Popular Science Monthly/Volume 14/April 1879/Sketch of Sir Humphry Davy
|SKETCH OF SIR HUMPHRY DAVY.|
HUMPHRY DAVY, one of the world's greatest chemists, and the discoverer of the electric light, was born December 17, 1778, at Penzance, in Cornwall. His father, a wood-carver and gilder by trade, died in 1794, leaving his widow and five children, the oldest of whom was Humphry, in destitute circumstances.
Humphry was a strong, active, healthy child, and gifted with a singularly retentive memory. Sent to an elementary school at the age of six, he made such rapid progress that soon the master had him transferred to the town grammar-school. In his boyhood he manifested a strong liking for open-air sports—riding, fishing, shooting, and the like—also for making collections of natural-history specimens. This bias was anything but pleasing to his teachers and guardians, who feared that, unless he gave more time and attention to his book-lessons, he would grow up to be a ne'er-do-well. Fishing was his favorite amusement. When a little child he was to be seen after every rain—and rains are exceptionally frequent at Penzance—fishing in the street-gutters. At nine years of age he went to live in the household of a Mr. Tonkin, a friend of his mother's family, resident at Varfell, a little village in Mount's Bay. The site of Varfell is a charming one, and the surrounding country is rich in minerals. Young Davy, who was of a poetic temperament, was at home in this delightful nook, and what with his shooting, fishing, and collecting, his days were full of enjoyment. Evidently he loved nature rather than books, and though his guardian feared that his studies—if study that may be called which was all play—were taking a wrong direction, he was in reality acquiring the rudiments of a very solid education—acquaintance with nature's ways. The little child who fished in the gutters of Penzance later wrote that charming work, "Salmonia, or Days of Fly-Fishing," wherein, mingled with notes of his piscatorial exploits in the trout-streams of the Austrian Alps, are philosophical reflections on the deepest problems of the universe. As a boy he loved to roam among the hills of his native Cornwall; in the fullness of his fame he was passionately fond of traveling, and his latest book was "Consolations of Travel"—the work of a dying Plato, as it was called by Cuvier.
On the death of his father, Davy, who was then just entering on his sixteenth year, was apprenticed to Mr. Borlase, apothecary and surgeon of Penzance. He now resolved to begin a systematic course of study, literary and scientific. In his boyish ardor, the task he set himself was nothing less than the acquisition of universal knowledge. His MSS. of this period contain the germs of many of the thoughts which found more perfect expression in his maturer writings. In his notebooks, a voluminous collection of which he left behind him, he was accustomed to make a record of every chance observation, and of every more important thought which occurred to his mind. Says a writer in the "Chemical News," to whom we are indebted for many of the particulars of Davy's career contained in the present sketch: "Observations of every kind and sort are included in these pages. At one time he notes down a peculiarity of flight in a swallow, at another a philosophical or theological puzzle, at another the anomalous behavior of certain reagents, with a view to further investigation; whatever, in fact, he observes, down it goes for future reference or consideration."
In 1796 he read Lavoisier's "Elements of Chemistry," and so was led to the experimental study of that science, in which later he attained the highest eminence. The following year he began to write his "Researches on Light and Heat," published in 1799. One of his first chemical researches had for its object to determine the nature of the air which fills the vesicles of common sea-weed; and he demonstrated that the marine plants act upon the air precisely in the same way as the terrestrial, by decomposing carbonic acid under the influence of the sun's rays. These physical and chemical researches won for him in 1798 an invitation from Dr. Beddoes, director of the "Pneumatic Institution" at Clifton—a sort of hospital for the treatment of pulmonary diseases by the inhalation of different gases—to become his assistant. Having removed to Cifton, Davy made use of the facilities which the Pneumatic Institution afforded for studying the physiological effects of various gases—as nitrous oxide (laughing-gas), carbonic acid, nitrogen, etc. These experiments more than once came very near being fatal to the venturesome young chemist, and indeed his health was seriously impaired, so that he was forced for a time to intermit his researches. While at Clifton he also took up the subject of galvanism, and thus laid the foundations for bis brilliant discoveries in electro-chemistry.
In 1801 Count Rumford offered him the position of lecturer on chemistry in the London Royal Institution, which he had recently founded. This post he held for one year, and then was formally appointed Professor of Chemistry in the same institution. Davy was a remarkably handsome man, of good stature, gifted with great eloquence, and above all an enthusiast. His lectures at once became the talk of the town, and the highest ranks of society began to throng the theatre of the Royal Institution whenever Davy was announced to give a lecture. He was, as the saying goes, the lion of the metropolis, and was carried away by the tide of fashionable life. During the hours of the day he attended to his duties at the Royal Institution, and pursued his scientific researches with the same ardor as ever, but he "devoted the evening to social intercourse with the aristocracy of birth and brain, with all the thoroughness of his nature."
