from
The Collaborative International Dictionary of English v.0.48
Precipitate \Pre*cip"i*tate\, n. [NL. praecipitatum: cf. F.
pr['e]cipit['e].] (Chem.)
An insoluble substance separated from a solution in a
concrete state by the action of some reagent added to the
solution, or of some force, such as heat or cold. The
precipitate may fall to the bottom (whence the name), may be
diffused through the solution, or may float at or near the
surface.
[1913 Webster]
2. atmospheric moisture condensed as rain or snow, etc.; same
as {precipitation[5]}.
[PJC]
{Red precipitate} (Old. Chem), mercuric oxide ({HgO}) a heavy
red crystalline powder obtained by heating mercuric
nitrate, or by heating mercury in the air. Prepared in the
latter manner, it was the {precipitate per se} of the
alchemists.
{White precipitate} (Old Chem.)
(a) A heavy white amorphous powder ({NH2.HgCl}) obtained
by adding ammonia to a solution of mercuric chloride
or corrosive sublimate; -- formerly called also
{infusible white precipitate}, and now {amido-mercuric
chloride}.
(b) A white crystalline substance obtained by adding a
solution of corrosive sublimate to a solution of sal
ammoniac (ammonium chloride); -- formerly called also
{fusible white precipitate}.
[1913 Webster]