The medicinal uses to which Magnesia has hitherto been applied are in
general so well known, that it will be necessary only to give a short
summary of the cases in which it is beneficial, for the information
of young practitioners, and of those of my readers who may not be
acquainted with medical subjects, this medicine being frequently
administered without the advice of a physician. If it should appear in
the subsequent part of this treatise that Magnesia is possessed of any
properties hitherto unsuspected in it, the sagacious reader will in a
great measure be left to draw his own practical inferences therefrom.
MAGNESIA ALBA is a powerful absorbent, and is given with great
success in disorders of the stomach and bowels arising from acidity.
This preparation had been introduced into the materia medica abroad
several years before it attracted the attention of our countrymen. The
celebrated Hoffman having strongly recommended it to the medical world,
some English practitioners began to prescribe it, and Dr. Cadogan
bestowing high encomiums on it, in his treatise on the nursing and
management of children, it soon made its way into general practice, and
supplied the place of the testaceous powders and chalk, which before
this period were the medicines usually given to correct acidities
in the primæ viæ. The acquisition of this medicine was of the more
importance, on account of its entire and easy solution in acids, and of
the purgative quality which it possesses; whereas the common absorbents
are apt to form concretions, and to induce costiveness; strong
objections to their free exhibition, as these properties render them
peculiarly unfit for the bowels of tender infants who are particularly
liable to diseases of this class.
This tendency to acidity generally attends children during the first
months and the time of dentition, and discovers itself when too
redundant by the green stools, sour vomitings, gripes and purgings
which it occasions: and as the nerves of children are extremely
irritable, spasmodic affections are often the consequence of this acrid
stimulus being retained in their bowels. In these cases Magnesia may be
administered in doses from five to twenty or thirty grains, according
to the age of the infant; and in proportion as it is intended to act,
either as an alterative, or as an easy purgative.
It has been a common practice to give Magnesia to children as a
preventive, and to mix it for this purpose with their food, in order
to correct that disposition which milk and the farinaceous aliments
have to turn sour. This however should be done with caution, for it
is only the excess of acidity which is prejudicial to infants,[l] some
degree of it is necessary; and should we too officiously and entirely
destroy, what we ought only to restrain within due bounds, we may
create disorders of an opposite nature to those we have endeavoured to
prevent, and instead of an acid, produce an alkalescent disposition
in the first passages. Indeed I fear that diseases have been more
frequently created than obviated by the use of preventive medicines,
and they should only be allowed in cases where the approach to disease
is manifest. But when a child is in a healthy state, the best means to
preserve him from a superabundant acidity, is to pay due attention to
the regulation of his diet, to give him proper exercise, not to confine
him too much in the foul air of hot unventilated rooms, to wash his
whole body every day in cold water, and to rub him very well night and
morning with a dry flannel, taking care that his stomach be not too
full at the time when this friction is performed.
[l] Hactenus monstravimus, sicut cordis, musculorumque vires debiles
erant, ita et solidorum quoque statum necessario imbecillem fuisse, et
succos tenues, dilutosque; ut natura ampliationem vasculorum facilius
efficeret, et incrementum animale minori cum molestiâ perageret.
Sed ne status iste tonusque partium debilis laxusque ultra modum
procederet (quod sæpe accidit, morbosque excitare solet) acidum quoddam
juvenilium animalium stomachis datum est, quod quamvis aluminis
instar, lac coagulat, atque ob eam causam aliquando morbum procreat,
tamen fibrarum tonum astringet confirmatque, et putredinem omnem
alkalinam, a qua alioquin periculum esset, reprimit. Quod quidem
videri est, vel in coagulo stomachi vitulini, vel in aliis animalibus:
sed istud tamen acidum, quod infantibus tarn idoneum est, redundat
fortasse nonnumquam, et vel per testaceas pulveres, vel per medicamenta
antiacida, ut supra dixi, corrigi debet.
Russelli OEconomia Naturæ, p. 56.
Nor would I advise parents to rely with too much security on the
virtues of this medicine, where the disorders of their children
are complicated, or obstinate. The advice of the sagacious and
distinguishing practitioner will then be necessary to direct what
method of treatment is to be pursued. Nor can I here avoid lamenting
that the management of children when diseased, is so often in the hands
of nurses and ignorant women, from an absurd notion that their diseases
are not proper subjects of medical investigation; when in truth, there
are none which require a clearer judgement, a quicker penetration, or a
greater share of medical knowledge in the prescriber.