In 1802-'3 he delivered a course of lectures on agricultural chemistry. These lectures were afterward published under the title of "Elements of Agricultural Chemistry," and the work passed through many editions at home, besides being translated into almost every language of Europe. His observations on the chemistry of tanning were published in 1803 in the "Philosophical Transactions." His researches on electro-chemistry, begun at Clifton, were continued at the Royal Institution. His two famous "Bakerian Lectures," the first on the laws of electricity in relation to chemical combination, and the second on the results of the application of these laws, were delivered in 1806 and 1807 respectively. He discovered the base potassium October 6, 1807; sodium and other bases soon afterward. We are told that "when he saw the globules of potassium appear and take fire as they entered the air, his delight was so great that for some time he could not compose himself sufficiently to continue the experiment." Indeed, his mental labor and the excitement over his discoveries had such an effect on his general constitution, that for several weeks he lay seriously ill. On his recovery he presented to the Royal Institution the battery of two thousand cells with which he had made these great discoveries. It was with this battery that, in 1813, he produced for the first time the electric light. When the current from this pile was passed between two pointed pieces of wood charcoal, attached to conducting wires, a light was produced of such dazzling brilliancy as to be comparable only with sunlight. The length of this electric arc was four inches.
In 1803 he was elected a Fellow of the London Royal Society. He was knighted in 1813, and the same year married a wealthy widow, Mrs. Apreece. His "Elements of Chemical Philosophy" were published this year. He now resigned his professorship at the Royal Institution, and in the following year visited the Continent of Europe. At Paris he was received with distinguished honor by the Academy of Sciences, and demonstrated to that august body that iodine is an element. He remained abroad some two years, in the mean time diligently pursuing his chemical researches. At Florence he investigated the nature of the diamond, which he proved to be an allotropic form of carbon. His researches on colors and on the iodine compounds were also carried on during this period.
In 1815 he made the tour of Scotland, and on his homeward journey visited the coal districts of England. A committee of colliery proprietors waited on him to induce him to study the causes of the numerous explosions of fire-damp which were annually attended with fearful loss of life. He began his investigation by analyzing the gas and ascertaining in what proportions its mixture with air renders it most explosive. Having observed that the combustion was not communicated through tubes of small dimensions, he gradually reduced the length of the tubes till he found that a simple metallic gauze, with spaces not exceeding 22 of an inch square, was sufficient to prevent the burning gas on the one side from igniting the explosive mixture on the other. On this principle he constructed his "safety-lamp."
At the recent celebration of the centenary of Davy's birth, held at his native town of Penzance, it was remarked by one of the orators, a colliery proprietor, that but for the discovery of Davy's lamp some of the best seams of coal in England would have remained unworked, or could only have been worked at such cost that none but the rich could afford to use coal. "Davy's lamp," he further said, "is still the best, and if properly constructed, and used in conjunction with efficient ventilation, is an infallible guide to the presence of dangerous gases."
Urged to have his lamp patented, Davy made this noble reply: "My sole object was to serve the cause of humanity; and if I have succeeded I am amply rewarded in the gratifying reflection of having done so." In 1817 the colliery owners and miners of England presented Davy with a magnificent service of plate worth £2,500. This was bequeathed to the Royal Society by Lady Davy, who directed it to be sold and the proceeds applied to the encouragement of science.
In 1818 Davy was created a baronet. The same year he again visited the Continent, traveling extensively in Germany, Hungary, and Italy. The possibility of unrolling the Herculanean papyri engaged his attention while in Naples, and he published observations on volcanic phenomena, and on Oersted's electro-magnetic experiments. He was elected President of the Royal Society in 1820, and held that office for seven years. In 1823 he succeeded in devising a method of preventing the corrosion of the copper sheathing on ships' bottoms.
He now fell into ill health, and but little scientific work was done during the remaining years of his life. Three or four times he visited the Continent, but received little benefit from the change of scene and of climate. He died at Geneva, May 29, 1829, and there, in accordance with his own wishes, was buried. His widow founded a prize in his honor, to be awarded biennially by the Geneva Academy of Sciences for "the most original and important discovery in chemistry."