458 SULPHURETTED HYDROGEN

barrels, and in the rural districts sulphur is often burned in old cider barrels to purify them. Sulphurous acid is extensively used in bleaching straw, woollen, and silken goods, and also isinglass and other articles which would be injured by chlorine. (See BLEACHING.) It is a powerful antiseptic, and is now employed to preserve meats. (See PRESERVATION OF FOOD, vol. xiii., p. 824.) For its most important use, see SULPHURIC ACID. Sulphurous acid is dibasic, forming normal, neutral, and double salts. (See SULPHITES.) The binary compounds of sulphur with the metals, or the sulphides, are, when important, mentioned in the articles on the respective metals, or under SULPHIDES. One of the principal uses of sulphur is in making gunpowder. (See GUNPOWDER.)-Medical Properties and Uses. Sulphur is termed in therapeutics a laxative, diaphoretic, and alterative. It is supposed to be carried into the circulation by the fatty matters in the alimentary canal. That it is discharged by the skin is shown by the fact that silver worn about those who are taking it becomes blackened with a coating of sulphide. It is used in cutaneous and other diseases, both internally and externally, sometimes artificially prepared, and sometimes as it exists in natural springs. (See MINERAL SPRINGS.) It has been successfully employed in diphtheritic croup, given suspended in water, and in sciatica and chronic articular rheumatism, applied externally upon dry flannel and bandaged to the limb for several days. The officinal preparations embrace confections, plasters, and ointments, and precipitated sulphur or lac sulphuris. This latter preparation is made by boiling sulphur with milk of lime, which forms bisulphide of calcium and hyposulphite of lime, from the solutions of both of which the sulphur is precipitated by the action of hydrochloric acid. It has the general properties of ordinary sublimed sulphur, but is in a state of finer division.

SULPHURETTED HYDROGEN. See HYDROSULPHURIC ACID.

SULPHURIC ACID, the hydrate of sulphuric anhydride, or teroxide of sulphur, SO,+H,O= H.SO.. It may also be regarded as a salt of hydrogen, this element holding the place of a basyle to the radical sulphion, SO. (See SALTS, vol. xiv., pp. 582, 583.) The discovery of sulphuric acid is ascribed to Basil Valentine, a monk of Erfurt in Saxony, about 1440. He obtained it by distilling green vitriol or the sulphate of iron, and as the liquid product had an oily appearance when poured out, it was called oil of vitriol. He also obtained it by burning sulphur under a bell glass containing moisture, calling the product oleum sulphuris per campanum, or oil of sulphur by the bell. This was the germ of the present process of manufacture, which consists in producing sulphurous acid and carrying it to a higher state of oxidation by nitrous and hyponitrous acids. The old process of distilla

red heat in earthen retorts placed in galleries in a furnace, as shown in fig. 1. As soon as the acid begins to distil over, the necks of the retorts are passed into receivers. The product is a brown oily liquid having a density of about 1.9, and fumes in the air, for which reason it is also called fuming sulphuric acid. Its composition may be expressed by the formula H2SO.,SO.. When gently heated it breaks up into sulphuric anhydride, SOs, and sulphuric acid, H.SO.. If fuming Nordhausen acid is distilled into a receiver cooled by ice, white fumes will solidify on its sides into white silky needles. This product was formerly called anhydrous sulphuric acid. It does not however possess acid properties like the residue in the retort, but requires to be united with water to enable it to combine with bases. It is tough and ductile, and can be moulded in the fingers for a short time if they are dry. It has a specific gravity of 1946 at 55.4°, fumes in the air, and when thrown into water hisses like red-hot iron, and forms sulphuric acid. It melts at 65° and boils at about 95°, forming a colorless vapor, which is decomposed in highly heated porcelain tubes into two volumes of sulphurous anhydride and oxygen. The common way of preparing sulphuric acid at present, known as the English process, is to oxidize sulphurous acid. It is said to have been introduced by Dr. Roebuck about the middle of the 18th century, but the invention is also

