PLUMBI OXYDUM SEMI-VITREUM. L.E.
Lithargyrum. D. Litharge.[[602]]
It is a yellow protoxide of lead, which has been melted and left to crystallize by cooling. It is only employed in pharmacy for forming other preparations of lead, and the following officinal plasters, Emplast. Plumbi, L. E.D. Ceratum Saponis. L. It is added to wines to remove their acidity; for the detection of which, evaporate the suspected liquor to a thick fluid, add charcoal, and calcine in a crucible: in the space of an hour metallic points will be obtained, consisting of lead surrounded by a quantity of yellow protoxide.
PLUMBI ACETAS. L.
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]]
PODOPHYLLUM PELTATUM.
May Apple. Radix.