subject. Let it be remembered, however, that the late Dr. Johnstone, of Worcester, recommended the use of muriatic acid vapour for this very purpose in the year 1756, and had probably repeatedly made use of it in private practice, and in the prison and hospital of that city, some years before its first application by M. Morveau.

The other paper of M. Morveau, already alluded to, has for its object the relation of experiments made to verify Dr. Brook Taylor's method of measuring the adhesion of surfaces.

James Bernouilli, in his dissertations on the weight of the atmosphere, published in 1682, maintains that the resistance which two pieces of polished marble oppose to their separation is owing to the pressure of the air. This, however, was disproved experimentally in 1713 by Hawksbee; and about the same time Dr. Brook Taylor, having observed the ascent of water between two planes of glass, was induced to make several experiments on the adhesion of surfaces, from which he concluded, that the degree of this force might be measured by the weight required to separate them. Nevertheless, in 1772, MM. Lagrange and Cigna, taking for granted a natural repulsion between water and oily substances, imagined, if there was any adhesion between water and a plate of tallow, that it must be occasioned by a cause different from attraction. The reality of the adhesion being then ascertained, they concluded that it must be occasioned by the pressure of the air, and, therefore, that Dr. Taylor's theory was unfounded.

Such was the state of opinions on the subject when M. Morveau's memoir made its appearance. In this paper, he shows first, that water will ascend between two plates of tallow separated from each other of a line, and in circumstances in which the pressure of the air does not appear to have any influence; secondly, he suspended a small polished disk of glass to one arm of a balance, and brought it in contact with a surface of mercury; then, by adding weights to the other arm till the disk separated from the mercury, he ascertained the adhesive force between these two substances; the same apparatus being transferred within the receiver of an air-pump, and a vacuum being produced, precisely the same results as before took place; hence the truth of Dr. B. Taylor's theory was satisfactorily established. In the subsequent part of the memoir, M. de Morveau appears in the higher character of an original discoverer. He observed that the same disk of glass which, when in contact with pure water, adhered to it with a force equal to 258 gr. required a counterpoise of only 210 gr. in order to separate it from a solution of potash, notwithstanding the superior density of this last. No adequate cause for the difference of these results presenting itself, except the difference of chemical affinity between each fluid and the glass, M. de Morveau was encouraged to undertake some other experiments in the hope of adapting an

arithmetical notation to the relative forces of chemical attraction. For this purpose equal plates of the different metals were procured; and being in turn suspended to the arm of an assay balance and counterpoised, were in this state applied to the surface of fluid mercury; and weights were added to the other arm till each disk was separated from its adhesion to the mercury. Each metal was thus found to adhere with a different force; the adhesion of gold equalled 446 gr. and that of iron only 115 gr. the other metals arranging themselves in the following order from gold downwards, viz. silver, tin, lead, bismuth, zinc, copper, antimony. The above order corresponds so nearly with that of the relative affinity of the several metals for mercury, as found by other means, as to render it highly probable that the chief part of the adhesive force thus found by experiment, is owing to chemical affinity, and, therefore, that the numerical series of the weights required to overcome the adhesion is an approximation towards the ratio of the respective affinities for mercury of the metals operated on. The two upper terms, however, of the series are manifestly more incorrect than the others, for mercury will adhere more or less to disks of these two metals, and, therefore, when, in consequence of the counter weight, the separation is effected, it will have taken place not between the gold and the mercury, but between the mercury adhering to the gold and the rest of this fluid.

The above-mentioned investigations had begun to extend the fame of Morveau to England, Germany, Sweden, and Italy, and to procure for him the correspondence of Bergman, Kirwan, and other illustrious foreigners; and the discoveries of Scheele, of Black, and of Priestley, had already begun to attract an unusual share of public attention to the science of chemistry. For these reasons it is not to be wondered at that those pursuits which were at first only the amusement of his leisure, should rapidly acquire in the mind of Morveau the predominance of a ruling passion. Hence in 1776 we find him taking the somewhat unprofessional step of delivering a series of public gratuitous lectures, in illus tration of his favourite science, before the Academy of Dijon, the substance of which was printed in four successive volumes in the course of the next two years, and added considerably to the public reputation already enjoyed by their author.

The name of Morveau now stood so high for extensive knowledge and philosophical views on the subject of chemistry, with most of the men of science at Paris, that when the New Encyclopedia was projected, an offer of the chemical department was made by the proprietors to Morveau. The solicitations of the booksellers being warmly seconded by Buffon and others of his scientific friends, M. Morveau was induced to undertake the laborious and important office of drawing up the chemical and mineralogical dictionary, forming part of this great work, having, however, secured a most able coadjutor for the metallurgical

articles in M. Duhamel. The variety and extensive research, historical, literary, and experimental, required for the execution of an undertaking which should be not unworthy of the reputa tion of the author, and of the high anticipations formed of the great and almost national work of which it constituted a part; the critical state too of the science of chemistry itself, in the very agony of contest between two fundamental theories, and receiving almost daily accessions of newly discovered and highly important facts, soon convinced M. Morveau that nothing less than his undivided attention would enable him to fulfil the engagements into which he had entered. Accordingly in 1783 he resigned all his professional employments, and wholly devoted himself to the service of science.

