Tartris Antimonii. E. Tartarum Antimoniatum. D.
_Tartar Emetic._[377]
QUALITIES. _Form_, crystals whose primitive form is the regular
tetrahedron, although it assumes a variety of secondary forms. _Colour_,
white. _Odour_, none. _Taste_, slightly styptic and metallic; on
exposure to the air, the crystals slightly effloresce and become opaque;
thrown upon burning coals, they become black and afford metallic
antimony. CHEMICAL COMPOSITION. This is involved in much doubt and
obscurity; it is stated in the various dispensatories to be a triple
salt, consisting of tartaric acid, oxide of antimony,[378] and potass,
and which therefore, says Mr. Thomson, on the principles of the reformed
nomenclature, ought to be termed a _tartrate of antimony and potass_.
The truth of these views, however, is extremely questionable. I am
inclined to believe with Gay Lussac, that in the various metalline
compounds, of which super-tartrate of potass is an ingredient, this
latter substance acts the part of a simple acid; an opinion which
receives much support from the great solvent property of cream of
tartar, and from the striking fact that it is even capable of dissolving
various oxides which are insoluble in tartaric acid, of which the
protoxide of antimony is an example. According then to this view, tartar
emetic is a salt composed of bi-tartrate (_super-tartrate_) of potass,
which acts the part of an acid, and protoxide of antimony: from the
experiments of Mr. Phillips, it would appear that 100 parts of the
bi-tartrate will dissolve 70 of the protoxide. In this state of doubt it
must be admitted that no name can be more appropriate than _Antimonium
Tartarizatum_, and the London College have therefore properly
disregarded the suggestions which have been offered for changing its
name. SOLUBILITY. Much discrepancy of opinion exists upon this subject,
owing probably to the variations and incidental impurities to which the
salt is liable. Dr. Duncan, who selected very pure specimens for
examination, states that it is soluble in three times its weight of
water at 212°, and in fifteen at 60°. This solution, when the salt is
pure, is perfectly clear and transparent, but if long kept, unless a
portion of spirit be added, it undergoes decomposition; a precipitate
indeed sometimes takes place very rapidly, but this is generally
tartrate of lime, an incidental impurity, derived from the
super-tartrate of potass. INCOMPATIBLE SUBSTANCES. _Mineral Acids,
Alkalies, and their Carbonates, most of the Metals, Soaps,
Hydro-Sulphurets, and many infusions and decoctions of bitter and
astringent Vegetables_, e. g. f℥j. of the decoction of yellow bark is
capable of completely decomposing ℈j of this salt, and of rendering it
inert.[379] Berthollet has accordingly recommended the immediate
exhibition of this decoction when an overdose of the salt has been
taken; and Orfila has given a very satisfactory case in which this
antidote succeeded. Infusion and tincture of galls throw down curdled
and inert precipitates of a dirty white colour, inclining to yellow.
Rhubarb is equally incompatible: the extract of this substance therefore
never ought to be employed in forming pills of tartar emetic: but it
deserves notice that this salt is not decomposed by the infusions of
gentian or wormwood. The _Alkaline Sulphates_, provided they be
perfectly neutral, produce no disturbance in solutions of _tartar
emetic_, and therefore cannot be considered incompatible with them; if
there be any excess of acid, as in _alum_, _bi-sulphate of potass_, &c.
then its decomposition is effected, and a white insoluble sulphate of
antimony is precipitated. It appears therefore that the famous
“Emeto-purgative” of the French school, consisting of sulphate of soda,
and tartarized antimony in solution, is by no means the unchemical
mixture which some have considered it to be, and that it really produces
its effects from the operation of its original ingredients, and not from
that of the compounds (_Sulphate of Antimony, Tartrate of Soda, and
Sulphate of Potass_) which have been erroneously supposed to result.
