eposits para-anthracene (C14H10)2, which melts at 244 deg. C.
and passes back into the ordinary form. Chlorine and bromine form both
addition and substitution products with anthracene; the addition
product, anthracene dichloride, C14H10Cl2, being formed when chlorine is
passed into a cold solution of anthracene in carbon bisulphide. On
treatment with potash, it forms the substitution product,
monochlor-anthracene, C14H9Cl. Nitro-anthracenes are not as yet known.
The mono-oxyanthracenes (anthrols), C14H9OH or

/CH\
C6H4< | >C6H3OH
\CH/

([alpha]) and ([beta]) resemble the phenols, whilst

/C(OH)\
C6H4< | >C6H4
\CH /

([gamma]) (anthranol) is a reduction product of anthraquinone.
[beta]-anthrol and anthranol give the corresponding amino compounds
(anthramines) when heated with ammonia.

Numerous sulphonic acids of anthracene are known, a monosulphonic acid
being obtained with dilute sulphuric acid, whilst concentrated sulphuric
acid produces mixtures of the anthracene disulphonic acids. By the
action of sodium amalgam on an alcoholic solution of anthracene, an
anthracene dihydride, C14H12, is obtained, whilst by the use of stronger
reducing agents, such as hydriodic acid and amorphous phosphorus,
hydrides of composition C14H16 and C14H24 are produced.

Methyl and phenyl anthracenes are known; phenyl anthranol (phthalidin)
being somewhat closely related to the phenolphthaleins (q.v.). Oxidizing
agents convert anthracene into anthraquinone (q.v.); the production of
this substance by oxidizing anthracene in glacial acetic acid solution,
with chromic acid, is the usual method employed for the estimation of
anthracene.

ANTHRACITE (Gr. [Greek: anthrax], coal), a term applied to those
varieties of coal which do not give off tarry or other hydrocarbon
vapours when heated below their point of ignition; or, in other words,
which burn with a smokeless and nearly non-luminous flame. Other terms
having the same meaning are, "stone coal" (not to be confounded with the
German _Steinkohle_) or "blind coal" in Scotland, and "Kilkenny coal" in
Ireland. The imperfect anthracite of north Devon, which however is only
used as a pigment, is known as _culm_, the same term being used in
geological classification to distinguish the strata in which it is
found, and similar strata in the Rhenish hill countries which are known
as the Culm Measures. In America, culm is used as an equivalent for