and especially from nitre. He next republished his paper upon the salubrity of common air at sea compared with the air of the sea-coast and of inland countries, which we have in the Transactions for 1780. Next a memoir on magnetism and artificial magnets: next a republication of his theory of gunpowder, and of pulvis fulminans. The 18th memoir is on the passage of heat through, and inflammability of, metals; with an attempt to determine the quantity of phlogiston which different metallic and other bodies contain.

Previous to his publication on vegetables, in 1779, he had in the year 1775 published in our Philosophical Transactions, vol. lxv. his experiments on the torpedo, which at that time, from the previous experiments of Mr. Walsh, was exciting much attention; and that subject was further cultivated by experiments on the gymnotus, and by the very accurate anatomical observations of the late eminent Mr. J. Hunter. In the year 1776, Dr. I. published, in vol. lxvi., an easy method of measuring the diminution of bulk taking place in the mixture of common and nitrous air, according to the discovery of Dr. Priestley; and he there describes an instrument he had contrived, whereby this nice experiment might be performed with much more facility and accuracy. In the same paper he published his experi ments on platina, which, then a new metal, he had taken much pains to investigate and render fusible. He valued highly a set of buttons of this metal, with which he had a coat mounted. He found platina to be as completely, though not so strongly, magnetic as iron; and that this power was increased by fusion in electrical fire, which he first effected, whilst common fire was found to diminish it. This magnetic virtue he constitutes as a specific property of platina, by which it may be always distinguished from gold, which cannot be rendered magnetic.

In the year 1778, we find a paper in the Phil. Trans. vol. lxviii. describing a ready way to light a candle by a very moderate electrical spark excited positively by a piece of glass, and a match made of cotton powdered with resin. The 48th paper of the same volume contain experiments to explain how far the phenomena of the electrophorus may be accounted for on Dr. Franklin's theory of positive and negative electricity, which he proves to agree perfectly with those exhibited by the late Mr. Canton with elder-pith-balls hanging by linen threads from a wooden box; which balls are excited either negatively or positively by a piece of excited glass.

In vol. Ixix. for the year 1779, he gives an account of a new kind of inflammable air, or gas, which can be made in a moment without apparatus, and is as fit for explosion as other inflammable gases in use for that purpose; together with a new theory of gunpowder.

In October of the same year (1779) he published the first edition of Experiments on Vegetables, before mentioned. To this he prefixes a most grateful dedication to Sir John Pringle, explaining at length the whole series of obligations he was under to him for his early patronage on his first arrival in this country, and for his very extraordinary mark of confidence and respect in recommending him

to the imperial family of Germany, leaving this as a public testimony of his gratitude, being then about to return to Vienna.

Vol. Ixix. contains, in a Bakerian lecture, a memoir on im provements in electricity, by the use of flat glasses, instead of globes or cylinders, which it now appears he had made use of for 15 years. In vol, lxx. for the year 1780, we find a paper on the degree of salubrity of the common air at sea in the Channel com pared with that on the shore, and in various parts of Holland. A letter written from Paris in January 1780, and in vol. lxxii., for the year 1782, contains some further considerations on the influence of the vegetable kingdom on the animal creation.

In the year 1784, two volumes, in octavo, of his various philosophical papers were published in German at Vienna. In 1785, we find Nouvelles Experiences et Observations sur divers Objets de Physique, which wholly consist of subjects of electricity, and the different kinds of air, being chiefly what had been before published in our Transactions. This he dedicates to Dr. Franklin, then residing at Paris, as Minister Plenipotentiary from the United States of Ame rica. In the year 1789, he published a second volume with the same title, dedicated to Baron Dimsdale, and printed under his own eye at Paris. The second volume contains chiefly experiments and observations relating to vegetables, and especially to that green matter produced in water, on which so much had been said by Dr. Priestley. These two volumes are pretty much the same with those that have been published in German, in which there were also some medical as well as physical papers, which, by a mistake of the editors, were omitted in the French edition.

