, as I should like, there are 

 some, notably those with propylbutyrate, where the agreement between 

 the observed and the calculated values is something marvellous, though 

 it is unfortunate that the solubility of propylbutyrate in water has 

 never been determined experimentally. 



As it might be thought a mere assumption that the first measure- 

 ments in several series were determinations of another equilibrium, 

 namely, of a saturated solution from which water or ester precipitated 

 water, I have made a few measurements with the few esters I had on 

 hand. The object of these measurements was to show that the change 

 from one equilibrium to another did come at the point shown by 

 Pfeiffer's results, and to make sure that the variations in Pfeiffer's data 

 were due to experimental error. On this account I have made no 

 measurements on the end curves, where water and where ester are part 

 solvents, and in the case of ethylisovalerate I have measured only one 

 series. The results are given in Tables XXXVII.-XXXIX. 



TABLE XXXVn. 



X = c.c. HoO ; y = c.c. Ethylisovalerate ; 5 c.c. Alcohol. Temp 20°. 

 Formula (x - 0.004^)" (y -0.002 x) / 3" + ^ = C; n = 2.45; log C = 1.149. 



1.148 



