cases, precocious merit enjoys but an ephemeral popularity; the sensations it excites are too vivid to be permanent, and the individual sinks into an obscurity rendered ten times more profound by the brilliancy of the flash which preceded it: but every event in Davy's life appeared as if it were created and directed for his welfare by a presiding genius, whose activity in throwing circumstances in his way was rivalled only by the energy and address with which he converted them to his purpose. The experiments to which we have alluded, favourably as they were received, would probably have shared the fate of many other discoveries, whose practical applications were not obvious; but before the impression produced on the scientific world had lost its glow, Count Rumford was seeking for some rising philosopher, who might fill the chemical chair of the recently-established Institution of Great Britain:could there be any doubt as to whom he should apply? Davy was proposed, and immediately elected.

It would not be difficult to cite some personal anecdotes in order to show what an alteration was suddenly effected in the habits and manners of Davy by his elevation. But where is the man of twenty-two years of age to be found, unless the temperature of his blood be below zero, who could remain uninfluenced by such a change? Look at Davy in the laboratory at Bristol, pursuing with eager industry various abstract points of research; mixing only with a few philosophers, sanguine like himself in the investigation of chemical phenomena, but whose worldly knowledge was bounded by the walls of the institution in which they were engaged. Shift the scene could the spells of an enchanter effect a more magical transformation? Behold him in the theatre of the Royal Institution! surrounded by an aristocracy of intellect, as well as of rank, by the flowers of genius, the élite of fashion, and the beauty of England,-whose very respirations were suspended in their eagerness to catch his novel and satisfactory elucidations of the mysteries of nature! We admit that his vanity was excited by such extraordinary demonstrations of devotion; that he lost that simplicity which constituted the

charm of his character, and assumed the garb and airs of a man of fashion;-is it wonderful if, under such circumstances, the robe should not have always fallen in graceful draperies? But the charms of the ball-room did not allure him from the pursuits of the laboratory. He had a capacity for both, and his devotions to Terpsichore did not interfere with the rites of Minerva. So popular did he become, under the auspices of the Duchess of Gordon, and other leaders of fashion, that their soirées were considered incomplete without his presence; and yet the crowds that repaired to the Institution in the morning were, day after day, gratified by newly-devised and instructive experiments, performed with the utmost address, and explained in language at once the most intelligible and the most eloquent. He brought down Science from those heights which were before accessible only to a few, and placed it within the reach of all. He divested the goddess of all her severity of aspect, and represented her as attired by the Graces. It may be said, and indeed it has been said by some modern Zoilus, who has sought only to discover the defects of Davy, that his style was too florid and imaginative for communicating the plain lessons of truth. But let us consider the class of persons to whom Davy addressed himself: were they students, prepared to toil with systematic precision in order to obtain knowledge, as a matter of necessity? No, they were composed of the gay and the idle, who could be tempted to admit instruction only by the prospect of receiving pleasure. It has been well observed, that necessity alone can urge the traveller over barren tracks and snow-topt mountains, while he treads with rapture along the fertile vales of those happier climes where every breeze is perfume, and every scene a picture. But in speaking of Davy's lectures, as mere specimens of happy oratory, we do injustice to the philosopher: had he merely added the festoon and the Corinthian foliage to a temple built by other hands, he might not have merited any other eulogium; but the edifice was his own-he brought the stone from the quarry, formed it into a regular pile, and then

with his masterly chisel added to its strength beauty, and to its utility grace.

On obtaining the appointment of Professor at the Royal Institution, Mr. Davy gave up all his views of the medical profession, and devoted himself entirely to chemistry.

