The Red Cloud chief., 1888-08-24
HOW GAS Is MADE.

Haines Losyaead, in Argonau'.
-
HOW GAS Is MADE.
An E~xpl.natisn Of the Details Which Com
plicste the Really simple Process.
The principle of gas manufacture is
very simple, but there are many prac-
ticaldetails which complicate the actual
process. 1t depends upon the fact that
when bituminous coal containing car
bon and hydrogen is subjected to heat
in a retort. it is partially decomposed.
giving of gaseous hydrocarbons and
other products. and leaving behind \
mass OF carbon commonly known e.
coke. But many other compounds are
formed ~ the same time. which must
be separated from the gas before it is
TT to be sent into the pipes. and deliv-
cred to the The products
of the distiIlation Of coal may be divi-
ded roughly into four classes-coke.
coal-tar. ammoniacal liquor and illum-
mating gas. Coke contains from ninety
to ninety-fve per cent. of pure carbon.
the remainder being ash and sulphide
of iron. The ammoniacal liquor con-
tains at least Eve different salts OF am
monia- The coal-tar contains about
forty different liquid and solid hydro
carbons. and the illuminating gas twen-
ty-tive or more gaseous hydrocarbons
a total of over seventy distinc:
chemical substances. all produced
by the distillation of apiece OF soft coal.
1t must be remembered that a few or
none Of these exist By themselves in
the coal. but are all formed by the
chemical reactions which take place
during the distillation. The retorts
in which the coal is distilled are
made either of cast-iron or tire-clay:
they are about nine feet long and
oae and a half feet in diameter.
After being filled with coal. they Ire
raised to q red heat, or even higher.
The impure gas thus formed passes OF
through an upright pipe. which con-
meets with a horizontal one partly
filed with water. known as the hydrau-
lie main. The pipe from the re:ort dips
under the water. so that all the gas
must pass through it. The coarser and
less volatile impurities. including a
large proportion Of the tar. are con-
densed in this main. The gas. however.
is still at q high temperature. and very
impure: SO it is n through a set OF
vertical pipes connected with each
other like ! steam radiator. which are
either exposed to the air. or cooled
artifcially. Many of the impurities
are condensed and separated from the
gas in the cooler. but it is sometimes
still further purified by being passed
through large icon vessels filed with
Jumps Of coke over which a stream of
cold water is constantly flowing. This
still further puriies the gas. especially
by absorbing the amnoliacal COM
pounds; but the offensive and danger
sulphur compounds remain. and 70
remove these the gas is sent through
large iron boxes containing movable
trays covered with moist. freshly
Stacked lime. The lime absorbs the
greater part of the compounds of sui
phry, and the gas is then ready
TO be stored in the large holders.
improperly called gasometers, and
from thence delivered to the GUS
toner. After absorbing the i'm
purities. the gas-lime. as it called.
possesses a most horrible odor. and in
thickly settled localities its disposal
without creating a nuisance is An i'm
portant aad sometimes q dificnlt mat
ter. A more effective and simpler
Of purifying gas is much to be
desired. What is known As water-gas
has been substituted to some extent for
that distilled from coal. 1t is essen
italy a mixture OF hydrogen and r.
bOnic oxide, and is formed by acurious
reaction which takes place when steam
is passed over red-hOt Goals. The steam
is ~decomposed. and hydrogen is set
free. while the oxygen unites with the
carbon Of the coal to form carbonic
oxide (CC). As this gas burns with a
mountainous flame. it must be Zen
riched' with light-giving h%ydrocar-
bOns. which are usually obtained from
the Installations Of crude petroleum. 1t
is claimed that this gas is much cheape,
than tina, produced by the old process;
but practica! trials have not as yet CON-
firmed this. and the presence of the
highly poisonous carbOnic oxide rem
ders it a much more dangerous agent
to introduce into dwellings.-Popxlar
Science Neus.
"A German authority attaches some
importance to a troublesome silk spin
ne- of Iadia-'-Gricula trifenestrata''
from which an excellent fiber has
been obtained. This silk worm is ex.