DISTILLATION WITH AN ALKALI. 709 



tances less complex than themselves, but which are not ele- 

 mentary ; as urea from cyanic acid and ammonia, the acid 

 named, in common with cyanogen itself and all its compounds, 

 being considered organic, because usually derived from the de- 

 composition of azotised matters. But it has unequivocally been 

 proved that nitrogen gas unites with charcoal under the influence 

 of carbonate of potash at a red heat, and forms cyanide of po- 

 tassium (L. Thompson, Fownes).* The last salt also yields 

 ammonia when decomposed by water ; so that cyanogen, and 

 through cyanogen ammonia, can be primarily derived from 

 their elements contained in the inorganic world. The usual 

 course however pursued by the chemist in this department is 

 to form new compounds by the alteration of compounds sup- 

 plied to him by nature. These changes he effects by various 

 agencies, such as hydrate of potash, distillation by heat, acids, 

 oxygen, chlorine, &c. The most uniform and definite of these 

 actions are those of a hydrated alkali and dry distillation. 



Distillation with an alkali. When an organic substance con- 

 taining no nitrogen is fused with a sufficient quantity of hydrate 

 of potash, no charcoal is liberated. The products formed are 

 those which result from oxidation ; water is generally decom- 

 posed, of which the oxygen enters into combination with the 

 hydrogen and carbon of the organic matter, while the hydrogen 

 is disengaged as gas. Thus when acetate of soda is decomposed 

 by hydrate of barytes, the hydrogen of the latter is liberated. 

 M. Dumas has shewn that alcohol and other bodies of the 

 same character, distilled at a moderate heat with a mixture of 

 hydrate of potash and quicklime, each gives rise to a peculiar 

 acid, which remains in combination with the potash, by losing 

 2 eq. of hydrogen (disengaged as gas), and acquiring 2 eq. of 

 oxygen ; alcohol to acetic acid, wood spirit to formic acid, fousel 

 oil to valerianic acid, ethal to ethalic acid ; and that this mode 

 of decomposition is characteristic of alcohols. Glycerine, which 

 in some respects resembles an alcohol, when treated in the 

 same way, but at a very low temperature, does not give a pe- 

 culiar glyceric acid, but resolves itself into acetic and formic 

 acids, with the loss of two equivalents of hydrogen and assump- 

 tion of two of oxygen. Acetone transmitted in the state of 



* Originally observed by Desfosses ; Journal tie Pharmacic, t. 14, p. 280 (1828)- 



