156 



OSMOTIC PRESSURE OF AQUEOUS SOLUTIONS. 



Series III.* 



Glucose III and cane sugar V were parallel series. Before they were 

 undertaken, the means of maintaining temperature and the manipula- 

 tion concerned in the closing and opening of the cells had been greatly 

 improved, with corresponding reduction in temperature fluctuations 

 and in dilution of the cell contents. 



The material employed in Series III was the same as in glucose 

 Series II. 



Table 43. — Glucose, Series III. 



The sum of all fluctuations in bath temperature was 1.60° and the 

 mean variation was 0.08°. In the companion cane-sugar series, the 

 mean variation was also 0.08°. 



The sum of the rotations of all the solutions employed in glucose 

 Series III was 541.70°, and the total loss was 1.05°, or 0.20 per cent. 

 The loss in the corresponding cane-sugar series was also 0.20 per cent. 

 The decline of the dilution from 1.06 per cent in glucose Series II to 

 0.20 per cent in Series III is a fair measure of the improvement which 

 had been made in the manipulation of the cells. The decline in dilu- 

 tion in the case of the parallel cane-sugar series was from 1.73 to 0.20 

 per cent. 



The ratios of osmotic to gas pressure in Series III are even more 

 uniform throughout the whole range of concentration than are those 

 of Series I and II. This uniformity of ratio, which is characteristic of 



*Measurements by H. N. Morse and W. W. Holland. Am. Chem. Jour., xl, 1. 



