M, Gelis on Hyposulphuric Acid. 189 



According to Stahlschraidt*, when iodide of nitrogen is mixed 

 with iodide of methyle, the mixture becomes heated if the masses 

 are at all considerable. After some time a brown liquid is formed, 

 from which a pulverulent body separates. On further standing, 

 crystals of the same body are formed. They are of a somewhat 

 dark colour, are difficultly soluble in boiling alcohol, and crystal- 

 lize out in yellow lamina?. 



From the original mother-liquor a second body is graduallv 

 deposited in green crystals, which have a remarkable lustre. The 

 author is engaged in the investigation of the composition of these 

 bodies, which may be expected to throw great light on the for- 

 mula of iodide of nitrogen. 



Gelis has described a new mode of preparing hyposulphuric 

 acidf. When carefully washed sulphurous acid is passed into a 

 water containing in suspension hydrated peroxide of iron, a deep- 

 red acid liquor is obtained with a strong odour of sulphurous 

 acid. During the reaction the mixture must be kept cool. For 

 each equivalent of peroxide of iron three equivalents of sulphu- 

 rous acid are absorbed, and the solution contains the elements of 

 a neutral sulphite of peroxide of iron, Fe 2 3 3S0 2 , a salt which 

 has not yet been obtained in the dry state. The solution does not 

 retain its red colour ; if the flask is corked, it is changed in the 

 course of twenty-four hours into the pale green of salts of the 

 protoxide. The sulphite has become resolved into two salts, the 

 hyposulphate and sulphite of the protoxide of iron. Thus 



Fe 2 3 3S0 2 = FeOS0 2 + FeOS 2 5 . 



To obtain hyposulphuric acid or any of its salts, this decolorized 

 liquor may be treated with milk of lime or baryta water, which 

 precipitates iron as the protoxide, and sulphurous and a little sul- 

 phuric acid present as sulphite and sulphate. The hyposulphu- 

 rous acid remains combined with baryta or lime : these salts are 

 readily soluble, and may be easily obtained in the crystalline 

 state. From the baryta- or lime-salt the free acid may readily 

 be prepared by the ordinary methods. 



Mendius has investigated a new decomposition of the nitriles %. 

 These substances take up hydrogen in the nascent state, and are 

 transformed in accordance with the general equation 



that is, that the nitrile, which may also be viewed as the cyanide 

 of an alcoholic radical, may be converted into the amine base of 



* Poggendorff 's Annalen, April 1362. 



+ Ann.de Chim. et de Phys., vol. lxv. p. 222. 



X Liebig's Annalen, Februaiy 1862. 



