[ELECTRICITY]. Set of three Grenet batteries. Batteries in a glass container, H: 18 cm, 17.5 cm and 23 cm. This is the first battery to wear out during use. It consists of a strip of zinc placed between two carbon electrodes, all immersed in an acid solution of potassium or sodium dichromate. The zinc is only immersed in the electrolyte when current needs to be produced. 2 volts. Late 19th century. One of the batteries made by Dr. A. Vincent ECT Paris, patented SGDG (Sans Garantie Du Gouvernement) is cracked. Provenance: José Henry collection.