_Lycopodium_; _Semen vel Sporulæ Lycopodii_; F. _Lycopode_; G.
_Bärlappsamen_, _Hexenmehl_.
=Botanical Origin=—_Lycopodium clavatum_ L.—This plant, the Common
Clubmoss, is almost cosmopolitan. It is found on hilly pastures and
heaths throughout Central and Northern Europe from the Alps and
Pyrenees to the Arctic reunions, in the mountains of the east and
centre of Spain, throughout Russian Asia to Amurland and Japan, in
North and South America, the Falkland Isles, Australia and the Cape of
Good Hope. It occurs throughout Great Britain, but is most plentiful on
the moors of the northern counties.
The part of the plant employed in pharmacy is the minute spores, which,
as a yellow powder, are shaken out of the kidney-shaped capsules
or sporangia, growing on the inner side of the bracts covering the
fruit-spike.
The manner in which those sporæ are able to reproduce the mother plant
is not yet satisfactorily ascertained.[2724]
=History=—The Common Clubmoss was well known as _Muscus terrestris_
or _Muscus clavatus_, to the older botanists, as Tragus, Dodonæus,
Tabernæmontanus, Bauhin, Parkinson and Ray, by most of whom its
supposed virtues as a herb have been commemorated. Though the powder
(spores) was officinal in Germany, and used as an application to wounds
in the middle of the 17th century,[2725] it does not appear to have
been known in the English shops until a comparatively recent period.
It is not included by Dale[2726] in the list of drugs sold by London
druggists in 1692, nor enumerated in English drug lists of the last
century; and it never had a place in the London Pharmacopœia.
[2724] The few particulars may be found in the excellent description of
Lycopodium in Luerssen’s “_Medicinisch-pharmaceutische Botanik_,” i.
(Leipzig, 1878) 635, with figures.
[2725] Schröder, _Pharmacopœia Medico-chymica_, ed. 4, Lugd. 1656.
538.—Flückiger, “_Documente_” (quoted p. 404) 63. 68.
[2726] _Pharmacologia_, Lond. 1693.
=Description=—Lycopodium is a fine, mobile, inodorous, tasteless powder
of pale yellow hue, having at 16° C. a sp. gr. of 1·062. It floats on
water and is wetted with difficulty, yet sinks in that fluid after
boiling. By strong titration it coheres, assumes a grey tint, and
leaves an oily stain on paper; it may then be mixed with water. It is
immediately moistened by oily and alcoholic liquids, chloroform, or
ether. It loses only 4 per cent. of moisture when dried at 100° C. When
slowly heated, it burns away quietly, but when projected into flame, it
ignites instantly and explosively, burning with much light, an effect
exhibited by some other pulverulent bodies having a peculiar structure,
as fern spores and kamala.
=Microscopic Structure=—Under the microscope lycopodium is seen to
be composed of uniform cells or granules, 25 mkm. in diameter, each
bounded by four faces, one of which (the base) is convex, while the
others terminate in a triangular pyramid, the three furrowed edges of
which do not reach quite to the base. These tetrahedral granules are
marked by minute ridges, forming by their intersections, regular five-
or six-sided meshes. At the points of intersection, small elevations
are produced, which, under a low magnifying power, give the granules a
speckled appearance. Below this network lies a yellow, coherent, thin,
but compact membrane, which exhibits considerable power of resistance,
not being ruptured either by boiling water or by potash lye. Oil of
vitriol does not act upon it in the cold, even after several days;
but it instantly penetrates the grains and renders them transparent,
while at the same time numerous drops of oil make their appearance and
quickly exude.
=Chemical Composition=—One of the most remarkable constituents of
lycopodium spores is a fixed oil, which they contain to the astonishing
amount of 47 per cent. Bucholz pointed out its existence in 1807, but
obtained it only to the extent of 6 per cent. Yet if the spores are
thoroughly comminuted by prolonged trituration with sand, and are then
exhausted with chloroform or ether, we find that the larger proportion
above mentioned can be obtained. The oil is a bland liquid, which does
not solidify even at -15° C.
By subjecting lycopodium or its extract to distillation with or without
an alkali, Stenhouse obtained volatile bases, the presence of which
we can fully confirm; but they occur in exceedingly small proportion.
The ash of lycopodium amounts to 4 per cent.; it is not alkaline; it
contains alumina, and one per cent. of phosphoric acid, constituents
likewise found in the green parts of the plant.
=Production and Commerce=—To obtain lycopodium, the tops of the plant
are cut as the spikes approach maturity, taken home, and the powder
shaken out and separated by a sieve. It is collected chiefly in July
and August, in Russia, Germany and Switzerland. The quantity obtained
varies greatly by reason of frequent failures in the growth of the
plant.
France imported in 1870, 7262 kilo. (16,017 lb.) of lycopodium, chiefly
from Germany. The consumption in England is probably very much smaller,
but there are no data to consult.
=Uses=—Lycopodium is not now regarded as possessing any medicinal
virtues, and is only used externally for dusting excoriated surfaces
and for placing in pill boxes to prevent the mutual adhesion of pills.
It is also employed by the pyrotechnist.
=Adulteration=—The spores are so peculiar in structure, that they
can be distinguished with certainty by the microscope from all other
substances. It is only the species of clubmoss that are nearly related
to _L. clavatum_,[2727] that yield an analogous product, and this may
be used with equal advantage.
The pollen of phænogamous plants, as of _Pinus silvestris_, looks
at first sight much like lycopodium, but its structure is totally
different and very easily recognized by the microscope.
Water, even on boiling, is unable to dissolve anything from lycopodium;
slight traces of sulphate of calcium are not seldom met with in the
filtrate. Yet an undue proportion of gypsum will be detected by the
following methods:—
Starch and dextrin, which are sometimes fraudulently mixed with the
spores, are easily recognized by the well-known tests. Inorganic
admixtures, as gypsum or magnesia, may be detected by their sinking in
bisulphide of carbon, whereas lycopodium rises to the surface; or by
incineration, a good commercial drug leaving about 4 per cent. of ash.