Production of Cyanogenc. I53 



PRODUCTION OF CYANOGENE BV THE ACTION OF CAKBON 

 UPON NITRIC ACID. 



The following particulars on this subject are derived from a 

 paper " On the Formation of Cyanogenc or Prnssine in saine 

 chemical Processes not heretofore noticed," published in Silli- 

 nian's Journal for January last (vol. vi. p. 149). The bulk of 

 the communication relates to the probable formation of cyano- 

 gene in certain processes of nature, and it may constitute the 

 basis of febrile miasmata. 



" Some time since I was exhibiting to my class some experi- 

 ments on the decomposition of nitric acid, and of nitrate of pot- 

 ash by charcoal, in relation to the subject of gunpowdei*. When 

 I affused nitric acid on charcoal, there was, as is usual, a disen- 

 gagement of the deutoxide of azote, and on standing, the acid 

 became thick and brown, and to all appearance resembled artifi- 

 ficial tannin, which we know is obtained by a similar process. It 

 struck me as a circumstance not improbable, that besides the 

 formation of nitrous gas and carbonic acid gas, cyanogenc 

 might be formed. It appeai'ed to me, that whilst a portion of 

 carbon combined with a part of the oxygen of the nitric acid, 

 and the deutoxide of azote was disengaged, a part of the cai'- 

 bon might unite with a portion of azote, and thus generate cy- 

 anogenc. Whether this explanation will hold good, I will not 

 pretend to say, but it is certain that cyanogenc was generated. 

 By putting the charcoal and nitric acid into a retort, and col- 

 lecting the gaseous products ill Woulfe's botdes, arranged in 

 the usual manner, the gases evolved were all, or the g-reater 

 part, absorbed ; that is to say, the nitrous gas was converted 

 into nitric acid, by its union with the oxygen of the air con- 

 tained in tiie botdes, &c. I saturated the water, thus impreg- 

 nated, with potash, by which I formed a nitrate, carbonate, 

 and cyanide of that alkali, as die latter was subsequendy ma- 

 nifest. To this fluid I added the common sulphate and the 

 persulphate of iron. The colour instantly changed, and be- 

 came more or less blue, proving the existence of the perferrc- 

 cyanite of iron, and consequently of cyanogene, which must 

 have been formed by the union of carbon and azote. We may 

 conclude then, diat during the action of the nitric acid on tlie 

 carbon, which caused the development of nitrous gas, a part 

 of the azote of the acid must have combined with the carbon, 

 and that another portion of the carbon, by uniting with the 

 oxygen of the decomposed nitric acid, produced carbonic acid. 

 The carbon in this case must have taken up a part of the azote, 

 as well as a part of the oxygen. 



If the carbon abstracted the whole of the azote from a given 

 portion of nitric acid, the inference would be, that pure oxygen 



Vol. G2. No. 304. Aug. 1823. U was 



