was regulated by a local act in 1801.

See A.P. Stanley, _Historical Memorials of Canterbury_ (London, 1855);
J. Brent, _Canterbury in the Olden Time_ (Canterbury, 1879); J.W. Legg
and W.H. St J. Hope, _Inventories of Christchurch, Canterbury_
(London, 1902); _Victoria County History, Kent_.

CANTHARIDES, or SPANISH FLIES, the common blister-beetles (_Cantharis
vesicatoria_) of European pharmacy. They are bright, iridescent,
golden-green or bluish-coloured beetles (see COLEOPTERA), with the
breast finely punctured and pubescent, head and thorax with a
longitudinal channel, and elytra with two slightly elevated lines. The
insect is from half-an-inch to an inch in length, and from one to two
lines broad, the female being broader in the abdomen and altogether
larger than the male. It is a native of the south of Europe, being found
in Spain, France, Germany, Italy, Hungary and the south of Russia, and
it is also obtained in Siberia. The Spanish fly is also occasionally
found in the south of England. The insects feed upon ash, lilac, privet
and jasmine leaves, and are found more rarely on elder, rose, apple and
poplar trees. Their presence is made known by a powerful disagreeable
odour, which penetrates to a considerable distance. They are collected
for use at late evening or early morning, while in a dull bedewed
condition, by shaking them off the trees or shrubs into cloths spread on
the ground; and they are killed by dipping them into hot water or
vinegar, or by exposing them for some time over the vapour of vinegar.
They are then dried and put up for preservation in glass-stoppered
bottles; and they require to be very carefully guarded against mites and
various other minute insects, to the attacks of which they are
peculiarly liable. It has been shown by means of spectroscopic
observations that the green colour of the elytra, &c., is due to the
presence of chlorophyll; and that the variations of the spectral bands
are sufficient, after the lapse of many years, to indicate with some
certainty the kind of leaves on which the insects were feeding shortly
before they were killed.

Cantharides owe their value to the presence of a peculiar chemical
principle, to which the name _cantharidin_ has been given. It is most
abundant in large full-grown insects, while in very young specimens no
cantharidin at all has been found. From about one-fourth to rather more
than one-half per cent, of cantharidin has been obtai