494 
THE EARL OF BERKELEY AND MR. E. G. J. HARTLEY ON THE 
experiments—they cover the whole range of pressures. The first of the two columns 
headed pressure gives the approximate pressure in atmospheres corresponding to the 
weights on the beam ; the second gives the accurate pressure delivered by the dead¬ 
weight standard gauge. The next column gives the height of the level of the water 
in the glass capillary at the times shown. The seventh column gives the rate of 
movement of the water level for ] 5 minutes, and the numbers are placed opposite to 
the pressures causing the movement. 
The process pursued will be clear from the following example. Referring to the 
experiment with dextrose, begun May 17, at 12.5 P.M., the height of the water was 
236*3 millims. ; immediately this level had been noted, the pressure was altered to 
28'92 atmospheres, and a short interval of time allowed for a steady state to be 
reached; at 12.10 the level was at 234'9 millims. Ten minutes after, at 12.20, the 
level had fallen to 233'2. The difference between the last two readings gives the 
rate corresponding to 28'92 atmospheres pressure. 
Table III. — Experiment with 200 grammes of Dextrose in the litre with Tube X. 
(It = 111,000 ohms.) 
I. 
II. 
III. 
IY. 
V. 
YI. 
VII. 
Pressure. 
Rate of 
Tern- 
Reading 
move- 
perature 
Pressure 
Dead- 
of 
ment of 
Date 
of 
given 
weight 
water 
water 
osmotic 
by beam 
pressure 
level 
in 
appa- 
in 
in 
in 
millims. 
ratus. 
atmo- 
atmo- 
gauge. 
per 15 
spheres. 
spheres. 
minutes. 
°C. 
March 17 . 
5.0 p.m. 
— 
— 
— 
— 
— 
,, 18 • 
5.15 „ 
0-05 
— 
— 
258-2 
— 
6.20 „ 
-- 
— 
— 
255-5 
0-6 
7.5 „ 
— 
— 
— 
253-7 
0-6 
9.35 a.m. 
— 
— 
— 
— 
— 
9.38 „ 
— 
29-4 
— 
— 
— 
10.47 „ 
0-04 
— 
28-92 
— 
— 
10.50 „ 
— 
— 
28-92 
230-9 
-3-0 
10.55 „ 
— 
— 
29-26 
229-9 
— 
IQ. 
11.0 „ 
— 
— 
29-26 
230-7 
+ 0-3 
y> J-t7 
11.5 „ 
— 
29-4 
— 
230-8 
— 
11.50 „ 
0-04 
— 
29-26 
— 
— 
11.55 „ 
— 
— 
29-26 
235 • 9 
+ 0-6 
12.5 P.M. 
— 
— 
28-92 
236-3 
— 
12.10 „ 
— 
— 
28-92 
234-9 
-2-5 
- 
12.20 „ 
— 
— 
28-92 
233-2 
— 
VIII. 
IX. 
Rate 
cor¬ 
rected 
for 
G.R.L. 
Remarks. 
Set up for G.R.L. in ice. 
Set up for O.P. in ice. 
Cut off beam apparatus. 
Cut off dead weight. 
Cut off beam apparatus. 
Took down and set up 
for “ solution leak.” 
21 . 9.0 A.M., 100 cub. centims. run through the tube gave 0 - 0007 gramme of sugar. 
The rate for a pressure of 29'26 atmospheres is + 0'6 millim. in 15 minutes. 
28'92 ,, —2'5 millims. ,, 
>9 
