218 Notices of the Labours of Continental Chemists. 



nitrogen could not be converted into ammonia. Direct ex- 

 periments, however, have convinced us, that on employing a 

 sufficient excess of the hydrated alkali, and not too low a tem- 

 perature, every compound containing cyanogen or nitrogen, 

 every substance, in fact, which does not contain its nitrogen 

 in the form of nitric acid, is decomposed in such manner that 

 all the nitrogen is obtained in the form of ammonia as the final 

 product. If cyanide of potassium, cyanate of potash, or para- 

 cyanogen be melted with an excess of hydrate of potash at a 

 red heat, or heated with a non-fusible mixture of the hydrate 

 of potash or soda and caustic lime, a considerable evolution 

 of ammonia takes place, and not a trace of cyanogen or of a 

 compound of cyanogen can be detected in the residuum. It 

 is necessary, on performing this experiment, to employ so 

 much of the hydrated alkali that all the carbon of the substance 

 may be oxidized by the oxygen of the water of the former. 

 The mixture should become again perfectly white. According 

 to the amount of carbon in the substance, and to the tempe- 

 rature, other permanent gases are evolved together with the 

 ammonia; such as marsh gas, olefiant gas, hydrogen, or a 

 mixture of these; and in many cases even liquid carbui'etted 

 hydrogens, asBenzin ; at least the oily drops sometimes formed 

 have quite the smell of the latter substance. 



Melamin, mellon, cyanogen and its compounds, belong to 

 the class of bodies which abounds most in nitrogen ; but these 

 all contain as much carbon, or even more than is necessary, to 

 set free by its oxidation hydrogen enough to form ammonia 

 with all the nitrogen, without any of the latter remaining un- 

 combined. In some of these compounds, as in mellon, which 

 is represented by the formula C" N^, in melamin C*" N'^ H'^, 

 the decomposition is effected by means of a sufficient quantity 

 of hydrated alkali without a trace of permanent gas being 

 formed. All the carbon is converted into carbonic acid, which 

 remains in combination with the alkali ; all the nitrogen into 

 ammonia, which is given off. Our method consists, as above 

 stated, in condensing this ammonia by means of an acid, and in 

 weighing it in a solid form as ammonio-chloride of platinum. 



The apparatus employed is as simple as that which is in 

 use for determining the carbon and hydrogen of organic sub- 

 stances according to Liebig's method, and we shall now pro- 

 ceed to a more particular description of it, and of the measures 

 of precaution to be observed. The apparatus consists of a 

 common tube of combustion, which may be smaller than those 

 used lor determining carbon and hydrogen, and glass bulbs 

 containing muriatic acid for the absorption of the ammonia 

 <renerated, fixed, air-tight, to the tube by means of a bored 



