278 ON PRUS.SIC ACID. 



not only to fhorten the expreffions, but to explain in proper 



terms fuch notions as indicate the real ftate of the fubftance 



under defcription. 



The gafeow Chemifts have never diftinguifhed the Pruffic acid, faturating 



lefs ox'genthan a meta l MC fubftance from the gazeous Prvjfire, They have 



when in com- always believed on the contrary that this laft, extracted from 



macion. an ^ p ru 0i a te whatever, was the fame as in its ftate of combir 



nation. But on a nearer examination, we find it impoffible to 



obtain fimple Pruffic acid ; that it can only exift in a combined 



ftate ; that its combinations can only take place by virtue of 



the oxigen afforded by the bafe to which it is united : laftly, 



It cannot exift that the fimple pruffire cannot exift with the pretence of oxi- 



withmoreoxi- without an immediate deftru.aion of the affinity which 



gen : ror this ° J 



laft will acidify held its three component principles together. The carbon in 

 itscarbon, while ^ rac |ical j s particularly difpofed to unite witli oxigen, and 

 the azote and . ' , r , • ,- , • ' • , , 



hydrogen form at the inftant when the iubtraction or this principle is made, 

 ammonia 5 and |j ie az ote and the hydrogen become liberated, and immediately 

 of ammonia will f° rm ammonia, which is alfo fafurated by the carbonic acid 

 be had. a t the moment of their mutual production. Water is the ox- 



igenated compound which has the ft rongeft effect in producing 

 thedecompofition of pruffire, without feparating its elements ; 

 that is to fay, the refult of this decompofjtion is always car* 

 bonic acid and ammonia. 

 Suppofed incon- Tlie fixity of pruffire (hewn by the high temperature at which 

 Utility* I or Ra-°" ** is formed, does not appear to me to agree with what is 

 zeous form) of already known relative to its extreme volatility, and of its little 

 orMnaVfixU ! " dif P of ' tion to unite direflly with faline bafes. I thought it ne- 

 ceffary to direft my enquiries to this object, in order to ascer- 

 tain, if poffible, the caqfe which produced fuch oppofite pro- 

 perties in the fame fubftance, and which, as I apprehend, 

 muft arife from facts not yet known and underftood. 

 The fixity of I could not attribute the Jixity of pruffire to the oxigen, 



ih-wnb'y the & nce > by the experiments which I publifhed five years ago ^, 

 great heat it fup- I have (hewn that this principle always oppofes its formation, 



ports during cal- an(1 even deftroys it when already formed. Thus, from the 



cination does not , 1 , 



arile from oxi- moment it was proved that the calcinations intended to form 



£ en » the pruffire is ineffectual wherever oxigen is prefent, I could 



no longer admit that this compound, when formed by calcina- 

 tion, with an alkali, can derive its fixity from oxigen. It be- 



* Journal de Pharmacie, cahier de Germinal, An 6. 



came 



