_Natron Vitriolatum_, P.L. 1787. _Sal Catharticus Glauberi_. P.L. 1745.
QUALITIES. _Form_, transparent prismatic crystals, which effloresce;
when exposed to heat, they undergo watery fusion, that is, they melt in
their own water of crystallization. _Taste_, saline and bitter. CHEMICAL
COMPOSITION. Sulphuric acid 24·64,—soda 19·36—water 56. SOLUBILITY. f℥j
of water at 60° dissolves ʒiiiss; in boiling water it is considerably
more soluble; it is quite insoluble in alcohol. INCOMPATIBLE SUBSTANCES.
The same as those which decompose _sulphate of magnesia_. MED. USES. A
common and useful purgative; its nauseous taste may be in a great degree
disguised by the addition of a small quantity of lemon juice, or _cream
of tartar_. DOSE, ℥ss to ℥ij. In an effloresced state it is just equal
in efficacy to double the weight of that which is in a crystalline form.
It is rendered more active by being combined with other purgative salts,
especially with sulphate of magnesia, and the compound is more soluble
and less nauseous; (_Form. 69, 72_.) A portion of triple salt, a
_magnesio-sulphate of soda_, probably results from the combination, a
salt which may be frequently detected in parcels of sulphate of
magnesia, and may be known by its crystals, which are regular rhomboids;
it is also contained, according to Dr. Murray, in the brine or _mother
liquor_ of sea-water; and it constitutes the whole of that salt which
was formerly sold under the name of “_Lymington Glauber’s Salts_”.[645]