Kahlenberg—Osmosis and Osmotic Pressure. 265 
experiment. It was after all this that the entire outer liquid 
was evaporated to dryness and the amount of LiCl in the resi¬ 
due determined with the result already recorded. The discus¬ 
sion of the results of this experiment will be deferred until after 
the next two experiments have been described. 
59) The inner liquid was a solution of sugar in pyridine 
containing 0.125 gram-molecule per liter. The outer liquid 
was pure pyridine and the septum vulcanized caoutchouc. The 
experiment was run with constant stirring or three days, the 
temperature being kept constant at 20° C. The maximum 
pressure reached was 98.3 cm., nearly the whole of which was 
attained during the first day. On concluding the experiment 
the whole of the outer liquid consisting of 400 cc. was evapor¬ 
ated to dryness; the residue was taken up with water, ard the 
sugar determined with Fehling’s solution, after inverting with 
HC1. It was found that the 400 ce. contained 0.1149 grams of 
sugar. 
60) This experiment was as nearly as possible a duplicate 
of the preceding one (59). On the fifth day the mercury in the 
manometer reached a height of 91.8 cm., the temperature having 
gradually gone up to 21° C. In this case, too, the pressure 
increased but little after the second day. On the morning of 
the seventh day the pressure was 94.0 cm., the temperature be¬ 
ing 21.95° O.; in the evening of the same day 95.5 cun. at 22.15. ° 
On the eighth day the outer beaker was packed in melting ice, 
the temperature in the beaker being 2.0° C. During this time 
the mercury in the manometer registered practically no pres¬ 
sure, or at best only a few millimeters. The ice was then per¬ 
mitted to melt gradually, and on the ninth day the pressure 
registered 92.0 cm. at 19.4° C. The temperature was then 
slowly raised to 46° C., where it was, kept for twelve hours. 
The pressure became constant after about three hours at 114.2 
cm. and remained there for nine hours. The experiment was 
then discontinued. The whole of the outer liquid consisting 
of 1200 cc. was then evaporated to dryness, and the sugar was 
taken up with water, inverted with HC1 and determined with 
Fehling’s solution. The result was that in the 1200 cc. 0.2205 
grams of cane sugar were found. 
