Progress of Foreign Science. 137 
fragments of the bodies to be acted on, and a large platinum 
spoon. : 
Let us now fix in the platinum forceps a little bit of caustic, 
soda, or potash, slightly moistened with water. At the moment 
when the alkali touches the acid, an energetic electrical current 
will take place, which will proceed from the acid to the alkali fol- 
lowing the curcuit. ‘Thus at the instant of contact of these two 
bodies the acid becomes enveloped with an atmosphere of positive 
electricity, and the alkali with one of negative. The electrical 
current is so strong that it may be observed without a galvanometer. 
It is sufficient for this purpose to present the conjunctive wire to a 
needle suspended at the filament of a silk-worm. In order to 
observe the electrical currents which result from the action of an 
acid on a metal, the same process is employed ; care only is taken 
to prevent the metal touching the platinum directly, by interposing 
a small slip of paper. The experiment is made in the same way, 
and the result is the same, whatever be the acid and the base. 
M. Becquerel next shews that during the solution of a body in 
water, or alcohol, no electricity is produced. But the smallest 
acid or alkaline particles are sufficient to modify the results. 
He then details some experiments on the solution in caustic 
potash of metallic oxides, such as oxide of zinc, and of lead newly 
precipitated. In these, electrical phenomena were exhibited. 
Whenever the oxide (generally contained in the thin ceecum of an 
animal,) touches the alkaline solution, the needle deviates from its 
magnetic direction, and the current goes from the oxide to the 
alkali, passing along the wire. Hence in these kinds of combi- 
nations, the oxides comport themselves like acids, and the alkalis 
are always surrounded with an atmosphere of negative electricity, 
as in their actions on the acids. 
Tn slow precipitations, as when an infusion of nut galls acts on 
sulphate of iron, a current is developed which goes from the infu- 
sion to the sulphate. Let us puta solution of sulphate of mag- 
nesia in contact with the caustic potash contained in the mem- 
branous bag. The needle will deviate slightly from its direction, 
and the current will be from the sulphate tothe alkali. In making 
nitrate of barytes act on sulphuric acid, the current goes from the 
acid to the nitrate. When two perfectly neutral salts were em- 
ployed, as sulphate of soda, and nitrate of barytes, he has not been 
able to discern the least appearance of a current. 
In a subjoined notice, M. Becquerel describes the following 
experiment. Take a plate of platinum, and placing it horizontally, 
fix by cement, two glass tubes vertically upon it. Liquids poured 
into these tubes will communicate through the medium of the pla- 
tinum plate. Let us pour in any liquids whatever; if they are 
susceptible of exerting chemical actions on the two ends of the 
wire of the galyanometer which are immersed, there will be na- 
