C. Oersted, of the action of the galvanic current on a magnet.
The writer made a contribution to the discussion in 1874 in a paper on " The Contact Theory of the Galvanic Cell," Phil.
Hankel still further improved the dry pile electrometer by giving a slow motion movement to the two plates, and substituted a galvanic battery with a large number of cells for the dry pile, and also employed a divided scale to measure the movements of the gold-leaf (Pogg.
In 1834 he continued and extended his researches "On the Influence of a Spiral Conductor in increasing the Intensity of Electricity from a Galvanic Arrangement of a Single Pair," a memoir of which was read before the American Philosophical Society on the 5th of February 1835.
Chemical reagents are sometimes added - lime or sulphuric acid, to neutralize an excess of acid or alkali; copper sulphate, to form cuprous chloride with sodium chloride; and iron and zinc, to make the galvanic action more energetic and reduce the consumption of iron.