In 1802, Mr. Davy, having been elected Professor of Chemistry to the Board of Agriculture, commenced a series of lectures before its members; which he continued to deliver every successive session for ten years, modifying and extending their views, from time to time, in such a manner as the progress of chemical discovery required. These discourses were published in the year 1813, at the request of the President and members of the Board; and they form the only complete work we possess on the subject of Agricultural Chemistry. When it is considered how many opportunities the author enjoyed of acquiring practical information from the intelligent members of the Board, and of putting to the test of experience the truth of those various theories which his science had suggested, it can scarcely be expected that another author should arise in the present times who will be able to produce a superior work. He has treated the interesting subject of manures with singular success; showing the manner in which they become the nourishment of the plant, the changes produced in them by the processes of fermentation and putrefaction, and the utility of mixing and combining them with each other. He has also pointed out the chemical principles upon which depends the improvement of lands by burning and fallowing; he has elucidated the theory of convertible husbandry, founded on regular rotations of different crops; and, in short, has brought his knowledge to bear on various other agricultural questions connected with chemistry, which the limits of our memoir will not allow us to detail. We must not, however, omit to mention the important information he has afforded on the subject of the composition of different soils, and the methods to be adopted for their analysis. The processes in use for such an examination, previous to his time, were always complicated, and frequently

fallacious: he simplified the operations, and introduced new and convenient apparatus for the purpose. Nor ought we to pass over in silence the curious results of his experiments on the quantity of nutritive matters contained in varieties of the different substances that have been used as articles of food, either for men or for cattle, by which he was enabled to explain numerous facts connected with the comparative excellence of different articles. Thus, for instance, in the south of Europe, hard, or thin-skinned wheat, is in higher estimation than soft, or thick-skinned wheat; a fact which he showed to depend upon the larger quantity of gluten and nutritive matter which the former contains.

In the year 1803, Davy was elected a Fellow of the Royal Society; he subsequently became its Secretary, and lastly its President. During During a period of five-and-twenty years, he constantly supplied its Transactions with papers; and it is not too much to say, that no individual philosopher, in any age or country, ever contributed so largely in extending truth, or ever achieved so much in eradicating error. The theory of Lavoisier, which was received throughout Europe with the homage due to an oracle, and was even classed in certainty with the doctrine of gravitation-which had withstood all the assaults of the Stahlian philosophers, in Germany, Sweden, and Britain, and passed unimpaired through the most severe ordeals to which any system was ever exposed-yielded, in some of its most essential points, to the cool and dispassionate reasoning of Davy. It is impossible not to admire the candour and humility with which Davy alludes to the circumstance; in speaking of the experiments which it was "his good fortune to institute," he says, "the novel results, while they have strengthened some of the doctrines of the school of Lavoisier, have overturned others, and have proved that the generalisations of the Antiphlogistic philosophers were far from having anticipated the whole progress of discovery."

As the advantages afforded by the history of any great scientific discovery, consist as much in exhibiting step by step, the intellectual operations by which it was accomplished, as

in detailing its nature, or in examining its relations with previously established truths, so must it prove highly interesting to fix the period at which Davy's mind was first directed to the subject of Voltaic electricity. In referring to the “ Additional Observations," appended to his "Chemical Researches," it appears that he had no sooner heard of the curious experiments of Volta upon the effects produced by the contact of two inorganic bodies, than, with his characteristic quickness of perception, he proceeded to enquire whether the fact, previously noticed by himself, of the conversion of nitrous gas into nitrous oxide by exposure to wetted zinc, might not depend upon Galvanic action. It was the early habit of his mind, not only to originate new enquiries, but without delay to examine the novel results of other philosophers; and in numerous instances it would seem that he only required to confirm their accuracy, before he succeeded in rendering the application of them subservient to further discovery.

In examining the numerous memoirs which he presented to the Royal Society, it is impracticable to preserve their chronological succession, without losing sight of that fine intellectual thread by which the mind of their author was conducted through the intricate labyrinths of nature: we shall therefore, in the first place, present to the reader a brief analysis of those several memoirs, in which the laws of electricity have been so profoundly investigated, and its chemical agency so successfully and beautifully displayed in the separation of the elements of hitherto undecompounded bodies. It is impossible to enter upon the subject of galvanic electricity, without recurring to the circumstance which first demonstrated the existence of such an energy, and to the sanguine expectations which it excited. It was natural to believe, when we witnessed the powerful contraction of a muscular fibre by the contact of a metal, that the nature and operation of the mysterious power of vital irritability would be at length developed by a new train of research. It is a curious fact, that an experiment so full of promise to the physiologist should hitherto have failed in affording him any assistance; while,