When there is an excess of tersulphide of tungsten, a brown Sect. VIII. salt is obtained, which dries to the consistency of a syrup. 8. Sulpho-tungstate of calcium may be formed by a process similar to the preceding. It does not crystallize, but dries to a dark yellow mass. It is easily soluble in water, and slightly soluble in alcohol. When there is an excess of sulphide, a reddish brown incrystallizable compound is obtained. Caustic ammonia throws down a light yellow powder which is a subsalt. 9. Sulpho-tungstate of magnesium is obtained in the same way as the preceding salts. The solution is easily decomposed when exposed to the air, but in a vacuum it dries to a yellow varnish, which dissolves easily in water and in alcohol. With an excess of sulphide the compound is brown, and does not crystallize. Ammonia throws down a light yellow powder, which is a subsalt. 10, 11, 12. The neutral salts of alumina, glucina, and yttria are neither precipitated by sulpho-tungstate of potassium, nor by the lemon yellow double salt. Hence it is probable that the sulpho-tungstates of these salts are soluble in water.‡ 13. Sulpho-tungstate of cerium is deposited in 24 hours in the state of a light yellow powder. The double yellow salt occasions a similar precipitate.§ 14. Sulpho-tungstate of zirconium forms a brownish yellow precipitate.|| 15. Sulpho-tungstate of iron is obtained by mixing sulphotungstate of potassium with sulphate of iron. The salt has a dark yellow colour, and is soluble in water.¶ 16. Sulpho-tungstate of bisulphuret of iron forms a bulky dark brown precipitate, which collects into a liver brown mass, and undergoes no farther alteration. The yellow salt gives a lighter coloured solution, which in a few days undergoes decomposition, and becomes white.** 17. Sulpho-tungstate of manganese is easily soluble in water, and the solution is yellow.++ 18. Sulpho-tungstate of nickel is similar to the following salt.‡‡ 19. Sulpho-tungstate of cobalt forms a dark brown, almost opaque liquid, which in 24 hours deposites a black precipitate.§§ * Berzelius, Kong. Vet. Acad. Handl. 1826, p. 62. + Ibid. Class VII. 20. Sulpho-tungstate of zinc is precipitated in 24 hours in the state of a dark yellow powder.' 21. Sulpho-tungstate of cadmium falls speedily in the form of a lemon yellow powder.† 22. Sulpho-tungstate of lead is a dark brown precipitate, almost black. The precipitate by the yellow double salt is smutty yellow.‡ 23. Sulpho-tungstate of tin is a flocky, brown, bulky precipitate. § 24. Sulpho-tungstate of bisulphuret of tin is precipitated in the form of grayish yellow flocks. 25. Sulpho-tungstate of copper is a liver brown precipitate, which, when collected, becomes dark brown. With the yellow double salt the precipitate is darker and almost black.¶ 26. Sulpho-tungstate of bismuth is a dark brown precipi 27. Sulpho-tungstate of mercury falls in fine yellow flocks. When there is an excess of tersulphide of tungsten the precipitate is black, and when there is an excess of the mercurial salt the precipitate is white. The neutral salt becomes darker in drying, and becomes at last yellowish brown. When pounded it becomes dark red, and assumes a polish under the pestle. When distilled it gives out sulphur, and cinnabar and sulphide of tungsten remain behind.†† 28. Sulpho-tungstate of disulphuret of mercury is a black precipitate. 29. Sulpho-tungstate of silver is a dark brown precipitate. which becomes speedily black. When distilled it gives out sulphur, and becomes lead gray and shining. §§ 30. Sulpho-tungstate of gold forms a deep brown transparent liquid, which, when exposed to the open air for a couple of days, gives a shining precipitate having a black colour. || || 31. Sulpho-tungstate of platinum gives a deep brown liquid, which remains transparent for about an hour, and then rapidly deposites a black precipitate.¶¶ 32. Sulpho-tungstate of chromium is, to a certain extent, soluble in water, and deposites a small quantity of a greenish brown precipitate. SECTION IX.- These salts consist of combinations of sulphide of tellurium with the sulphurets. Hitherto they have been examined only by Berzelius, to whom we are indebted for the first accurate examination of the sulphide of tellurium. It is best obtained by decomposing either the tellurates or the salts in which oxide of tellurium acts the part of a basis by a current of sulphide of hydrogen. A brown flocky precipitate falls, which is sulphide of tellurium. When heated in close vessels the sulphur is driven off, and pure tellurium remains behind. 1. Sulpho-tellurate of ammonia gives, when the solution is concentrated in vacuo over potash, crystals resembling those of sulpho-tellurate of potassium, and which are decomposed by exposure to the air. Even in vacuo it is partially decomposed, because a portion of the base flies off; but the rest may be concentrated without decomposition.