AMMELIDE, HYDROSULPHURETS OF CYANOGEN. 1001 



solved in caustic potash, from which it is obtained, on neutralis- 

 ing with acetic acid, as a gelatinous white precipitate, this is 

 washed and then redissolved in dilute nitric acid ; the solution 

 gives by evaporation crystals of pure nitrate of ammeline, 

 from which, dissolved in water, pure ammeline is precipitated 

 by carbonate of ammonia. It may also be obtained by dissolv- 

 ing melam in dilute and boiling hydrochloric acid. 



Ammeline forms very fine brilliant silky needles ; is insoluble 

 in water, alcohol, and ether, but dissolves in caustic alkalies. 

 Ammeline is a feeble base and combines only with the more 

 powerful acids. Its salts are crystalline, have an acid reaction, 

 and water precipitates ammeline from them. 



Ammelide, C 12 N 9 H 9 O 6 (Liebig), is a product of the decompo- 

 sition of melam, melamine, and ammeline by concentrated acids. 

 The solution is treated with alcohol, and the precipitate of am- 

 melide washed with cold water. It may be purified by solution 

 in nitric acid and precipitation by carbonate of ammonia. It is 

 a white powder insoluble in water, alcohol, and ether ; soluble 

 in alkalies and the stronger acids. It forms a crystalline com- 

 pound with nitric acid, which is decomposed by water. When 

 long boiled in dilute nitric or sulphuric acid, ammelide is com- 

 pletely decomposed and converted into ammonia and cyanuric 

 acid. 



Hydrosulphurets of cyanogen. Dry sulphuretted hydrogen 

 and cyanogen do not combine when mixed together over 

 mercury, but if a drop of water is added, the gases are con- 

 densed in the water, which affords thin yellow crystals by 

 evaporation, observed by Gay-Lussac, of which the com- 

 position is C 4 N 2 H 3 S 3 ; or an allantoin, in which the oxygen is 

 replaced by sulphur (Voelckel). When a stream of sulphuretted 

 hydrogen is conducted into an alcoholic solution of cyanogen, 

 the liquid soon becomes yellow, and deposits fine orange red 

 crystals, when artificially cooled, discovered by Woshler, of 

 which the composition is C 2 NHS + HS ; its compound with lead 

 C 2 NHS + PbS (Voelckel). 



Sulphocyanhydric acid and sulphuretted hydrogen. A com- 

 pound acid of these acids was obtained by Zeise, as one 

 of the products of the reaction between gaseous ammonia and 

 the bisulphuret of carbon in alcohol. Its empirical formula is 

 CyS 3 H 2 



