SULPHUR

From Agepedia

SULPHUR. We shall first give the mineralogical history of this substance. It occurs abundantly in nature, both crystallized and massive. The form of its crystals is an acute octahedron, either perfect, or variously modified, and derivable from an octahedron with equal and similar scalene triangular planes, of which the common base of the two pyramids is rhombic; cleavage imperfect; fracture conchoidal; lustre resinous ; color several shades of sulphuryellow, inclining sometimes to red or green; streak sulphuryellow, passing into white; transparent or translucent; sectile; hardness between gypsum and calcareous spar; specific gravity 2.072. The massive varieties occur in imbedded globules, also in large pieces, having a granular or impalpable composition, and an uneven or flat conchoidal fracture. The present species has usually been treated of under two divisions, viz. common and volcanic sulphur, in allusion to the geological situation of the two varieties; the volcanic sulphur being a product of sublimation, while the common sulphur is found in strata not immediately connected with volcanic rocks. Volcanic sulphur appears in the shape of crusts, superficial coatings, stalactites, or loose, mealy masses, and consists generally of columnar particles of composition, not unfrequently terminating in crystalline points. Common sulphur has been further divided into compact and earthy, the last of which comprehends those varieties which, on account of the smallness of the individuals in the granular compositions, appear as a friable, mealy powder. Sulphur is principally met with in beds of gypsum, or in the accompanying strata of clay. It is generally associated with sulphate of strontian. It also occurs with copper pyrites, galena, and orpiment. It is deposited from several springs, and in large quantities from volcanoes. In Sicily,.and several provinces of Italy, sulphur is found in splendid crystals, as well as in globular concretions, It occurs in imbedded spheroidal masses of a brown color, which is owing to bitumen, at Radoboy, near Crapina, in Croatia. The finest crystals, after those of Sicily, are brought from Conil, near Cadiz, in Spain. It occurs in veins in Suabia, Spain and Transylvania. The earthy sulphur is found in Poland, in Moravia, and other countries; the volcanic sulphur in Iceland, near Vesuvius in the Solfatara, in fine crystals in Teneriffe, in great profusion near the volcanoes of Java, and in the vicinity of most other active volcanoes. In general, it requires to be purified, either by melting or by sublimation, in order to render it fit for use in the arts. Sulphur, in a state of purity, is destitute of odor, and of a weak, though perceptible taste. It is a nonconductor of electricity, and of course becomes electric by friction. The specific gravity of roll sulphur varies from 1.97 to 2.00. Il undergoes no change from exposure to the air, and is insoluble in water. If a considerable piece of sulphur be exposed to a sudden, though gentle heat, by holding it in the hand, for instance, it breaks to pieces with a crackling noise. Whon heated to the temperature of about 170° it rises up in'the form of a flue powder sulphur. When heated to the temperature of 218°, it melts, and becomes as liquid as water. Between the melting point and 252°, it is as liquid as varnish, and its color is that of amber. About the temperature of 340°, it begins to grow thick, and assumes a reddish tinge ; and if we continue to increase the temperature, it becomes so thick, that the vessel containing it may be turned upside down without the risk of spilling any of it. Between the temperature of 428° and that of 482°, it is thickest of all, and its color is reddishbrown. From 482° to its boiling point, which is not far from 750°, it becomes thinner, but never so thin as it was when below the temperature of 248°; and its reddishbrown color does not alter. If it be suddenly cooled while in the most liquid state, as by throwing it into water, it becomes instantly brittle ; but if it was so hot as to be viscid, and be suddenly cooled, it remains quite soft; so that it may be drawn into threads. In the first case, it crystallizes 5 in the second, it does not. This state of softness is probably connected with the viscidity; which, when the cold is suddenly applied, prevents the possibility of the particles arranging themselves in regular order If sulphur be melted in a ladle, or oval vessel, and, as soon as its surface begins to congeal, the liquid portion beneath the surface be poured out, the internal cavity wTill exhibit long, needleshaped crystals. Alcohol, sulphuric ether and the oils dissolve a small portion of sulphur. It combines in five proportions with oxygen, and fcrms five compounds, which have received the names of sulphuric acid, sulphurous acid, hyposulphurous acid, suhsulphurous acid, and hyposulphuric acid. We shall describe the sulphurous acid first. It is formed when sulphur is burnt, either in the open air or in oxygen gas. But the way in which it is usually obtained for experiment, is to heat a mixture of sulphuric acid and mercury in a small retort ; a gas is evolved, which is sulphurous acid. It is colorless, is possessed of an* exceedingly suffocating and disagreeable smell, precisely similar to that of burning sulphur. Its taste is intensely acid and sulphureous. It converts vegetable blues to red, and then gradually destroys