^* MATERIA MEDICA. 



confection, (Confectio Rosae,) and the compound infusion, (Infusum 

 Rosse compositum,) are officinal. The Hundred-leaved Rose (Rosa 

 centifoha), is not astringent. The latter species fumishes the rose- 

 water {Aqua Uoscb) of the shops, and the Unguentu?n Aqucz Rosce, or 

 cold crearn. 



MINERAL ASTRINGENTS. 

 Lead. — (Plumbum, U. S.) 



Not employed in medicine, in the metallic state. Its preparations 

 are characterized by the union of astringent with sedative proper- 

 ties ; and they may all be regarded as poisonous in over-doses, with 

 the exception of the sulphate, which is extremely insoluble. The 

 poisonous impression may be produced in two modes, either by 

 their being absorbed into the blood, or by their local irritant action. 

 Lead is very apt, when taken in improper quantities, to cause a 

 series of symptoms called colica picto7iu7n, or painters' colic; of 

 which the most prominent symptoms are, loss of appetite, painful 

 and constipated state of the bowels, acute pain about the umbihcus, 

 with a knotty feel of the abdominal muscles, followed by general 

 cramps, convulsions, and death. It also occasionally produces a 

 paralysis, most generally of the upper extremities, denominated 

 lead palsy. These poisonous effects are generally the result of 

 long exposure to the fumes of melted lead, and are usually met with 

 in workmen of lead factories, painters, solderers, &c. It is recom- 

 mended that such persons should use diluted sulphuric acid, for the 

 purpose of converting any preparation of lead, which may be in the 

 system, into the sulphate. 



Litharge.— {Plumbi Oxidmn Semivitrium, U. S.)~Prepared in 

 the extraction of silver from the argentiferous galena. It is in the 

 form of small semi-vitrified scales, of a flesh colour. They usually 

 contain some carbonic acid. Its chief use is in the preparation of 

 Lead Plaster, (Emplastrum Plumbi,) made by boiling together 

 litharge, olive-oil, and water ; it consists of an oleo.marga?ate of 

 lead. It IS the foundation of most of the other plasters. 



Carbonate of Lead. — {Plumbi Carbonas, U. S.) — Called also 

 White Lead. Prepared by exposing lead in thin sheets to the action 

 of the vapours of vinegar, at the temperature of fermentino- manure: 

 the vinegar furnishes both the oxygen and carbonic acid.° 



Prop. — A white, heavy, insoluble substance, without smell and 

 taste; one of the most poisonous of the salts of lead; not used as a 

 medicine internally ; occasionally applied to excoriated and burnt 

 surfaces ; used also in the manufacture of the plaster, (Emplastrum 

 Plumlyi Carbonatis) made to imitate Mahy's Plaster. It is applied 

 to bed-sores. ^^ 



Acetate ofLead.—{Plun^hi Acetas., U. S.)— Sugar of Lead.— Pre- 



