460 SULPHURIC ACID SULPICIANS with its spout to the gutter <Z, the outer limb of the syphon, which is' constantly full, becomes lengthened below n (the end of one of the leaden pans), and the acid flows out, fills the movable vessel, and runs out of the spout and through the gutter d into the retort B. The FIG. 8. Platinum Retort. head communicates by means of tubing, not shown in the engraving, with a worm, where the watery vapor and the very weak acid me- chanically 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 con- tains a slight excess of water beyond that required for the formula H 2 O,S0 3 or H 2 SO 4 . This formula gives 18-36 per cent, of the ele- ments of water, while Marignac obtained 19-62 per cent, from the concentrated acid. Accord- ing to Playfair, if the concentration is con- ducted at a temperature not exceeding 500 F., the true compound, of sp. gr. 1-844, is ob- tained; but if heated to ebullition, there is partial decomposition. Properties. The oil of vitriol of commerce is an oily-looking, col- orless, and odorless liquid, of sp. gr. 1-842. It chars nearly all organic substances, in conse- quence of abstracting from them the elements of water, leaving a carbonaceous residue. It mixes with water in all proportions, with con- densation of volume of the mixture, and con- sequent 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 sub- stances. The boiling point of sulphuric acid is 620-6 F., and it freezes at about 29, al- though 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 a SO 4 ,HjO, and the dihydrate, H a SO 4 ,2H 3 0. 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 po- tassium and sodium, and hydrochloric acid from common salt, at the same time furnish- ing 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 re- duced to biphosphate by the action of sulphu- ric acid. In medicine, diluted with water or spirits of wine and known as acidum sulpJiu- ricum dilutum and acidum sulphuricum aro- maticum, 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 ETHEK. SULPHUROUS ACID. See SULPHUR. SULPICIANS, or Priests of the Society of St, Sol- pice, 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 train- ing of candidates for the priesthood. In 1642 Olier and two other clergymen formed a com- munity at Vaugirard, and bound themselves to found ecclesiastical seminaries. His compan- ions 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 Sul- picians 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. There- by 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 after- ward 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 Sulpi- cians in 1656. In 1657 the Sulpicians De Quey- lus, Souard, and Galinier took possession of
