Davy was born in Penzance, Cornwall near the extreme southwestern tip of England. When he was nine years old, his family moved away and he was put in charge of his godfather, John Tonkin, who was an apothecary-surgeon. Davy did not excel at school and always regarded himself as basically self-educated. After his father’s death, Davy was apprenticed to John Borlase, another apothecary-surgeon. This man had a dispensary and Davy liked to tinker there with chemicals. It is said that his friends complained that he might blow them all up.

When Davy was 19 read he Lavoisier’s Traité élémentaire de chimie, probably in an English translation. The book was considered revolutionary at the time because of its clear classification of the known elements. Davy was particularly interested in Lavoisier’s views on heat which was regarded there as a weightless element called “caloric”. In a well-known experiment, Davy took two pieces of ice and rubbed them together to produce water by melting. He saw this as disproving Lavoisier’s theory because no substance could have been added in the process.

The next chapter in Davy’s life begins with the oft-quoted anecdote that Davis Giddy (who later changed his name to Gilbert), a well-connected man with scientific interests, saw Davy swinging on the half-gate of Dr. Borlase’s house. Gilbert was impressed by the young boy, allowed him to use his library, and introduced him to a Dr. Edwards who lectured in chemistry at St. Bartholomew’s Hospital in London. Edwards encouraged Davy to use the equipment in his laboratory and this was a catalyst in Davy’s developing a love of science.

In addition to his scientific interests, Davy enjoyed literature and painting. He wrote several poems at this time and at least three of his paintings still survive. One of his poems, written when he was only seventeen, presages his scientific curiosity. Here is one stanza:

To scan the laws of Nature, to explore

The tranquil reign of mild philosophy;

Or on Newtonian wings sublime to soar

Thro’ the bright regions of the starry sky

[14]

Five of his early poems were included in an anthology of Bristol poets [9]. Although he moved on from writing poetry, Davy maintained strong literary connections and had friendships with eminent poets of the Romantic Movement including Samuel Taylor Coleridge, William Wordsworth, and Robert Southey. His influence on Wordsworth has been documented [9]

This interesting organization was formed to exploit the use of the recently discovered respiratory gases for medical practice. Davy joined the Institution in October 1798, and this date emphasizes the very rapid progress in the discovery of the respiratory gases. To recap, Joseph Black had discovered carbon dioxide in 1756 and this was soon followed by the work of Joseph Priestley, Carl Wilhelm Scheele, Antoine-Laurent Lavoisier, and Henry Cavendish, who together not only discovered oxygen, but clearly elucidated the roles of oxygen, carbon dioxide and nitrogen in respiration. So in the space of just 42 years, these critically important gases were discovered and understood, and it was argued that now the time had come to investigate their use in medical practice.

The Pneumatic Institution was the brainchild of Thomas Beddoes (1760–1808) (Fig. 14.2). This colorful man had studied under Joseph Black in Edinburgh, and then continued his work in London and Oxford. As a reader in chemistry at Oxford his lectures were extremely popular. In fact he claimed that the classes were the largest assembled in the University since the thirteenth century! Georgiana, Duchess of Devonshire, visited Beddoes in his laboratory in Bristol where he had started to study the possible medical uses of respiratory gases. She suggested that he should replace the laboratory with a medical pneumatic institution. She tried to persuade the eminent Sir Joseph Banks to give financial support, but he declined partly because of scientific concerns, and partly because he objected to Beddoes’ support of the French revolution. Beddoes corresponded with Priestley and the physician Erasmus Darwin (1731–1802), and was also familiar with the Wedgewoods and other members of the Lunar Society in Birmingham. A grateful patient gave him £1500, and Thomas Wedgewood added £1000 with the rather cynical note “that it was worthwhile expending the sum subscribed in order to assure us that elastic fluids would not be serviceable as medicine” [15].

James Watt (1738–1819), famous for his work on the development of the steam engine, was also interested because his son had pulmonary tuberculosis and he thought that the new gases might be helpful in his cure. As, a result, Watt built a portable gas chamber for some of the experiments. The Institution was set up in Dowry Square, Bristol (Fig. 14.3) and by April 1800 had several inpatients and some 80 outpatients [8]. Davy moved to Bristol in 1799 as Beddoes’ assistant, and soon the Institution was a focus of a number of interesting people including Southey and Coleridge as mentioned earlier. For example Davy was in correspondence with William Wordsworth who asked for Davy’s opinion on his poems.