During the period between dentition and puberty, the diseases attendant
on a lax fibre still continue, though not so predominantly as in the
former stage; yet acescency is the manifest cause, or at least the
concomitant of many of the complaints to which children are at this
time liable. To this they are disposed, notwithstanding the change
in their diet to a more alkalescent kind, by the great quantities
of fruit, frequently crude and unripe, cakes, and other sweet and
greasy food with which they are too often indulged. By these errors
their bowels are overcharged, their digestion impaired, and the
aliment remaining too long in the stomach becomes sour, and occasions
vomitings, head achs, and other complaints which are often thought
to proceed from worms, and indeed are frequently attended with that
disorder; as the crudities thus generated in the bowels serve as a
nidus for these destructive vermin. Here likewise Magnesia may be of
considerable advantage as an alkaline purgative, neutralizing the
offending acid, and at the same time promoting its discharge by stool.
But if the stomach be overloaded with mucus or undigested aliment, a
gentle vomit ought to precede the exhibition of the Magnesia.
And even in a more advanced stage of life, persons of weak habits, and
who lead sedentary lives, are often afflicted with indigestion, sour
eructations, heart-burn, vomitings, and costiveness. These disorders
very frequently attend women during their state of pregnancy, and
are sometimes almost instantly removed by the use of Magnesia. Dr.
Watson[m] has published the case of a pregnant woman, who was afflicted
with such severe vomitings as to bring on convulsions, hiccoughing, and
violent pain at her stomach. What she brought up was acid, and so very
acrimonious, as to inflame and excoriate her mouth and throat; and the
great uneasiness she felt at her stomach upon swallowing any liquor
that had the least degree of acrimony, or was more than lukewarm, made
it probable that the internal surface of the stomach was affected
in the same manner. In this desperate situation, after a variety
of remedies had been tried in vain, the stomach was washed with
unsalted mutton broth, till the liquor was discharged without any acid
taste. Her pain was by this means abated, but in about two hours was
apparently returning with the same violence as before. This ingenious
Physician then directed a drachm of Magnesia to be given in mutton
broth, and to be repeated as often as her pain returned, without any
regard to the quantity the whole might amount to, supposing her pain
to continue severe. The first dose relieved her, and in three days she
took three ounces of Magnesia; and in the next three days, two ounces
more, by which time all her symptoms were removed. It is remarkable
in this case that a hypercatharsis was not the consequence of taking
so large a quantity of Magnesia, where there was so much acid to
neutralize it.
[m] Medical Observations and Inquiries, Vol. III. p. 335.
In bilious habits, where there is generally a disposition in the
stomach contrary to acidity, Magnesia is usually esteemed to be
improper, taken alone: but I am dubious whether this opinion is well
founded, and many reasons for these doubts may be deduced from the
experiments hereafter to be recited. However, where putrid bile is to
be corrected and discharged, by stool, very good purposes may, perhaps,
be answered by taking the Magnesia, joined with a sufficient quantity
of acid to neutralize it, while in a state of effervescence; or by
swallowing the Magnesia and the acid, one immediately after the other,
so as to produce the fermentation in the stomach: for thus the fixed
air with which the Magnesia so greatly abounds, being let loose, may
powerfully correct the tendency to putridity in the contents of the
primæ viæ, and at the same time evacuate them downwards.
How far Magnesia may be of service in diseases of the skin I do not
take upon me to determine. Several authors have attributed cutaneous
eruptions, and indeed the ancient chemists ascribed almost all
disorders, to the presence of an acid in the blood; whilst others
absolutely deny that an acid can be admitted into the lacteals, or,
if admitted, exist in the blood in a state of acidity. In these cases
however, if an acid acrimony abounds in the stomach and bowels, with
a costive habit, and pale complexion, Magnesia will be a useful
corrector, and entering into the circulation in the form of a mild
neutral salt, may act as an excellent alterative,[n] proving both
diaphoretic and diuretic.
Having thus given a cursory detail of the medicinal properties of
Magnesia, in its natural state, I shall now proceed to consider it
in a state of calcination: but before any description of its uses in
medicine be given, it may be proper to take a view of the changes which
are produced in the nature of it by this operation.
[n] Neque enim tantum absorbentem et catharticam, si acidum primâ in
regione stabulatur, virtutem exserit; verum etiam si in remissiore
dosi, ad grana xv. vel xx. usurpatur, diaphoreticum et diureticum
effectum sequi, non semel observavimus.
Hoffman. circa Magnesiam. Oper. Tom. 4. p. 481.