496 
THE EARL OF BERKELEY AND MR. E. G. J. HARTLEY ON THE 
Table V.—Experiment with 750 grammes of Cane Sugar in the litre with Tube X. 
(R = 111,000 ohms.) 
I. 
II. 
III. 
IY. 
Y. 
YI. 
YII. 
VIII. 
IX. 
Pressure. 
Rate of 
Tem- 
Reading 
move- 
Pressure 
Dead- 
perature 
of 
ment of 
cor¬ 
rected 
for 
G.R.L. 
Date. 
Time. 
of 
osmotic 
given 
by beam 
weight 
pressure 
water 
level 
water 
in 
Remarks. 
appa- 
in 
in 
in 
millims. 
ratus. 
atmo- 
atmo- 
gauge. 
per 15 
spheres. 
spheres. 
minutes. 
March 27 . 
5 . 0 P.M. 
°C. 
Set up for G.R.L. in ice. 
9 . 6 A.M. 
— 
— 
— 
242-9 
— 
— 
9.26 „ 
0-05 
— 
— 
242-2 
-0-5 
— 
9.55 „ 
— 
— 
— 
— 
— 
— 
Set up for O.P. in ice. 
10.5 „ 
— 
132-0 
— 
— 
— 
— 
10.50 ,, 
— 
134-0 
— 
— 
— 
— 
11.45 „ 
0-04 
— 
132-69 
■—- 
— 
— 
Cut off beam apparatus. 
11.50 „ 
— 
— 
132-69 
258-0 
- 1-5 
-1-0 
11.55 „ 
— 
134-0 
— 
257-5 
— 
— 
Cut off dead weight. 
12.35 P.M. 
— 
— 
133-37 
— 
— 
— 
Cut off beam apparatus. 
28 • 
n 
12.40 „ 
— 
— 
133-37 
274-4 
+ 1-5 
+ 2-2 
12.45 „ 
— 
134-0 
— 
274-7 
— 
— 
Cut off dead weight. 
2.40 „ 
— 
— 
133-37 
— 
— 
— 
Cut off beam apparatus. 
2.45 „ 
— 
— 
133-37 
308-7 
+ 0-1 
+ 0-6 
2.55 „ 
— 
134-0 
— 
308-8 
— 
— 
Cut off dead weight. 
5.0 „ 
— 
— 
133-37 
— 
— 
— 
Cut off beam apparatus. 
5.5 „ 
— 
— 
133-37 
342 • 2 
-o-l 
+ 0-5 
5.15 „ 
— 
— 
133-03 
342-1 
— 
— 
5.20 „ 
— 
— 
133-03 
341 ■ 0 
-1-3 
-0-8 
5 . 30 ,, 
— 
— 
— 
340-1 
— 
— 
Took down and set up 
for “ solution leak.” 
„ 30 . 
9 . 0 A.M., 
100 cub. centims. run through the tube 
gave 0 • 
0009 gramme of sugar. 
April 1 . . 
9.0 „ 
100 
>3 
)5 
„ o- 
0013 
3 5 3 3 
Note.— The “solution leak” was not pursued any further on account of our absence from the laboratory. 
The apparent turning-point pressure is 133 - 42 atmospheres. 
The corrected turning point is 133 *23 atmospheres. 
This experiment was selected so as to give an idea of the influence that a small 
solution leak lias on the experiments. It will be noticed on examining the tabular 
statement of results that the experiment gives a value of the turning-point pressure 
slightly below another experiment where there was practically no leak. 
Substances Used. 
For the cane-sugar solutions, “double refined” loaf sugar was used; it was tested 
for invert sugar and only a trace found ; tests were also made of the solution at the 
end of an experiment, and the quantity of invert sugar showed a scarcely appreciable 
increase, 
