A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 99
acid is obtained in large colourless crystals, which are odourless and
have a slightly acid taste. It is not poisonous.
Arsmrmmomethyl Compound*.—Araendimethyl trichloride yields, as
we have seen, on heating, methyl chloride and arsenmonomethyl
dichloride. The latter compound is also obtained by the action of
dry hydrochloric acid upon cacodylic acid:—
A8(CH,)«2 J 0 + 3HC1 = AsCCH^Clj + CH8C1 + 2H,0
Arsenmonomethyl CMorvk AsCHsCls is a colourless strotigly refracting
liquid boiling at 135°; its vapours violently attack the mucous
membranes. On adding water and potassium carbonate to it the
oxide AsCHgO is obtained in colourless crystals, which smell like
asafcetida. By y the action of water and silver oxide upon p the oxide
or chloride the silver salt arsenmonomcthylic acid AsCHg I QJ^J is
formed. The free acid, obtained by decomposing the barium salt with
sulphuric acid, crystallizes in colourless plates and possesses a jnire
acid taste.
METHTTIiBORINE OR BOltON-METHYl, B(CH3)8
is formed by a singular reaction; it is obtained by acting on ethyl
borote with zinc-methyl:—
3
It is a colourless gas, having a pungent smell •, exposed to air it
takes fire, burning with a smoky green flame. By strong pressure or
* cold it can be condensed to a liquid. It combines with dry ammonia,
forming the compound B^H^gNHg, a white crystalline mass.
COMPOUNDS OF JJKTHYL WITH METAW.
Zinc Methidc or Zmcmdhyl Zn(CHs)a is produced by heating ssinc
with methyl iodide. It is, however, much mote readily formed when
mercuric methide is heated vrith grannlated zinc in a sealed tube for
24 hours to 120°. Zinc tnetlude is a colourless mobile liquid, possessing
a peculiar disagreeable smell. It takes fire in the axe, burning
with a greenish blue flame, and with the formation of dense clouds of
zinc oxide. With water it forms zinc hydroxide and methane:—