472
ELEMENTS OF MATERIA MEDICA.
adults. Salivation is a rare occurrence in them: indeed, Mr. Colles(Pract. Observ. p. 281) asserts, that mercury never produces ptyalism, orswelling or ulceration of the gums, in infants.
Pilulje Hydrargyri Chloridi Compositje, Ph . Lond.; Pilules.Calomelanos Composites, Ph . Dubl.; Pilules Sub-muriatis HydrargyriComposites, Ph . Edinb.; Plummer's Pills, or Pilules Plummeri (chlorideof mercury; oxysulphuret of antimony, JaT 5ij.; guaicum resin, pow-dered, Sss.; treacle, 5ij. M. The Edinburgh College uses mucilage ofgum arabic instead of treacle).—These pills are frequently employed asalteratives in chronic skin diseases, in the papular and pustular forms ofthe venereal disease, in chronic liver affections, and inv arious disorderedconditions of the digestive organs. The dose is from five to ten grains.
Pilulje Catharticje Compositje, Ph . U. S. (Compound extractofcolocynth, Sss. ; extract of jalap, in powder; calomel, aa" 5iij.; gam-boge, in powder, 3ij. M. Divide into 180 pills). This pill is intendedto combine smallness of bulk with efficiency and comparative mildnessof purgative action, and a peculiar tendency to the biliary organs(United States Dispensatory). Each pill contains one grain of calomel.Three pills are a full dose.
Unguf.ntum Hydrargyri Chloridi (calomel, 5j.: lard, Sj. M.)This is a most valuable application in porrigo favosa, impetigo, herpes,and the scaly diseases (psoriasis and lepra). Indeed, if I were requiredto name a local agent pre-eminently useful in skin diseases generally, Ishould fix on this. It is well deserving a place in the Pharmacopoeia .
Hydrar gyri Bichldridum. — Bichlo'ride of Mer'cury.
History. —We have no account of the discovery of this preparation.Geber (Inv. of Ver. viii. 252) described the method of preparing it; butit is supposed to have been known long anterior to him. Like calomel,it has had various synonymes, of which the principal are the following :chloride, hydrochlorate or muriate of mercury (hydrargyri chloridum,hydrochloras seu murias), corrosive sublimate (mercurius sublimatus cor-rosions), corrosive muriate of mercury (hydrargyri murias corrosivus),and aculum chloro-hydrargyricum).
Preparation. —Mercury and sulphuric acid are boiled together, as inthe process for making calomel; and the bipersulphate of mercury issublimed with chloride of sodium, without the addition of metallic mer-cury. The sublimation is usually effected in an earthen alembic, placedin sand.
The nature of the changes which occur in the manufacture of biper-sulphate of mercury have been already explained (p. 465). When thissalt is sublimed with chloride of sodium, double decomposition takesplace, and we obtain bichloride of mercury and sulphate of soda.
REAGENTS.
RESULTS.
52eq.Chlorine .... 72-
< 2 eq. Sodium. 48 f
< 1 eq, Mercury _202
(. 2 eq. Sulphur*-'- Acid 80
2eq,Soda64
1 eq. Biclilde. Merc. 274
2 eq. Sulphate Soda 144
Properties. —As usually met with in commerce, bichloride of mer-cury is a semi-transparent crystalline mass, in which perfect crystals arerarely found. Occasionally, however, they are obtained either by slow