from
The Collaborative International Dictionary of English v.0.48
Saltpeter \Salt`pe"ter\, Saltpetre \Salt`pe"tre\,
(s[add]lt`p[=e]"t[~e]r), n. [F. salp[^e]tre, NL. sal petrae,
literally, rock salt, or stone salt; so called because it
exudes from rocks or walls. See {Salt}, and {Petrify}.]
(Chem.)
Potassium nitrate; niter; a white crystalline substance,
{KNO3}, having a cooling saline taste, obtained by leaching
from certain soils in which it is produced by the process of
nitrification (see {Nitrification}, 2). It is a strong
oxidizer, is the chief constituent of gunpowder, and is also
used as an antiseptic in curing meat, and in medicine as a
diuretic, diaphoretic, and refrigerant.
[1913 Webster]
{Chili salpeter} (Chem.), sodium nitrate (distinguished from
potassium nitrate, or true salpeter), a white crystalline
substance, {NaNO3}, having a cooling, saline, slightly
bitter taste. It is obtained by leaching the soil of the
rainless districts of Chili and Peru. It is deliquescent
and cannot be used in gunpowder, but is employed in the
production of nitric acid. Called also {cubic niter}.
{Saltpeter acid} (Chem.), nitric acid; -- sometimes so called
because made from saltpeter.
[1913 Webster]