to many uses for which borax is employed. In 1855 Dr T. Richardson patented a process for using the picked and washed boronatrocalcite as a substitute for borax in the glass manufacture and preparation of pottery glazes. It id, however, chiefly employed as a source of boracic acid, aiid there are also several methods of obtaining borax
direct from the compound salt.Commercial boracic acid usually contains a considerable percentage of sulphates of ammonium, magnesium, and calcium besides other impurities. To prepare borax from this acid, from 110 to 120 parts of crystallized sodium carbonate are required for 100 parts of boracic acid. The soda is dissolved in a lead-Lined vessel heated with steam, to which the boracic acid is added in repeated charges. The vessel is covered and the carbonate of amirionia given off is led into a solution of sulphuric acid and fixed. For the production of ordinary or prismatic borax the solution is brought to a strength of 20 to 22 Bauine (1 161 to 1 180 sp. gr.) and allowed to cool down as slowly as possible, so that the crystals may assume the large size demanded in commerce. Octahedral borax is deposited when a solution indicating 30 Baume (sp. gr. 1*204:) is slowly cooling down from 79 to 56 C. Below this point the formation of ordinary borax takes place.
Under the blowpipe borax parts with its water, and melts into a clear glass which has the peculiar property of dissolving many metallic oxides, and thereby exhibiting characteristic colours, on which account it is of great value in blowpipe analysis. The same property also renders it a valuable material for pottery glazes and enamels, and as it adheres closely to clean surfaces of metal and prevents their oxidation under high heat, it is indispensable for use in hard soldering, and is largely employed in brass manu factures. It is also one of the ingredients employed in glass-making. Borax forms with oils and fats a soap which has been proposed as a detergent ; but experiments con ducted by the late Professor Thomas Anderson of Glasgow show that it has a more corrosive influence on fibres than common soap. In Belgium powdered borax is used in domestic washing, with the object of economizing soap. Borax is used in medicine as an external application in skin diseases, and the preparation known as mel boracis is a useful gargle in ulceration of the mouth and throat. In Sweden boracic acid is extensively employed for the preservation of meat and milk ; and while it forms an efficient antiseptic, food prepared with it is said to be perfectly fit for use. A very beautiful pigment, now much used in calico-printing, under the name of Guignet s green, is a borate of chromium.
BORDA, Jean Charles, mathematician and nautical astronomer, was born at Dax on the 4th May 1733. He studied at La Fleche, and at an early age obtained a com mission in the cavalry. In 1756 he presented a valuable paper to the Academy of Sciences, who elected him a mem ber. He was present at the battle of Hastembeck, and soon afterwards joined the naval service. He visited the Azores and the Canary Islands, of which he constructed an admir able map. In 1782 his frigate was taken by a British squadron ; he himself was carried to England, but was almost immediately released on parole, and returned to France. He died on the 20th February 1799. Borda was an admirable mathematician, and contributed a long series of valuable memoirs to the Academy of Sciences. His researches in hydrodynamics were highly useful for marine engineering, while the reflecting and repeating circles, as improved by him, were of great service in nautical astronomy. He was associated with Delambre and M6- cliain in the attempt to determine an arc of the meridian, and the greater number of the instruments employed in the task were invented by him. (See Biot, " Notice sur Borda" in the Mem. de TAcad. des Sciences, iv.)
cial cities of France, formerly the capital of Guienne and Bordelais, and now the chief town of the department of Gironde. It is situated 370 miles S.E. of Paris, in 44 50 N. lat. and 25 W. long., on the left bank of the Garonne, about 60 or 70 miles from its mouth, and in the midst of an extensive plain which comprises the district of M6doc, well-known for its red wines. Opposite the town the river makes a semicircular curve, and widens out into an extensive basin, which serves as a harbour, and is lined with quays on both sides for a distance of three miles. Vessels of 800 tons can come up to the town, and ships of the greatest ordinary tonnage have depth enough as far as Pauillac, about 35 miles from the mouth of the river. The basin is crossed by a magnificent stone bridge of 17 arches, 1534 feet long, which was built in 1821, and remained in the hands of a company till 1861 when it was declared free. A short distance further up the river is spanned by a railway bridge. Few cities in Europe can show such a striking water-front as Bordeaux ; and though the streets of the older part are narrow and mean, those of the newer portions are wide and well paved, and contain handsome houses and public buildings. The principal square is the Place des Quinconces, which is adorned with statues of Montaigne and Montesquieu. Among the ecclesiastical buildings the most important are the cathedral of Saint Andre, a fine Gothic structure with two spires 160 feet high; the church of Saint Michel, founded in 1160, and formerly remarkable for a spire 319 feet in height, destroyed by a storm in 1768; Saint Croix, pro bably in existence before the 7th century, restored in 1864-5 ; Saint Paul, built by the Jesuits in 1676 ; and the church of the College Royal, in which is the tomb of Montaigne. The great intellectual activity of the city may be seen from the fact that it possesses an academy (with faculties of theology, law, science, and literature), a medico-pharmaceutical school, a lyceum, a school for deaf- mutes, a normal school, and a school of navigation ; numbers among its societies an academy of sciences, arts, and belles lettres, a medical society (founded in 1798), an agricultural society, a philomathic, a Linnsean, a horti cultural, and an archaeological society ; and maintains nine daily papers, about as many weeklies, and two or three monthly periodicals, besides the official publications of several of the above-mentioned societies. Its communal library, which dates from 1566, contains about 200,000 volumes ; and it has also an antiquarian museum, a museum of natural history, and a picture gallery. Among its benevolent institutions are the hospital of Saint Andre, founded in 1825 to replace an older building of the same name, which dated from 1390, a children s hospital, originated in 1619, a hospital for incurables, a maternity and a military hospital, the lock hospital of Saint Jean, and a magnificent deaf and dumb asylum. Of theatres there are five, the Grand Theatre, finished in 1780 and seated for 1300 ; the Thdatre Louit, opened in 1868, for 2500; the Th6atre Francais, dating from 1857, for 1300; the Th6atre National, opened in 1866, for 1000 ; and the Theatre des Folies Bordelaises built in 1872. A few buildings are of merely antiquarian interest, the most im portant being the Palais Gallien, which is really an old Roman amphitheatre of the 3d century, and the tower of Pey Borland. Bordeaux is the seat of an archbishop, and has a court of appeal, a court of assize, and tribunals of primary instance and commerce. It has also a mint, the coinage of which is marked by the letter K. Its commercial institutions are necessarily numerous and varied;
comprising an exchange, banks, insurance-offices, custom-