A Manual of the Chemistry of the Carbon Compounds

130 THE CHEMISTRY OF
colourless liquid, boiling at 60°, and possessing a pungent smell, irri-
.taMng the eyes. With hydrochloric acid it forms a liquid compound
boiling at 95°, which by water is decomposed into carbon dioxide
and ethylamine. The same products are formed when the carbimide
is boiled with cauBtic potash:—
N + H2O = C ***} N + CO2
When gaseous cyanic acid is passed into absolute alcohol, so much
heat is evolved that the liquid begins to boil. On cooling, colourless
shining prisms of ethyl allophanate C2H8N!Og.Ci!H6 crystallize out.
By the action of caustic baryta on this ether the barium salt of
allophanic acid C2H4N30? is obtained, but from this salt the free acid
cannot be isolated, nor indeed are other salts known. A series of
allophanic ethers, however, has been prepared by acting with cyanic
acid on different alcohols.
When barium allophanate is treated with a dilute acid, carbon
dioxide is given off and urea is formed. This decomposition explains
the constitution of allophanic acid, which stands to biuret in the
same relation as carbamic acid to urea:—
Biuret. Allophanic Acid.
/CON^ fCONH
Ethyl SnlpJiocyanate ^ J- S, a colourless oily liquid, boiling at
146°, and possessing a smell like leek, is formed by distilh'ng a mixture
of potassium sulphocyanate and potassium ethylsulphate, When
this ether is heated with sulphuric acid, a copious evolution of carbon
dioxide take3 place, and a colourless volatile liquid, having a strong
alliaceous smell, is formed, which has the composition and the same
boiling-point as ethyl xanthate. These bodies are, however, not identical,
for whilst the latter compound is decomposed by an alcoholic
solution of potash into potassium ethyl sulphocarbonate and ethyl
hydrosulphide, the isomeric compouud, which has been called carbonyMisulpluhdiethyl,
yields by the same treatment potassium carbonate
and ethyl hydrosulpliide. The cause of this isomerism is
explained by the following equations:—-
Ethyl Xanthate.
c s \ OG;H5 + H
Carbonyl'disulphodiothyl.
ElhykidphocarUmide or Ethyl Mustard-oil N-< A^r, which is iso-