nitre, equal to one tenth of the sulphur, is put, with a little sulphuric acid. The combustion of the sulphur is regulated by a sliding door on the oven. In the roof of the remote end of the large chamber, a small orifice is left for the escape of the atmospheric nitrogen, and other incondensable gases. This apparatus is used for the continuous process; but there is another, or that of the intermitting combustion, which is worthy of notice. Large flat trays, containing the sulphur and nitre, are introduced into the interior of the chamber, or into the oven, and fire is applied to the materials. When the sulphur is burned, and the chamber filled with sulphurous and nitrous acids, the steam of water is thrown in, in determinate quantity, by a small pipe at the side. This causes a tumultuous motion among the gases and the atmospheric oxygen, which favors the mutual reaction. As the steam condenses, the sulphuric acid falls with it. After some time, the chamber is aired by opening valves of communication with the external atmosphere. The operation is then commenced anew. Sulphuric acid was formerly obtained by distillation from sulphate of iron; sixty-four pounds are yielded by six hundred pounds of the sulphate of iron. The following are the properties of pure sulphuric acid. It is colorless, has somewhat of an oily or glutinous consistency, and hence the ancient name of oil of vitriol. It speedily chars animal and vegetable substances, when placed in contact with them. It converts vegetable blues to red, and is possessed of an exceedingly acid taste. Acid of the specific gravity 1.85, boils at the temperature of 620°. The boiling point diminishes with the strength. Acid of the specific gravity 1.78, boils at 435°, and acid of the specific gravity 1.65, at 350°. The quantity of water present in one hundred parts of concentrated and pure sulphuric acid is very nearly 18.46. It consists of three proportionals of oxygen, one of sulphur, and one of water; and by weight, therefore, of 3.0 oxygen +2.0 sulphur +1.25 water, which equals 6.125, which represents the combining weight of the concentrated sulphuric acid; while 3+2 5, which is the equivalent of the dry acid. Sulphuric acid strongly attracts water, which it takes from the atmosphere very rapidly, and in larger quantities if suffered to remain in an open vessel-imbibing one third of its weight in twenty-four hours, and more than six times its weight in a year. If

four parts by weight be mixed with one of water at 50°, they produce an instantaneous heat of 300°; and four parts raise one of ice to 212°. On the contrary, four parts of ice mixed with one of acid, sink the thermometer to 4° below 0. It requires a great degree of cold to freeze it; and, if diluted with half a part or more of water, unless the dilution be carried very far, it becomes more and more difficult to congeal; yet, at the specific gravity 1.78, it may be frozen by surrounding it with melting ice. Its congelation forms regular prismatic crystals, with six sides. All the simple combustibles decompose sulphuric acid with the assistance of heat. At about 400°, sulphur converts sulphuric acid into sulphurous acid. Several metals at an elevated temperature decompose this acid, with evolution of sulphurous acid gas, oxidizement of the metal, and combination of the oxide with the undecomposed portion of the acid. Sulphuric acid is of very extensive use in chemistry, as well as in metallurgy, bleaching, and some of the processes for dyeing. In medicine, it is given as a tonic and stimulant, and is sometimes used externally as a caustic. The combinations of this acid with the various bases are called sulphates, and constitute a very important class of salts; for an account of which, see their respective bases.-Subsulphurous acid. It has been found, that sulphurous acid has the property of dissolving iron, without the evolution of any gas. The acid gives out half its oxygen to the iron, and converts it into the protoxide of iron, which combines with the acid in question, and which consists of half the oxygen found in sulphurous acid. When the salt is decomposed, the subsulphurous acid is resolved into sulphurous acid and sulphur. It seems incapable of existing except in combination with a base. When insulated, half the sulphur separates, and sulphurous acid remains. The hyposulphurous acid also seems incapable of existing except in combination with a base. When sulphuric acid in a slight excess is poured into a dilute solution of hyposulphite of strontites, the whole strontites is thrown down, and the filtered liquid consists chiefly of a solution of hyposulphurous acid in water. This liquid is transparent and colorless, is destitute of smell, and has an acid, astringent, and very bitter taste. On standing a few hours, it undergoes spontaneous decomposition, the liquid becomes milky, sulphur is deposited, and sulphurous acid remains in so

