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Sir Humphry Davy

discoverer of several elements

Sir Humphry Davy

Humphry Davy was born in Penzance, Cornwall, England, on December 17, 1778, the son of an impoverished woodcarver. As a child, he showed talent as both artist and poet, but his parents insisted that he pursue a practical career. At 17 he was apprenticed to a local surgeon and apothecary to train as doctor, but his interest soon turned away from medicine and towards chemistry.

In 1798, Davy took a position at Thomas Beddoe's Pneumatic Institution in Bristol, and there he conducted experiments on gases. His first published works were "An Essay on Heat, Light, and the Combinations of Light" and "On the Generation of Phosoxygen (Oxygen gas) and the Causes of the Colours of Organic Beings," in Contributions to Physical and Medical Knowledge, Principally from the West of England (edited by Beddoes, 1799). In these articles, he refuted Antoine-Laurent Lavoisier's "caloric" by arguing that heat is motion but light is matter. His faulty experiments and reasoning led to his paper being ignored by many and ridiculed by others, and it would be many years before Davy would realize that he had been too hasty in publishing his arguments.

Davy's arguments against Lavoisier may have earned him ridicule, but the same experiments that led to those arguments also resulted in his discovery of nitrous oxide, also known as "laughing gas," which he detailed in Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide ... and its Respiration (1799). His recommendation that nitrous oxide could be used as an anesthetic went largely unheeded, but his public demonstrations of the gas led to it becoming a very popular recreational gas among the wealthy and elite. His discovery won him an appointment to the Royal Institution in London in 1801, where he became a very popular lecturer, and, in 1803, election to the Royal Society, of which he served as president from 1820 to 1827.

At the Royal Institution, Davy heard reports of a newly discovered technique called electrolysis by means of which water could be decomposed into its elements (hydrogen and oxygen). The technique involved immersing electrodes in a fluid and passing electricity through it, and Davy wondered whether the same technique could be used on other compounds besides water. To test his idea, he first constructed the most powerful electric battery ever built to that time, and then used it for a series of experiments with commonly available minerals. In 1807, Davy used his apparatus to pass a current through molten potash, resulting in the isolation of potassium. He isolated sodium from soda that same year, and then went on to isolate strontium, calcium, magnesium, and barium. Davy's work established electrolysis as an important industrial process, and it is still widely used to extract many metals from their ores.

Davy's battery troughs and electrolysis equipment

Davy was knighted on April 8, 1812, and, three days later, married Jan Apreece. Later that same year he published Elements of Chemical Philosophy, which he dedicated to his new bride. In 1813 he published Elements of Agricultural Chemistry, the first text on the application of chemistry to agriculture.

Davy's work with electrolysis won him much scientific acclaim, but his popular acclaim came for the invention of a new kind of miners lamp. One of the most common causes of deaths in mines in the early-1800's was the explosion of pockets of underground gas ignited by the naked flame of miners' candle lamps. The most dangerous gas was methane, which cannot be detected by smell. In 1815, a society stuyding mine safety approached Davy for advice. After some experimentation, Davy determined that it was the high temperature of the flame that ignited the gases, not the flame itself, and that if a light had a temperature lower than the ignition point of gases no explosions would occur. He eventually found a way to dissipate the flame's heat by surrounding it with a metal gauze. Although enough oxygen could pass through the gauze to feed the flame, its surface always remained below the ignition point of the gases. In addition, the lamp flame burned with a bluish light when methane was present, warning miners of potential danger. The Davy Lamp, as it became known, made Davy's name familiar to many who knew little about his scientific achievements. It also led to his being created a baronet in 1818.

miners lamps designed by Davy

examples of miners' lamps from The Collected Works of Sir Humphry Davy

Davy's habit of sniffing and tasting unknown chemicals took a toll on his health and by the age of 33 he was a partial invalid. In 1827, hoping to regain his health, he decided to take a break from science and relax in Europe. Although the break from work did serve to relax him it did little to repair his health, and, after suffering a series of paralyzing strokes, he died in Geneva, Switzerland, on May 29, 1829; he is buried in that city's Cimetière des Plainpalais.

Source of Pictures

Anthony Feldman and Peter Ford. Scientists and Inventors, The People Who Made Technology from Earliest Times to Present Day. New York: Facts on File, 1979

See Also

Antoine-Laurent Lavoisier
Calcium

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This page was last updated on 09/03/2018.