Alessandro Volta

By Nadia El-Masri

Alessandro Volta was born in 1745 in Como, in Lombardy, into the minor nobility, and educated by the Jesuits — a classicist by training who fell in love with the new experimental physics. In the 1790s the scientific world was electrified by his countryman Luigi Galvani's claim that frog legs twitched because of an "animal electricity" inherent in living tissue. Volta, professor of physics at Pavia, was skeptical. He suspected the twitch came not from the frog but from the metals: two different metals touching through a moist conductor made the current. To prove it, he set out to build the current without any animal at all.

In 1800 he announced the result to the Royal Society in London: the voltaic pile — a stack of alternating discs of zinc and silver (or copper), each pair separated by cardboard soaked in salt water, piled into a column. Touch the top and bottom and a steady, continuous electric current flowed — the first human-made source of sustained current, as opposed to the momentary spark of the Leyden jar. It was a quiet device, no bigger than a stack of coins, but it ended the age of static electricity and opened the age of current electricity. Napoleon summoned Volta to Paris in 1801, watched the pile split water into hydrogen and oxygen, and made him a count and a senator of the Kingdom of Italy.

The pile's children arrived fast: within months, Nicholson and Carlisle used it to decompose water; within a decade, Humphry Davy used giant piles to isolate sodium, potassium, calcium, and magnesium — new elements pulled from common compounds by Volta's current. Oersted, Ampère, and Faraday all began with the pile on the bench. Volta spent his last years honored across Europe and died in 1827 in Camnago, near Como. The unit of electric potential, the volt, carries his name — the measure of the push his pile first gave to the current that now runs the world. The quarrel with Galvani was the making of him. Galvani insisted the electricity lived in the animal; Volta insisted it lived in the metals, and stacked his discs to prove the frog unnecessary — the pile was an argument in hardware. He was right about the source and wrong about the mechanism — the current comes from chemical action, which neither man understood — but the device settled the debate by working. Napoleon, who loved science as theater, had the pile demonstrated before the Institute in Paris and struck a gold medal for its inventor. Volta accepted the honors, the countship, the senate seat, and retired to his villa at Camnago, where he watched from a distance as Davy's giant piles tore new elements out of potash and soda. The frog twitched; the pile endured.

Impact on civilization

The voltaic pile gave humanity its first continuous electric current, and continuous current made electricity a tool instead of a curiosity. Before Volta, electricity was a parlor trick — sparks from a jar, gone in an instant. After him, it was a flow that could be studied, measured, and put to work: it decomposed compounds and revealed new elements, it deflected compass needles and revealed electromagnetism, it drove the first motors and carried the first telegraphs. Every battery in every phone, car, and pacemaker is a descendant of the pile — the same chemistry of dissimilar metals in an electrolyte, refined but unbroken in lineage. More fundamentally, the pile made the electrical sciences possible: without a steady source, there is no Ohm, no Faraday's induction, no Maxwell, no grid. Volta put the current in scientists' hands; they electrified the planet with it. The pile also founded electrochemistry: Davy's isolation of new elements with giant piles showed that electricity could take matter apart, a power that runs from the aluminum smelter to the lithium battery. Chemistry became an electrical science.