His last publication, in 1798, the year preceding his death, is an Essay on the Food of Plants and the Renovation of Soils, written at the desire of Sir John Sinclair, and published by the Board of Agriculture, of which Sir J. was president, and of which our philosopher had been made a foreign honorary member. In this paper we have an abridged recapitulation and very ingenious application of his experiments and opinions, so fully illustrated in his Experiences sur les Vegetaux, published at Paris, in two volumes, 8vo. in the year 1787 and 1789, to which he continually refers. He surely was the first who demonstrated clearly the singular facts of pure oxygen being continually emitted by vegetables when under the influence of light, by which the air was continually ameliorated, and that of their constantly emitting azote in the dark, by which it is corrupted. It is very true that Dr. Priestley had before him discovered that living plants always ameliorated the atmospheric air, by absorbing phlogiston, a theory in direct opposition to that of our philosopher, who thought this purification was occasioned by their perspiration instead of absorption, which continual absorption of atmospheric air he also allows; and proves, by some most ingenious experiments, that plants derive great part of their nourishment by their leaves; and that respirable air and heat are absolutely necessary to vegetation, though light is not, as they can grow very luxuriantly in the dark, but will emit no oxygen, acquire no green colour, and rather

taint than ameliorate the air. As far as concerns the economy of vegetables, he certainly has thrown more light than any other philo sopher since the time of Hales, whose ingenuity and success must render him immortal. Though it would require too much of the reader's time to enumerate the variety of ingenious inventions and discoveries which he has published, yet I cannot omit making mention of that very brilliant experiment-the deflagration of solid iron in vital air; of which he was so very fond that he always carried a phial of it in his pocket, in which he used frequently to burn a piece of iron wire, to the great entertainment of his female friends.→ Annals of Philosophy.

Account of the Life and Writings of BARON GUYTON DE MORVEAU, F.R.S. Member of the Institute of France, &c. &c.*

LOUIS BERNARD GUYTON DE MORVEAU was born at Dijon, on the 4th January 1737. His father, Anthony Guyton, professor of civil law in the university of Dijon, was descended from an ancient and respectable family.

Young Guyton's early education was not neglected. But, while his father and his tutor were initiating him in the old routine of theories, Nature taught him to resort to the practical acquisition of knowledge. Accustomed every day to see the various artificers, whom his father employed about his house, to indulge a caprice for building, young Guyton insensibly caught the spirit of mechanics.

A visit which he paid to Voltaire in 1756, at Ferney, seems to have given him at one time, a turn for poetry; particularly of the descriptive and satiric kind. At the age of twenty-four, Guyton had pleaded several important causes at the bar, when the office of advocate-general at the parliament of Dijon was advertised for sale. It is well known that all public situations, even of the greatest responsibility, were then sold in France to the best bidder. Guyton's father having ascertained that this place would be acceptable to his son, purchased it for forty thousand francs. In 1764, he was admitted an honorary member of the Academy of Sciences, Arts, and Belles Lettres of Dijon, then one of the most learned societies of Europe: and here begins that brilliant career, which he followed with so much ardour and glory. A few months after, Guyton delivered an Eloge on the President Jeannin, at a public meeting of the Dijon academy: it was full of chaste eloquence, and virtuous sentiments.

The exact sciences were so ill taught, and lamely cultivated, at the time of Guyton's University education, that, after his admission into the academy of Dijon, his notions of mechanical and natural philosophy were scanty and insufficient. He, therefore, applied himself to study the theoretical and practical Chemistry of Macquer; and the Manual of Chemistry, which Beaumé had just published. To the latter chemist he also sent an extensive order for chemical

* Abstracted from Dr. A. B. Granville's Memoirs, in the last Journal of the Royal Institution.

preparations

preparations and utensils, with a view of forming a small laboratory next his office. The fresh pursuits of Guyton did not prevent him, however, from continuing to cultivate literature with success. French academy had proposed for the subject of an Essai, the Eloge of Charles V. of France, surnamed the Wise, and Guyton was one of the candidates.

The

Chance, which led Guyton to become a chemist, was also favourable in procuring him the means of forming an elaboratory, at a very moderate expense, and with little trouble, by the death of a young chemist at Dijon.

In July of the same year, Guyton went to Paris, for the purpose of visiting the scientific establishments of that metropolis, and of purchasing books, preparations, and instruments, which he still wanted, to enable him to pursue his favourite study. The person to whom he addressed himself for this purpose, was Beaumé, who was then among the first of the French chemists.