claimed for a calico printer at Rouen, with improvements by Chaptal, such claimants giving credit to Dr. Roebuck only for the invention of the leaden chambers in which the process was carried on. A large and long chamber, divided into sections by partitions which alternately leave open spaces at the top and bottom, has at one end a small furnace in which the flame of sulphur heats a crucible containing a mixture of nitre and oil of vitriol. The chamber is lined with sheet lead, and its floor is covered with a thin stratum of water. Jets of steam are also introduced. The sulphur in burning produces sulphurous anhydride, SO2, which in the presence of moisture becomes sulphurous acid (SO2+H,O=H,S0.), and this again, by the action of NOs, becomes sulphuric acid, H2SO4, the nitric acid being at the same time reduced to a lower oxide. According to the researches of Weber and Winkler, the following is the rationale of the process: The oxidation of the sulphurous acid to sulphuric acid takes place in the leaden chambers under the influence of the vapor of water, at the expense of the oxygen of the nitric or nitrous acid, which is converted into deutoxide of nitrogen. It is necessary however that the nitrous acid be first absorbed in plenty of water, which takes up the free nitrous acid and decomposes the deutoxide of nitrogen, a process greatly promoted by the presence in the chamber of sulphurous acid purposely introduced. The water, usually in the form of steam (practical experience proving that a certain elevation of temperature is required), acts in this process as in others wherein sulphurous acid effects reduction. By the presence of atmospheric air in the chamber the deutoxide of nitrogen is oxidized into hyponitric or nitrous acid, and this acid again is decomposed by sulphurous acid. A peculiar crystalline substance sometimes forms, having the formula H2S04+N2O3,S03, and formerly thought to play

FIG. 2.-Class-room Apparatus for Sulphuric Acid. an important part in the transformation; but according to R. Weber this substance only appears when the process is not well managed, and is chiefly due to want of water. The process of forming sulphuric acid may be illustrated on a small scale by means of the apparatus

shown in fig. 2. A flask, b, furnishes sulphurous anhydride, and the bottle e deutoxide of nitrogen, to the large glass balloon r, and the flask w supplies steam when it is required. Air is occasionally blown into the balloon through the bent tube t, the effete products passing out at o. If but little vapor of water is present, the white crystalline solid above mentioned makes its appearance upon the sides of the globe; but when sufficient water is present the substance is not deposited, neither is it supposed to be formed as a necessary stage of the process. Gay-Lussac invented what is called a condenser as an attachment to the large leaden chambers, for the purpose of economizing the consumption of nitre, which formerly amounted to from one eighth to one twelfth of the weight of sulphur. The condenser consists of a leaden tower filled with fragments of coke, through which sulphuric acid of 66° Baumé is constantly trickling. Through this condenser the spent gases are passed, and the oxides of nitrogen which they may contain are absorbed. The sulphuric acid which collects at the bottom of the chambers is too dilute for most purposes; it is not found advantageous to allow it to attain a specific gravity of quite 16, because at that strength it absorbs too much of the nitrous fumes. It may be used at this strength for the manufacture of salt cake (see SODA), but for other uses it must be further concentrated. This is generally effected by two different stages, the first in leaden pans, the second in platinum or glass retorts. Some makers concentrate to 60° Baumé (sp. gr. 1.71) in leaden pans; others use them only till the acid is raised to 55° Baumé (sp. gr. 1.59). The leaden pans are rectangular, long and wide, supported by iron plates to protect the lead from immediate contact with the flame which is used for evaporation. The pans are generally arranged in steps, the acid being conveyed from the upper to the lower ones by syphons, the density of the acid increasing from one pan to the next lower. When it has attained a density of from 1.65 to 172 in the leaden pans, it is known as brown oil of vitriol, and may be used by bleachers, calico printers, dyers, &c.; but to raise it to the strength of commercial oil of vitriol, it is further concentrated in the glass or platinum retorts above mentioned. Glass retorts holding 20 gallons or more are often used, set in an iron pot, the bottom of which is covered with dry sand. The concentration requires from 12 to 16 hours; the vapors which distil over toward the last, carrying some acid with them, are passed into condensers and returned to the lead pans. Platinum retorts are more costly, but are thought by many to be more economical in the end on account of their not being liable to break. Fig. 3 shows a section of a platinum retort. The syphon is worked without a stopcock by the vessel c, in the following ingenious manner. When the vessel is lowered

