805 



SULPHUR. 



SULPHUR. 



000 



graphic picture. This it does by dissolving the aqueously insoluble 

 silver salts, with which it forms double compounds having an intensely 

 sweet taste. Hyposulphite of soda is made by dissolving sulphur in 

 sulphite of soda, NaO, SO, + S becoming NaO, 8,0.,. 



II>il>oiulphuric Acid (HOS 2 S ). Ditkionic Add. This acid was dis- 

 covered in 1819 by Gay-Lussac and Welter. It is prepared by sus- 

 pending finely-powdered binoxide of manganese in water, and passing 

 sulphurous acid gas into the mixture : if this be not kept cold, sul- 

 phuric acid is formed : but otherwise the oxide of manganese is dis- 

 solved and hyposulphate of its protoxide formed : to the filtered solu- 

 tion sulphide of barium is to be added, by which sulphide of manganese 

 is precipitated, and hyposulphate of baryta remains in solution : when 

 the proper quantity of sulphuric acid is added to this, sulphate of 

 baryta is precipitated, and the hyposulphuric acid is liberated, the 

 filtered solution of which is to be evaporated in racuo over sulphuric 

 acid till it acquires a density of 1'347 : if it be carried further than 

 this, it is decomposed into sulphurous acid, which escapes, and sul- 

 phuric acid, which remains dissolved. 



This acid has not been obtained free from water : the aqueous 

 solution is sour, inodorous, and reddens vegetable blues : if heated to 

 _'li', it is decomposed into sulphurous and sulphuric acids; and when 

 1 to the air, it slowly absorbs oxygen ; and becomes sulphuric 

 acid. Unlike sulphuric acid, it forms soluble compounds with lime, 

 baryta, strontia, and oxide of lead ; but, like diluted sulphuric acid, it 

 acts upon and dissolves zinc, with the evolution of hydrogen gas, and a 

 solution of hyposulphate of zinc is formed ; its salts are decomposed at 

 a high temperature, yielding sulphurous acid and sulphates remaining. 



Trilhionic acid (HO, S 3 O 5 ). Sulphuretted hyposulphuric acid. As a 

 potash salt this acid is formed when sulphur is digested in bisulphite 

 of potash for several days, or until all yellow colour has disappeared. 

 The resulting solution gives a black precipitate with subnitrate, and a 

 white with pernitrate of mercury. From the trithionate of potash the 

 acid may be liberated by tartaric acid, and obtained in unstable pris- 

 matic crystals by evaporation. By heat the trithionates split up into 

 .Milplmr, sulphurous acid, and sulphate of the base. 



Tetratlii'Mic acid (HO,S,O S ). Jtimlfih nrctted liypntulpkuric acid. Two 

 equivalents of hyposulphite of baryta and one of iodine yield iodide of 

 barium and tetrathionate of baryta. The latter may be purified by 

 recrystallisation, and the acid liberated by the cautious addition of 

 .-ulphuric acid. It is somewhat unstable. 



:d (HO, S a O 5 ). Trisulphurctlcd hyposulphuric acid. 

 \Vlieii sulphurous and hydrosulphuric acids come into contact, the 

 following decomposition occurs : 



Sulphurous 



I- 5IIS 



Hy.lrMuI- 

 phuric acid. 



110, 



+ 4HO 



Sulphur. 



Water. 



lYntithionic acid is very unstable. Its baryta compound may be 

 1 in silky scale*. 



"dd or chloride i>f eulphuryl (SOjCl). A colourless 

 liquid of pungent udnur and powerful eye -irritating properties, formed 

 on bringing together <lry sulphurous acid and chlorine gases in bright 

 sunlight. It in volatile without decomposition, but water instantly 

 breaks it up. It does not appear to combine with bases. 



