_Of the General Properties of Mercury._
MERCURY is a production of the mineral kingdom. In its natural state, it
is of an opaque metallic substance, of very considerable specific
gravity. To the eye, it appears like melted lead, or silver; from which
it has derived the name of _quicksilver_. In this condition, when freed
from every admixture, it has neither any perceptible smell nor taste;
and, as its application to the most sensible parts of the body occasions
no irritation, we may conclude, that it is void of all acrimony.
By very intense cold, artificially excited, mercury may be brought to a
solid form; but, in the greatest natural cold hitherto known, it remains
always in a fluid state. By heat it is rendered very volatile, exhaling
totally in fumes; these fumes, upon being exposed to cold, condense
again into running mercury.
Mercury, like most other metallic substances, is found in the earth,
either in a pure state, or in that of an ore. The first has been called
_virgin-mercury_, and is in general found by the miners in drops or
small grains; sometimes indeed it is observed in larger quantities, and
forms the appearance of small streams. In the state of ore, it is most
frequently combined either with sulphur, or with earthy matters; from
which it is readily extracted by distillation. It is found in both these
states in different places of Europe, particularly in Spain and in
Hungary; but Britain is principally supplied with it from the
East-Indies.
Mercury was not unknown to the antients. In the early ages of medicine,
indeed, it seems to have been esteemed a virulent poison; but it has
now, for some centuries past, been much, and successfully, employed for
the purposes of medicine, as well as of other arts.
The Arabians were the first who employed it in the cure of diseases; but
they seem to have used it externally only, and applied it for discussing
tumors, cleansing ulcers, and curing cutaneous eruptions. Soon after the
introduction of the venereal disease into Europe, mercury was found to
be the most expeditious and most effectual, if not the only certain,
remedy. The advantages which are to be derived from its employment in
this disease, both when applied externally, and taken internally, have
now been confirmed for a length of time too considerable for allowing
the least foundation either to doubt its efficacy, when properly used,
or to dread its deleterious effects, when judiciously managed.
The effects of mercury on the human system in a sound state are very
various. When mercury, in its crude state, is introduced by the mouth
into the alimentary canal, it passes off by stool, without producing any
effect. It has indeed been alledged, that in this state, in some morbid
affections, it may be useful in removing obstructions by its weight. But
it is to be remembered, that, in a great part of its passage through the
intestines, it rises in opposition to gravity, and that it is very apt
to divide in such a manner as to make its way through very small
openings. This effect, then, is perhaps in general, if not always, to be
disregarded.
When mercury is prepared in such a manner as to be readily soluble in
the fluids of the human body, the effects it produces are much
diversified. Its action is often immediately exerted upon the stomach;
in which case vomiting is produced. This effect is observed from the use
of many mercurial preparations. The brown and green precipitates and
calcined mercury act as rough and strong emetics; but the preparation
principally used, where it is intended to act as an emetic, is the
yellow precipitate, or Turpeth mineral.
Many of those mercurials, which have not such an influence upon the
stomach as to produce vomiting, upon entering the intestinal tube, act
as purgatives. This effect of mercurials is, among other preparations,
particularly remarkable on the use of the Coralline mercury, Prince’s
powder, or calomel.
Mercurials, which fail in producing either purgative or emetic effects,
frequently act as diaphoretics. Diaphoresis, or even a profuse sweat, is
often the consequence of many of the mercurials already mentioned. But
when this effect is wanted, by means of mercurials, it is most commonly
obtained by the use of a solution of corrosive sublimate.
Mercury entering the circulating system exerts particular effects on
different excretories; but in a more especial manner on those of the
saliva. Salivation is an effect which may be obtained from the proper
administration of almost every mercurial preparation; but for this
purpose either the mercurial pills, or friction with mercurial ointment,
are most frequently employed.
Mercury may enter the system, exist in considerable quantity there, and
be carried off by the different excretories, without producing any
remarkable evacuation, or other apparent change, on the sound state of
the body. That it is actually present in the system in such cases, is
demonstrated by a general tendency to an increase in all the secretions.
Mercury in this way, although it produces no visible effect on a healthy
person, often procures the removal of a diseased state. Its action,
therefore, in such circumstances, is termed _alterative_; an effect
which may be obtained from most of the mild mercurials, especially when
used in small doses.
From these various modes of operating, it may readily be concluded, that
mercury must be a powerful remedy in the cure of many diseases. The
undoubted effects which it produces on the human system, when labouring
under the venereal distemper, it would be both difficult and unnecessary
fully to enumerate. It heals ulcers, removes swellings, alleviates
pains, and cures eruptions. In short, the almost infinite variety of
symptoms under which this disease makes its appearance may, by a proper
application of mercury, be effectually eradicated from the constitution.
From these effects, it is not surprising, that, in this distemper,
mercury is the almost universal remedy. But, while it cannot be denied
that peculiar advantages may be reaped from the employment of mercury in
the venereal disease, it must at the same time be acknowledged, that,
from the injudicious use of this medicine, very great evils have been
produced. Whatever, therefore, relates to its proper administration,
must be esteemed of importance. But to determine this, it is in the
first place requisite to ascertain the principles upon which it
operates. In treating of the present subject, then, an examination of
the most probable opinions, with regard to the mode of its operation in
the venereal disease, first claim our attention.
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