lution.-Hyposulphuric acid. By causing a current of the sulphurous acid gas to pass through black oxide of manganese, suspended in water, a neutral salt is formed, which, when dissolved, consists of a mixture of neutral sulphate and hyposulphate of manganese. By pouring into this solution barytes water, the whole of the sulphate of manganese is thrown down, while the hyposulphate is converted into hyposulphate of barytes, which remains in solution. A current of carbonic acid throws down any excess of barytes that may have been added; and then, by evaporating the liquid, the hyposulphate of barytes is obtained in crystals. These crystals are dissolved in water, and the barytes they contain precipitated, by

1. Hyposulphurous acid, 2. Subsulphurous acid, 3. Sulphurous acid, 4. Sulphuric acid, 5. Hyposulphuric acid,

1

1

1

2

Sulphur combines readily with chlorine, forming a liquid compound called chloride of sulphur. It is formed by passing a current of chlorine through flowers of sulphur, or by heating sulphur in a dry glass vessel, filled with chlorine gas. Its color is brownish-red, and it possesses an odor similar to sea-plants. Its taste is acid, hot and bitter. It does not change the color of litmus paper; specific gravity 1.67. When dropped into water, it is decomposed, sulphur being evolved. It is composed of sulphur 2 and chlorine 4.672. By pouring bromine on flowers of sulphur, an analogous compound is formed, called bromide of sulphur. Cold water has but little action on it, but, at a boiling temperature, a slight detonation takes place, and hydrobromic acid is formed, together with sulphuric acid and sulphureted hydrogen. It consists of bromine 10 and sulphur 2. Sulphur has the property of combining with iodine, and of forming a compound called iodide of sulphur. It is easily formed by mixing together the two constituents in a glass tube, and exposing them to sufficient heat to melt the sulphur. It is of a grayishblack color, and has a radiated texture. It has not been analyzed. Sulphur has the property of combining with hydrogen, and of forming a gaseous compound, which has received the name of sulphureted hydrogen. It has also been called hydrosulphuric acid. It may be obtained by pouring sulphuric or muriatic acid upon several metallic sulphurets. Sul

Oxygen.

1 atom

1

2

3

5

Combining Weight.

5

3

4

59

phuret of iron is commonly employed, and may be formed by heating together iron filings and sulphur in a covered crucible. Sulphureted hydrogen gas is colorless, and has a strong, fetid smell, not unlike that of rotten eggs. It does not support combustion, nor can animals breathe it without suffocation. Its specific gravity is 1.1805. It is rapidly absorbed by water,-100 cubic inches of this liquid absorbing 308 cubic inches of sulphureted hydrogen. The water thus impregnated is colorless, but it has the smell of the gas; and a sweetish, nauseous taste. It converts vegetable blue colors to red. When the gas is mixed with common air, it burns rapidly, but does not explode. When three volumes of sulphureted hydrogen gas, and two volumes of sulphurous acid gas, both dry, are mingled over mercury, they unite together, and are condensed into a solid body, which adheres firmly to the sides of the vessel. To this compound, which possesses acid properties, the name of hydrosulphurous acid is applied. Its taste is acid and hot; and it leaves an impression in the mouth, which continues for some time. It requires a greater heat to produce fusion than sulphur. Another compound of sulphur and hydrogen, called bisulphuret of hydrogen, is formed as follows: Carbonate of potash is fused with an excess of sulphur in a covered crucible, by which a sulphuret of potash is formed. A concentrated solution of this sulphuret is poured, by little and little. into dilute muri

