Sulphuretted Hyposulphuric Acid

Discovered by Fordos and Gelis. When iodine is dissolved 

Here 2 e(j. of hyposulphite of baryta and 1 eq. of iodine yield 1 eq. of iodide of banum and 1 eq. of the bar3da salt of the new acid. Alcohol dissolves the former, and leaves the latter pure. By the cautious addition of diluted sulphuric acid, the baryta is precipitated, and the new acid is obtained dissolved in -water. It resembles the two preceding acids, and, like the last, it is resolved, when heated, into sulpnurous acid, sulphur, and sulphuric acid, S, 0, = S 0, -b S, S 0,. Here the quantity of sulphur separated is exactly double or that yielded by the last-described acid. 

The salts of this acid ciystallise, and when heated yield 1 eq. of sulphurous acid, 2 eqs. of sulphur, and 1 eq. of sulphuric acid MO, S 0,=S0,-bS, -bMO, SO,. 

The following table exhibits the composition of the compounds of sulphur and oxygen above described, with their formulae, and those of their neutral salts, according to the older and newer views of the constitution of acids. 

If we take the radical of sulphurous acid as the first member of the series, all the above acids may be thus represented — 

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When chloride of sulphur, SCI, acts on dry ammonia, NH, a compound is formed, SCI, 2 NH,. By the action of water on this there is formed, among other products, a greenish yellow solid body, which is sulphuret of nitrogen NS,. By contact with water, it is gradually converted into hyposulphurous acid and ammonia for 2 NS, + 6 H 0 = 2 NH, -f 3 S, 0,. (Soubeiran). 

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