A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 101
triad radicals, but as they bear very little relation to other groups
of carbon compounds they will be treated of here.
Afethene BvMoride, Dichkromelhane CILClj can be obtained by the
action of chlorine upon marsh-gas, or by adding hydrochloric acid and
zinc to an alcoholic solution of chloroform. It is a heavy liquid,
smelling like chloroform and boiling at 41°.
Chloroform, Trichloromethane CHCL,.—The third substitution product
of marsh-gas is also formed by the action of bleaching powder on
ethyl alcohol, and other carbon compounds. To prepare it ten parts
of bleaching powder are mixed with forty parts of hot water in a
large still, and one part of spirits of wine is added; a reaction soon
sets in by which sufficient heat is evolved to drive the chloroform
over.
Chloroform is a colourless mobile liquid, possessing a peculiar
sweetish smell and taste. It boils at 62°, and has at 0° the specific
gravity 1-525. The inhalation of its vapour produces anaesthesia,
and it is therefore largely employed in surgical operations. It is also
used as a solvent for iodine, bromine, alkaloids, gutta percha, &c.
The smallest quantity of chloroform can be easily detected by
adding to the liquid to be tested a monamine (or aniline) and an
alcoholic solution of caustic potash. When it is present in larger
quantities the peculiar odour of the carbamines is given off at once,
or after gently heating when only traces are present. Vice versd,
chloroform can be used for detecting the presence of a monamine.
TetrachlorometAane, Carbon TetrackloruU CCL is best prepared by
acting with chlorine upon chloroform in the sunlight; it may also be
obtained by passing chlorine and carbon disulphide through a porcelain
tube filled with fragments of porcelain. It is a heavy liquid, boiling
at IT and possessing the odour of chloroform. On heating it with an
alcoholic solution of potash it yields potassium chloride, potassium
carbonate, and water :—
CC1, + 6E0H = CO 15J! + 4KC1 + 3HaO
When its vapour mixed with hydrogen is passed through a glasstube
filled with broken glass, and lmted to a dull red beat, hexaeltforethane
CaCl0 is formed :—
2CC1, + H3 = 2HC1 +
Bromqfwm, Tnhrommdlmm CHBr., a liquid resembling chloroform
and boiling at 152°, is obtained by adding bromine to a solution of
potash in ethyl alcohol; bromoform very often occurs in commercial
bromine.
Tetrahwnomethane, Carbon Tdrabromide CBr4.—On heating bromine
with carbon disulphide in sealed tubes to 180°, an exceediugly slow
action sets in, which is very much accelerated by adding some iodine.
To prepare tetrabromomethane, two parts of carbon disulphide, four,
teen parts of bromine, and three parts of iodine are heated to 150°