Chemical Science. 2l5 



quadricarburet, the other metal remains combined with carbon 

 in an inferior degree as a tri or bi-carburet. 3. The reducible 

 metals lose their cyanogen, and retain no carbon. 



M. BerzeHus then remarks on the nature of these new car- 

 burets of the metals, which, containing four, three, and two 

 proportions of carbon, present a class of bodies analogous to 

 the sulphurets, arseniurets, ^-c. ; he considers the decomposition 

 of the cyanogen in the cyanurets as due to the affinity of the 

 metals of the carbon ; and observes, that in distilling vegetable 

 metallic salts the residues which are obtained, and which till 

 now have been considered as mixtures of carbon and the metal, 

 are true compounds. 



The observations which then follow on the plicnomenon of 

 ignition, observed in many of these experiments with the quadri- 

 carburets, ^c, are highly interesting, but we must refer the 

 reader to the original paper for them ; the great length of this 

 abstract prevents us from noticing any thing but matter imme- 

 diately connected with the object of the paper. 



The cyanurets with concentrated sulphuric acid are more or 

 less dissolved without decomposition ; those of iron and po- 

 tassa, of iron and baryta, dissolve entirely, yielding a colour- 

 less solution, which is not decomposed at 212° Falir., others 

 dissolve in small quantity, whilst the greater proportion remain 

 undissolved in combination with the acid. When the acid is 

 poured into the powdered cyanurets, the mixture heats, swells, 

 becomes pulpy, and if soluble, gradually dissolves, though 

 a great quantity of sulphuric acid is required for this effect. 

 The addition of a little water troubles the sohition, and part 

 of the acid compound falls, but if much water be added decom- 

 position takes place, super-hydrocyanate of iron and super- 

 sulphate of the other base are produced, or if the cyanuret is 

 insoluble it re-appears with its common chVacters. If the 

 acid solution be heated at a certain temperature, the cyanuret 

 is decomposed, sulphurous and carbonic acids with nitrogen 

 are disengaged, and super-sulphates of ammonia and of the 

 bases employed, remain. M. Berzelius could not succeed in 

 producing the new gas, which Dr. Thomson says is found on 

 those occasions, nor does there appear to be any reason to 

 believe in its existence. M. Berzelius describes the action of 

 sulphuric acid on several of the double cyanurets, and con- 

 cludes this part of his paper, by expressing his opinion, that 

 they should be considered as double acid salts, where two 

 bases are combined at the same time with excess of the two 

 acids. 



M. Berzelius concludes this very importaiit paper by some ob- 

 servations on the preparation of alkaline cyanurets from prus- 

 sian blue; if prussian blue of commerce and potassa in excess 

 he made to act on eacl) other, und llu^ solution l^e nuide hv 