* 2. Sulpho-tellurate of potassium, when concentrated without the contact of air, shoots into regular four-sided prisms of a dark yellow colour. A concentrated solution may be evaporated at the temperature of 104° in the open air, and it crystallizes better when thus evaporated than when cooled. The salt becomes moist in damp air, and assumes almost a black colour. It fuses easily, and is black while in a liquid state, but on cooling it becomes brownish yellow, and dissolves again in water.† 3 and 4. Sulpho-tellurate of sodium and lithium could not be made to crystallize. They dry in vacuo into a dark yellow mass, easily decomposed in the air, especially the lithium salt.‡ 5. Sulpho-tellurate of barium is best obtained by boiling sulphuret of barium with sulphide of tellurium, and evaporating the solution in vacuo. The salt shoots into large, dark yellow, translucent, flat four-sided prisms. They dissolve slowly in water, and are not altered by exposure to the air. § 6. Sulpho-tellurate of strontium, when concentrated to the consistency of a syrup, gives marks of crystallization, and dries into a mass of a dark yellow colour, still soluble in water. It is not decomposed by exposure to the air. [] 7. Sulpho-tellurate of calcium dries to a yellow mass, not crystalline, and very easily decomposed by exposure to the air.¶ ⚫ Berzelius, Kong. Vet. Acad. Handl. 1826, p. 70. + Ibid. || Ibid. p. 71. ¶ Ibid. Sect. IX. Class VII. 8. Sulpho-tellurate of magnesium is obtained when solutions of sulpho-tellurate of barium and sulphate of magnesia are mixed and concentrated in vacuo. It gives a dark yellow crystalline mass, which is soluble, without alteration, in water, and moderately soluble in alcohol. * 9. When Berzelius attempted to obtain sulpho-tellurates of the earths by mixing together solutions of sulpho-tellurate of sodium and an oxygen acid salt of the respective earth, sulphide of hydrogen was given off, while the earths precipitated, mixed with sulphide of tellurium, in the state of a black powder. The salts of chromium and of uranium behave in exactly the same way.† 10. The Sulpho-tellurates of cerium, manganese, zinc, and cadmium precipitate at first with a yellow colour inclining to brown; which speedily darken, and at last assume the colour of sulphide of tellurium. When distilled they give out sulphur.‡ 11. Sulpho-tellurate of iron is a black precipitate. Sulphotellurate of bisulphuret of iron, a dark brown flocky mass, which speedily concretes into a lump. It melts easily after being dried, and when ignited in a distilling vessel it gives out much sulphur, while a gray metallic mass remains. § 12. Sulpho-tellurate of nickel and cobalt are both precipitated of a black colour.] 13. Sulpho-tellurates of lead, bismuth, tin, and copper are all brown or brownish yellow precipitates, which become black while drying; when distilled give out sulphur, and leave a gray metallic mass. ¶ 14. Sulpho-tellurate of bisulphuret of tin has a much darker colour than the preceding salts.** 15. Sulpho-tellurate of mercury and sulpho-tellurate of disulphuret of mercury are the latter yellow brown and the former dark brown.+t 16. Sulpho-tellurate of silver is a black bulky precipitate, which, when polished, assumes the metallic lustre. When distilled it gives out sulphur, and leaves a fused, lead gray, metallic button, which is not altered when again fused in the open air. It is malleable.‡‡ 17. Sulpho-tellurate of gold is soluble in water, with so deep a brownish yellow colour that the liquid is opaque. In about * Berzelius, Kong. Vet. Acad. Handl. 1826, p. 71. † Ibid. Ibid. a couple of days it is mostly precipitated in black bulky flocks, which, when distilled, give out sulphur having a dark colour, and leave a fused gray alloy of tellurium and gold.* 18. Sulpho-tellurate of platinum remains long in solution with a deep brown yellow colour, but the liquid lets fall in a few days brown flocks, which become black on being dried.† SECTION X.-—OF SULPHO-ANTIMONIATES. There are three sulphides of antimony, namely: Sesqui-sulphide, analogous to oxide of antimony. Each of these is capable of combining with sulphurets and of forming a genus of sulphur salts. These will come to be distinguished by the terms Sulpho-antimoniates, Sulpho-antimonites, According to the mode of naming which we have adopted for the sulphur salts of arsenic. But the antimonial sulphur salts have not yet been investigated. Of course it is impossible to give any account of them here. The subject, however, is interesting, and is calculated to throw much light upon some of the most complicated ores in the mineral kingdom. We are not yet acquainted with any sulpho-antimoniates; but there are two sulpho-antimonites; namely, 1. Feather ore, which used to be considered as a mere variety of common sesqui-sulphide of antimony. Its nature was first established by Mr. H. Rose, who showed it to be a sulphoantimonite of lead, composed of 2. Jamesonite, a mineral first distinguished from common sesqui-sulphide of antimony by Mohs. It is a compound of 1 atom bisulphide of antimony, 1 atom sulphuret of lead. There are at least 5 different species of hyposulpho-antimonites, whose existence has been recognised in the mineral kingdom. These are the following: • Berzelius, Kong. Vet. Acad. Handl. 1826, p. 73. † Ibid. Sect, X. |