Biographies of Scientific Men/Davy
TWO years after the Declaration of Independence of America, and the same year that an alliance between France and America was signed, England's great chemist, Humphry Davy, was born at Penzance, in Cornwall, on 17th December 1778—four years after the discovery of oxygen.
He went to school until he was fifteen years of age, and was then apprenticed to a surgeon-apothecary. In these young days he was endowed with great observing power and a keen appreciation of Nature. In 1798 he began the study of chemistry by reading Lavoisier's Traité de Chimie; and about this time Davy became acquainted with Mr Davies Gilbert (afterwards President of the Royal Society) and Dr Beddoes. He was employed by the latter to superintend the Pneumatic Institution at Bristol, and from this date his scientific career began—a career that placed Davy's name in the front rank of scientific investigators. " His was an ardent boyhood," says Professor Forbes; " educated in a manner somewhat irregular, and with only the advantages of a remote country town, his talent appeared in the earnestness with which he cultivated at once the most various branches of knowledge and speculation. He was fond of metaphysics; he was fond of experiment; he was an ardent student of Nature; and he possessed at an early age poetic powers which, had they been cultivated, would, in the opinion of competent judges, have made him eminent in literature as he became in science. All these tastes endured throughout life. Business could not stifle them—even the approach of death was unable to extinguish them. The reveries of his boyhood on the sea-worn cliffs of Mount's Bay may yet be traced in many of the pages dictated during the last year of his life amidst the ruins of the Colosseum."
Davy's first paper, published while at Bristol, was on heat, light, and respiration. The memoir laid the foundations of the present dynamical theory of heat. At this period he showed great abilities, was young, enthusiastic, energetic, and ambitious. He was bound to succeed.
While at Dr Beddoes', Davy was introduced to Samuel Taylor Coleridge (poet and philosopher) and Robert Southey (poet, essayist, and historian), and there is no doubt that meeting such men helped to develop his genius and erudition. Davy was one of the most remarkable chemists of his or any age. Chemistry in those days was a young science. "The chains with which Stahl and his successors had so long bound the limbs of the young science had been broken by Lavoisier."
Modern chemistry was developing, and developing at a rapid rate. There were giants in those days whose names are immortal: Berthollet, Proust, Gay-Lussac, Thénard, Dalton, Berzelius, and others.
In 1797 Davy discovered the anæsthetic properties of nitrous oxide gas—a gas used largely by the dentist. About the same time he published his Researches—a work "characterized by vigour and novelty of conception." This work attracted the attention of Count Rumford, the founder of the Royal Institution in London, who required a lecturer for the Institution. Davy was appointed to the post, and about a year later he was elected professor of chemistry. He came to London with the utmost enthusiasm, but "his ungainly appearance was against him," as his lectures were delivered before the élite of London society. Soon, however, "the ability of the young man won the approval of this aristocratic audience, until, in a year or two, he was courted by the highest society in the metropolis, and took that position in the fashionable world which was so well suited to his temperament."
The words of Dr S. Johnson are appropriate for Davy's career in London:—
Me toils and pleasures alternate share,
Books and the converse of the fair,
To see is to adore them;
With these and London for my home,
I envy not the joys of Rome,
The circus or the Forum.
At the Royal Institution he had plenty of time for research, a good laboratory, and influential friends who took the greatest interest in his work and welfare. How different it was with poor Linnæus!
Concerning Davy's first course of lectures at the Royal Institution, it has been stated that
. . . the enthusiastic admiration which they obtained is scarcely to be imagined. Men of the first rank and talent, the literary and the scientific, the practical and the theoretical, blue-stockings and women of fashion, the old and the young—all crowded, eagerly crowded, the lecture room. His youth, his simplicity, his natural eloquence, his chemical knowledge, his happy illustrations and well-conducted experiments, excited universal attention and unbounded applause. Compliments, invitations, and presents were showered upon him in abundance from all quarters; his society was courted by all, and all appeared proud of his acquaintance.
The age of Davy was essentially the age of the voltaic battery in chemical research; and what he did with the battery, recently invented by Volta, were discoveries in chemistry second to no others.