Mtrotulphuric acid (IK J, SO..NO.). If nitric oxide (NO.,) be passed 

 through a cold solution of sulphite of ammonia containing large excess 

 of ammonia, white crystals of nitrosulphate "J ammonia (NH.O.SOjNO.,) 

 are deposited. Other nitrosulphates may be formed, but they are very 

 uiMtul'lt:, and the acid cannot be liberated from them. 



fii'lli/ia-.oiiifl aciil*, discovered by Fremy, form with potash, but not 

 with soda, a remarkable series of salts. They are derived from basic 

 nitrite of potash, sulphurous acid and water, as indicated in the follow- 

 ing equations : 



Sulphazitc of potash . . . . 3KO, SjNII.,0,., 



from 3KO, NO 3 + 3SO, + 3HO. 

 fiulphazatc of poUsh ..... 3KO, S 4 NH 3 O 1( 



from 3KO, NO, + 48O, + 3IIO. 

 Sulphazotate of potash . . . . 3KO, S 5 NH 3 O 16 



from 3KO, NO,-f SSO,-t-3HO. 



Kulphammonate of potash . . . . 4KO, S e XHjO S j 

 from 4KO, N 



Nitrogen, and Sulphur. 



f/!/tli-'*lin n,,<l Sulphur combine in two proportions, forming hydro- 



<;<: aci'l (HS), frequently called sulphuretted hydroyen, and per- 

 sulphide of hydrogen (HS 5 ?). 



,-<jtulj,huric acid, formerly known by the name of hepatic gas, 

 exists in sulphurous waters, such as those of Harrowgate. It may be 

 formed, to a certain extent, by heating or subliming sulphur in hyilro- 

 gcn gas. It is usually produced by the action of hydrochloric acid on 



'!e of antimony, or by acting upon protosulphide of iron with 

 dilute sulphuric acid : in the former case the hydrogen of the hydro- 

 chloric acid unites with th sulphur of the sulphide, chloride of anti- 

 mony lieing alao formed; while in the latter, the decomposed water 

 yields hydrogen to the sulphur and oxygen to the iron, which latter, 



t.lien dissolved by the acid, constitutes sulphate of iron. As 

 it is difficult to combine the whole of any given quantity of iron 



with sulphur, the uncombined portion yields a little free hydrogen 

 with the hydrosulphuric acid; but this, in most eases, is of no con- 

 sequence. Although hydrosulphuric acid is soluble in one-fourth its 

 bulk of water, yet the gas may for most purposes be received by dis- 

 placement in vessels filled with that liquid. 



Hydrosulphuric acid is colourless, and gaseous at common tempera- 

 tures and pressures : it has a peculiarly nauseous and fetid odour, 

 resembling that of putrid eggs ; its taste is also extremely disagreeable. 

 Its specific gravity is about T192. 100 cubic inches weigh about 38 

 grains. It is composed of one equivalent of hydrogen and one equiva- 

 lent of sulphur, as indicated in the above formula. It reddens moist 

 litmus-paper, but not strongly, and is soluble in about one-third of its 

 bulk of water. At a temperature of 50, and under a pressure of about 

 17 atmospheres, it is rendered a limpid liquid, of specific gravity about 

 0'9 : this does not congeal till cooled down to 122 Fahr. It is ex- 

 tremely poisonous to animals : air containing l-1500th of its bulk 

 immediately killed a bird, and 1-1 000th a middle-sized dog. When 

 mixed and detonated with oxygen gas, the results are water and sul- 

 phurous acid. 



The aqueous solution of hydrosulphuric acid is employed as a test 

 of metals, and, more especially, for the discovery of minute portions of 

 lead, with which it gives a dark-coloured precipitate of sulphide of 

 lead : with the salts of antimony it gives an orange precipitate, and 

 with arsenious acid a yellow one. 



Hydrosulphuric acid forms salts which are termed liydrosulpfiatcs, 

 and these are probably formed when it is combined with ammonia, 

 potash, soda, and the alkaline earths ; but by metallic oxides, properly 

 so called, it is decomposed, the results not being hydrosulphates of 

 metallic oxides, but water and a metallic sulphide : this is the case 

 with oxide of lead, silver, &c. 



