100 



METHODS OF ANALYSIS 



[Chap. 



100 P 



P+ Y 



100 -R 



CuF 



W 



R, approximate per cent of sucrose in mixture of sugars; 

 I, approximate per cent of invert sugar; 

 per cent of invert sugar. 



The factor F for calculating copper to invert sugar is then found from 40. 



40 Table 3. 



Meissl and Hiller's^ factors for determinations in materials in which, of tfie total 

 sugars -present, 1.5%, or more, is invert sugar, and 98.5%, or less, is sucrose. 



Example: The polarization of a sugar is 86.4, and 50 cc. of solution containing 

 3.256 grams of sample gave 0.290 gram of copper. 



Cu 0.290 



By consulting the table it will be seen that the vertical column headed l/iO is 

 nearest to Z, 145, and the horizontal column headed 95: 5 is nearest to the ratio of 

 R to I, 95.1 : 4.9. Where these columns meet, we find the factor 51.2 which enters 

 into the final calculation: 



CuF 

 W 



0.290 X 51.2 

 3.256 



= 4.56 per cent of invert sugar. 



In case there is no sucrose present, the following table may be used instead of the 

 factors given in 40. 



