out 18%. The oil is obtained as a
commercial product by submitting the cloves with water to repeated
distillation. It is, when new and properly prepared, a pale yellow or
almost colourless fluid, becoming after some time of a brown colour; and
it possesses the odour and taste peculiar to cloves. The essential oil
of cloves--the _Oleum Caryophylli_ of the British Pharmacopoeia--is a
mixture of two substances, one of which is oxidized, whilst the other is
not. _Eugenol_, or eugenic acid, C10H12O2, is the chief constituent. It
is capable of forming definite salts. The other constituent is a
hydrocarbon C15H24, of which the distilling point differs from that of
eugenol, and which solidifies only with intense cold. Oil of cloves is
readily soluble in alcohol and ether, and has a specific gravity of
about 1.055. Its dose is 1/2-3 minims. Besides this oil, cloves also
contain two neutral bodies, eugenin and caryophyllin, the latter of
which is an isomer of camphor. They are of no practical importance. The
British Pharmacopoeia contains an infusion of cloves (_Infusum
Caryophylli_), of which the strength is 1 part in 40 of boiling water
and the dose 1/2-1 oz. Cloves are employed principally as a condiment in
culinary operations, in confectionery, and in the preparation of
_liqueurs_. In medicine they are tonic and carminative, but they are
little used except as adjuncts to other substances on account of their
flavour, or with purgatives to prevent nausea and griping. The essential
oil forms a convenient medium for using cloves for flavouring purposes,
it possesses the medicinal properties characteristic of a volatile oil,
and it is frequently employed to relieve toothache. Oil of cloves is
regarded by many dental surgeons as the most effective local anaesthetic
they possess in cases where it is desired, before cutting a sensitive
tooth for the purpose of filling it, to lower the sensibility of the
dentine. For this purpose the cavity must be exposed to cotton wool
saturated with the oil for about ten days.

CLOVIO, GIORGIO GIULIO (1498-1578), Italian painter, by birth a Croat
and by profession a priest, is said to have learned the elements of
design in his own country, and to have studied afterwards with intense
diligence at Rome under Giulio Romano, and at Verona under Girolamo de'
Libri. He excelled in historical pieces and portraits, painting as for
microscopical examination, and yet contriving to handle his subjects
w