210 
PROFESSOR GRAHAM ON OSMOTIC FORCE. 
The osmose of the Off per cent, solution of carbonate of soda is lowered by the 
addition of ] per cent, chloride of sodium, from 179 ms. to 32 ms. The osmose of 
1 per cent, carbonate of soda, with the addition of an equal proportion of chloride of 
sodium, is 56 ms., and of 1 per cent, carbonate of soda alone, immediately following, 
157 ms. The osmose of these mixtures appears to be assimilated to that of chloride 
of sodium itself, which comes out as 18 and 25 ms. in the same series of observations. 
The rise of an alkaline liquid in the osmometer appears to be equally repressed by 
chloride of sodium, placed outside or dissolved in the fluid of the water-jar. 
In illustration of this statement, I may adduce a short series of observations made 
with fresh ox-bladder, having its thickness unreduced, which further show that the 
repressing power that appears in the chloride of sodium does not extend to two other 
substances, alcohol and sugar. 
Table XVIII. — Solutions in Osmometer P of ox- bladder for five hours. 
Salt in osmometer. 
Rise in 
millimeter 
degrees. 
Carbonate of potash, 0*25 per cent 
76 
Same, 0*25 per cent 
96 
Carbonate of potash, 1 per cent., against alcohol, 1 per cent., in jar. 
108 
Same, 1 per cent., against sugar, 1 per cent., in jar 
104 
Same, 1 per cent-, against chloride of sodium, 1 per cent., in jar 
18 
Same, 1 per cent., against pure water in jar 
114 
Same, 1 per cent., against chloride of sodium, 1 per cent., in jar 
18 
Carbonate of potash, 1 per cent. -(-chloride of sodium, 1 per cent., against water in jar 
Carbonate of potash, 1 per cent., alone, against pure water in jar 
64 
134 
Same repeated 
114 
Now another neutral salt, sulphate of potash, will be found to have the reverse 
effect upon the osmose of an alkaline carbonate, supporting and promoting the latter. 
Such results show how far we still are from a clear comprehension of the agencies at 
work in membranous osmose. Another property of chloride of sodium, equally sin- 
gular, is, that the association of this salt (by itself so indifferent) with small propor- 
tions of hydrochloric acid, such as one-tenth per cent., determines a positive osmose 
in membrane, which is sometimes very considerable. 
The osmotic action of the albuminated calico of Table XVII. is moderate in 
amount, but remarkably uniform. The small tenth per cent, solution assumes a pre- 
eminence in activity which is very curious. It was often observed in the inquiry, 
that the small proportions of active salts were more favoured in albuminated calico 
than in membrane ; may it not thence be inferred that it is in the albumen plate 
that the chemical agency operates to most advantage ? 
Taking the mean diffusates of chloride of sodium and carbonate of soda from the 
lower part of the same Table, we have 0‘354 chloride of sodium against 0’201 
carbonate of soda, or 1 of the former to 0 - 568 of the latter. The diffusates of the 
