37^ TRANS. ST. LOUIS ACAD. SCIENCE. 



As it was possible to form the cyanogen Titanium compound 

 in the reducing- flame of various combustibles, it seems desirable 

 to ascertain whether the presence of Cyanogen or Hydrocyanic 

 acid could be demonstrated in these same flames under condi- 

 tions precluding the presence of an inducing agent. It was 

 attempted to ascertain whether Cyanogen or Hydrocyanic acid 

 occur in these flames due to the direct action of atmospheric 

 nitrogen, or, in other words, whether atmospheric nitrogen plays 

 a role chemically in the ordinary process of combustion of 

 carbon compounds. 



For this purpose the gases of the reducing flame were tapped, 

 as in the ordinary lecture of experiment, to show the combustible 

 nature of the gases in the flame of a candle. However, since 

 glas^s is dissociated to a great extent, and the alkali metals vola- 

 tilized under such conditions, and as these are inducing agents for 

 formation of cyanogen compounds, and as these were to be en- 

 tirely eliminated, a platinum tube was taken. This was mounted 

 in a glass tube for conducting the gases. It was 90 mm. long and 

 5 mm. in diameter, and of very thin platinum. The gases were 

 conducted into a test tube containing a few cubic centimetres of 

 caustic soda solution, and the end of the gas-conducting tube 

 made to closely approach the surface of the liquid without being 

 obstructed. This mode of experiment was found to give results 

 only. When the gases were made to actually bubble through the 

 caustic soda : no reactions could be obtained. The reason is ob- 

 vious, for the gases contain such large amounts of Carbon dioxide 

 that any Cyanogen or Hydrocyanic acid is displaced from solu- 

 tion, or, in other words, it cannot accumulate. 



The time of combustion necessary before one can obtain a pre- 

 cipitate of Prussian blue, in the well known manner in the test- 

 tube liquid, is about one hour. When coal oil or candles are 

 experimented with, the platinum tube must frequently be cleared 

 of soot, and the caustic soda must be filtered for the same reason^ 

 before the tests can be made. In much less time, however, one 

 can obtain the reaction as indicated by the green color of the 

 liquid, the prussian blue remaining in solution on account of its 

 minuteness of quantity. I will also say that never was it possible 

 for me in one hour to obtain an immediate precipitate ; but only 

 so after several hours' standing of the intensely green liquid. 



