( 370 ) 

 Contribution to the Chemistry of Combustion. 



By C. LUEDEKING, Ph.D. 



The ordinary combustion of organic substances in atmospheric 

 air produces as final products carbon dioxide and water, and also 

 gaseous nitrogen if the substance be nitrogenous. These are the 

 products of combustion of alcohol, coal oil, coal gas, wood. etc. 

 In the course of certain experiments on Titanic acid, it was no- 

 ticed that in the inner part of the Bunsen flame made just slightly 

 luminous by properly regulating the air supply, the well known 

 cyanogen Titanium compound, so often found in iron blast 

 furnaces when titaniferous iron ores are smelted, was readily 

 formed. By its characteristic appearance, in fact, it is possible 

 by this means to detect or confirm quickly very minute quantities 

 of Titanic acid. The manner of procedure is to dissolve in a 

 small quantity of carbonate of soda, on the loop of a platinum 

 wire, the precipitate or substance in question, and volatilize all 

 the alkali in the inner flame, when the copper-red cyanogen Tita- 

 nium compound will be formed if Titanium be present. The en- 

 tire test requires but very little substance, only a few minutes' time, 

 and is exceedingly delicate. 



I employed this test in a reverse manner, viz., to discover the 

 presence of cyanogen in various flames. Herein I was perfectly 

 successful in most different cases. The copper-red compound 

 was formed in the flame of a tallow candle, parafR i candle, coal- 

 oil lamp flame, and alcohol flam?. It was evident, therefore, 

 that in all the above-named flames cyanogen is formed and bound 

 by the Titanium. Is Titanium now the inducing agent so that 

 cyanogen does not ordinarily exist in these flames.-* This question 

 is quite justified in view of the following experiments. 



Bunsen & Playfair (Journ. f. prakt. Chem., vol. xlii. p. 397) 

 Slowed that carbonate of Potassium, intimately mixed with Car- 

 boa and heated in a current of Nitrogen to the reduction temper- 

 ature of Potassium, is completely converted into cyanide of Po- 

 tassium. This, and not the nitrogen of the nitrogenous fuel is 