them. Its specific gravity is 2.2293. The gas may be collected over mercury, or received into water, which, at the temperature of 61° will absorb thirtythree and oxygen 50. It is used in bleaching, particularly for silks: it likewise discharges vegetable stains and iron moulds from linen. In combination with the salifiable bases, it forms sulphites, which differ from the sulphates in their properties. The alkaline sulphites are more soluble than the sulphates; the earthy, less so. They are converted into sulphates by an addition of oxygen, which they acquire even by exposure to the air. By putting sulphuric acid and mercury into the sealed end of a recurved glass tube, then sealing the other end, and applying heat to the former, a liquid sulphurous acid may be obtained: it remains in a liquid state in the air at 0° Fahr.: it is colorless, transparent, and very volatile; specific gravity 1.45. It boils at 14°; but, in consequence of the cold produced by the evaporation of the portion that flies off, the residue remains liquid. It causes a feeling of intense cold when dropped on the hand. Sulphuric acid is obtained by burning a mixture of about seven parts sulphur, and one part nitre, in large chambers, lined with lead. By this combustion, sulphurous acid and deutoxide of nitrogen are formed. The deutoxide absorbs oxygen from the atmosphere, and is converted into nitrous acid. Both the acids are absorbed by water. The nitrous acid gives out part of its oxygen to the sulphurous acid, and converts it into sulphuric acid; and, being reduced to the state of deutoxide, again flies off, unites to oxygen, is converted to nitrous acid, and absorbed by the water. This process goes on till the whole of the sulphurous acid is converted into sulphuric acid. The water, thus acidulated, is evaporated in leaden vessels to a certain point. The evaporation is then continued in glass retorts, till the acid acquires the requisite degree of strength. The ordinary form of a sulphuric acid lead chamber is the parallelopiped, and its dimensions about seventy feet long, ten or twelve high, and sixteen wide. At the middle height of one end, a small oven is built up, with a castiron sole, having a large lead pipe, ten or twelve inches in diameter, proceeding from its arched top into the end of the lead chamber. On the sole the sulphur is burned ; the combustion being aided, when necessary, by heat applied from a little furnace, below it. Above the flaming sulphui*, a castiron basin is supported in an iron frame, into which *he 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 aide. 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; sixtyfour 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 reel, 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°, andr acid of the specific gravity 1.65, at 850°. 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 f1.25 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 vesselimbibing one third of its weight in twentyfour 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 BUT rounding it with melting ice. Its conge lation forms regular prismatic crystals with six sides. All the simple combusti bles 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.Sub sulphurous acid. It hag been found, that sulphurous acid has the property of dissolving iron, without the evolution of any gas. The acid giveg 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 hyposulphwous 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 hi so 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, by1. Hyposulphurous acid,2. Subsulphurous acid,3. Sulphurous acid,4. Sulphuric acid,5. Hyposulphuric acid, Sulphur combines readily with chlorine, forming a liquid compound called chloride of sulphur. It is formed bypassing a current of chlorine through flowers of sulphur, or by heating sulphur in a dry glass vessel, filled with chlorine gas. Its color is brownishred, and it possesses an odor similar to seaplants. 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 hydrosuljphuric acid. It may be obtained by pouring sulphuric or muriatic acid apon several metallic sulphurets. Sul cess. The liquid now consists of water holding hyposulphuric acid in solution* This acid is colorless and destitute of smell. It may be concentrated till its specific gravity is 1.347. It then begins to be decomposed by heat, sulphurous acid flies off, and sulphuric acid remains behind. It is found that it can be completely resolved into sulphurous and sulphuric acids, in the proportion of four parts of the former to five parts of the latter. Thus we know five compounds of oxygen and sulphur, all of which are acids. Their names, constituents, and combining weights, are as follows: Sulphur. Oxygen. Combining Weight2 atoms 1 atom 51 J 1 31 2 41 3 52 5 9 phnret 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 hydrosidphurous 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, whicn 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 wellclosed vessels, being converted into sulphur and sulphureted hydrogen. Sulphur has the property of combining with carbon, ancl of forming a very remarkable compound, called bisulpkuret 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 sulphur 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 wit!) boron, silicon and phosphorus, and forms sulphurets of these substances. (For an account of the sulphuretsof the metals, see the different metals.)