atic acid, which gives rise to a yellow, oilylooking liquid, which collects at the bottom of the vessel. This liquid is the bisulphuret of hydrogen. It cannot be kept, for it undergoes spontaneous decomposition even in well-closed vessels, being converted into sulphur and sul phureted hydrogen. Sulphur has the property of combining with carbon, and of forming a very remarkable compound, called bisulphuret of carbon. It is formed as follows:-Fill a porcelain tube with charcoal, and make it pass through a furnace in such a way, that one end shall be considerably elevated above the other. To the lower extremity lute a wide glass tube, of such a length and shape, that its end can be plunged to the bottom of a glass bottle filled with water. To the elevated extremity lute another wide glass tube, filled with small bits of sulphur, and secured at the further end, so that the sul phur may be pushed forward by means of a wire, without allowing the inside of the tube to communicate with the external air. Heat the porcelain tube, and, consequently, the charcoal which it contains, to redness, and continue the heat, till air bubbles cease to come from the charcoal; then push the sulphur slowly, and piece after piece, into the porcelain tube. A substance passes through the glass tube, and condenses, under the water of the bottle, into a liquid. This liquid was obtained by Lampadius in 1796, and described under the name of alcohol of sulphur. It is as transparent and colorless as water; its taste is acid, pungent, and somewhat aromatic; its smell is nauseous and fetid, though quite peculiar; specific gravity 1.27. It boils at 105°, and does not congeal when cooled down to 60°. It is one of the most volatile liquids known, and produces a greater degree of cold by its evaporation than any other substance. It takes fire in the open air, at a temperature scarcely above 620°. It is scarcely soluble in water; but alcohol and ether dissolve it readily. It is composed of sulphur 84.83 and carbon 15.17. Bisulphuret of carbon was found by doctor Brewster to exceed all fluid bodies in refractive power. In dispersive power, it exceeds every fluid substance except oil of cassia, holding an intermediate place between phosphorus and balsam of Tolu. Sulphur combines with boron, silicon and phosphorus, and forms sulphurets of these substances. (For an account of the sulphurets of the metals, see the different metals.)

SULPHURIC ACID. (See Sulphur.)

SULTAN, in Arabic, signifies mighty. The Turkish emperor is called sultan, or grand sultan, although the title of padishah (q. v.) is more dignified. The princes of the family of the khan of the Crim Tartars are also styled sultan. The pacha of Egypt is likewise honored with this title, by the inhabitants of the country, but not at the court of Constantinople. In common life, every person is addressed, out of civility, as sultanum (my lord). The Europeans also call the wives of the sultan, sultanas; but the Turks call them merely first, second, or third wife, &c. The first is she who first bears a son to the sultan. She is likewise called by Europeans the favorite sultana. She has the precedency of all the women of the seraglio, unless her son dies before the sultan, and another of the wives has a son older than any of hers surviving. The title of sultana is applied properly only to one of the wives, who is actually declared wife and empress; but this is rarely done, on account of the expense of a second court, which would be necessary. At Constantinople, only the daughters of the sultan are called sultanas; and they retain this title even after marriage with the officers of the sultan. The daughters of such a marriage are termed kanum sultanas (ladies of the blood). If the mother of the sultan is living, she is styled Walidet-sultana, or sultana Valide. She is treated with great respect, and her son cannot choose a new wife or concubine without her consent. (See Harem.) Sultana is also the name of a Turkish ship of war, carrying about sixty-six guns, with 800 men.

SUMACH (rhus); a genus of plants, belonging to the natural family terebinthacea, consisting of shrubs or small trees, with small, inconspicuous flowers, disposed in racemes or panicles, and leaves usually pinnate, somewhat resembling those of the walnut, but in some species ternate or simple. More than seventy species are known: all have a lactescent juice, more or less acrid, and containing a gumresin.-R. coriaria is found in the countries about the Mediterranean. The young branches, dried and powdered, were used by the ancients for tanning leather; and at the present time, in some parts of Spain and Italy, the black morocco is chiefly prepared with this plant. The roots contain a brown, and the bark a yellow dye. The seeds are in common use at Aleppo, at meals, to provoke an appetite. Both leaves and seeds are used in medicine, as astringent and styptic.-R. typhina is a

