considerable fame. In 1735 it was the scene of a severe battle, in which the Austriaus were defeated by the Spaniards under Mortemar, in whose honour Philip V. caused a pyramid to be erected on the spot. Population
in 1871, 24,978.BITSCH (French, Bitche), formerly Kaltenhausen, a town and fortress in German Lorraine, on the Iliver Horn, at the foot of the northern slope of the Vosges, between Hagenau and Saargemuud. " It was originally a countship in the possession of the counts of Alsace and Flanders, but was bestowed by Frederick III. on the dukes of Lorraine, and at length passed with that duchy to France in 1738. After that date it rapidly increased, and its citadel, which had been constructed by Vauban on the site of the ducal palace, was restored and strengthened. The attack upon it by the Prussians in 1793 was repulsed, and although the Bavarians occupied the town in 1815 and 1818, they did not get possession of the fort. In the war of 1870 it was blockaded by the Germans in vain, and only surrendered in 1871, after the campaign was over. A large part of the fortification is excavated in the red-sandstone rock, and rendered bomb-proof ; while a supply of water is secured to the garrison by the possession of a deep well in the interior. The inhabitants of the town, who in 1871 numbered 3047, manufacture watch- glasses and matches, and carry on a trade in grain, cattle, wood, and peats.
BITTERN, a genus of Wading Birds, belonging to the family Ardeidce, comprising several species closely allied to the Herons, from which they differ chiefly in their shorter neck, the back of which is covered with down, and the front with long feathers, which can be raised at pleasure. They are solitary birds, frequenting countries possessing extensive swamps and marshy grounds, remaining at rest by day, concealed among the reeds and rushes of their haunts, and seeking their food, which consists of fish, reptiles, insects, and small quadrupeds, in the twilight. The Common Bittern (Botaurus stellaris) is nearly as large as the heron, and is widely distributed over the eastern hemisphere. Formerly it was common in Britain, but the extensive drainage of late years has greatly diminished its numbers, and it is now a permanent resident only in the fen districts of England. The bittern in the days of falconry was strictly preserved, and afforded excellent sport. It sits crouching on the ground during the day, with its bill pointing in the air, a position from which it is not easily roused, and even when it takes wing, its flight is -neither swift nor long sustained. When wounded it requires to be approached with caution, as it will then attack either man or dog with its long sharp bill and its acute claws. It builds a rude nest among the reeds and flags, out of the materials which surround it, and the female lays four or five eggs of a uniform dusky brown. Daring the breeding season it utters a booming noise, from which it probably derives its generic name, Botaurus, and which has made it in many places an object of supersti tious dread. Its plumage for the most part is of a pale buff colour, rayed and speckled with black and reddish brown. The American Bittern (Botaurus lentiginosus) is somewhat smaller than the European species, and is found throughout the central and southern portions of North America, where it forms an article of food. It also occurs in Britain as an occasional straggler.
BITTERS, an aromatized alcoholic beverage, so named originally in the United States, where it was first used on account of its flavour and tonic influence. The drink by itself, or as an addition to unflavoured spirits, is used with considerable frequency in Europe, and especially in France it has come to be be favourably regarded as a sub stitute for the insidious and deleterious absinthe. In the year 1867 the daily consumption of bitters in Paris alone had reached 4000 litres. The preparation of bitters in Europe was at first a specialite of the Dutch, and Dutch bitters are the staple used in Great Britain. A consider able variety of recipes are in use for the preparation of Dutch bitters, but generally gentian root is the leading bitter ingredient in the beverages. The following is given as the composition of brandy bitters : Gentian root, 4 oz. ; orange peel, 5 oz. ; cassia bark, 2 oz. ; cardamoms, 1 oz. ; and proof spirits, 1 gallon, coloured with oz. of cochineal. Bitters prepared in the great French cities Bordeaux, Rouen, Havre, Paris, &c. contain extracts of gentian root, bitter orange peel, and orange flowers, with a proportion of sugar, and possess an alcoholic strength of about 40.
BIZERTA, or Benzert, a seaport of North Africa, in Tunis, 38 miles from the capital, on a gulf or salt lake of the same name, which communicates with a shallow fresh water lake in the interior, formerly called Sisara, and now the lake of Gebel Ishkel. It occupies the site of the ancient Tyrian colony Hippo Zaritus, the harbour of which, by means of a spacious pier, protecting it from the north east wind, was rendered one of the safest and finest on this coast. This important work, however, having been neglected by the Turks, the port has been to a great extent choked up. It is still visited by small vessels, and a certain amount of trade is carried on. The exports in 1869 were valued at 19,759. The town is about a mile in circuit ; it is defended by several forts. The principal employment of the inhabitants is fishing. The adjoining lake abounds in fish, particularly mullets, the roes of which, dried and formed into the substance called botargo, form a considerable article of Mediterranean commerce. N. lat. 37 17 , E. long. 9 50 . Population, 8000.
BLACK, Dr Joseph, a celebrated chemist, was born, in 1728, at Bordeaux, where his father a native of Belfast, but of Scottish descent was engaged in the wine trade. He was educated from his twelfth to his eighteenth year at a grammar school in Belfast, whence he removed, in 1746, to the university of Glasgow. There he chose medicine as his profession, and devoted himself earnestly to physical science, being encouraged and guided by Dr Cullen, who then lectured on chemistry in Glasgow, and whose liberal and original views were in unison with Black s own aspirations. From a,ssisting in Cullen s chemical experiments he acquired the delicate manipula tive skill essential to success in original scientific research.
In 1751 he went to complete his medical studies at Edinburgh, and after taking his medical degree there in 1754 revealed himself as a great scientific discoverer. At that time the causticity of the alkalies was attributed to their absorbing an imaginary fire-essence known as phlo giston, an hypothesis which Black overthrew by showing that their causticity depended on their combining with a ponderable gas, carbonic acid, which he named fixed air, meaning that it was found not only as a separate fluid, but as fixed in solid bodies. This discovery, made by Black in his twenty-fourth year, was first sketched in a treatise, De Acido e Cibis orto, et de Magnesia, and afterwards embodied in his work, Experiments on Magnesia, Quicklime, and other Alkaline Substances, which Lord Brougham has declared to be " incontestibly the most beautiful example of strict inductive investigation since the Optics of Sir Isaac Newton."
tigators imagined that atmospheric air was the sole permanently aeriform element, a belief to which even Hales, who had shown that solids contain elastic fluids, had adhered. But when Black proved that a gas not identical with
atmospheric air was found in alkalies, it was made plain