an early electric battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and copper. Initially he experimented with individual cells in series, each cell being a wine goblet filled with brine into which the two dissimilar electrodes were dipped. The voltaic pile replaced the goblets with cardboard soaked in brine. Early battery In announcing his discovery of the voltaic pile, Volta paid tribute to the influences of William Nicholson, Tiberius Cavallo, and Abraham Bennet. The battery made by Volta is credited as one of the first electrochemical cells. It consists of two electrodes: one made of zinc, the other of copper. The electrolyte is either sulfuric acid mixed with water or a form of saltwater brine. The electrolyte exists in the form and . Zinc metal, which is higher in the electrochemical series than both copper and hydrogen, is oxidized to zinc cations (Zn2+) and creates electrons that move to the copper electrode. The positively charged hydrogen ions (protons) capture electrons from the copper electrode, forming bubbles of hydrogen gas, H2. This makes the zinc rod the negative electrode and the copper rod the positive electrode. Thus, there are two terminals, and an electric current will flow if they are connected. The chemical reactions in this voltaic cell are as follows: Zinc: Sulfuric acid: Copper metal does not react, but rather it functions as a catalyst for the hydrogen-gas formation and an electrode for the electric current. The sulfate anion () does not undergo any chemical reaction either, but migrates to the zinc anode to compensate for the charge of the zinc cations formed there. However, this cell also has some disadvantages. It is unsafe to handle, since sulfuric acid, even if diluted, can be hazardous. Also, the power of the cell diminishes over time because the hydrogen gas is not released. Instead, it accumulates on the surface of the copper electrode and forms a barrier between the metal and the electrolyte solution. Last years and retirement In 1809, Volta became associated member of the Royal Institute of the Netherlands. In honour of his work, Volta was made a count by Napoleon Bonaparte in 1810. Volta retired in 1819 to his estate in Camnago, a frazione of Como, Italy, now named "Camnago Volta" in his honour. He died there on 5 March 1827, just after his