Davy was soon working hard in the laboratory and one of his first interests were the oxides of nitrogen. Here he took considerable risks because one of the gases he inhaled was nitric oxide which, because of its combination with water to form nitrous and then nitric acid, was potentially very dangerous. However he soon began experiments with nitrous oxide (N₂O) which had previously been prepared by Priestley. His initial experiments were done by adding nitric acid to zinc but later he found that he could prepare pure nitrous oxide by heating ammonium nitrate.

In April 1799 he re-breathed four quarts of the gas from a silk bag with his nose closed and reported “a sensation analogous to gentle pressure on all the muscles, attended by a highly pleasurable thrilling, particularly in the chest and extremities… Towards the last inspirations the thrilling increased, the sense of muscular power became greater, and at last an irresistible propensity to action was indulged in” [3] (p. 458). In recovering from a period of inhaling the gas he stated “My emotions were enthusiastic and sublime; and for a minute I walked about the room perfectly regardless of what was being said to me…I exclaimed… Nothing exists but thoughts!—the universe is composed of impressions, ideas, pleasures and pains” [3] (pp. 488–489). In another experiment he noted the following “by degrees as the pleasurable sensations increased, I lost all connection with external things, traces of vivid images rapidly passed through my mind and were connected with words in such a manner as to produce perceptions perfectly novel” [3] (p. 488). These reactions have much in common with the poetry of the Romantic Movement.

Davy’s reports created considerable interest among his friends and more than 20 of them were keen to try the effects of breathing his new gas. For example, the poet, Robert Southey, reported that breathing the gas “excites all possible mental and muscular energy and induces almost a delirium of pleasurable sensations without any subsequent dejection” [13]. Davy’s friend, Samuel Taylor Coleridge, an eminent poet of the Romantic Movement, inhaled the gas and commented on the subsequent euphoria. He reported that while he was inhaling the gas “towards the last, I could not avoid, nor indeed felt any wish to avoid, beating the ground with my feet; and after the mouth-piece was removed, I remained for a few seconds motionless, in great extacy [sic]” [3] (p. 517).

Coleridge and Wordsworth produced a book titled “Lyrical Ballads, with a few other poems”, the first poem being Coleridge’s “Rime of the Ancient Mariner”. In the preface to the book Wordsworth wrote “The first volume of these poems has already been submitted… to ascertain, how far, by fitting to metrical arrangement a selection of the real language of men in a state of vivid sensation, that sort of pleasure and that quality of pleasure may be imparted…” [19]. This suggests that nitrous oxide may have played a part. Certainly Coleridge also had an addiction to opium.

Davy also made another remarkable finding. In reviewing his experiments, he included the following perceptive statement. “As nitrous oxide in its extensive operation appears capable of destroying physical pain, it may probably be used with advantage during surgical operations in which no great effusion of blood takes place” [3] (p. 556). Further experiments were conducted and in one of these while he was suffering from severe toothache he stated that the “uneasiness was for a few minutes swallowed up in pleasure” but the pain returned when he ceased breathing the gas [3] (p. 465). Therefore Davy was close to recognizing that inhaled nitrous oxide could be valuable for anesthesia. However the gas was not used as an anesthetic until 1844 by the American, Horace Wells (1815–1848).

Davy followed up his initial observations on nitrous oxide with an extensive research program. He studied its effects on a series of animals and he measured its absorption by blood in a test tube. Of special interest to us today is that in order to interpret some of the results he obtained by re-breathing the gas from a bag, he realized that he needed to know the volume of the lungs at the end of a forced expiration, that is the residual volume. He therefore measured this by re-breathing hydrogen which he believed was not absorbed by the blood and reported his residual volume as 41 cubic inches. This is equivalent to about 0.72 l and must have been an underestimate since the normal value is at least double that. Nevertheless Davy can be credited with making the first measurement of residual volume. The next measurement was by the French physiologist, Nestor Gréhant (1838–1910). The same principle is used today in the helium dilution method for measuring lung volumes. Davy’s results of his work at this time were published in full [3].