The Superior times. [volume] (Superior, Wis.) 1870-1912, 1885-05-23
TIE BGyDERS OF cor TAR.
Gorgeous Dyes and Most Useful Products
Obtained from "a Troublesome Refuse.

TIE u cNDERS OF CCfI TAR.
Gorgeous Dyes and Most Useful Products
Obtained from "a Iroubiesorue Refuse.
From the New York SUM-
Chemistry Is capable OF wonderful
things said an expert in chemical
science, "but in nothing to which its
principles were ever applied have such
marvellous results followed as are
witnessed in its manipulation OF com
mon gas or coal tar. Thirty years
ago the problem of how they were to
rid themselves Of this foul and then
utterly useless refuse of the rttorts
was puzzling manufacturers of gas,
and the AID OF chemistry was sought
IN working out the solution They
had no thought beyond the utter an
initiation OF the offensive tar. In
their experiments with the refuse the
chemists discovered the sO-called
burning naphtha, which, however,
could be applied with safety to no
practical purpose. After the naphtha
was extracted the tar was left in the
form Of heavy oil, which was still
more OF a nuisance than the original
compound, as it was more difficult to
store and handle. The chemist Bell
iel discovered a channel OF utility for
this oil in applying 1t ar a pickle for
the preservation OF railroad ties,
bridge timbers, and similarly exposed
woods. This used up large quantities
OF the refuse, but only partially re-
lleved the tar nuisance.
"The only hope that gas men now
had was that some discovery might
be made in chemical experimenting
which would give a commercial value
to the refuse Faraday next awoke
interest in coal tar by his discovery OF
benzineas a product OF the tar oil. 1t
was in experimenting with the volatile
substances of these oils that the great
chemist Mansfield lost his life, by an
explosion in his laboratory, and it
was probably this casualty that dl-
rected greater attention to the posi-
bilities of the despised gas tar.
ut was not until 1857, however,
that the great value Of coal tar as a
raw material was demonstrated. In
that year Perkins discovered its ami
line properties, discovery that has
almost revolutiOnized the trade in
dyestutfs. Perkins took cOal-tar
naphtha, and, boiling it III a retOrt,
obtained a chemical action which re-
suited in benzole and nitro benzOle.
Adding water to this, the enItrO-benzOle
was deposited in the form OF a thick.
oily mass. This he experimental
with in various ways, and finally, by
the addition OF acetic acid and iron
filings, he produced a COlOrless fluid
which is aniline This liquid ne treat
ed with different chemical salts, and
the result was green crystals OF a me
tallic luster. These he found were ca
pable Of producing, under different
chemical reactions, the most brilliant
and gorgeous dyes-the aniline hues OF
the paint and dye trades of to-day.
This discovery has made the long
detested coal tar a desirable product
of the gas retorts, but it neld still
greater surprises. From the light oil
of the tar a valuable naphtha solvent
for India-rubber was obtained, and
then the invaluable discovery OF car
bolic acid was made. How many peO-
pie in ordinary life know that this
great disinfectant Is one OF the prod
ucts of common gas tar? After these
properties were eXtraCtedfrOm the tar
there were left heavy oils and reslduum
for which chemistry was puzzled to
find a practical use. 1t was not until
1869 that any satisfactory result was
obtained by experimenting with this
refuse. and then the great discovery OF
alizarine was made. This product
was first obtained by the German
chemists Graebe and Liebermann, but
Prof. Perkins, vino had developed the
aniline coIors from tar, was the first
to give a practical application to the
German work. The Importance OF
this discovery may be understood
when It is known that in the first ten
wears followingt the introduction OF the
artificial alizarine in the dyestutfs
trade. it exceeded the total amount OF
natural alizarine, or madder root,
that had been handled in the trade
previous to its introduction. 1t was,
If ANYTHING, superior to madder, and
so much cheaper that the saving by
its use up to 1880 had amounted to
over S20,OOO, 900. The discovery OF
aiizarine in coal tar converted 4OO,-
600 acres of land that had been used
for growing madder root INTO fertile
fields of corn and other cereals. With
vegetable madder it required nine
weeks to perfect the dyeing OF a ma
terial Turkey red. The artificial mad
de- accomplished the desired result in
as many hours. Three years ago the
chemist produced an artificial indigo
from the residuum OF gas tar, and, in
connection with the aniline dyes and
alizarine of thesamc base it is rapidly
taking the place of vegetable indigo
Later. the naphthalene yeIlows and
reds, with which entirely new effects IN
color were made possible, were derived
from coal tarresiduum. Chemists are
still experimenting with the tar prod
ucts and other important develop,
ments will no doubt be made"