OSMOTIC PRESSURES OF SOME CONCENTRATED AQUEOUS SOLUTIONS. 503 
equivalent to about 0'15 atmosphere, showed that equilibrium pressures of less than 
12 atmospheres could not be measured with any degree of accuracy with this 
apparatus. 
Discussion of the Results. 
On looking over the tables it will be noticed that the experiments which give the 
highest values for the turning point are always those in which there was no “ solution 
leak”; and the difference between these and the other results follows roughly the 
ratio # that the “ solution leak ” rate bears to the rate per increment of pressure. 
(In other words, the larger the “solution leak” the lower the equilibrium pressure.) 
No satisfactory method of correcting for these deviations was found ;t so it was 
decided to use, for the final computation, only those experiments (marked by an 
asterisk) in which there was little or no “ solution leak.” 
It has been stated already that the turning-point pressures in. these experiments 
are the equilibrium pressures, and therefore the arithmetical mean would give the 
best value ; but we have felt justified in giving double weight to experiments which 
showed no “ solution leak whatever. 
The following tabular statement gives the final values for the equilibrium pressures 
at 0° C. of the various solutions when there is a pressure of one atmosphere on the 
solvent. 
Table X. 
Cane Sugar. 
180*1 grammes in the litre gives a pressure of 13*95 atmospheres. 
300*2 „ „ „ 26*77 
420*3 „ „ „ 43*97 
540*4 „ „ „ 67*51 
660*5 „ ,, ,, 100*78 „ 
750*6 „ „ „ 133*74 
Dextrose. 
99*8 grammes in the litre gives a pressure of 13*21 atmospheres. 
199*5 „ „ „ 29*17 
319*2 „ „ „ 53*19 
448*6 „ „ „ 87*87 
548*6 „ „ „ 121*18 
Galactose. 
250 grammes in the litre gives a pressure of 35*5 atmospheres. 
380 „ „ „ 62*8 
500 „ ,, „ 95*8 „ 
Recovered Galactose. 
500 grammes in the litre gives a pressure of 97*3 atmospheres. 
Mannite. 
100 grammes in the litre gives a pressure of 13*1 atmospheres. 
HO „ „ „ 14*6 
125 „ „ „ 16.7 
* The ratio is not tabulated, as it was not considered of sufficient importance, 
f See Appendix A. 
