A Manual of the Chemistry of the Carbon Compounds

410 TEE CHEMISTRY OF
scale by heating dimethylaniline with potassium chlorate and cupric
sulphate:—
3C8HnN + 30 = CgJLaNgO + 2H20
The free base is a reddish-browa powder, dissolving in alcohol with
a violet colour. Its salts, as well as those of triuiethyl-rosaniline and
triethyl-rosaniline, possess in the dry state a golden-yellow lustre,
and are found in commerce under the name of " Aniline- violets "and
"Hofniann's violet."
In the process of manufacturing these violets, by the action of
methyl or ethyl iodide on rosaniline, there is always produced a
quantity of a dark resinous body, which is called "Hofmanngum."
This bye-product yields by dry distillation a large quantity of methylaniline
or ethylamline.
Aniline-green is obtained by heating rosaniline with methyl alcohol
and an excess of methyl iodide. The product is exhausted with
boiling water, whicn leaves the greater part of the violet behind. To
the solution salt is added to remove all the violet, and then it is
neutralized with soda, and precipitated by picric acid. The salts of
aniline-green contain the ammonium-base CwH,?(CH^8N^CHsO)j,
which has not been much examined. The commercial product is a green
paste, consisting of the pierate C2(!H1(I(CH8)8lf8(CH8.OC8H2(NO2)»)i!,
which in the pure state forms yellowish-green prisms, showing a
copper-red reflection.
Flwnyl-rosmiilines.—Whenarosaniline.salt is heated with aniline,
hydrogen is replaced by phenyl, and ammonia is given off.
The salts of moiwphcnylrosaniKne L'g,H,,(CeHt)N. have a reddish-
violet colour, r, and those of dipkmyl-rosan.tline diphenyt-rosantline CaoH,»(C,,H6)Jir., C^Hj^CaH^^Nj, am
bluish-violet. The salts of triphcnyl-rosimiline CojHjqiCjHjJgN. have
a, pure blue colour, aud are kuown by the name of" night-blua'
The formation of these blues takes place more readily in presence
of acetic, benzoic, or other organic acids.
"When triplienyl-rosaniline is submitted to dry distillation, it yields
a considerable quantity of diphenylamine.
Tripkenyl-rosanilincsiilphonic Acid C?0H,0(C6H8)2(C|)H4.SOSH)N'3 is
obtained by dissolving triphenyl-rosaniline in concentrated sulphuric
acid, and adding water to the solution, as a dark-bine mass, which
dries up to grains having a beautiful metallic lustre. Its sodium salt
is found hi commerce under the name of "Nicholson's blue," or
" alkali-blue;" it is a dark.grey, amorphous mass, dissolving in water,
with a fine blue colour.
By the further action, of sulphuric acid, other sulphonic acids are
formed, which occur as sodium salts in several "soluble aniline
blues."
Eenxyl'rosaniline.—Vfhm a mixture of rosaniline, benzyl chloride,
methyl iodide, and methyl alcohol is heated in a water-bath, the compound
C^H^C^.CH^jNj.CHal is formed, crystallizing in beetle-