plant contain nitre abundantly.
The leaves may be usefully applied as poultices.

But another Pellitory, which is more widely used because of its
pungent efficacy in relieving toothache, and in provoking a free
flow of saliva, is a distinct plant, the _Pyrethrum_, or Spanish
Chamomile of the shops, and not a native of Great Britain, though
sometimes cultivated in our gardens. The title "Purethron" is from
_pur_, fire, because of its burning ardent taste. Its root is
scentless, but when chewed causes a pricking sensation (with heat,
and some numbness) in the mouth and tongue. Then an abundant flow of
saliva, and of mucus within the cheeks quickly ensues. These effects
are due to "pyrethrin" contained in the plant, which is an acid fixed
resin; also there are present a second resin, and a yellow, acrid oil,
whilst the root contains inulin, tannin, and other substances. When
sliced and applied to the skin it induces heat, [425] tingling, and
redness. A patient seeking relief from rheumatic or neuralgic
affections of the head and face, or for palsy of the tongue, should
chew the root of this _Pyrethrum_ for several minutes.

The "Pelleter of Spain" (_Pyrethrum Anacyclus_), was so styled,
not because of being brought from Spain; but because it is grown
there.

A gargle of _Pyrethrum_ infusion is prescribed for relaxed uvula,
and for a partial paralysis of the tongue and lips. The tincture made
from the dried root may be most helpfully applied on cotton wool to
the interior of a decayed tooth which is aching, or the milder
tincture of the wall Pellitory may be employed for the same
purpose. To make a gargle, two or three teaspoonfuls of the
tincture of _Pyrethrum_, which can be had from any druggist,
should be mixed with a pint of cold water, and sweetened with
honey, if desired. The powdered root forms a good snuff to cure
chronic catarrh of the head and nostrils, and to clear the brain by
exciting a free flow of nasal mucus and tears--_Purgatur cerebrum
mansa radice Pyrethri_.

Incidentally, as a quaint but effective remedy for carious toothache,
may be mentioned the common lady bird insect, Coccinella, which
when captured secretes from its legs a yellow acrid fluid having a
disagreeable odour. This fluid will serve to ease the most violent
toothache, if the creature be placed alive in the cavity of the hollow
tooth.

Gerard says this _Pyrethrurn_ (Pellitory of Spain, or Pelletor) "is
most singular for the surgeons