head O communicates by means of tubing, not shown in the engraving, with a worm, where the watery vapor and the very weak acid mechanically carried over with it are condensed. The fire under the retort communicates with the flue A, which passes under the leaden pans. The concentrated acid left in the retorts contains a slight excess of water beyond that required for the formula H2O,SO or H2SO4. This formula gives 18.36 per cent. of the elements of water, while Marignac obtained 19-62 per cent. from the concentrated acid. According to Playfair, if the concentration is conducted at a temperature not exceeding 500° F., the true compound, of sp. gr. 1-844, is obtained; but if heated to ebullition, there is partial decomposition.-Properties. The oil of vitriol of commerce is an oily-looking, colorless, and odorless liquid, of sp. gr. 1-842. It chars nearly all organic substances, in consequence of abstracting from them the elements of water, leaving a carbonaceous residue. It mixes with water in all proportions, with condensation of volume of the mixture, and consequent evolution of heat. Its attraction for moisture is so great, that if exposed to the air for a few days in a shallow vessel it frequently doubles its weight; and advantage is taken of this in the laboratory for drying various substances. The boiling point of sulphuric acid is 620-6° F., and it freezes at about -29°, although when frozen it does not melt below 32. Marignac finds that the true sulphuric acid when heated parts with a small quantity of vapor of the anhydride, and the remaining liquid boils at 640-4°. Sulphuric acid forms

two definite hydrates, the monohydrate, H, SO,,H,O, and the dihydrate, H,SO,,2H,O. The first, of sp. gr. 1-78, crystallizes at 47° in splendid rhombic prisms, of sp. gr. 1.951. From this property it is often called glacial sulphuric acid. It boils at about 400°. The dihydrate may be formed by concentrating a dilute acid in vacuo at 212° till it ceases to lose weight. Its sp. gr. is 1.62; boiling point, 370°.-Uses. Sulphuric acid is the starting point of nearly all the great chemical manufactures. It is used to procure nitric acid from the nitrates of potassium and sodium, and hydrochloric acid from common salt, at the same time furnishing salt cake, from which the carbonates of soda are obtained. It is therefore used in the preparation of various bleaching compounds. Phosphate of lime in artificial manures is reduced to biphosphate by the action of sulphuric acid. In medicine, diluted with water or spirits of wine and known as acidum sulphuricum dilutum and acidum sulphuricum aromaticum, it is used as a tonic, refrigerant, and astringent. It is given in typhoid fevers, in convalescence from various fevers, and as an aid to digestion.

SULPHURIC ETHER. See ETHER.
SULPHUROUS ACID. See SULPHUR.

SULPICIANS, or Priests of the Society of St. Salpice, a congregation of priests in the Roman Catholic church founded in the parish of St. Sulpice, Paris, in 1645, by Jean Jacques Olier de Verneuil, and specially devoted to the training of candidates for the priesthood. In 1642 Olier and two other clergymen formed a community at Vaugirard, and bound themselves to found ecclesiastical seminaries. His companions soon abandoned him, and becoming in the same year rector of the parish of St. Sulpice, he set about realizing his plan there. The act founding the society of St. Sulpice is dated Sept. 6, 1645, and was immediately sanctioned by the proper authorities. The corner stone of the present seminary of St. Sulpice was laid in September, 1649; the edifice was completed and occupied in August, 1651. The society formed two bands, the one devoted to parish work, the other to that of teaching. The Sulpicians were warmly befriended from the be ginning by St. Vincent de Paul, and the estab lishment of Sulpician seminaries in nearly all the dioceses of France soon followed. Thereby the society came to have the chief part in the education of the French clergy down to the revolution of 1789. They were at first favored by Napoleon, but were suppressed by him in 1812 for their attachment to Pius VII.; they were restored by Louis XVIII., and ever afterward directed the most important diocesan seminaries in France.-Olier in 1636 formed a company for colonizing the island of Montreal. They purchased it in 1640, sent out Sieur de Maisonneuve with priests and nuns in 1641, and transferred their proprietorship to the Sulpicians in 1656. In 1657 the Sulpicians De Queylus, Souard, and Galinier took possession of