In 1782 he published a memoir in the Journal de Physique to show the necessity of establishing a scientific and systematical mode of nomenclature for the various substances, simple and compound, which are the objects of chemical investigation. This memoir is generally considered by his countrymen as the first attempt to emancipate chemistry from the trammels of a barbarous jargon, endurable only while the number of substances was yet small, and while much of mystery still continued to veil from vulgar eyes the higher and more recondite processes of the hermetic philosophy. Without the smallest wish to detract from the real merit and just views of M. Morveau on this occasion, it is only common justice to the memory of the illustrious Bergman, to mention that in his essay De Analysi Aquarum, published in 1778, he employs a nomenclature for the compound salts, derived from the sound Linnæan principles of designating every natural substance by a generic and specific appellation, and in more respects than one preferable to that proposed by Morveau. In Bergman's essay, already mentioned, we find alkali vegetabile äeratum, vitriolatum, nitratum, salitum; calx aerata, vitriolata, salita, &c. ; ferrum and argentum vitriolatum, salitum, &c.; hydrargyrus nitratus, together with many other similar examples, showing that the fundamental principles of correct nomenclature were both understood and applied by Bergman, and were borrowed from him by Morveau, with whom he was in constant and intimate correspondence. In the tableau accompanying M. Morveau's paper, we find the following names invented by him, and which are still retained, viz. muriatic and fluoric acids; muriates, phosphates, citrates, &c. as generic terms; barote, potasse, soude, ammoniac, instead of the more circuitous expressions terra ponderosa, alkali vegetabile, alkali minerale, alkali volatile, which still continued to be used by Bergman. The merit of M. Morveau, therefore, on this occasion is not the invention of the great principle of scientific nomenclature, for this is due to Linnæus ; nor the first application of this general principle to the naming of chemical substances, for this praise is due to Bergman; but the adoption of

a few simple, short, and convenient names for some of the supposed simple bodies, and the strenuous and successful exertions which he made to naturalize in France both the principle and the practice.

Two years before the date of the above-mentioned paper, M. Morveau published a translation into French, with notes, of the Opuscula Chemica, &c. of Bergman; he also contributed his valuable superintendence of the translation of Scheele's essays by Madame Picardet, and of a number of memoirs by foreign chemists, which, about this time, enriched the pages of the Journal de Physique. He also, with what success we are not informed, established a manufactory of soda from the decomposition of common salt by a process detailed by Scheele in one

of his

essays.

The

The publication of the first volume of the chemical part of the Encyclopedie Methodique, which now took place, completely justified the high expectations of the chemical world." articles acide, adhesion, affinité, contain a vast fund of information, clearly detailed and drawn up in that truly equitable and philosophic spirit which ensures the permanent value of this volume as an historical record, although for practical use it has now become even obsolete. What the reasons were which induced M. Morveau so soon to discontinue his connexion with this work we are not informed; whatever they were, however, their consequences are much to be regretted.

The high character for integrity and abilities which had been acquired by M. Morveau in his practice as a barrister and a magistrate, drew him again into public life on the breaking out of the French revolution. He was first employed in organizing the department of the Côte d'Or, and was subsequently elected a member of the second National Assembly, and was appointed Solicitor General of his department. At this period, his residence in Paris becoming necessary, he resigned the chemical chair in the university of Dijon to his friend Dr. Chaussier, and established himself in the metropolis. In 1794 he was nominated Professor of Chemistry at the Ecole Polytechnique, and in 1795 was appointed member of the National Institute. In the same year he was re-elected a member of the Council of Five Hundred; but, disengaging himself as soon as possible from political employments, he devoted his whole energy, as Director of the Polytechnic School, to perfecting the system of public instruction, and assisting the progress of general science. His indefatigable efforts in the important trust thus confided to him, were rewarded first, by the post of Administrateur General of the Mint, then by the Cross of the Legion of Honour; and, lastly, in 1811, by the rank of Baron of the Empire. His advanced age and meritorious services now obtained for him an honourable retreat from active life, which he enjoyed for about four years; and then, on Dec.

21, 1815, he quietly expired, having just completed his 80th

year.

The services rendered by M. Morveau to chemistry were undoubtedly very considerable, though it is not easy specially to point them out. By his extensive foreign correspondence he became the medium through which his countrymen derived much of their knowledge of the discoveries made by foreign chemists. To his zeal and ability, as a lecturer and a director of public instruction, much of the popular favour which attached itself in France to chemical investigations is to be attributed; while the general integrity and disinterestedness of his moral character kept him aloof from petty squabbles and intrigues, and thus enabled him quietly and unostentatiously, but effectually, to contribute in various ways, which were rather felt than acknowledged, to the progress of his favourite science.

ARTICLE II.

Memoir upon the Geography of the Plants of France, considered more especially with Regard to their Height above the Level of the Sea. By M. De Candolle. (Abridged from the Third Volume of the Memoirs of the' Society of Arcueil.)

THE geography of plants is almost a new science; although it had been attended to by Linnæus and some of his successors, yet the first writer, who can be considered as having treated upon it in a regular and systematic manner, is M. De Humboldt.* As the facts that are stated in this paper are deduced from observations made in France, and of course in the temperate zone, while M. de Humboldt's are derived from the torrid zone, there may appear to be some difference in the results; but upon

a close examination this difference will be found to be more apparent than real. All the general laws that are laid down as applicable to France may be shown to be conformable to those established by M. de Humboldt; and, indeed, the difference which there is in the facts is itself a verification of the general laws.

One of the most important points in botanical geography is to analyze with accuracy the influence which the absolute height of a place above the level of the sea produces upon vegetation. It is a complicated circumstance, depending upon a variety of causes, which are not necessarily connected together; in order,

* "Essai sur la Geographie des Plantes," 1 vol. 4to. 1807,"avec un Tableau représentant les Hauteurs des Plantes des Cordiliéres."-(See Ann. of Phil. vii. 373.)