electropoion

from The Century Dictionary.

• noun A mixture of sulphuric acid, bichromate of potash, and water, used as the liquid for batteries in which zinc and carbon are the poles.

from the GNU version of the Collaborative International Dictionary of English.

• (Elec.) An exciting and depolarizing acid solution used in certain cells or batteries, as the Grenet battery. Electropoion is best prepared by mixing one gallon of concentrated sulphuric acid diluted with three gallons of water, with a solution of six pounds of potassium bichromate in two gallons of boiling water. It should be used cold.