easily dissociated on heating. Antimony trifluoride, SbF3, is
obtained by dissolving the trioxide in aqueous hydrofluoric acid or by
distilling antimony with mercuric fluoride. By rapid evaporation of
its solution it may be obtained in small prisms. The pentafluoride
SbF5 results when metantimonic acid is dissolved in hydrofluoric acid,
and the solution is evaporated. It forms an amorphous gummy mass,
which is decomposed by heat. Oxyfluorides of composition SbOF and
SbOF3 are known.

Two sulphides of antimony are definitely known, the trisulphide Sb2S3
and the pentasulphide Sb2S5; a third, the tetrasulphide Sb2S4, has
also been described, but its existence is doubtful. Antimony
trisulphide, Sb2S3, occurs as the mineral antimonite or stibnite, from
which the commercial product is obtained by a process of liquation.
The amorphous variety may be obtained from the crystalline form by
dissolving it in caustic potash or soda or in solutions of alkaline
sulphides, and precipitating the hot solution by dilute sulphuric
acid. The precipitate is then washed with water and dried at 100 deg.
C., by which treatment it is obtained in the anhydrous form. On
precipitating antimony trichloride or tartar emetic in acid solution
with sulphuretted hydrogen, an orange-red precipitate of the hydrated
sulphide is obtained, which turns black on being heated to 200 deg. C
The trisulphide heated in a current of hydrogen is reduced to the
metallic state; it burns in air forming the tetroxide, and is soluble
in concentrated hydrochloric acid, in solutions of the caustic
alkalis, and in alkaline sulphides. By the union of antimony
trisulphide with basic sulphides, livers of antimony are obtained.
These substances are usually prepared by fusing their components
together, and are dark powders which are less soluble in water the
more antimony they contain. These thioantimonites are used in the
vulcanizing of rubber and in the preparation of matches. Antimony
pentasulphide, Sb2S5, is prepared by precipitating a solution of the
pentachloride with sulphuretted hydrogen, by decomposing "Schlippe's
salt" (q.v.) with an acid, or by passing sulphuretted hydrogen into
water containing antimonic acid. It forms a fine dark orange powder,
insoluble in water, but readily soluble in aqueous solutions of the
caustic alkalis and alkaline carbonates. On heating in absence of air,
it decomposes i