shrub, twelve or fifteen feet high, common in the northern parts of the U. States. The young branches are thick, and covered with a dense coating of hairs; hence the common name of stag's horn sumach. The leaves are pinnate, and composed of eleven to fifteen serrated leaflets. The flowers are small and numerous, disposed in an upright hairy panicle, and are succeeded by small berries, which finally turn red, and render this shrub a conspicuous object in the woods. It has been long cultivated in the European gardens for ornament. The berries possess the same properties as those of the preceding, and a very abundant milky juice flows from the bark. This last is pulverized, and employed for tanning.-R. glabra precisely resembles the preceding in habit, and is only distinguished by the smoothness of the leaves and young shoots. It extends farther south, and is common in the Middle States; often overrunning land left for a few years in pasture. The berries dye red, and the branches boiled with the berries afford a black, ink-like tincture. It is likewise cultivated for ornament, in the European gardens, and possesses the same properties as the preceding.-R. pumila is a low, pubescent species, from the mountains of Carolina, which is said to be the most poisonous of the genus.-R. venenata, commonly called dog-wood or poison sumach, is not uncommon in the Northern and Middle States. It attains the height of twelve to twenty feet. The leaves are smooth and entire; the flowers greenish-white, disposed in loose panicles, and succeeded by whitish berries. The poisonous qualities of this plant are well known. Some persons are affected by touching or smelling any part of it, or even by coming within a certain distance; while others appear to be entirely exempt from its influence. When the poison has been communicated, inflammation appears on the skin, in large blotches, in a day or two; soon after, small pustules rise in the inflamed parts, and fill with watery matter, attended with intolerable itching and burning, and lasting several days.-R. copallina is abundant in sandy soil, in many parts of the Middle and Southern States. It is easily distinguished by the leafy expansion on each side of the common petiole. The flowers are greenish-yellow, and are disposed in panicles at the extremities of the branches.-R. radicans, often called, in this country, poison ivy, is a climbing, woody vine, which adheres to the trunks and branches of trees, by means of root-like suckers.

The leaves are ternate, and the flowers are disposed in little axillary racemes. It is common in the Northern and Middle States, and affects certain individuals in the same manner as the poison sumach; but it seems to be less virulent, and fewer persons are exposed to its influence.-R. aromatica differs widely in habit from the others. It is a small shrub, with ternate leaves, having the flowers disposed in aments, which grows chiefly on the Alleghanies, and in the Western States. The berries are hairy and red. The celebrated Japan varnish is obtained from a species of rhus, which was formerly considered identical with our poison sumach; but now is recognised as a distinct species, having the under surface of the leaves downy and velvety. This varnish oozes from the tree, on its being wounded, and grows thick and black when exposed to the air. It is so transparent, that when laid pure and unmixed upon boxes or furniture, every vein of the wood may be clearly seen. With it the Japanese varnish over the posts of their doors and windows, their drawers, chests, boxes, cimeters, fans, tea-cups, soup-dishes, and most articles of household furniture made of wood.

SUMAROKOFF, Alexander Petrowitsch, a distinguished Russian tragic poet, who formed himself on French models, was born in 1718, and died at Moscow in 1777. His tragedies, in point of harmony, taste, and purity of style, are compared to those of Racine, though inferior in poetical inspiration. His principal works are Sineus and Truwor (which appeared in 1755), Semire, Jaropolkund Deinise, Korew and Aristone; all of which were translated into French in 1801. He also wrote Hamlet, Ritschelas, and the Pseudo-Demetrius. The last is considered his best work (translated into French in 1800, also into English). Sumarokoff also wrote comedies, fables and epigrams.