FORMS OF EXHIBITION. Solution is its best form, see _Liquor Antimonii
Tartarizati_. DOSE. It either vomits, purges, or sweats, according to
the quantity exhibited; thus gr. 1/4 will, if the skin be kept warm,
promote a diaphoresis; gr. ½ will procure some stools first, and
sweating afterwards; and gr. j will generally vomit and then purge, and
lastly sweat the patient; in very minute doses, as gr. 1/10 or 1/12
combined with squill and ammoniacum, it acts as an expectorant, see
_Formulæ 1, 2, 3, 8, 60_. It is decidedly the most manageable, and the
least uncertain of all the antimonial preparations, and the practitioner
would probably have but little to regret, were all the other
combinations of this metal discarded from our pharmacopœias. Some
authors have considered this substance as possessing sedative powers,
independent of its nauseating and diaphoretic effects. It undoubtedly
acts upon the heart, and controls the force of the circulation in
fevers, without occasioning any other sensible effect. Mr. Brodie, after
having given large doses of this salt to animals, found that the heart
beat very feebly, and although artificial respiration was kept up, it
soon ceased to act altogether. Lenthois of Montpellier advises small
doses of it in incipient phthisis, and it would on some occasions appear
to diminish the febrile excitement. The following is the form in which
Dr. Lenthois recommends it to be exhibited upon such occasions. He
directs a grain of Tartarized Antimony to be dissolved in eight table
spoonsful of distilled water, which are to be added to six or eight
pints of water, and to be taken as common drink. Tartar emetic, when
triturated with lard, in the proportion of ʒiss or ʒij to ℥j of the
latter, forms a very powerful rubefacient, occasioning a pustular
eruption on the skin, and proving very serviceable in deep-seated
inflammation; or the application may be made by dusting a piece of
adhesive plaster with tartarized antimony, taking care to leave a margin
untouched that it may more firmly adhere. Dr. Jenner, in a late Essay on
the influence of artificial eruptions on certain diseases, recommends
the following formula for such a purpose.—℞. _Antimonii Tartarizati_
(_in pulverem subtilem trit._) ʒij—_Unguenti Cetacei_ ʒix;—_Sacchari
albi_[380] ʒj;—_Hydrargyri Sulphureti Rubri_ gr. v. M. ut fiat
Unguentum. The Pustules which are produced by the inunction have been
generally compared to variolous pustules, they are, however, in general
much smaller, not so red at the base, nor so tense and white when fully
suppurated. They are very painful. In Hooping cough, frictions with this
ointment upon the region of the stomach have been greatly extolled. By
this application, says Dr. Jenner, we can not only create vesicles, but
we can do more,—we have at our command an application which will at the
same time both vesicate and produce diseased action on the skin itself,
by deeply deranging its structure beneath the surface. This is probably
one cause why the sympathetic affection excited by the use of
Cantharides, and those changes produced by Tartar Emetic are very
different. The eruption should be kept up for some time, either by the
re-application of small portions of the diluted tartaremetic ointment,
to the affected part, or by other gently stimulating ointments. Should
they become much irritated and very painful, a soft bread and milk
poultice will in general afford relief, without interfering with the
progress of the eruption. OFFICINAL PREPARATIONS. gr. j. is contained in
f℥ss of _Liquor Antimonii Tart:_ L. and _Vinum Tartratis Antimonii_.
E.[381] ADULTERATIONS. It should be always purchased in its crystalline
form; and a solution of it in distilled water ought to furnish a copious
gold coloured precipitate with sulphuret of ammonia; a precipitate
soluble in nitric acid, with acetate of lead; and a white and extremely
thick precipitate, dissolving with facility in pure nitric acid, with
lime water. If the crystals deliquesce, the presence of other salts may
be inferred. _M. Sexullas_, in a memoir of which there is a copious
extract in the _Journal de Pharmacie_ for 1821, has shewn that all the
antimonial preparations used in medicine, except carefully crystallized
_Tartar Emetic_, contain more or less arsenic, which metal was
originally combined with the antimony in the ore, and has continued
pertinaciously associated with it through all its modifications.