St. Landry democrat. (Opelousas, La.) 1878-1894, 1892-03-12
LRIOsITLES OF COAL.
interesting Facts Of the Products of
This Material,

Professor +. w. Clarke, chief chemist
OF the United States geological survey,
has been delivering public lecture on
The Chemistry OF Coal"
lie began, saws the WASHINGTON Star
by discussing the origin, nature and com.
position OF coal. He gave an interesting
table showing the gradual elimination Of
the oxygen amt hydrogen gases from de-
Cayed wood in the various forms of peat
| ignite, earthly brown coal, bitu.ninous
coat and anthracite coal, through which,
uuder certain condition, it passes. Wood
contains o2.6 per cent. Of carbon, 5. 25
| per cent. OF hydrogen and Ill per cent.
OF oxygen, while anthracite coal 9l.6 per
cent. carbon, $50 per cent. hydroeen
and only 40 per cent. Oxygen. Coal
also contains ash, sulphur, nitrogen, etc.
When coal is heated in Il large brick,
iron or tire-cIay retort for from three to
tive hours it gives rise to two products
coal gas, which rises and escapes into the
air, and the coke which is left.
Coal gas was first used for Illuminating
purposes by William Murdoch, who in
1892 illuminated by its means his work
shops in Cornwall, England. In 1902 if
was used for the same purpose at the
Soho foundry, near Birmingham, by tho
firm OF Boulton Il Wait. In 1912 the
streets OF London were lighted with it
and in 1920 the streets of Paris. The
gas as it first rises is very impure. To
purify it it is first passed through water,
by which two important products, ammo
MIA and coal tar, are removed from it.
Then through "scrubbers.' or apart
ments filled with coke treated with GER
tain chemicals, by which it is freed from
carbonic acid and sulphurated hydrogen.
The composition of cas- varies considera.
bly,.
The incidental products of the gus
factory, which were at first only nui-
sance, have become very valuable. The
coke is used extensively for fuel, espe-
clully in iron toundries and similar es-
adjustments. The ammonia used in
domestic affairs, for smelling salts and
in refrigeration and agriculture, is de-
rived almost wholly from coal gas.
1t is the most important ingredient of
all fertilizers, and it is by its means that
artificial ice is produced and the new and
important developments Of the coal stor-
age system have taken place
The coal tar has been found to yield on
immense number of products of extraor-
binary scientific and commercial value.
Among the most remarkable are the ami
line dyes which have almost driven other
dyeing stutfs out of the field and which
produce every color in the rainbow, be-
side vast number Of most delicate tints,
some of which are not otherwise obtain
able. Bitter almond oil and vanillin are
two tlavoring extracts obtained from coal
tar, and saccharine, another substance
from the same source, is several hundred
times as sweet us sugar.
Musk and other perfumes also are de-
rived from it.
Of late many valuable medicines have
sprung from the same fecund substance,
notable among which is antipyrine. The
time may come when gourmand may
sit down to an elaborate dinner, most of
which has been derived from coal Ice
cream may be frozen by ammonia,
swcetened with sacchariue favored with
vanilla or "btter almond from coal tar
and coorod by u compound Of anaine.
And Il dose of coal-tar medicine will re-
Gve the results the next day!