Humphry Davy

views updated

Humphry Davy


English Chemist

Humphry Davy is most famous for his discoveries of potassium, sodium, chlorine, and other elements using powerful voltaic batteries. Through his research he established the science of electrochemistry. On a more practical note, Davy also invented the miner's safety lamp.

Davy was born to a family of modest means in the remote coastal town of Penzance in Cornwall, England. A mediocre student, he preferred the rocky ocean cliffs to the classroom and spent his spare time writing poetry and reading philosophy. At age 16 he entered an apprenticeship as an apothecary to a local doctor, hoping some day to become a medical doctor himself. At age 18 he began studying chemistry and performing his own experiments.

The young Davy's chemical research so impressed a few local scientists that in 1798 at age 19 he was recommended for a position at Dr. Thomas Beddoes's Pneumatic Institution in Bristol, an institution dedicated to researching the medical uses of gases. It was there that Davy discovered through self-experimentation the intoxicating effects of breathing nitrous oxide. Davy carefully researched the chemical and physiological properties of nitrous oxide and thereby secured his reputation as a chemist.

In 1801 Davy left Bristol for London to accept a position at the recently established Royal Institution. In the next 12 years he enjoyed tremendous success as both a lecturer and a chemical researcher. As a lecturer Davy's spectacular demonstrations and especially his inspired scientific discussions laced with religious, metaphysical, and patriotic references so thrilled audiences as to make chemistry all the rage among London's wealthiest and most fashionable classes. Even more successful were Davy's experiments using the voltaic battery. The battery, invented in 1799, was simply a concatenation of copper and zinc plates, separated by fluid, that generated a continuous current of electricity. Davy was convinced that the battery would revolutionize chemical understanding. In 1806 and 1807 Davy presented his most brilliant research on the battery and his theories of electrochemistry (a term he coined.) Through a series of rigorous experiments he demonstrated how the processes of chemical composition and decomposition correspond to electrical states of bodies. Based on his findings, he argued that electricity is identical to chemical attractive and repulsive forces and that indeed electricity is an essential property of matter.

Davy became most famous, however, for his discovery of potassium and sodium in 1807. Davy subjected the alkali potash (and then soda) to the strongest electrical powers he could elicit from three connected batteries totaling 600 double plates. The unusual lustrous globules that appeared at the negative pole of the battery proved to be a new chemical element. Across Europe chemists sought to duplicate Davy's experiments and to re-evaluate the order of chemistry. Meanwhile, Davy built larger and larger batteries and used them to discover numerous other chemical elements and to prove that chlorine, as he called it, is an element rather than an acid. Davy was knighted for his achievements in 1812.

Davy traveled widely in the following years while also continuing his scientific researches. Most importantly, he invented the miner's safety lamp in 1815 in response to disastrous explosions in British coal mines. He discovered that by encasing the lamp's flame in wire mesh it would not ignite methane gas trapped in a mine. As reward for his invention Davy was made a baron. Davy served as president from 1820 to 1827 of the Royal Society, Britain's most prestigious scientific institution.

In his final years the ailing Davy traveled, studied natural history, and wrote poetry and metaphysical treatises. Soon after turning 50 he died and was buried in Geneva, Switzerland.



Humphry Davy spent ten months experimenting with breathing nitrous oxide. He varied the concentration of the gas, increased the quantity, and tested its effects upon headache, indigestion, and dental pain. Changes in hearing, vision, thought, emotion, and desire plus physical changes in the pulse, blood, and breathing were observed and recorded. Ultimately, Davy was seeking to understand the chemical bases of passion and life. For all his experimental caution Davy almost asphyxiated (suffocated) himself at points.

Davy tested the gas publicly on others, often to great spectacle and hilarity. He always first administered regular air to the unknowing subject to check for what we now call the placebo effect. After having been administered the real gas, the subject was observed and—once effects had diminished—questioned as to his or her experiences. Some subjects reported despondent feelings; others reported feelings of ecstasy. A few jumped up and fled the room!

These experiments came under political and social attack. Political essayist Edmund Burke linked the gas and Davy's employer, Dr. Beddoes, to the destructive chaos of the French Revolution.