PROFESSOR GRAHAM ON OSMOTIC FORCE. 
225 
Osmose in membrane of I per cent, solutions expressed in millimeter degrees. 
Oxalic acid .... 
— 148 
Chloride of zinc 
45 
Hydrochloric acid (0‘1 pe 
cent.) 
- 92 
Chloride of nickel 
88 
Terchloride of gold 
— 54 
Nitrate of lead 
. 204 
Bichloride of tin . . 
- 46 
Nitrate of cadmium .... 
. 137 
Bichloride of platinum 
- 30 
Nitrate of uranium . . . . 
. 458 
Nitrate of magnesia 
- 22 
Nitrate of copper 
. 204 
Chloride of magnesium 
— 2 
Chloride of copper .... 
. 351 
Chloride of sodium 
+ 12 
Protochloride of tin ... . 
. 289 
Chloride of potassium 
18 
Protochloride of iron .... 
. 435 
Nitrate of soda . . . 
14 
Chloride bf mercury .... 
. 121 
Nitrate of silver . . 
34 
Protonitrate of mercury . . . 
. 350 
Sulphate of potash . . 
. 21 
to 60 
Pernitrate of mercury . . . . 
. 4/6 
Sulphate of magnesia . 
14 
Acetate of sesquioxide of iron . 
. 194 
Chloride of calcium 
20 
Acetate of alumina .... 
. 393 
Chloride of barium . . 
21 
Chloride of aluminium . . . 
. 540 
Chloride of strontium . 
26 
Phosphate of soda 
. 311 
Chloride of cobalt . . 
26 
Carbonate of potash .... 
. 439 
Chloride of manganese 
34 
It will be observed that acid and alkaline salts are found at opposite ends of the 
series, or, while the acids possess negative osmose, the alkaline salts exhibit positive 
osmose in the highest degree. The remark will suggest itself, that in osmose water 
always appears to pass to the alkaline side of the membrane ; as water also follows 
hydrogen and the alkali in electrical endosmose. 
The chemical action must be different on the substance of the membrane at its 
inner and outer surfaces to induce osmose ; and according to the hypothetical view, 
which accords best with the phenomena, the action on the two sides is not unequal in 
degree only, but also different in kind. It appears as an alkaline action on the 
albuminous substance of the membrane at the inner surface, and as an acid action 
on the same substance at the outer surface. The most general empirical conclusion 
that can be drawn is, that the water always accumulates on the alkaline or basic side 
of the membrane. 
The analogy does not fail even when the osmometer is charged with an acid solu- 
tion and the osmose is negative. The stream is then outwards to the water, which 
is a basic body compared with the acid within the membrane. 
The high positive osmose of the salts of the alumina type is exceedingly remarkable. 
The property is common to salts of alumina, sesquioxide of iron, sesquioxide of 
chromium, and the corresponding oxide of uranium. Now the property in these salts 
is small where the salt is stable, as in the sulphates, but becomes great where the 
affinity between the acid and base is comparatively weak, as in the chlorides, nitrates 
and acetates of these bases, salts which can be shown to be largely decomposed in the 
2 G 
MDCCCLIV. 
