MEMOIR OF SIR HUMPHRY DAVY, BART. LL. D.

PRESIDENT OF THE ROYAL SOCIETY, &c.

THE life of a votary of science affords but scanty materials for the species of biography most interesting to the majority of readers. It presents no "hair-breadth 'scapes," no marvellous adventures-none of those brilliant "sketches of life," which evince a lamentable knowledge of the world; nothing, in short, which is calculated to satiate the thirst of irrational curiosity, or suspend the ennui of indolence and apathy. It is a history of the march of intellect, developing a concatenation of ideas, in natural order and succession; and the interest it is capable of exciting, can only be experienced by those who are qualified, by their own attainments, to participate in the triumphs of reason.

Of the sciences, which have been advanced by the discoveries and improvements of modern times, chemistry stands first; and so extensive, rapid, and important have been the late acquisitions in that branch of human knowledge, that the present age is almost entitled to claim it as its own exclusive discovery. These attainments are chiefly to be attributed to the substitution of the analytical for the synthetical method of philosophising; and, in the next place, to the profound judgment and indefatigable ardour, with which the subject of this memoir has availed himself of that great improvement, in developing the mysterious constitution of the infinitely diversified matter, amongst which we are destined to exist. When we consider that by chemistry we are taught to combine and adapt to our use or pleasure the elements which surround us, and that every discovery in this infinite field of inquiry, confers new powers on man, we have a faint glimpse of a possible futurity, in which the human mind may find a far more extensive scope, for the employment of its energies, than we are now able to conceive. Such anticipations may impress us with a just estimation of this science, and of those eminent professors, to whose labours we are indebted for its present improved state.

The discoveries of Black, Priestley, and Cavendish, Lavoisier, Franklin, and Bergman, had already introduced into chemical science the long neglected requisites of close investigation and logical deduction; but it was reserved for Sir Humphry Davy to demonstrate the vast superiority of modern principles, by the most brilliant career of discovery, which, since the days of Newton, has graced the annals of science.

Sir Humphry Davy was born December 17, 1779, at Penzance in Cornwall. His family is ancient, and above the middle class; his paternal great grandfather had considerable landed

property in the parish of Budgwin, and his father possessed a small paternal estate opposite St. Michael's Mount, called Farfel, on which he died in 1795, after having injured his fortune by expending considerable sums in attempting agricultural improvements. Sir Humphry received the first rudiments of his education at the grammar schools of Penzance and Truro: at the former place he resided with Mr. John Tonkin, surgeon, a benevolent and intelligent man, who had been intimately connected with his maternal grandfather, and treated him with degree of kindness little less than parental.

He was always considered as a distinguished boy; and there are many natives of Penzance, who remember his poems and verses written at the early age of nine years. At that period, his mind seems to have received a bias in favour of poetry, which he continued to cultivate till his fifteenth year, when he became the pupil of Mr. (since Dr.) Borlase, of Penzance, a very ingenious surgeon and accomplished man, intending to prepare himself for graduating as a physician at Edinburgh. Conscious of uncommon powers, and resolved to attempt a nobler career than circumstances appeared to promise, or his friends could expect, Mr. Davy laid down for himself a plan of education, which embraced the circle of the sciences. By his eighteenth year, he had acquired the rudiments of botany, anatomy, and physiology, the simpler mathematics, metaphysics, natural philosophy, and chemistry. But chemistry soon arrested his whole attention, for he at once saw that this science offered the best unexplored field for the exertion of talent. Having made some experiments on the air disengaged by sea-weeds from the water of the ocean, which convinced him that these vegetables performed the same part in purifying the air dissolved in water, which land vegetables act in the atmosphere; he communicated them to Dr. Beddoes, who had at that time circulated proposals for publishing a journal of philosophical contributions from the west of England. This produced a correspondence between Dr. Beddoes and Mr. Davy; in which the Doctor proposed, that Mr. Davy, who at this time was only nineteen years of age, should suspend his plan of going to Edinburgh, and take a part in experiments, which were then about to be instituted at Bristol, for investigating the medical powers of factitious airs; to which proposal Mr. Davy consented, on condition that he should have the uncontrolled superintendence of these experiments. About this time, he became acquainted with Davies Gilbert, Esq. M. P., a gentleman of high scientific attainments, with whom he formed a friendship, which has always continued. Mr. Davy consulted with Mr. Gilbert on his plan of study, and his attachment to chemistry, when that gentleman judiciously advised him to pursue his career in this science. With Dr.

Beddoes, Mr. Davy resided for a considerable time, and was constantly occupied in new chemical investigations, being occasionally assisted by his friend Mr. W. Clayfield, a very respectable and amiable gentleman of Bristol, who was ardently attached to chemical pursuits. Here, he discovered the respirability of nitrous oxide, and made a number of laborious experiments on gaseous bodies, which he afterwards published in "Researches Chemical and Philosophical," a work that was universally well received by the chemical world, and created a high reputation for its author, at that time only twenty-one years of age. This led to his introduction to Count Rumford, and to his being elected Professor of Chemistry in the Royal Institution, established in Albemarle-street, for the purpose of diffusing knowledge, of facilitating the general introduction of useful mechanical inventions and improvements, and of teaching, by courses of philosophical lectures and experiments, the application of science to the common purposes of life. Among the beneficial effects of this Institution, it is not to be accounted the least that it proved the means of removing Mr. Davy to a station which afforded scope and opportunity for the exercise of his talents. On obtaining his appointment, Mr. Davy gave up all his views of the medical profession, and devoted himself entirely to chemistry, with what success the "Transactions of the Royal Society," his "Elements of Chemical Philosophy," of "Agricultural Chemistry," and his work of "Researches on Flame," and on the "Safety Lamp for Coal Mines," will best show.

