OSMOTIC PRESSURES OF SOME CONCENTRATED AQUEOUS SOLUTIONS. 495 
Therefore a difference of pressure of (P34 atmosphere causes a difference in the 
rate of 3T millims., hence the correction to he subtracted from 2 9'2 6 atmospheres to 
obtain the pressure at which no movement of the water would have taken place, that 
is, the apparent turning point, is 0’6x0’34/3T = (P06 atmosphere. The apparent 
turning point is, therefore, 29-20 atmospheres. As the “ guard-ring leak” is also 
0-6 millim. in, 15 minutes, the correction to be subtracted from the apparent turning 
point will also be 0'06 atmosphere, and the corrected turning point is 29d4 
atmospheres. 
Table I Ah—Experiment with 540 grammes of Cane Sugar in the litre with Tube X. 
(E = 143,000 ohms.) 
I. 
II. 
j hi. 
| IY. 
Y. 
YI. 
YII. 
VIII. 
IX. 
Pressure. 
Rate of 
Tem¬ 
perature 
Reading 
° f 
move¬ 
ment of 
Pressure 
Dead- 
Rate 
Date. 
Time. 
of 
osmotic 
given 
by beam 
weight 
pressure 
water 
level 
water 
in 
cor¬ 
rected 
for 
G.R.L. 
Remarks. 
appa- 
m 
in 
in 
millims. 
ratus. 
atmo- 
atmo- 
gauge. 
per 15 
spheres. 
spheres. 
minutes. 
Oct, 22 i 
10.0 A.M. 
5.0 p.m. 
°C. 
— 
310-5 
— 
— 
Set up for G.R.L. in ice. 
{ 
.1 5.10 „ 
— 
— 
— 
309-8 
1-0 
_ 
8.20 a.m. 
— 
— 
— 
256-8 
_ 
_ 
| 8.30 „ 
— 
— 
— 
256 • 3 
0-8 
— 
9.28 „ 
10.55 „ 
0-15 
67-1 
— 
— 
— 
— 
Set up for O.P. in ice. 
12.5 P.M. 
12.7 „ 
0-06 
— 
67-37 
67-37 
358-7 
- 1-7 
— 
Cut off beam apparatus. 
12.15 „ 
— 
— 
68-05 
357-8 
— 
_ 
12.17 ., 
— 
— 
68 ■ 05 
359-4 
+ 3-4 
_ 
i12.25 
— 
— 
67-37 
361-2 
_ 
_ 
12.27 
— 
— 
67-37 
359 • 8 
-2-1 
_ 
„ 23 \ 
12.35 „ 
| 3.5 „ 
0-06 
0-04 
67-5 
_ 
67*37 
358-7 
— 
— 
Cut off dead weight. 
Cut off beam apparatus. 
3.1U ,, 
— 
— 
67-37 
364-9 
-2-0 
- 1-2 
i 3.20 „ 
— 
_ 
68-05 
363-6 
— 
_ 
j O - „ 
— 
— 
68-05 
365-0 
+ 3-4 
+ 4-2 
3.30 „ 
-— 
— 
67-37 
366-8 
_ 
_ 
3.32 „ 
-— 
— 
67-37 
365 • 1 
-2-1 
- 1-3 
| 3.40 „ 
— 
— 
68-05 
364-0 
— 
_ 
3.42 ., 
— 
— 
68 • 05 
365-6 
+ 3-2 
+ 4-0 
| 3.50 „ 
— 
— 
67-37 
367 • 3 
_ 
_ 
3.52 „ 
— 
— 
67-37 
365 • 8 
-2-1 
- 1-3 
4.0 „ 
— 
— 
67-37 
364-7 
— 
— 
Took down and set up 
1 
for “ solution leak.” 
„ 26 . . 
7.30 A.M., 
100 cub. centims. run through the tube 
gave no 
trace of 
sugar. 
_ 
In a manner similar to that detailed in the previous experiment, the apparent 
turning point is 68’08 —3’2 x 0’68/5 - 3 = 67'67 atmospheres, and the corrected turning 
point is 67'67 —0'8 x 0'(58/5'3 = 67‘56 atmospheres 
