JEAN

See also:

• LEBEUF, EDMOND (1809-1888)
• JEAN LEBEUF (1687–176o)

LEBEUF (1687–176o)  , French historian, was born on the 7th of March 1687 at Auxerre, where his father, a councillor in the parlement, was receveur des consignations . He began his studies in his native town, and continued them in Paris at the College Ste Bathe, He soon became known as one of the most cultivated minds of his time . He made himself master of practically every branch of medieval learning, and had a thorough knowledge of the sources and the bibliography of his subject . His learning was not drawn from books only; he was also an archaeologist, and frequently went on expeditions in France, always on foot, in the course of which he examined the monuments of architecture and sculpture, as well as the libraries, and collected a number of notes and sketches . He was in correspondence with all the most learned men of the day . His correspondence with President Bouhier was published in 1885 by Ernest Petit; his other letters have been edited by the Societe des sciences historiques et naturelles de l' Yonne (2 vols., 1866–1867) . He also wrote numerous articles, and, after his election as a member of the Academic des Inscriptions et Belles-Lettres (1740), a number of Memoires which appeared in the Recueil of this society . He died at Paris on the loth of April 176o . His most important researches had Paris as their subject . He published first a collection of Dissertations sur l'histoire civile et ecclesiastique de Paris (3 vols., 1739-1743), then an Histoire de la ville et de tout le diocese de Paris (15 vols., 1745-1760), which is a mine of information, mostly taken from the original sources . In view of the advance made by scholarship in the 19th century, it was found necessary to publish a second edition . The work of reprinting it was undertaken by H .

Cocheris, but was interrupted (1863) before the completion of vol. iv . Adrien

Augier resumed the work, giving Lebeuf's text, though correcting the numerous typographical errors of the original edition (5 vols., 1883), and added a sixth volume containing an analytical table of contents . Finally, Fernand Bournon completed the work by a volume of Rectifications et additions (189o), worthy to appear side by side with the original work . The bibliography of Lebeuf's writings is, partly, in various numbers of the Bibliotheque des ecrivains de Bourgogne (1716-1741) . His biography is given by Lebeau in the Histoire de l'Academie royale des Inscriptions (xxix., 372, published 1764), and by H . Cocheris, in the preface to his edition . LE BLANC, NICOLAS (1742–1806), French chemist, was born at Issoudun, Indre, in 1742 . He made medicine his profession and in 1780 became surgeon to the duke of Orleans, but he also paid much attention to chemistry . About 1787 he was attracted to the urgent problem of manufacturing carbonate of soda from ordinary sea-salt . The suggestion made in 1789 by Jean Claude de la Metherie (1743–1817), the editor of the Journal de physique, that this might be done by calcining with charcoal the sulphate of soda formed from salt by the action of oil of vitriol, did not succeed in practice because the product was almost entirely sulphide of soda, but it gave Le Blanc, as he himself acknowledged, a basis upon which to work . He soon made the crucial discovery—which proved the foundation of the huge industry of artificial alkali manufacture—that the desired end was to be attained by adding a proportion of chalk to the mixture of charcoal and sulphate of soda . Having had the soundness of this method tested by Jean Darcet (1725–1801), the professor of chemistry at the College de France, the duke of Orleans in June 1791 agreed to furnish a sum of 200,000 francs for the purpose of exploiting it .

In the following

September Le Blanc was granted a patent for fifteen years, and shortly afterwards a factory was started at Saint-Denis, near Paris . But it had not long been in operation when the Revolution led to the confiscation of the duke's property, including the factory, and about the same time the Committee of Public Safety called upon all citizens who possessed soda-factories to disclose their situation and capacity and the nature of the methods employed . Le Blanc had no choice but to reveal the secrets of his process, and he had the misfortune to see his factory dismantled and his stocks of raw and finished materials sold . By way of compensation for the loss of his rights, the works were handed back to him in 1800, but all his efforts to obtain money enough to restore them and resume manufacturing on a profitable scale were vain, and, worn out with disappointment, he died by his own hand at Saint-Denis on the 16th of January 1806 . Four years after his death, Michel Jean Jacques Dize (1764-1852), who had been preparateur to Darcet at the time he examined the process and who was subsequently associated with Le Blanc in its exploitation, published in the Journal de physique a paper claiming that it was he himself who had first suggested the addition of chalk; but a committee of the French Academy, which reported fully on the question in 1856, came to the conclusion that the merit was entirely Le Blanc's (Corn. rend., 1856, p . 553) . LE BLANC, a town of central France, capital of an arrondissement, in the department of Indre, 44 M . W.S.W. of Chateauroux on the Orleans railway between Argenton and Poitiers . Pop . (1906) 4719 . The Creuse divides it into a lower and an upper town . The church of St Genitour dates from the 12th, 13th and 15th centuries, and there is an old castle restored in modern times .

It is the seat of a subprefect, and has a tribunal of first instance and a communal college .

Wool-spinning, and the manufacture of linen goods and edge-tools are among the industries . There is trade in horses and in the agricultural and other products of the surrounding region . Le Blanc, which is identified with the Roman Oblincum, was in the middle ages a lordship belonging to the house of Naillac and a frontier fortress of the province of Berry .