a time. In the campaign of Marengo he was the nominal head of the Army of Reserve, but the first consul accompanied the army and Berthier acted in reality, as always, as chief of staff to Napoleon. At the close of the campaign he was employed in civil and diplomatic business. When Napoleon became emperor, Berthier was at once made a marshal of the empire. He took part in the campaigns of Austerlitz, Jena and Friedland, and was created duke of Valengin in 1806, sovereign prince of Neuchâtel in the same year and vice-constable of the empire in 1807. In 1808 he served in the Peninsula, and in 1809 in the Austrian War, after which he was given the title of prince of Wagram. Berthier married a niece of the king of Bavaria. He was with Napoleon in Russia in 1812, Germany in 1813, and France in 1814, fulfilling, till the fall of the empire, the functions of “major-general” of the Grande Armée. He abandoned Napoleon to make his peace with Louis XVIII. in 1814, and accompanied the king in his solemn entry into Paris. During Napoleon’s captivity in Elba, Berthier, whom he informed of his projects, was much perplexed as to his future course, and, being unwilling to commit himself, fell under the suspicion both of his old leader and of Louis XVIII. On Napoleon’s return he withdrew to Bamberg, where he died on the 1st of June 1815. The manner of his death is uncertain; according to some accounts he was assassinated by members of a secret society, others say that, maddened by the sight of Russian troops marching to invade France, he threw himself from his window and was killed. Berthier was not a great commander. When he was in temporary command in 1809 the French army in Bavaria underwent a series of reverses. Whatever merit as a general he may have possessed was completely overshadowed by the genius of his master. But his title to fame is that he understood and carried out that master’s directions to the minutest detail.
BERTHOLLET, CLAUDE LOUIS (1748-1822), French chemist, was born at Talloire, near Annecy in Savoy, on the 9th of December 1748. He studied first at Chambery and afterwards at Turin, where he graduated in medicine. Settling in Paris in 1772, he became the private physician of Philip, duke of Orleans, and by his chemical work soon gained so high a reputation that in 1780 he was admitted into the Academy of Sciences. In 1785 he declared himself an adherent of the Lavoisierian school, though he did not accept Lavoisier’s view of oxygen as the only and universal acidifying principle, and he took part in the reform in chemical nomenclature carried out by Lavoisier and his associates in 1787. Among the substances of which he investigated the composition were ammonia, sulphuretted hydrogen and prussic acid, and his experiments on chlorine, which he regarded, not as an element, but as oxygenated muriatic (oxymuriatic) acid, led him to propose it as a bleaching agent in 1785. He also prepared potassium chlorate and attempted to use it in the manufacture of gunpowder as a substitute for saltpetre. When, at the beginning of the French Revolution, the deficiency in the supply of saltpetre became a serious matter, he was placed at the head of the commission entrusted with the development of its production in French territory, and another commission on which he served had for its object the improvement of the methods of iron manufacture. He was also a member in 1794 of the committee on agriculture and the arts, and technical science was further indebted to him for a systematic exposition of the principles of dyeing—Élémens de l’art de la teinture, 1791, of which he published a second edition in 1809, in association with his son, A. B. Berthollet (1783-1811). After 1794 he was teacher of chemistry in the polytechnic and normal schools of Paris, and in 1795 he took an active part in remodelling the Academy as the Institut National. In the following year he and Gaspard Monge were chosen chiefs of a commission charged with the task of selecting in Italy the choicest specimens of ancient and modern art for the national galleries of Paris; and in 1798 he was one of the band of scientific men who accompanied Napoleon to Egypt, there forming themselves into the Institute of Egypt on the plan of the Institut National. On the fall of the Directory he was made a senator and grand officer of the Legion of Honour; under the empire he became a count; and after the restoration of the Bourbons he took his seat as a peer. In the later years of his life he had at Arcueil, where he died on the 6th of November 1822, a well-equipped laboratory, which became a centre frequented by some of the most distinguished scientific men of the time, their proceedings being published in three volumes, between 1807 and 1817, as the Mémoires de la société d’Arcueil. Berthollet’s most remarkable contribution to chemistry was his Essai de statique chimique (1803), the first systematic attempt to grapple with the problems of chemical physics. His doctrines did not meet with general approval among his contemporaries, partly perhaps because he pushed them too far, as for instance in holding that two elements might combine in constantly varying proportions, a view which gave rise to a long dispute with L. J. Proust; but his speculations, in particular his insistence on the influence of the relative masses of the acting substances in chemical reactions, have exercised a dominating influence on the modern developments of the theory of chemical affinity, of which, far more than T.O. Bergman, whom he controverted, he must be regarded as the founder.
BERTHON, EDWARD LYON (1813-1899), English inventor, was born in London, on the 20th of February 1813, the son of an army contractor and descendant of an old Huguenot family. He studied for the medical profession in Liverpool and at Dublin, but after his marriage in 1834 he gave up his intention of becoming a doctor, and travelled for about six years on the continent. Keenly interested from boyhood in mechanical science, he made experiments in the application of the screw propeller for boats. But his model, with a two-bladed propeller, was only ridiculed when it was placed before the British admiralty. Berthon therefore did not complete the patent and the idea was left for Francis Smith to bring out more successfully in 1838. In 1841 he entered Magdalene College, Cambridge, in order to study for the Church. There he produced what is usually known as “Berthon’s log,” in which the suction produced by the water streaming past the end of a pipe projected below a ship is registered on a mercury column above. In 1845 he was ordained, and after holding a curacy at Lymington was given a living at Fareham. Here he was able to carry on experiments with his log, which was tested on the Southampton to Jersey steamboats; but the British admiralty gave him no encouragement, and it remained uncompleted. He next designed some instruments to indicate the trim and rolling of boats at sea; but the idea for which he is chiefly remembered was that of the “Berthon Folding Boat” in 1849. This invention was again adversely reported on by the admiralty. Berthon resigned his living at Fareham, and subsequently accepted the living of Romsey. In 1873, encouraged by Samuel Plimsoll, he again applied himself to perfecting his collapsible boat. Success was at last achieved, and in less than a year he had received orders from the admiralty for boats to the amount of £15,000. Some were taken by Sir George Nares to the Arctic, others were sent to General Gordon at Khartum, and others again were taken to the Zambezi by F. C. Selous. Berthon died on the 27th of October 1899.
BERTHOUD, FERDINAND (1727-1807), Swiss chronometer-maker, was born at Plancemont, Neuchâtel, in 1727, and settling in Paris in 1745 gained a great reputation for the excellence and accuracy of his chronometers. He was a member of the Institute and a fellow of the Royal Society of London, and among other works wrote Essais sur l’horlogerie (1763). He died in 1807 at Montmorency, Seine et Oise. He was succeeded in business by his nephew, Louis Berthoud (1759-1813).
BERTILLON, LOUIS ADOLPHE (1821-1883), French statistician, was born in Paris on the 1st of April 1821. Entering the medical profession, he practised as a doctor for a number of years. After the revolution of 1870, he was appointed inspector-general of benevolent institutions. He was one of the founders of the school of anthropology of Paris, and was appointed a professor there in 1876. His Démographie figurée de la France (1874) is an able statistical study of the population of France. He died at Neuilly on the 28th of February 1883.
His son Alphonse Bertillon, the anthropometrist, was born in Paris in 1853. He published in 1883 a work Ethnographie