_Kali Præparatum_, P.L. 1787. _Sal Absinthii._
_Sal Tartari._ 1745.
Before the nature of this salt was well understood, it received various
appellations according to the different methods by which it was
procured, and it was supposed to possess as many different virtues, as
_Salt of Wormwood_, _Salt of Tartar_, _Salt of Bean Stalks_, &c.
QUALITIES. _Form_, coarse white grains, so deliquescent, that by
exposure to air they form a dense solution, (_Oleum Tartari per
deliquium_, P.L. 1720.) _Taste_, alkaline and urinous.[610] CHEMICAL
COMPOSITION. This salt, although far from being pure, is sufficiently so
for every pharmaceutical purpose. It consists of one proportional of
acid and one proportional of potass, with variable quantities of
_sulphate of potass_, _muriate of potass_, _siliceous earth_, _alumina_,
together with the _oxides of iron_, and _manganese_. SOLUBILITY. It is
dissolved by twice its weight of water; the residue, if any, may be
considered as impurity; it is insoluble in alcohol; with oils it
combines, and forms soaps. INCOMPATIBLE SUBSTANCES. They are enumerated
under _Potassæ Carbonas_. MED. USES. Antacid, and diuretic, (_Form. 101,
107, 129_), but it is far less pleasant than the carbonate; it is
principally used for making saline draughts, see _Acid. Citric._ and
_Form. 107_. DOSE, grs. x to ʒss. OFFICINAL PREP. _Potassæ Acetas_,
L.E.D. (=I=) _Liquor Potassæ_ L.E.D. (=K=) _Potassæ Sulphuretum_ (=I=)
L.E.D. _Potassæ Tart._ L.E.D. (=I=) _Liquor Arsenicalis_ (=I.L.=)
ADULTERATIONS. Its degree of purity may be estimated by the quantity of
nitric acid, of a given density, requisite for the saturation of a given
weight. The purest _sub-carbonate_ is that obtained by incinerating
_cream of tartar_, since most of the impurities are decomposed by the
heat during the process, (_Sub-carbonas Potassæ Purissimus._ E.); it
however generally contains lime.