on. Several indistinct varieties have been named, the
most important of which is jeffersonite. (L. J. S.)

CHLOROFORM (trichlor-methane), CHCl3, a valuable anaesthetic, a
colourless liquid, possessing an agreeable smell and a pleasant taste.
It may be prepared by the action of bleaching powder on many carbon
compounds, such, for example, as ethyl alcohol and acetone (E.
Soubeiran, _Ann. chim. phys._, 1831 [2], 48, p. 131; J.v. Liebig,
_Ann._, 1832, I, p. 199), by heating chloral with alkalis (Liebig),
CCl3CHO + NaHO = CHCl3 + NaHCO2, or by heating trichloracetic acid with
ammonia (J. Dumas, _Ann._, 1839, 32, p. 113). In the preparation of
chloroform by the action of bleaching powder on ethyl alcohol it is
probable that the alcohol is first oxidized to acetaldehyde, which is
subsequently chlorinated and then decomposed. Chloroform solidifies in
the cold and then melts at -62 deg. C.; it boils at 61.2 deg. C., and has a
specific gravity 1.52637 (0 deg./4 deg.) (T.E. Thorpe). It is an
exceedingly good solvent, especially for fats, alkaloids and iodine. It is
not inflammable. The vapour of chloroform when passed through a red-hot
tube yields hexachlorbenzene C6Cl6, perchlorethane C2Cl6, and some
perchlorethylene C2Cl4 (W. Ramsay and S. Young, _Jahresberichte_, 1886,
p. 628). Chromic acid converts it into _phosgene_ (carbonyl chloride,
COCl2). It reacts with sodium ethylate to form ortho-formic ester,
CH(OC2H5)3, and when heated with aqueous ammonia for some hours at
200-220 deg. C. gives carbon monoxide and ammonium formate, 2CHCl3 + 7NH3 +
3H2O = NH4.HCO2 + CO + 6NH4Cl (G. Andre, _Jahresb._, 1886, p. 627). When
digested with phenols and caustic soda it forms oxyaldehydes (K. Reimer,
_Ber._, 1876, 9, p. 423); and when heated with alcoholic potash it is
converted into potassium formate, CHCl3 + 4KHO = KHCO2 + 3KCl + 2H2O. It
combines with acetoacetic ester to form the aromatic compound
meta-oxyuvitic acid, C6H2.CH3.OH.(COOH)2. A hydrate, of composition
CHCl3.18H2O, has been described (G. Chancel, _Fresenius Zeitschrift f.
anal. Chemie_, 1886, 25, p. 118); it forms hexagonal crystals which melt
at 1.6 deg. C.

Chloroform may be readily detected by the production of an isonitrile
when it is heated with alcoholic potash and a primary amine; thus with
aniline, phenyl isocyanide (recognized by its nauseating smell) is
produced,

CHCl3 + C6H5NH2 + 3KHO = C6H5NC + 3KCl + 3H2O.

For the action and use of chloroform as