1 54 Dr. Cutbush on the Formation, 4''C- 



trefaction of certain substances under particular circum- 

 stances and conditions. 



The fact, however, I purpose to notice is, that sometime 

 since I was exhibiting to my class some experiments on 

 the decomposition of nitric acid, and of nitrate of potash 

 by charcoal, in relation to the subject of gunpowder. Whea 

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

 disengagement of the deutoxyde of azote, and on standing, 

 the acid became thick and brown, and to all appearance 

 resembled artificial tannin, which we know is obtained by 

 a similar process. It struck me as a circumstance not im* 

 probable, that besides the formation of nitrous gas and car- 

 bonic acid gas, cyanogene might be formed. It appeared to 

 me, that whilst a portion of carbon combined with a part 

 of the oxygen of the nitric acid, and the deutoxyde of 

 azote was disengaged, a part of the carbon might unite 

 with a portion of azote, and thus generate cyanogene. 

 Whether this explanation will hold good, I will not pretend 

 to say, but it is certain, that cjanogene was generated. By 

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

 lecting the gaseous products in Woulfe's bottles, arranged 

 in the usual manner, the gases evolved were all, or the 

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

 converted into nitric acid, by its union with the ox3'gen of 

 the air contained in the bottles, &c. I saturated the wa- 

 ter, thus impregnated, with potash, by which I formed a ni- 

 trate, carbonate, and cyanide of that alkali, as the latter 

 was subsequently manifest. To this fluid, I added the com- 

 mon sulphate, and the persulphate of iron. The colour in- 

 stantly changed, and became more or less blue, proving the 

 existence of the perferrocyanite of iron, and consequently 

 of cyanogene, which must have been formed by the union of 

 carbon and azote. We may conclude then, that during the 

 action of the nitric acid on the carbon, whiph caused the 

 developement of nitrous gas, apart of the azote of the acid 

 must have combined with the carbon, and that another 

 portion of the carbon, by uniting '»vith the oxygen of the de- 

 composed nitric acid, produced carbonic acid. The carbon 

 hi 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, 



