‘ Intelligence wnd Miscellaneous ‘Articles. 159 
distinguished. I propose to undertake a series of experiments 
froni this point of view, the results of which I shall lay before the 
Academy.:—Comptes Rendus, Sept. 3, and Oct. 29, 1860. 
ON BLECTRIC ENDOSMOSE. BY M. C. MATTEUCCI. 
Having recently had occasion to examine into the construction 
and operation of the galvanic batteries used in our telegraph offices, 
I have been led to make certain original experiments on the subject 
of electric endosmose, a short description of which, as they seem to 
throw some light on the true nature of the phenomenon in question, 
I beg to lay before the Academy. MM. Porret and Becquerel were 
the first who called attention to the fact that a liquid mass, sepa- 
rated into two compartments by a porous diaphragm, and traversed 
by an electric current, appears to be transported in the direction of 
that current; that is to say, the level of the liquid is lowered in the 
compartment that contains the positive pole, and raised in that which 
contains the negative pole. ‘The determination of the law of this 
phenomenon is due to M. Wiedemann, who proved that the quantity 
of water transported is directly proportional to the intensity of the 
current and the electric resistance of the liquid. M. Wiedemann 
seems to have regarded this mechanical effect of the current as a 
different phenomenon from its electrolytic action; while other phy- 
Sicists have considered that the transportation of the liquid was only 
‘a secondary effect of electrolysis. I should mention also that 
MM. Van Breda and Logemann have in vain endeavoured to as- 
certain whether, in the absence of a diaphragm, there is any displace- 
ment of the electrolysed liquid, or whether a very light moveable 
diaphragm is itself displaced in the direction of the current. Theo- 
retical considerations, which easily suggest themselves to the mind, 
and which I need not here specify, founded on the equality of the 
electrolytic effects, whether endosmose be produced or not, give 
probability to the conclusion that these phenomena are caused by 
some secondary action of electrolysis. The following experiments 
seem to show that this supposition is correct. 
I divided a rectangular vessel of varnished wood into six com- 
partments, by means of diaphragms of porous porcelain. All these 
compartments were filled to the same height with well-water, the 
level of which was indicated by a line of white varnish. A platinum 
plate of the same size as the diaphragms was placed in each of the 
end compartments, Through this apparatus I caused a current to 
pass, produced sometimes by 10, sometimes by 15, and sometimes by 
20 cells of a Grove’s battery. ‘The endosmose became apparent after 
the current had lasted for some hours, and in every case the first 
effect produced was as follows :—The level of the liquid was raised 
in the compartment that contained the negative electrode, and was 
lowered in the compartment next to it, while it was lowered in the 
compartment that contained the positive electrode (though to a less 
degree than it was elevated in the compartment at the opposite ex- 
tremity), and raised in the adjoining compartment. These effects 
were invariably produced, notwithstanding the change of the dia- 
phragm and the reversal of the position of the vessel with respect ta 
