_Cerussa Acetata._ P. L. 1787. _Saccharum Saturni._ 1745.
ACETAS PLUMBI. E. Acetas Plumbi. D.
vulgo, Sugar of Lead.
QUALITIES. _Form_, irregular masses resembling lumps of sugar, being an
aggregation of acicular four-sided prisms terminated by dihedral
summits, which are slightly efflorescent; by careful crystallization, it
may be obtained in quadrangular prisms. _Taste_, sweet and astringent.
CHEMICAL COMPOSITION. Although it has been termed a _Super_-acetate, it
appears to be a neutral salt, and that its power of reddening valuable
blues is attributable to a partial decomposition; for when dissolved in
water containing the least portion of carbonic acid, a white carbonate
of lead is precipitated, and a corresponding portion of acetic acid is
necessarily disengaged. The College have therefore now designated it as
an _acetate_. According to the experiments of Berzelius, this salt, in
its anhydrous state, consists of one proportional of acetic acid, and
one proportional of oxide of lead; so that the proportion of the
metallic base is one-third of that in the _sub_-acetate. SOLUBILITY. It
is dissolved in 25 parts of water, hot or cold; it is also soluble in
alcohol. When common water is employed the solution is quite turbid,
unless a small proportion of acetic acid be previously added.
INCOMPATIBLE SUBSTANCES. _The alkalies, alkaline earths and their
carbonates_; _most of the acids_; _alum_; _borax_; the _sulphates, and
muriates_; _soaps_; _all sulphurets_; _ammoniated, and tartarized iron_;
_tartarized antimony_; _undistilled water_. The solution of _acetate of
ammonia_ decomposes that of this salt, in consequence of the carbonic
acid which is generally diffused through it. It has lately been
discovered that _Gallic acid_ and _Tannin_ are capable of combining with
lead in solution, and of forming a perfectly insoluble substance, which
falls to the bottom of the vessel; hence all vegetable astringents must
be considered as incompatible with this medicine. On this account,
liquors which have been kept in oak casks,[603] for a certain time, must
be freed from lead. This explains a fact, with respect to the effect of
new rum in the West Indies, of some importance. This spirit, when newly
distilled, is found to contain traces of lead, derived from the leaden
rims of the coppers, and the leaden worm, used for its condensation;
but, by being kept about twelve months in oaken casks, it loses its
deleterious properties, and no longer exhibits any traces of this
metal.[604] Certain bodies appear likewise to be incompatible with the
compounds of lead, not from the _chemical_ changes they induce, but from
the contrary effects they produce upon the body; thus mercury appears to
invalidate their powers and to counteract their effects, as we may have
observed in treating saturnine cholic. I suspect also that antimony
operates in the same manner; M. Merat relates the case of an apothecary
who was cured of a desperate saturnine cholic, after having taken, in
the course of eight days, eighty grains of tartarized antimony. MED.
USES. I feel no hesitation in pronouncing this salt of lead to be one of
the most valuable resources of physic; from the results of numerous
cases, I state with confidence that it is more efficient in stopping
pulmonary and uterine hemorrhage, than any other known remedy—“_nil
simile, nec secundum_,”—and that its application is equally safe and
manageable; but it must not be combined with substances capable of
decomposing it, nor must it be simultaneously administered with the
medicines which are frequently prescribed in conjunction with it, as an
_Infusion of Roses_, _Sulphate of Magnesia_, &c. Alum has also been in
some cases added to it, with the intention of increasing its
astringency. It is evident that under such circumstances an insoluble
and inert _Sulphate of Lead_ will be produced. The experiments of Orfila
confirm the truth of these views, and shew that such substances act as
counter-poisons for the salts of lead. According to my experience, those
vegetable acids which decompose the acetate of lead, and form insoluble
salts with its base, are not _medically_ incompatible, when administered
simultaneously with it, although no scientific physician would prescribe
such a mixture; this fact is shewn by the circumstance of potations,
containing malic and tartaric[605] acids, not having been found to
invalidate the efficacy of this salt. Whether the stomach in the first
instance prevents the decomposition, and its necessary results, or
allows the operation of the usual affinities, and then subsequently
decomposes the insoluble compound which results from them, by the
abstraction and _digestion_ of its vegetable constituent, are questions
for future inquiry, when the laws of gastric chemistry shall be better
understood, and more justly appreciated. I have also seen much benefit
accrue from this medicine in protracted diarrhœa, when it has checked
the bowels more effectually even than opium. M. Gaspard has communicated
to the public, through the medium of _Majendie’s Journal de
Physiologie_, (3 numéro Juillet, 1821,) a paper upon the operation of
_Acetate of Lead_, entitled “_Experiences Physiologiques et Medicales
sur L’Acetate de Plomb_,” in which he asserts that this metallic salt
cannot be administered without risk in any dose, unless indeed it be
given in vehicles which decompose it, and which, he adds, appears
generally to have happened in the prescriptions of those who have given
it extensively. He observes, that “it produces a slow and peculiar
inflammation of the bowels, as well as of the lungs; and that it,
moreover, occasions _Cholica Pictonum_.” No one, I apprehend, will deny
the poisonous quality of acetate of lead, any more than that of arsenic;
and yet both may, by proper management, be rendered therapeutical agents
of value and safety. FORMS OF EXHIBITION. In that of pill, guarded by
opium; it will be prudent to recommend an abstinence from all potation,
except that of cold water, or draughts, composed of diluted acetic acid,
for at least an hour after the ingestion of the pill.[606] DOSE, gr. ½
to gr. j. _Form. 57._ OFFICINAL PREP. _Cerat. Plumb. acetat_. L.[607]