260
ELEMENTS OF MATERIA MEDICA.
to counteract, in part, the unpleasant odour of sulphur. The unguentumsulphuris compositum is composed of half a pound of sulphur, two ouncesof powdered white hellebore, half a pound of soft soap, a pound and ahalf of lard, and thirty minims of the oil of bergamot: it is a much moreirritant application than the simple ointment of sulphur. Both areemployed for the cure of itch, and, sometimes also, in the various formsof porrigo which affect the heads of children.
1. Sulphur Prjecipitatum. —This preparation, commonly termedmilk of sulphur (lac sulphuris ), was known to Geber . It may be pre-pared by boiling one part of sublimed sulphur, two parts of slacked lime,and eight parts of water. To the filtered solution add sufficient hydro-chloric acid to precipitate the sulphur, which is to be washed and dried.
The theory of the process is the following: —When sulphur and limeare boiled in water, six equivalents or 96 parts of sulphur react on threeequivalents or 84 parts of lime, and produce two equivalents or 104parts of bisulphuret of calcium, and one equivalent or 76 parts of thehyposulphite of lime. By the action of three equivalents or 111 parts ofhydrochloric acid on these two salts, we obtain three equivalents or 168parts of chloride of calcium, six equivalents or 96 parts of sulphur, andthree equivalents or 27 parts of water.
RKAGENTS.
3 eq. Lime.. 84 s 2eq . 0xygi( 2 eq. Calc**'.6eq Sulphur96 |2eq.Sulph
16-40-32"
4 eq. Sulph. 64-
first stage.
_1 eq.Lime .28 s
(1 eq. Otrpg. 8J 1 eq. Calcm. 20
leq.HppomlpK. A cii 48 j \ J®'
^-.2 eq.Bimlph. Calc™. 104 ^ s“jpZ'u
N
8ECOND STAGE.
3 eq. Water_ 27
^3eq.Chlor.CaIcoi. 168
-6 eq. Sulphur .. 96
Properties. —Precipitated sulphur agrees in most of its propertieswith sublimed sulphur, but is much whiter, and is in a finely pulverentform. Berzelius says, that when melted, it gives out a little sulphurettedhydrogen; and on cooling, resumes the yellow colour it had beforeit was boiled with the alkali.
Composition. —It is composed of sulphur with a little water; andhence it is frequently termed hydrate of sulphur. According to Bucholz,however, when well dried, it contains hardly a trace of water, and, there-fore, any present under ordinary circumstances must be regarded ashygroscopic; so that the term hydrate is hardly applicable to it.
Impurities. —If sulphuric be substituted for hydrochloric acid, in themanufacture of this substance, sulphate of lime will be formed, and mixedwith the precipitated sulphur. The impurity may be detected byvolatilizing the sulphur in a crucible, or by solution in oil of turpentine orliquor potassae.
The Effects, Uses, and Doses, are the same as those of commonsublimed sulphur.
2. Oleum Sulphuratum. —Sulphur is soluble in both volatile andfixed oils, and formulae are still found in some continental works for thepreparation of pharmaceutical compounds of them. A formula for sul-phurated oil is still retained in the Edinburgh Pharmacopoeia, but hasbeen omitted in the last edition of the London Pharmacopoeia. Thispreparation was formerly denominated balsam of sulphur.
It is prepared by boiling one part of sublimed sulphur in eight parts of