CONCENTRATION OF ALCOHOL 



261 



together the three observed differences (between x v corresponding 

 to y = and 10 per cent; 10 and 20 per cent; 20 and 50 per 

 cent) and dividing their sum by 5. In this way A was ascer- 

 tained to possess, for these solutions (at 30 degrees) the average 

 value 1.0248. In the following table the actual and computed 

 values of x v are compared : 



TABLE V. CONCENTRATION OF KOH NEUTRALIZED BY 

 CASEIN 0.0125 N 



It is evident that the law holds good for solutions containing 

 from to 60 per cent of alcohol inclusive, but that it does not 

 hold good for solutions containing 75 per cent alcohol, since for 

 these solutions the calculated and observed values of x v are 

 widely divergent. Moreover the law does not hold good for 

 solutions of the caseinates of the alkaline earths in alcohol-water 

 mixtures; this is evidenced by the lack of constancy in the first 

 differences of logic z corresponding to equal increments of y. In 

 the accompanying table are given the values of logio # correspond- 

 ing to various values of y for solutions of calcium caseinate at 

 30 degrees, containing 1.5 per cent of casein combined with 

 80 X 10~ 6 equivalents of base per gram. 



TABLE VI 



In the following table are given the corresponding data for solu- 

 tions of strontium caseinate at 30 degrees, containing 1.5 per 