the island and founded there a missionary establishment; but their claims to exclusive parochial jurisdiction being resisted, De Queylus in 1659 obtained in Rome a bull erecting Montreal into an independent parish, and used the powers thus conferred in spite of Bishop de Laval, till a lettre de cachet forcibly removed him in October, 1660. This conflict of jurisdiction broke out anew in 1821, on the erection of the see of Montreal, and has been kept up till the present time, the most eminent Canadian jurists taking sides in the controversy. Both parties appealed to Rome, and a final decision had not been reached in the beginning of 1876. The Sulpicians François de Fénelon, brother of the author of Télémaque, and Claude Trouvé, founded in 1668 the first Iroquois mission at the western extremity of Lake Ontario. In July, 1669, a party of Sulpicians under Dollier de Casson first explored Lake Erie and sailed round it and Lake St. Clair. But their missionary labors were soon necessarily limited to the Indian tribes in the immediate neighborhood of Montreal, where they collected the remnants of the Christian Algonquin and Iroquois tribes into two contiguous settlements at the lake of Two Mountains on the Ottawa. In Montreal city, besides the seminary proper attached to the church of Notre Dame as a parochial residence, founded in 1657, they possess the theological seminary, to which students are sent from every part of the United States, the preparatory seminary or "college of Montreal," founded in 1773, and several other succursal churches with their residences.-In April, 1791, at the call of Bishop (afterward Archbishop) Carroll, a band of four Sulpicians and three seminarians, headed by François Charles Nagot (died 1816), sailed for Baltimore, where they formed for a time the clergy of the cathedral. They sent some of their number to teach in Georgetown college, and founded in Baltimore the theological seminary of St. Mary's, with a collegiate or preparatory school. The seminary was raised by Pope Gregory XVI. to the rank of a Catholic university; the collegiate school was removed to near Ellicott City, Howard co., in 1849, and suppressed in 1852.

SULPICIUS SEVERUS, a Roman historian, born near Toulouse about A. D. 363, died at Marseilles about 410. He was a lawyer, but on the death of his wife adopted an ascetic life. His father disinherited him; but, encouraged and assisted by his father-in-law, he formed with his own freedmen and a few followers a monastic establishment near Marseilles. He wrote the life of St. Martin of Tours, an abridgment of the Scriptural narrative, which was a favorite text book in the schools of the middle ages, and a continuation to his own time, under the title of "The Chronicle of Sulpicius Severus." His works, which have been often printed, include also "Three Dialogues" and a collection of letters. The last critical edition is that of Halm, forming vol. i. of the Vienna Corpus (1866).

SUMACH, or Sumac (Arab. summak), the common name for plants of the genus rhus (the ancient Greek and Latin name), of the cashew family or anacardiacea, which includes, besides the cashew, the mango and other tropical fruits. The sumachs are represented in the United States by about 12 species, which are shrubs or small trees, with alternate, sometimes simple, but generally trifoliolate or oddpinnate leaves, and small polygamous flowers in terminal or axillary panicles; the sepals and petals are five, and the stamens, also five, are inserted under the margin of a disk which lines the calyx; fruit a small, dry, nut-like drupe. Our species are separable into several well marked sections or subgenera. 1. The sumachs proper, with pinnate leaves, flowers in a terminal crowded panicle, and the globular fruit clothed with acid hairs; the plants not poisonous, and containing an abundance of tannin. The smooth sumach (rhus glabra) is the most common, often covering extensive tracts of barren soil; it grows from 2 to 12 ft. high, with leaves a foot or more long, consisting of 11 to 31 lance-oblong, pointed, serrate leaflets, which are whitish beneath; the yellowish green flowers appear in June, and are pleasantly fragrant; the fruit, in dense clusters, is of the richest crimson, with a velvety appearance from the number of small hairs; it has a pleasant acid taste, due to the presence of a great abundance of bimalate of lime; an infusion of the berries is sometimes used to make a cooling drink in fevers, and as a gargle in affections of the throat and mouth. The leaves of this species are among the first which put on autumn colors, and