OF ALIPHATIC COMPOUNDS. 45 



Hydrocyanic Acid. Electrosynthesis : Berthelot l 

 obtained hydrocyanic acid by passing the electric 

 spark through a mixture of acetylene and nitrogen. 

 The reaction is, however, reversible. On allowing 

 the electric spark to act on hydrocyanic-acid gas it 

 was decomposed into acetylene and nitrogen. Hydro- 

 cyanic acid is also obtained by passing the electric 

 spark through mixtures of ethylene or aniline vapor 

 with nitrogen, acetylene with nitric oxide (Hunting- 

 ton a ), nitrogen with benzol (Perkin 3 ), etc. 



Electrolysis: In sulphuric-acid solution hydro- 

 cyanic acid breaks up smoothly, according to Gay- 

 Lussac, 4 into hydrogen and cyanogen. Concentrated 

 hydrocyanic acid to which a drop of sulphuric acid 

 has been added gives carbon monoxide and ammonia 

 (SchlagdenhaufTen 5 ). 



Potassium Cyanide. In the investigation of this 

 salt, conducted by the author last mentioned, it 

 was found that no oxygen escaped at the anode, 

 but the potassium cyanide was oxidized to potassium 

 cyanate. 



Potassium Ferrocyanide. This compound gives at 

 the anode hydrocyanic acid and Prussian blue and at 

 the cathode hydrogen and potassium hydroxide 



Bull. soc. chim., 13, 107. 



English patent, 14855; German patent, 93852. 



Jahresb. f. Chem., 1870, p. 399. 



Gilbert's Ann., 1811-1815; Ann. chim. phys., 78, 245. 



Jahresb. f. Chem., 1863, p. 305. 



