194 
PROFESSOR GRAHAM ON OSMOTIC FORCE. 
escaped from the osmometer with the weight of water which has entered the osmo- 
meter in the same time. It is necessary however to recollect, that the apparent 
osmose or rise observed, is only the excess in volume of the liquid which has entered 
over the volume of the liquid which has left the osmometer. To obtain the full 
volume of water which has entered (the true osmose), it is therefore necessary to add 
the bulk of the substance diffused to the osmose observed. 
Table I. — Alcohol in Osmometer A of double membrane during five hours. 
I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
Alcohol in 
solution. 
Rise or osmose 
in millimeter 
degrees. 
Rise or osmose 
in grammes 
of water. 
Diffusate of 
alcohol in 
grammes. 
Previous 
maceration of 
membrane. 
Hydrostatic 
resistance of 
membrane. 
Temperature, 
Fahr. 
per cent. 
0-25 
12 
davs. 
H 
min. 
8 
63 
0-25 
7 
i 
8 
63 
1 
10 
l 
6 
66 
1 
15 
l 
6 
66 
2 
20 
i 
6 
67 
2 
22 
l 
6 
69 
5 
45 
1-984 
0-521 
2 
6 
72 
5 
45 
1-984 
0-452 
) 
8 
70 
10 
70 
3-072 
i 
8 
67 
10 
76 
3-328 
i 
8 
67 
20 
107 
4-672 
i 
8 
67 
20 
- 
109 
4-800 
i 
8 
67 
A second series of observations was made simultaneously, in another membrane 
osmometer, in order to ascertain the degree of concordance to be expected in such 
experiments. 
Table II. — Alcohol in Osmometer B of double membrane for five hours. 
I. 
II. 
III. 
IV. 
V. 
VI. 
VII. 
Alcohol in 
solution. 
Rise or osmose 
in millimeter 
degrees. 
Rise or osmose 
in grammes 
of water. 
Diffusate of 
alcohol in 
grammes. 
Previous 
maceration of 
membrane. 
Hydrostatic 
resistance of 
membrane. 
Temperature, 
Fahr. 
per cent. 
davs. 
min. 
1 
14 
n 
12 
63 
1 
14 
i 
12 
63 
2 
19 
i 
8 
66 
2 
19 
i 
8 
66 
5 
46 
i 
8 
67 
5 
54 
2-432 
0-579 
i 
8 
69 
10 
90 
4-028 
1-505 
2 
6 
72 
10 
96 
4-332 
1 
8 
70 
20 
120 
5-396 
1 
8 
67 
20 
123 
5-472 
1 
4 
67 
20 
137 
6-156 
1 
4 
67 
20 
142 
6-384 
1 
4 
67 
It will be observed that the osmose increases with the proportion of alcohol, but 
not in so rapid a ratio ; the osmose of the 20 per cent, solution being about only ten 
