Only some few of our native Ferns are known to possess medicinal
virtues, though they may all be happily pronounced devoid of
poisonous or deleterious properties. As curative simples, a brief
consideration will be given here to the common male and female
Ferns, the Royal Fern, the Hart's Tongue, the Maidenhair, the
common Polypody, the Spleenwort, and the Wall Rue. Generically,
the term "fern" has been referred to the word "feather," because of
the pinnate leaves, or to _farr_, a bullock, from the use of the plants
as litter for cattle. Ferns are termed _Filices_, from the Latin word
_filum_, a thread, because of their filamentary fronds. Each of those
now particularized owes its respective usefulness chiefly to its
tannin; while the few more specially endowed with healing powers
yield also a peculiar chemical acid "filicic," which is fatal to worms.
In an old charter, A.D. 855, the [183] right of pasturage on the
common Ferns was called "fearnleswe," or _Pascua procorum_, the
pasturage of swine (from _fearrh_, a pig). Matthiolus when writing
of the ferns, male and female, says, _Utriusque radice sues
pinguescunt_. In some parts of England Ferns at large are known as
"Devil's brushes"; and to bite off close to the ground the first Fern
which appears in the Spring, is said, in Cornwall, to cure toothache,
and to prevent its return during the remainder of the year.
The common Male Fern (_Filix mas_) or Shield Fern, grows
abundantly in all parts of Great Britain, and has been known from
the times of Theophrastus and Dioscorides, as a specific remedy for
intestinal worms, particularly the tape worm. For medicinal
purposes, the green part of the rhizome is kept and dried; this is then
powdered, and its oleo-resin is extracted by ether. The green fixed
oil thus obtained; which is poisonous to worms, consists of the
glycerides of filocylic and filosmylic acids, with tannin, starch,
gum, and sugar. The English oil of Male Fern is more reliable than
that which is imported from the Continent. Twenty drops made into
an emulsion with mucilage should be given every half-hour on an
empty stomach, until sixty or eighty drops have been taken. It is
imprudent to administer the full quantity in a single dose. The
treatment should be thus pursued when the vigour of the parasite has
been first reduced by a low diet for a couple of days, and is lying
within the intestines free from alimentary matter; a purgative being
said to assist the action of the plant, though it is, independently,
quite efficacious. The knowledge of this remedy had become lost,
until it was repurchased for fifteen thousand francs, in 1775, by the
French king, under the advice of his principal physicians, from
Madame Nouffer, [184] a surgeon's widow in Switzerland, who
employed it as a secret mode of cure with infallible success. Her
method consisted in giving from one to three drams of the powdered
root, after using a clyster, and following the dose up with a purge of
scammony and calomel. The rhizome should not be used medicinally
if more than a year old. A medicinal tincture (H.) is now
prepared from the root-stock with proof spirit, in the autumn
when the fronds are dying.
The young shoots and curled leaves of the Male Fern, which is
distinguished by having one main rib, are sometimes eaten like
asparagus; whilst the fronds make an excellent litter for horses and
cattle. The seed of this and some other species of Fern is so minute
(one frond producing more than a million) as not to be visible to the
naked eye. Hence, on the doctrine of signatures, the plant--like the
ring of Gyges, found in a brazen horse--has been thought to confer
invisibility. Thus Shakespeare says, _Henry IV_., Act II., Scene 1,
"We have the receipt of Fern seed; we walk invisible."
Bracken or Brakes, which grows more freely than any other of the
Fern tribe throughout England, is the _Filix foemina_, or common
Female Fern. The fronds of this are branched, whilst the male plant
having only one main rib, is more powerful as an astringent, and
antiseptic; "the powder thereof freely beaten healeth the galled
necks of oxen and other cattell." Bracken is also named botanically,
_Pteris aquilina_, because the figure which appears in its succulent
stem when cut obliquely across at the base, has been thought to
resemble a spread eagle; and, therefore, Linnaeus termed the Fern
_Aquilina_. Some call it, for the same reason, "King Charles in the
oak tree"; and in Scotland the symbol is said to be an impression of
the Devil's foot. [185] Again, witches are reputed to detest this Fern,
since it bears on its cut root the Greek letter X, which is the initial
of _Christos_.
In Ireland it is called the Fern of God, because of the belief that if
the stem be cut into three sections, on the first of these will be seen
the letter G; on the second O; and on the third D.