SUMATRA ; an island in the eastern seas, the largest and most westerly of the Sunda islands, separated from the continent by the straits of Malacca, and from Java by the straits of Sunda. It is divided obliquely by the equator into almost equal parts, and its general direction is from N. W. to S. E.; lat. of one extremity 5°56/ N., of the other 5° 56' S. It is about 1000 miles long, and 165, on an average, broad; square miles, about 160,000. A chain of high mountains runs through the whole extent of the island, and the ranges are, in many parts, double and treble. Mount Ophir, immediately under the equinoctial

line, is supposed to be the highest visible from the sea, its summit being elevated 13,842 feet above that level. Among the ridges of mountains are extensive plains of great elevation, and of temperate climate, the most valuable and best inhabited portion of the island. Here, too, are found many large and beautiful lakes. The ridges of mountains lie towards the western shore; in consequence, all the greatest rivers are found on the eastern side. The climate varies with the height of the ground; but on the plains, the heat, is not so great as might be expected from the position; the thermometer, in the greatest heat, about two o'clock P. M., generally fluctuating from 82° to 85°: at sunrise, it is usually as low as 70°. The soil is generally fertile; the population for the most part thin; and a great portion of the island is covered with an impenetrable forest. The most important article of cultivation is rice, of which there are many different species. Of articles of commerce, the most abundant is pepper, formerly obtained in greater quantities than at present. Other productions are, gumbenzoin, camphor, cassia, cotton, coffee, &c. The upas (q. v.) tree, and the gigantic rafflesia (q. v.), are among the vegetable curiosities. It is rich in mineral and fossil productions; has long been famous for gold, which is still procured in considerable quantities; and has mines of iron, copper, and tin. It produces a great variety and abundance of fruits, and wild animals, as elephants, tigers, rhinoceroses, alligators, &c.; also birds of various kinds. The inhabitants are rather below the middle size: their limbs are for the most part slight, but well shaped. The women flatten the noses and compress the skulls of children newly born; and the males destroy their beards. The inhabitants have made but little, progress, generally, in the arts of industry, though they excel in some particular manufactures. The Malay language is every where spoken along the coasts of Sumatra. (See Malays.) Among the modern political divisions of the island, the principal are the empire of Menancabow and the Malays, the Achineese (see Acheen), the Battas (q. v.), the Rejangs, and the people of Lampong. The Dutch first began to form settlements on the coasts in 1666, and in 1685, the English also established themselves at Bencoolen. (q. v.) In 1825, the presidency of Bencoolen, of which the capital was Fort Marlborough, was ceded to the Dutch, in return for Malacca. (q. v.) The latter were already in possession of Pa

dang, a strong fortress on the western coast, and of Palembang (25,000 inhabitants), on the eastern coast. Previous to the late revolution in the Netherlands, they were making preparations to reduce the whole island. Sir Thomas Stamford Raffles (q. v.) was the first European who penetrated to the interior of the island, which he crossed from Bencoolen to Palembang. See Marsden's History of Sumatra, and Anderson's Mission on the East Coast of Sumatra (Edinb., 1826, 2 vols.).

SUMMER; in the northern hemisphere, the season comprehended in the months of June, July, and August; the warmest period of the year. South of the equator, the summer corresponds, in time, to our winter. The entire year is also sometimes divided into the summer, or warm season, and the winter, or cold season. The astronomical summer begins, in the northern hemisphere, when the sun has reached its greatest northern elevation,— therefore about June 21,-and ends when it crosses the equator the second time in the year, about September 23. Notwithstanding the changes in the signs of the ecliptic, produced by the precession (q. v.) of the equinoxes, the ancient signs of summer have remained in the calendar. In the northern hemisphere, they are Cancer, Leo, Virgo; in the southern, Capricorn, Aquarius, Pisces. Our summer takes place at the time when the earth is at the greatest distance from the sun, and hence moves the slowest. The diameter of the sun, therefore, appears considerably smaller at this season than in winter, and the summer of the northern hemisphere has ninety-three and a half days,—a few days more than the winter,— and, therefore, more than the summer of the southern hemisphere. Notwithstanding the greater distance of the sun in summer, his rays have much more effect than in winter, because they fall more directly upon the northern hemisphere. He also rises much sooner, and sets much later, and, therefore, describes a much greater arc in the heavens than in winter. At the time when he has reached the tropic of Cancer, he ascends highest in the heavens, and remains longest above the horizon; and we might, therefore, suppose that this would be the period of the greatest heat. But experience shows that the greatest heat generally takes place in August, throughout the whole northern hemisphere, far beyond the polar circle. The reason of this circumstance is, that, in August, the influence