Considered to be one of the greatest British chemists, Humphry Davy was born in Penzance, Cornwall on 17 December, 1778, the son of a woodcarver. He attended Penzance Grammar School1 followed by a final year at Truro Grammar School in 1793. Strangely, he wasn't particularly interested in scientific or most other subjects at school, preferring to translate Greek poetry and to write stories.
Humphry left school just before the age of 15 and the following year his father died, leaving his mother with substantial debts and five children, including Humphry, to support. In order to clear her debts and 'make ends meet', Mrs Davy moved house, started a millinery business in Penzance and, in partnership with a young refugee Frenchwoman, took in lodgers. One such lodger was Gregory Watt, son of James Watt2.
With the financial help of a family friend the 16-year-old Davy became apprenticed to Dr John Borlase, a surgeon-apothecary in Penzance, where his work involved mixing potions in the laboratory. This opened up a new life for the West Country lad and he commenced upon a prodigious programme of self-education to prepare himself for a career in medicine. However, within a year, a burgeoning interest in electricity and chemistry caused him to divert his studies into these areas.
In 1798, at the age of 20, Davy moved to work at Thomas Beddoes's Pneumatic Institution in Bristol. While there, Davy performed a number of experiments on gases including chlorine. He discovered the anaesthetic properties of nitrogen (I) oxide (nitrous oxide, N2O; 'laughing gas'3), which was first used for this purpose in 1844 by Horace Wells, a Connecticut dentist, for the extraction of teeth. Hitherto this operation was accomplished without the benefit of painkillers. Nitrogen (I) oxide is still used as a light anaesthetic in up to half the operations carried out in the UK, although there have been recent questions concerning its safety, due to post-operative complications. When he wasn't investigating its uses as an anaesthetic, Davy organised 'hilarious evenings' when other scientists were given the opportunity to try it out for themselves.
In Bristol Davy met and socialised with Robert Southey and Samuel Taylor Coleridge, at whose instigation he edited the 2nd edition of William Wordsworth's Lyrical Ballads. Both these attended Davy's laughing gas parties and Southey wrote (in a letter to Thomas ('Tom') Wedgwood, son of the potter Josiah Wedgwood):
Davy has invented a new pleasure, for which language has no name - it makes one so strong and so happy! And without any after disability, but instead of it, increased strength of mind and body. O excellent air-bag! Tom I am sure the air in heaven must be this wonder-working gas of delight.
Davy's work on nitrous oxide attracted attention and, in 1801, he was appointed to a lectureship at the Royal Institution4. He was subsequently appointed to a Professorship in 1802, where he gave a number of public lectures, thus establishing the Royal Institution's excellent reputation in this field. People flocked to these lectures which became very fashionable.
Electricity and Electrolysis
In 1807, he used electricity, in a process called electrolysis, to isolate for the first time the Group 1 metals sodium and potassium. This achievement may be recalled in a verse form known as a Clerihew, said to have been devised by Edmund Clerihew Bentley during a particularly boring chemistry lesson:
Sir Humphry Davy
He lived in the odium
Of having discovered sodium.
Subsequently he isolated the Group 2 metals, calcium, strontium, barium and magnesium in 1808, and also boron.
Davy's discoveries relating to the chemical effects of electricity won him a special dispensation to visit France, in October, 1813, to be presented with the emperor's prize from Napoleon Bonaparte, despite the state of war that existed between Britain and France at that time5. The whereabouts of this medal is unknown.
The Davy Safety Lamp
Davy's genius spread to many fields. The enormously increased requirement for coal for industrial purposes towards the end of the 18th Century brought with it a corresponding increase in the number of mining fatalities, especially those caused by explosion of flammable gases. On 1 October, 1813 The Society for Preventing Accidents in Coal Mines in Sunderland was founded and the chairman, Sir Ralph Milbanke, wrote to Humphry Davy to ask for his help in improving safety. On visiting coal mines in the north of England, Davy was appalled at the risks run by miners who were digging coal by the light of naked flames from candles and oil lamps. There were many fires and explosions caused by flames or sparks coming into contact with methane gas, better known to the miners as 'firedamp'. This seeps through cracks and fissures in the coal face and forms a very explosive mixture with air. In 1815 he invented the eponymous 'Davy Lamp', which improved the safety in coal mines by facilitating lighting while avoiding ignition of flammable gases. This lamp also facilitated the detection of methane as the flame in the lamp turned blue if this gas was present, thus enabling the miners to get out before it exploded.
In coming up with the design for this lamp Davy realised that he had to overcome two problems. Firstly, oxygen had to reach the flame to keep it burning and, secondly, the heat of the flame had to be prevented from reaching the potentially explosive gases surrounding it. Davy solved this problem by enclosing the flame in a cylinder of wire gauze, whch allowed the heat to dissipate before it could ignite any methane outside the gauze. At the same time, oxygen from the air could reach the flame.
Although Davy lamps have long been superseded by electric lamps, they will always be remembered as an important application of science in the interests of human safety.
Davy discovered the elemental nature of chlorine and, with Gay-Lussac, discovered the elemental nature of iodine, realising the similarities between these two elements. He also discovered that diamond is a form of carbon. In the 1820s Davy advised the Admiralty on the protection of ships' copper hulls6 and on improving optical glass.
Davy's research on ships involved the invention of sacrificial protection of copper, a process that worked so well that the copper remained entirely unoxidised, allowing the hulls to be colonised by shellfish. Hence, this research was dropped!
Despite all these achievements, Davy once very magnanimously said that 'My greatest discovery was Faraday.' On 1 March, 1813 Davy appointed a young Chemical Assistant by the name of Michael Faraday at the Royal Institution7. Subsequently, they worked closely together on experiments with electricity, one of the many outcomes being the development of a new type of storage battery.
In addition to the honours already mentioned, Humphry Davy was Professor of Chemistry at the Royal Institution from 1802 until he retired in 1812 following his marriage to Jane Apreece, a wealthy heiress. However, he retained an Honorary Chair for many years. Davy was elected a Fellow of the Royal Society8 (FRS) in 1803 and was awarded its Copley Medal in 1805. He was knighted in 1812.
Humphry Davy was also one of the founders of The Geological Society of London, a learned society with the aim of 'investigating the mineral structure of the Earth', and the oldest national geological society in the world.
Sir Humphry Davy was President of the Royal Society from 1820 to 1826, when he resigned due to ill health and embarked upon a tour of the continent. He suffered a heart attack while in Rome and eventually died in Geneva, Switzerland on 29 May, 1829.