CANE SUGAR. 



131 



while that in Table 19 bears upon one particular source of dilution. 

 The reduction of the total loss in rotation from 38.40° in 22 determina- 

 tions to 27.65° in 27 experiments, signified considerable improvement, 

 especially in manipulation. Expressed in pressure, the loss was reduced 

 from 9.37 atmospheres in Series II to 6.75 in Series III. The com- 

 parison is better made by means of percentages. The sum of all 

 rotations of the solutions of Series II was 1342.30° and the sum of all the 

 losses was 38.40°, or 2.86 per cent. The corresponding numbers for 

 Series III were 1598.27°, 27.65°, and 1.73 per cent. 



Table 21. 



-Cane sugar, Series III. Observed osmotic pressures corrected for dilution, and the 

 ratios of osmotic to calculated gas pressure of the solute. 



The osmotic pressures which are given in Table 18 are those which 

 were actually observed, that is, they have not been corrected for 

 inversion or dilution. When the first account of the work in Series III 

 was published, it was still imagined that inversion might be responsible 

 for a portion of the loss in rotation, though it was conceded that a con- 

 siderable part of it must be due to dilution. Accordingly, three tentative 

 tables of "corrected" results were given. In one of them the whole loss 

 in rotation was ascribed to inversion; and in another, to dilution. In the 

 third table, one-half of the loss was ascribed to inversion and one-half to 

 dilution. The difference between the corresponding values in the first 

 and second tables was called the "limit of uncertainty" as to the true 



