3. (Ph. D.) Pure sulphuric acid, 1 fl. oz.; distilled water, 13 oz. Sp. gr. 1·084.
4. (B. P.) Sulphuric acid, 3; distilled water, q. s. to measure 353⁄4; mix by adding the acid gradually to the water.—Dose, 4 to 20 minims.
Prop., &c. Antiseptic, tonic, and refrigerant.—Dose, 10 to 30 drops, largely diluted with water, several times daily; in low typhoid fevers, passive hæmorrhages, profuse perspiration, in various skin diseases to relieve the itching, in dyspepsia, &c. It is also used externally.
Sulphuric Acid, Nordhausen. Syn. Fuming sulphuric acid; Acidum sulphuricum fumans, L. Prep. By distilling calcined ferrous sulphate (‘green vitriol’) in earthen retorts. The retorts, which are shown at A in the plate after the ‘green vitriol’ has been put into them, are placed in a galley-furnace, as shown below, the necks passing through the wall of the furnace, and being properly secured to the necks of the receivers (B B.). Into each of the flasks 21⁄2 lbs. of green vitriol are put; on the first application of heat only sulphurous acid and weak hydrated sulphuric acid come over, and are usually allowed to escape, the receivers not being securely luted until white vapours of anhydrous sulphuric acid are seen. Into each of the receiving flasks 30 grams of water are poured, and the distillation continued for 24 to 36 hours. The
retort flasks are then again filled with raw material, and the operation repeated four times before the oil of vitriol is deemed strong enough. The residue in the retorts is red (peroxide) of iron, still retaining some sulphuric acid. The product is a brown oily liquid, which fumes in the air, is intensely corrosive, and has a sp. gr. about 1·900. When heated to about 100° Fahr. the anhydrous acid is given off, and ordinary oil of vitriol is left. According to Marignac, crystals of normal sulphuric acid (H2SO4) are formed in this acid when it is submitted to a low temperature. Nordhausen acid is so called from the place of its manufacture in Saxony. It may be regarded as a mixture or compound of H2SO4 and SO2. It is chiefly used for dissolving indigo.
SULPHURIC ANHYDRIDE. See Sulphuric acid, Anhydrous.
SULPHURIC E′THER. See Ether.
SUL′PHUROUS ACID. SO2. Syn. Sulphurus anhydride; Acidum sulphurosum, B. P. This compound is freely evolved in the gaseous form when sulphur is burnt in air or oxygen, and when the metals are digested in hot sulphuric acid; and, mixed with carbonic acid, when charcoal, chips of wood, cork, and sawdust, are treated in the same way.
Prep. 1. By heating together sulphur and strong sulphuric acid.