Guyton's first essay on his return to Dijon, was presented in a note which he read to the academy that same year, but which, not having been printed, has probably been lost. His next memoir was of more importance. The phenomenon of the increase of weight in metals, after a long exposure to the action of fire, had been, in fact, explained by Jean Rey in 1630; but lost sight of almost imme diately afterwards. His explanation was forgotten, and the calcination of metals became once more the subject of controversies and conjectures amongst the successive philosophers who cultivated the science of chemistry.

Various other occupations distinguished the next four or five years of Guyton's life, in his double capacity of a chemist and a lawyer. In a dissertation in defence of the theory of phlogiston, then attacked by several eminent men, we find another instance of the accuracy of M. Guyton's mode of making experiments. That theory was ultimately overthrown by the labours of many of our countrymen, and of the illustrious Lavoisier; but the facts relative to combustion, the calcination of metals, and the increase of weight resulting from it, observed and recorded by Guyton in that dissertation, have not only withstood the shock of that mighty fall, but were afterwards admitted by the latter celebrated reformer of chemistry, as some of the best proofs of his new doctrine.

This and the following year of Guyton's life, were particularly rich in useful and ingenious researches. His experiments on adhe sion are too well known to need particular mention in this place. The results he had obtained from them were afterwards confirmed by other philosophers, who, like him, found, that a disk of glass, ten lines in diameter, adhered to the surface of mercury with a force equal to a weight of 66.5 grains.

About this time, the theory of gases was beginning to threaten the phlogistic doctrine. Guyton took part in the contest, and perceiving the weak side of the doctrine he had hitherto supported, without, however, being yet wholly convinced of the soundness of that of his opponents, in a publication, which does him infinite credit, and in

which his theories and conjectures are supported by new facts and experiments, showed a disposition to adopt the pneumatic doctrine, provided several doubts were explained to him, which yet perplexed and forbade him to embrace its otherwise luminous principles.

[We shall not enter into the controversy concerning the disinfecting powers of gases, or the discoverers of them.]

In 1778, M. Guyton published the first volume of a Course of Chemistry, which shortly afterwards was succeeded by a second, a third, and a fourth volume. The pleasing and desultory part of the science, however, was not the only one that Guyton cultivated. Aware, from his every day increasing knowledge of new and interesting facts, that they were applicable to various objects of public and domestic life, and that they might thus be rendered highly important to society, he studied the different modes of their application; and amongst other enterprises, of which we cannot here undertake to speak, the establishment of a manufacture of nitrate of potash, on a large scale, ought more particularly to be mentioned, This enterprise called forth the thanks of the then minister of finances the celebrated Necker.

The republic of letters had, in that year, to mourn the loss of two men equally celebrated-Rosseau and Voltaire. Burial service had been refused in Paris to the remains of the latter; and the unprejudiced, as well as the most honest, exclaimed against the proceedings. Guyton, in a discourse pronounced at Dijon, thought it necessary to make an allusion to that event, and to express his indignation, that, in a country like France, men such as Voltaire, whose rights to national gratitude and posthumous fame were countless, should be persecuted even beyond the grave. Although this candid and open avowal of his sentiments exposed, for a moment, the attorney general to the attacks and libels of bigots, yet the ap probation of the good and the just was with him; and what other is worth courting?

In 1777 he was charged to examine the quarries of regular schistus and the coal-mines of Burgundy, for which purpose he performed a mineralogical tour through that province. In the memoirs of the Dijon academy for 1779, we find another instance of the useful results of Guyton's new scientific pursuits, in a memoir, giving an account of a rich lead-mine discovered by him, and to work which, for want of other combustibles, he sought for beds of coal in the neighbourhood, though unsuccessfully. A few years later, when Bergman had so well described the properties of the heavy spar and the earth obtained from it, Guyton, greatly assisted by his geological knowledge, searched for it in Burgundy, and found it in considerable quantity at Thôte, so as to be enabled to give to the Dijon academy an accurate description of that mineral, and of the earth which enters into its composition, and which he afterwards called barote, or barytes.

Known for his writings and his researches, he was requested by Pankouke, who meditated the great project of the Encyclopedie Methodique, to undertake the new edition of all the chemical arti

cles