The researches, indicated in his Bakerian lecture of 1806, were rewarded with a prize of three thousand francs by the Académie des Sciences. He began his electrochemical researches in the early years of the last century. In his Elements of Chemical Philosophy he says:—
Electrical effects are exhibited by the same bodies, when acting as masses, which produce chemical phenomena when acting by their particles; it is not therefore improbable that the primary cause of both may be the same, and that the same arrangements of matter, or the same attracting powers, which place bodies in the relations of positive and negative, i.e. which render them attractive of each other electrically, and capable of communicating attractive powers to other matter, may likewise render their particles attractive, and enable them to combine, when they have full freedom of motion. . . . That the decomposition of the chemical agents is connected with the energies of the pile, is evident from all the experiments that have been made; as yet no sound objection has been urged against the theory that the contact of the metals destroys the electrical equilibrium, and that the chemical changes restore it, and, in consequence, that the action exists as long as the decompositions continue.
The Wollaston battery of two hundred cells was constructed for Davy in 1807, and by it many brilliant researches were performed, which excited the rivalry of foreign savants. Among these were the investigations of Gay-Lussac and Thénard, entitled Recherches Physico-Chimiques, published in 1811, and in which are to be found many remarkable observations on the physical and chemical effects of the voltaic battery.
Davy's brilliant researches with the Wollaston battery caused Napoleon I. to have one constructed in 1813 for the École Polytechnique; and one day the Emperor, when speaking to Berthollet, said: "Pourquoi ces découvertes n'avaient pas été faites en France." "Sire," said Berthollet, "c'est que jusqu'à jour nous n'avons pas possédé de pile voltaïque assez puissante." Napoleon had one constructed with six hundred cells (with elements of copper and zinc). This battery, although non-existent now, was the means of producing valuable discoveries in the hands of Gay-Lussac and Thénard.
Davy proved that oxygen was not the acidifying principle of acids, as stated by Lavoisier; and he led the way to the ultimate definition of an acid.
In 1803 Davy was elected F.R.S.; in 1807, Secretary of the Royal Society; and in 1820, its President. During these years a vast number of papers were published by him; and he published the following books: Elements of Agricultural Chemistry (1813); Elements of Chemical Philosophy; Salmonia, or Days of Fly-fishing; and Consolation in Travels, or the Last Days of a Philosopher (published in 1831, two years after his death). The last-named book contains some finely written theories on ethical and moral questions, with descriptions of Italian scenery.
In his book on Agricultural Chemistry, Davy says:—
The attractions of society and his early death (he was only fifty) stopped his work on agricultural chemistry; and it was not until 1840, eleven years after Davy's death, that Liebig published his ever famous work on the same subject.
Rumford and Davy proved that heat was not matter, as had been previously supposed, but a form of energy—the vis viva of the molecules. But the crowning discoveries of Davy were those necessitating the use of the electric battery. To Davy, "the electrolysis of every chemical compound was a new application of the great law established by Newton: 'to every action there is an equal and opposite reaction." By means of the electric battery he decomposed bodies which were generally regarded as elements or simple bodies.
On 19th October 1807 Davy isolated the metals potassium and sodium by electrolyzing potash and soda. In the former case, potassium and hydrogen were evolved at the negative pole, and oxygen at the positive pole of the battery. When Davy first saw the metallic globules of potassium, "he could not contain his joy—he actually bounded about the room in ecstatic delight; and some little time was required for him to compose himself sufficiently to continue the experiment." This was the reward for six years' hard work. His discoveries he described in his second Bakerian lecture before the Royal Society.
The decomposition of potash and soda, proving their compound nature, led to the discovery of barium, strontium, calcium, magnesium, and boron. Thus, by means of the electric battery, Davy proved that the alkalis and alkaline earths were compounds, and contained metals. These discoveries were the foundation of Davy's fame, and are, perhaps, "the greatest in chemistry." As Professor T. E. Thorpe says: "It was a wonderful triumph, and all London marvelled at the production from such common and familiar substances of new, white, soft, easily-oxidized, shining metals, which the eye of man had never seen before!"
In 1812 Davy was knighted, and married a rich Scottish lady, Mrs Apreece. The same year he resigned the chair at the Royal Institution, and in 1813 travelled with his wife on the Continent.
From 1802 to 1812 his labours were intense, and his discoveries were of the highest importance.
