Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1885-08-20

WONDERS OF COAL TAR.
Gorgeous Dyes and Most Useful Products
Obtained From "a Troublesome
Refuse.

Gorgeous Dyes and Most Useful Product.
I Obtained From "a Troublesome
| Refuse.
Chemistry is capable of wonderful
things" said an expert in chemica
science, ''but in nothing to which its
principles were ever applied have sucl
marvellous results followed as are wit.
messed in its manipulation of common
gas or coal tar Thirty years ago the
problem of how they were to rid them.
selves of this foul and then utterly
useless refuse Of the retorts was puz-
zling manufacturers of gas, and the
aid of chemistry was sought in work.
ing out the solution. They had nc
thought beyond the utter humiliation
OF the offensive tar. In their expert
ment with the refuse the chemists dis
covered the so-called burning naptha,
which, however, could be applied with
safety to no practical purpose. After
the naptha was extracted the tar was
left in the form Of heavy oil, which
was still more of nuisance than the
original compound. as it was more diff
ficult to store and handle. The chem
list Belief discovered a channel of util-
ity for this oil in applying it as 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 relieY-
ed 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 benzine
as product of the tar oil. 1t was
In experimenting with the volatile sub.
stances OF these oils that the great
chemist Mansfield lost his life, by an
explosion in his laboratory, and it was
probably this casualty that direct
ed greater attention to the possibilities
OF the despised gas tar.
1T was not until 1857, however, that
the great value of coal tar as raw
material was demonstrated. In that
year Perkins discovered its aniline
properties, a discovery which has al
most reyolutionized the trade in dye-
stuffs. Perkins took coal-tar naptha,
and, boiling, it in retort, obtained a
chemical action which resulted in ben
zolc and nitro-benzole. Adding water
10 this, the nitro-benzole was deposited
ia the form of 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. The
liquid he treated with different chemic-
al salts, and the result was green crys-
tails OF a metallic luster These he
found were capable of producing, under
different chemical reactions, the most
brilliant and gorgeous dyes-the ami
line hues OF the paint and dye trades of
to-day.
This discovery made the long-de-
serted coal tar a desirable product of
the Gas retorts, but it held still greater
surprises. From the light oil of the
tar valuable naptha solvent for india
rubber was obtained, and then the in
valuable discovery of carbolic acid was
made. How many people in ordinary
life know that this great disinfectant is
one of the products of common gas tar?
After these properties were extracted
from the tar there were left heavy oils
and residuum for which chemistry was
puzzled TO find practical use. 1t was
not until 1859 that any satisfactory re-
suit was obtained BY experimenting
with this refuse, and then the great dis
covery of alizarine was made. This
product was first obtained by the Ger
man chemists Graebe and Liebermann,
but Prof. Perkins, who had developed
the aniline colors from tar was the
first to give application to the German
work. The Importance Of this discoV-
cry may be understood when il is
known that in the first ten years fol-
lowing the introduction of the artificial
alizarne in the dyestutfs trade, it ex-
ceeded the total amount of natural ali
zarine, or madden root, that had been
handled in the trade previous to its in
PRODUCTION. 1t was, if anything, supe-
rlor to madden, and so much cheaper
that the saving by its use up to 1880
had amounted to over $50, GOO. 600.
The discovery of alizarine in coal tar
converted 100000 acres of land that
had been used for growing madden,
root into fertile fields of corn and other
cereals. With vegetable madden it re-
dulieu nine weeks TO perfect the aye
ing Of a material Turkey red. The ar
tifcial madden accomplished the de-
sired result in as many hours. Three
years ago the chemist produced an ar
tiiicial indigo from the residuum Of gas
tar, and in connection with the aniline
dyes and alizarine of the same base, it
is rapidly taking the place of indigo.
Later, the napthaline yellows and reds,
with which entirely new effects in col
or were made possible, were derived
from coal-tar residuum. Chemists are
still experimenting with the tar pro-
ducts, and other important develop
ments will no doubt be made. IN. y
San.