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DUM * DUMAS,, an eminent French chemist, member of the institute, and senator, was born at Alais, department of Gard, in July, 1800. Like Scheele, Davy, and many other illustrious chemists, he commenced with the study of pharmacy, which he began when very young in his native village, and in 1814 was articled to an apothecary in Geneva. Here he devoted himself with so much ardour to the study of botany and medicine as to attract the notice of the celebrated De Candolle, who kindly encouraged him with his counsels, and gave the young student free access to his library and herbarium. He formed also the acquaintance of Prevost, first as pupil, and afterwards as scientific associate of that distinguished man, in concert with whom he published several papers on the blood, the secretions, the spermatic animalcules, and other physiological and pathological subjects; and when in 1821 he removed to Paris, his reception afforded a flattering proof that his reputation had preceded him, and that his name was already known in scientific circles. It was, therefore, with general approval that in 1823 he was appointed demonstrator of chemistry at the polytechnic school, and professor of chemistry at the Athénée, from which period he abandoned the special study of medicine, and devoted himself exclusively to chemical science. About this time, also, he married the daughter of the celebrated chemist, Alexandre Brogniart. He now commenced a series of researches and publications, which soon obtained for him the highest rank, not only as a skilful experimentalist, but as an original thinker. His early physiological pursuits had particularly prepared him for the study of organic chemistry, which was still in its infancy, and was encumbered with an infinite number of ill-defined bodies, which no one had yet been able to group methodically. His labours and investigations inaugurated a new era in this department of science; and his researches on the ethers and isomeric bodies, his exact determinations of several atomic weights, and particularly his doctrine of substitutions, have placed him in the front rank of chemists. On the latter subject he sustained a successful controversy with Berzelius, a man of whom it has been said, that "of all the philosophers of Europe, he could least endure contradiction." It was in 1815 that Dr. Prout announced anonymously his celebrated doctrine, that the atomic weights of all bodies, solid as well as gaseous, are multiples of the atomic weight of hydrogen. The late Dr. Thomas Thomson of Glasgow, who was the first to acknowledge the truth and appreciate the importance of this theory, published in 1818 a revised table of atomic weights, which strongly supported it, and the results of which were further confirmed by a series of systematic researches into the atomic constitution of bodies, which were published by the same chemist in 1825. Even with these illustrations in its favour, Berzelius refused to accept the doctrine of Prout, and actually charged Dr. Thomson with assuming or adapting the numbers to agree with the theory. But Dumas, in a series of carefully-conducted experiments, obtained similar results; and it is chiefly in consequence of his powerful advocacy that Front's theory is now recognized as the expression of a fundamental law that is all but established. At the same time there are few chemists who are quite prepared to follow Dumas to his extreme inference, that all the simple bodies are merely hydrogen in different degrees of condensation—a theory which would bring us back to the ancient idea of a first principle, and the absolute unity of matter.

In 1828 Dumas commenced his great work—a "Treatise on Chemistry applied to the Arts"—which appeared in successive portions, and was completed in 1845 in eight volumes 8vo. This work embodies his prelections at the central school of arts and manufactures, of which he was one of the founders in 1829, and in which he officiated as one of the teachers of chemistry. In 1832 he was elected a member of the Academy of Sciences, and in 1834 a member of the Academy of Medicine, which led to his appointment, after a brilliant concours, to the chair of organic chemistry in the école de medicine. In 1845 he was elected president of the Society for the Encouragement of Industry; and at different times he was named on government commissions charged with the preparation of projects of law on subjects of national importance, such as the imposts on salt and sugars, the ventilation of hospitals and prisons, the new coinage, &c. It was not, however, until 1849 that he appeared on the political arena as member of the legislative assembly for the department of the Nord; and towards the close of the same year he was intrusted with the porte-feuille of agriculture and commerce, which he held till his resignation of office in January, 1851. As one of the ministry, he presented several important projects of law, chiefly with reference to the establishment of institutions for the social and sanitary amelioration of the working classes, and for the improvement of agriculture. It was also during his tenure of office, and under his zealous and enlightened superintendence, that preparations were so extensively and successfully made in France for the Great Exhibition in London, of which he acted as one of the vice-presidents. After the coup d'état of December 2, he became one of the consultative commission, and was named a member of the senate, and vice-president of the superior council of public instruction.

In the midst of these active employments, and his various engagements as a professor, Dumas has found time to be a voluminous writer: and to enumerate even the titles of his various contributions to chemical science published in different journals, would exceed the limits necessarily assigned to these memoirs. In addition to his early physiological papers, written in conjunction with Prevost, and his great work on applied chemistry, which will ever remain an enduring monument of his industry and extensive research, we may mention the admirable work on "Chemical Statics," in which he was associated in his researches with M. Boussingault, and a volume entitled "Memoires de Chimie," which was published in 1843, containing papers on chemical types, the atomic weight of carbon, the composition of water, &c. The reader is referred also to the Annales de Physique et de Chimie, vols. xxxi. to lviii., for several important memoirs on some new chemical compounds, on the atomic theory, isomerism, the nature of indigo, the ethers, wood-spirit, the combination of hydrogen with carbon, and various other subjects. He likewise contributed several important articles to the Annales de l'industrie française et etrangère, a periodical which was founded by himself in 1828; also to the Annales des Sciences Naturelles, and the Journal de Chimie Medicale; and, lastly, a great number of his reports and communications are contained in the Comptes-Rendus de l'Academie des Sciences.

Dumas is one of those men who reflect honour on France by showing that in that country the highest political offices are open to men of eminent talent, especially when solid attainment and profound knowledge are combined, as in the case of this philosopher, with a graceful simplicity of style and a copious fluency of diction. These qualifications, added to a boldness in philosophical speculation—which has sometimes been imputed to him as a fault, but which is ever united in his works with a tendency to practical application—and a spirit of patient research which shrinks not from the minutest details, have justly raised him to the highest position in the philosophical world, and have enabled him to exert an important influence in moulding the opinions of his contemporaries.—G. BL.  DUMAS,, Count, was born of a good family at Montpellier, September 23, 1753. In his fifteenth year he entered the regiment of Medoc as sub-lieutenant. When France armed itself in favour of the revolted American colonies, Dumas, now a captain, was appointed aid-de-camp to the marquis of Puy Sègur, charged to make a descent upon England. That foolish project being abandoned, he took part in the American war. Major in 1784, he was sent, on his return to France, to Constantinople and the Black Sea. In 1791 he organized at Metz the first company of horse artillery formed in France. The department of Seine et Oise nominated him member of the legislative assembly in the same year; of which he became the president the year after in the room of Condorcet. In this office he showed the highest moderation. In 1795 he was appointed a member of the council of ancients, when he made a remarkable oration, offering a crown of oak to Generals Bonaparte and Berthier. He now fled to Hamburg, disgusted with public affairs. Recalled to France in March, 1800, Bonaparte set him to organize the army of reserve at Dijon. In the campaign of 1801 he saved the artillery of the vanguard, engaged during four days at Splugen. To the success of this war he contributed by his zeal, prudence, and activity; and at its close, being nominated councillor of state, he proposed in the name of the government the creation of the legion of honour. Attached to the suite of Joseph Bonaparte, in 1805 he became minister of war at Naples. In 1809 he took part in the passage of the Danube and the battle of Wagram. In 1812 he was intendant-general of the army during the Russian expedition, followed 