In 1813 Michael Faraday became Davy's assistant, and he helped the master in the work on the explosive chloride of nitrogen.
In 1815 (the year of the battle of Waterloo) Sir Humphry Davy invented the miner's safety-lamp. For this invention he was created a baronet in 1818; and the coal-owners of the north of England presented him with a service of plate worth £3000. How many lives this invention has saved from a horrid death it is impossible to estimate.
Davy proved the elementary nature of chlorine, and that hydrochloric acid is a compound of chlorine and hydrogen. His experiments were always most convincing as well as brilliant. While in Paris, he proved that iodine was an element, using the simplest of appliances.
Unremitting devotion to chemistry and society had undermined his constitution to such an extent that in 1826 he was attacked by paralysis, and was forced to relinquish most of his work. He visited the Continent for the benefit of his health; but another attack of paralysis seized him while visiting Rome. He, however, rallied sufficiently to continue the homeward journey. At Geneva he was attacked again, and died on Royal Oak Day (29th May) 1829. Sir Humphry Davy was buried in the cemetery outside the city of Geneva, Switzerland.
He was an untiring and enthusiastic worker, a brilliant experimentalist, an eloquent lecturer, a genius: and "he was full of eager desire to know the secrets of the world in which he lived"; in fact, as Cuvier said of him, "he occupied the first rank among the chemists of this or of any other age."
His work on the elemental nature of chlorine, iodine, etc., his synthesis of hydriodic acid, and his work on the chloride and iodine of nitrogen are examples of first-class work; but they are as nothing to the isolation of the metals of the alkalis and alkaline earths. The era of Davy has been called the "golden age of chemistry in this country"; certainly it was most brilliant, and one never to be forgotten in the history of science.
Sir Humphry Davy said: "The foundations of chemical knowledge are observation, experiment, and analogy. By observation facts are distinctly and minutely impressed on the mind; by analogy similar facts are connected; by experiment new facts are discovered; and in the progress of knowledge, observation, guided by analogy, leads to experiment; and analogy, confirmed by experiment, becomes scientific truth."
Sir Humphry Davy "was a somewhat vain and irritable man, whom early success had made haughty to his inferiors. Indeed, in the recollections of Faraday, who as a young man attended upon him in his travels, we have a rather disagreeable picture of the savant who had forgotten the 'pit out of which he was digged.'"
Later on, however, he appreciated the talents of Faraday, although he strongly opposed the latter's nomination for the fellowship of the Royal Society. Was he jealous of Faraday's successes? Davy was never popular with assistants and colleagues. He was far too imperious, and was "regardless of minor etiquette." Snobbish to aristocrats, arrogant to inferiors, "it is mortifying to think that this great man, captivated by the flatteries of the fashionable world, lost much of the winning simplicity of his early manner and his devotion to science."
Davy received every honour awarded to men of science, but he was refused the Order of the Bath, which he expected.
Of posthumous honours, the Royal Society awards a Davy medal; Dr Ludwig Mond has endowed a research laboratory (called the "Davy-Faraday Laboratory") at the Royal Institution; and there is a statue to his memory in Market Jew Street, Penzance.
It was Count Rumford who was instrumental in bringing Davy to the Royal Institution; therefore a few words about him will not be out of place. Benjamin Thompson Rumford was born in America in 1753, and at the outbreak of the War of Independence he embraced the royalist cause. He was a commander of the King's American Dragoons; in 1784 he entered the Bavarian service, rose to be Minister of War, and was created Count of the Holy Roman Empire. In 1806 he married the widow of Lavoisier, but the marriage was a failure, and they separated in 1809.
Rumford was a celebrated physicist. He invented the photometer known by his name, and his researchesin heat and light are well known to men of science—so much so that the Royal Society perpetuates his name by awarding a Rumford medal for researches in physics. He was the founder of the Royal Institution, and a philanthropist. Rumford died on 21st August 1814, and lies buried in the Cimetière d'Auteuil, Paris.
The large and beautiful monument on his grave was destroyed by a shell during the Commune in 1871, but was restored in 1876, at the expense of the American Academy of Arts and Sciences of the College of Harvard, at Cambridge, Massachusetts, U.S.A.
- Mémoires sur la Chaleur (1809); Recherches sur la Chaleur développée dans la Combustion (1813), etc.