COLOURS FROM ANILINE.
175
parts of nitro-benzol are mixed with an equal quantity of acetic acid and200 parts of iron filings, when the following rea&ion ensues:—
8Fe + C I 2 H 5 N0 4 4-8H0 + i 2 C 4 H 3 03 =: 4 (Fe st 03 . 3 C 4 H 303 ) + C r2 H 7 N + 6H. .The mixture, after the addition of a quantity of lime sufficient to decomposeany acetate of aniline which may have been formed, receives a current ofsteam, preferably superheated, which carries over the aniline, partly dissolvedand partly in a state of mechanical suspension, into a condenser. When coldthe aniline settles out of the water and is readily colle&ed.
The products met with in the market under the name of aniline vary ex-ceedingly. It may, indeed, almost be said that we meet with as manyqualities as makers. The boiling-points vary from i8o°or 182° to 195° C., andagain from 200° to 210° C. The chemical chambers vary according to thenature of the benzol employed. The following table illustrates thesevariations. Eleven kinds of benzol were taken, and their boiling-points andspecific gravities having been noted, they were converted into nitro-benzols.Here, again, the boiling-points and specific gravities were observed, and theywere transformed into anilines. The amount obtained, the specific gravity,and boiling-point of each was registered, and the anilines having been finallyconverted into magentas, the yield and quality was tabulated in each case.
Table B shows
the nature and composition
of some mixtures made with
the above anilines
as well as the yield of these mixtures in colouring matter.
These mixtures consist of equal parts of two or more of the anilines shown
in Table A.
TABLE B.
Boiling-pointsof the
corresponding
Hydrocarbons.
Mixtures of theDifferent Anilines.
of Colour obtainedcompared withCrystallineRosaniline.
Shades on Stuffs.
b-\-c .
0
O
CTt
1
0
O
00
16
(Very violet red. Rosaniline( and mauvaniline.
d-\-e .
90°-100°
17
Red.
f+s .
100°—110°
32
Red.
h+i .
24
(Reddish-yellow. Rosaniline
IIO°— 120 °
( and chrysotoluidine.
/ + * .
120°—130°
18
Red.
b+c + d + e..
8o°—ioo°
24
Red violet.
d +‘+f+g■■ ■■
go 0 '—no 0
37
Red.
f+g+h + i.. ■■
100°—120°
31
Red.
k+i+j+k ..
1X0°—130°
19
Red.
b+c+d+e+f+g+ h i-i+j + k..
8o°—130°
25
Red.
To ascertain the commercial value of samples of aniline a careful deter-mination of the boiling-point is always sufficient for the purposes of themanufa&urer. The absence of water, benzol, and nitro-benzol, must first beproved. The presence of water and benzol is diredUy seen, upon submittinga portion to distillation, both by the thermometer and by examination of thefirst few drops which come over. Nitro-benzol is easily detedfed by saturatingthe suspedted aniline with pure hydrochloric acid. If free from nitro-benzolthe mixture will remain perfedUy clear. Even a slight trace of nitro-benzol issufficient to render the mixture milky.