His first experiments in the capacity of Professor of Chemistry in the Royal Institution, were made on the substances employed in the process of tanning, with others to which similar properties were ascribed, in consequence of the discovery made by M. Seguier of Paris, of the peculiar vegetable matter, now called tannin; but after much investigation, Mr. Davy candidly declared, that practical experiments had already done so much for the art, that very little improvement could be expected from any known theory. He was, during the same period, frequently occupied in experiments on galvanism.

In 1802, he commenced his interesting course of lectures before the Board of Agriculture, which he continued for ten years. The dependence of agriculture upon chemical causes, had previously been noticed, but was first completely demonstrated in these lectures, which, at the same time, conveyed much practical information. But so rapid were the discoveries of the author, that, in preparing these discourses for publication a few years afterwards, he was under the necessity of making several alterations, to adapt them to the improved state of chemical knowledge, which his own labours had, in that short time, produced.

In 1803, he was elected F. R. S., and, in 1805, a Member of the Royal Irish Academy. He had already acquired, by his talents and urbanity, the friendship of most of the distinguished literary men and philosophers of the metropolis, and enumerated among his intimate friends, the late venerable President of the Royal Society, the celebrated philosophers Cavendish, Hatchett, Wollaston, Babington, Children, Tennant, and others equally eminent. At the same time he corresponded with the principal chemists of every part of Europe.

Being appointed in 1806 to deliver the Bakerian lecture of the Royal Society, he displayed some very interesting new agencies of electricity, by means of the well-known galvanic apparatus. Soon afterwards he made one of the most brilliant discoveries of modern times, in the decomposition of two fixed alkalies, which, in direct refutation of the hypothesis previously adopted, were found to consist of a peculiar metallic base united to a large quantity of oxygen. These alkalies were potash and soda, and the metals thus discovered were called potassium and sodium. Mr. Davy was equally successful in the application of galvanism to the decomposition of the earths. About this time he became secretary of the Royal Society.

In 1808 Mr. Davy received a prize from the French Institute, as a tribute to his indisputable merit, from which even national enmity could not withhold the meed of admiration.

In pursuing his experiments on the application of electricity to chemistry, and on the alkalies, phosphorus, sulphur, carbonaceous matter, and the acids which had not been decomposed, he succeeded in proving the simplicity of the oxymuriatic acid. During the greater part of 1810, Mr. Davy was employed on the combinations of oxymuriatic gas and oxygen, and their chemical relations to inflammable bodies; and his experiments were confirmed by those of several French chemists, and by Berzelius of Stockholm. But the inferences drawn by them from these experiments, differed in some instances from those deduced by Mr. Davy. The partisans of Lavoisier would not allow that oxygen is one of the principles of alkalies; they denied the metallism of potash and soda as metallic oxides; and maintained that they were simple bodies, which in combining with hydrogen formed hydrurets.

Towards the latter end of 1810, Mr. Davy delivered a course of lectures before the Dublin Society, and in December received from the provost and senior fellows of Trinity college, Dublin, the honorary degree of LL.D.

In the following year, although we believe Mr. Davy made few discoveries of great public interest, there is reason to believe that he effected one of the greatest importance to his own happiness; and it may fairly be questioned whether the success of

any of his former experiments gave him half the pleasure, which he experienced on the first dawn of the hope that he had excited some interest in the bosom of his present amiable lady, then Mrs. Apreece, widow of Shuckburgh Ashby Apreece, esq. and daughter and heiress of the late Charles Kerr, of Kelso, esq. By his union with this lady, in 1812, Sir Humphry acquired not only a considerable fortune, but the inestimable treasure of an affectionate and exemplary wife, and a congenial friend and companion, capable of appreciating his character and attainments. A few days previously to his marriage, he received the honour of knighthood from his Majesty, then Prince Regent, being the first person on whom he conferred that dignity.

The researches, which led to the invention of the safety-lamp for coal mines, which has been so generally and successfully adopted throughout Europe, may justly be considered as the most important of all Sir Humphry Davy's labours, since they enabled him to provide the means of preserving many valuable lives, and preventing horrible mutilations more dreadful even than death. The frequency of such accidents, arising from the explosion of the fire-damp, or inflammable gas of the coal mines, mixed with atmospherical air, occasioned the formation of a committee at Sunderland, for the purpose of investigating the causes of these calamities, and of endeavouring to discover and apply a preventive. Sir Humphry received an invitation, in 1815, from Dr. Gray, one of the members of the committee; in consequence of which he went to the North of England, and visiting some of the principal collieries in the neighbourhood of Newcastle, soon convinced himself that no improvement could be made in the mode of ventilation, but that the desired preventive must be sought in a new method of lighting the mines, free from danger, and which, by indicating the state of the air in the part of the mine where inflammable air was disengaged, so as to render the atmosphere explosive, should oblige the miners to retire till the workings were properly cleared. The common means then employed for lighting the dangerous part of the mines consisted of a steel wheel revolving in contact with flint, and affording a succession of sparks: but this apparatus always required a person to work it, and was not entirely free from danger. The fire-damp was known to be light carburetted hydrogen gas; but its relations to combustion had not been examined. It is chiefly produced from what are called blowers or fissures in the broken strata, near dykes. Sir Humphry made various experiments on its combustibility and explosive nature; and discovered, that the fire-damp requires a very strong heat for its inflammation; that azote and carbonic acid, even in very small proportions, diminished the velocity of the inflammation; that mixtures of the gas would not explode in metallic canals or troughs, where their