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are completely decomposed, the iron in the ferrocyanide of 
sodium becomes peroxide, and this in a few hours falls to the 
bottom of the pot. If the right quantity of saltpetre has 
been added, a colourless mass of fused caustic soda remains, 
but if too large an amount of nitre has been added, the liquor 
becomes coloured deep green, owing to the formation of man- 
ganate of soda. It is remarkable that, in the absence of nitrate 
of soda, the cyanogen compounds act reducingly upon the 
sulphide of sodium ; this is seen from the fact that a portion 
of the soda lye, which gives no sulphide reaction with a lead 
salt, produces a blackening after the caustic alkali has been 
heated to redness. 
The graphite may be skimmed off the surface of the fused 
alkali, and, when washed with water and hydrochloric acid, it 
appears in the form of an extremely fine bright powder. If 
allowed to swim on the top of the almost red hot fused soda, the 
graphite is oxidized gradually, and, after a lapse of about three 
or four hours, it altogether disappears. Heated in a platinum 
crucible by itself it is incombustible, but it generally contains 
small particles of charcoal mixed with it, and these undergo 
oxidation. 
The temperature at which this evolution of graphite takes 
place is a very low one, compared with that at which graphite 
is liberated from cast iron, for a thin iron wire can scarcely be 
brought to a visible red heat by dipping it into the fused 
alkali. 
From this peculiar decomposition it would appear that we 
have good reason to assume, that the carbon contained in 
cyanogen is present in the graphite modification; for, if this 
be not the case, how is it that the easily combustible charcoal 
can withstand the oxidizing action of the saltpetre, whilst none 
of the iron of the ferrocyanide of sodium is reduced to the 
metallic state ? 
It has, besides, been lately shown by M. Caron, that the 
formation of steel, i. e, the combination of iron with carbon in 