Persulphide of Hydroyen (HS S ?). This compound cannot be formed 

 by direct combination. To prepare it, equal weights of sulphur and 

 recently slaked lime may be boiled in three times their weight of 

 water for half an hour. The result is a deep reddish-yellow coloured 

 solution of persulphide of calcium, which, when clear and cold, is to 

 be added to an excess of hydrochloric acid diluted with about twice 

 its weight of water : by their mutual action sulphur is precipitated, 

 accompanied by a yellow oil-like fluid, which is the persulphide of 

 hydrogen. It is a viscid liquid, of a yellow colour, and of specific 

 gravity about 1'77 ; its smell is similar to, but not so powerful as that 

 of hydrosulphuric acid; its elements are held together by a feeble 

 affinity, so that even in the cold it is gradually converted into hydro- 

 culphurie acid and sulphur, and this change is immediately produced 

 at 212. 



Chlorine and Sulphur appear to form two compounds, the chloride 

 and di-chloride. According to Dumas, when sulphur is acted upon by 

 excess of chlorine, a neutral chloride is obtained, wlu'ch consists of one 

 equivalent of chlorine and one equivalent of sulphur (SCI). 



It usually contains some di-chloride, from which it is to be purified 

 by repeated distillation at about 140 Fahr. 



It may be formed either by heating sulphur in excess of dry chlorine 

 gas, or, at common temperatures, by passing excess of chlorine through 

 a tube containing powdered sulphur. 



Chloride of sulphur is liquid, has a reddish-brown tint, and a density 

 of l-ii-2 ; that of its vapour being about 3'7. Its boiling-point is 147. 



I>i-chloride nf Sulphur (S 2 C1). This substance was first obtained by 

 Dr. Thomson. When chlorine gas is passed over powdered sulphur, 

 gently heated, it gradually disappears, and the di-chloride is formed by 

 direct combination : the liquor obtained is to be distilled, and then 

 possesses the following properties : It is liquid, and is red by reflected, 

 and yellowish-green by transmitted light : it emits acrid fumes when 

 exposed to the air; its density is 1'628, that of its vapour being 47 ; 

 it is volatile below 200, and boils at 280. Dry litmus-paper is not 

 altered by it. It is energetically decomposed by and decomposes 

 water, the results being hydrochloric and hyposulphurous acids. It 

 does not combine with alkalies. 



Sulphur and Bromine. [BROMINE.] 



Carbon and Sidphnr. These form by direct action oi-iul-plude of 

 carbon (CS a ) or sulphocarbnnic acid. 



It may be obtained either by passing the vapour of sulphur over 

 charcoal heated to redness in a porcelain tube, or distilling a mixture 

 of bi-sulphide of iron and one-sixth of its weight of charcoal. It may 

 be condensed by being passed into cold water, and to free it from 

 uncombined sulphur and moisture it should be rectified from chloride 

 of calcium at a low temperature. 



It is a colourless transparent liquid, of density T272, that of its 

 vapour being 2'447 ; it has an acrid pungent taste, and a very fetid 

 odour ; its refractive power is very high ; it is insoluble in water, but 

 combines with alcohol and ether, from which water precipitates it ; it 

 is extremely volatile, boils at 118'5, and is not rendered solid at 

 the lowest obtainable temperature : owing to its great volatility, it 

 produces sufficient cold under the exhausted receiver of the air-pump 

 to freeze mercury : it is extremely inflammable, the results of its com- 

 bustion being carbonic and sulphurous acid gases, attended with a 

 brilliant greenish-white flame. It combines with metallic sulphides to 

 form a class of sulphur salts termed sulpha-carbonates ; for example, 

 sulpho-carbonate of potassium (KS,CS.,). 



It is a remarkable circumstance that so volatile a liquid should be 



