Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1869-03-26
From All the Year Round
Manufacture Of ParaffIne.


pure white candles, delicate as wax in then
hue and known popularity by the name Of
90 composites ;" and the clear oil, almost as
transparent as water, which is called 81 par
afine :" have any idea that both are produc-
ed from dull, compact coal, totally devoid
of the luster which gives to that mineral the
appellation of the 90 black diamond" And
yet this seeming miracle is achieved by the
aid Of chemistry-that strange science which
changes and transmutes substances and re-
yeals properties, hidden and mysterious. at
the will or instignation of the student. The
process by which the change is effected is com
plicated and laborious but, freed from its
technicalities, it may be easily explained.
The coal yields four different articles. all of
which are largely employed in daily life, and
have given rise to considerable commerce
There is, first, the parafhne oil for burning
at present manufactured by thousands of gal
Ions, which, in many parts Of England
where gas Is still unknown, is the staple COM
modify of illumination. Then a second
quality Of the same oil, considerably cruder
and cOarser, which, on account Of its cheap
ness and general aptitude, is largely employ
ed for lubricating machinery. Naphtha comes
next upon the list-a light, volatile fluid.
much used by travelling shOwmen to light up
their stalls and tents. Lastly, there is solid
parafine-a pure, white, shining, tasteless
substance, scarcely distinguishable from
wax, which is manufactured into candles.
These substances, though widely differing in
color, properties, and consistency, are all
manufactured by nearly the same process. the
difference consisting merely in the number Of
times that a particular operation IS repeated.
Boghead mineral is the name OF the coal
employed in the manufacture Of parafine
and this Is conveyed from the pits direct In
to the heart Of the works, By means of
branch lines Of railway. Arrived here, the
coal is passed through a huge iron crushing
machine. and broken into small pieces. to IA
cilitate the labor Of subsequent stages. The
first result to be achieved is TO extract the
crude oil from the coal This is effected by
means Of ret0rts, into which the mineral is
put, and the oleaginous matter extracted by
burning. These retorts may, for our purposes,
be described as huge upright iron pipes pass
ing through furnaces. The coal is filed into
the pipe or tube by the top, which is then
closed with an air-tiglt valve and the bot
tom Of the pipe Is led into pool of water 10
prevent the entrance Of air from below. 4
low red heat Of uniform temperature is main
tanned constantly in the retOrts. As the coal
is acted upon by the fire, it desceuds gradual
" in the tube and becomes entirely decom-
posed. The essential or oluagiuous property
Of the mineral passes of in yaIor. and the
refuse falls through the bottom Of the pipe
into the pool Of water, and is raked away.
The vap0r or steam, as it Il generated by the
decomposition Of the coal, is carried of by
a pipe in the side of the retort. This pipe
again communicates with series Of pipes
placed upright in the open air, and arranged
ON the same principle as the bars of a COM
mon gridiron, after the fashion that prevails
in gasworks. The yapor, IN travelling through
this labyrinth Of pipes, cools, Is condensed
into liquid, and If run of into an immense
reservoir sunk into the ground The crude,
oily liquor thus collected is thick black.
greasy fluid. not unlike tar. which moves
with a sluggish motion when stirred, and
gives off iutiammahle yapors al the usual at
m0spbelic temperature. This cllr-e oil,
both in its properties and appearance. closely
resembles natural petroleum
The raw material thus prepared by simple
burning is kept stored in the tank. and /,
only drawn of when required 10 the OBJ
server nothing seems stranger than that this
heavy. black, tarry liquid should produce oil
as pure as water, and solid Iaratine as white
as marble. And Yet the marvel is wrought
daily, and on "a sca,e which supplies distant
markets Of the world with oil. l. is mere
question Of refining. The black liquor is, as
+, were, boiled, washed, and biedched, re-
boiled. re-vashcl. and re-hleachci. until the
last particle Of It's darkness and impurity is
uurEed away. The fFst step in the work of
refinement Is in some respects similar 90 the
previous process of decomposition. Tie cru 60
tarry liquid is put into stills, which We may call
huge b1 lers of gigantic strength. with nova
bic doors or lids. When the stills have been
filed. the doors are closed, and the points aye
stuffed with clay. 80 as o. render the inter
i1r perfectly air-ti-ht Fires are then light
Cd IN the furnaces below the boilers. and kept
up % steady heat. Till the fund inside die
til,- over and Is transmitted again into yaVlr.
This yaplr, as 10 the former instance, perm
Gates through another series of cQutcus!ns
pipes and, during It's transit is re-transmut-
ed into liquor, and flows into q second reser-
voir. Collected in this tank. the oil shows
abundant evidence Of the severity OF the lr-
deal through which it has hccnput. ltpass
al into the stills black ana Qt the consistency
Of treaclc /. has come out u o dark-grcen
c0l0- of the consistency of pea soup. a large
portion u the c1al-black has, in iac-, been
boiled out af It. which Is now o. he found iu
The bottom Of the b0ilers I'M tie shape Of %
lusrous compact residue resembling coke, iIr
which il makes very good substitute.
The next stage in The process Of puriica-
ti1n Is of q different character. The DARK
green liquor is transferred to tanks, and
certain quantity of strong sulphuric acid is
added. Tie acid is employed in order still
further % bleach the oil, and purge il of
some Of the imVurity with which 10 is SD
largely imure-uated To effect this object 1t
is essential that the oil and the acid shoUld
be- mixed ny 1r assimilaJei as much as posi-
hle-a work Of some difficulty, on account Of
the tendency Of the former to llat on the top
BY reason Of its slghter specific gravity. This
tendency is ucutulizei hy the action of q
revolving surrer fitted with blades. which,
when put in motion. beats and agitates the
two lIguid.. and cause, them % min-ie equal
ly. For four hour, is this operation coutiu-
ucd until. under the biting influence Of the
acid, the green oil changes t0pale-greon,
and gives token Of having parted with much
If the urlsscr substances that had numbered
il dull and prague. The srirrer7 being nj
leugh stopped, the liquor is allowed Go settle,
and the organic impurities that have been
separated from it hv the action of the vltlI1i.
collect in the bottoms Of the tanks. The lees
in this case assume the shape of coarse
acid tar. which is also used as q subs itute for
fuel The oil, thus far cleanscd Of It's foul
ness. Is now transferred % clean tanks, mix
eli with a strong solution Of caustic soda, and
again subjected % the beating Of the stirrers.
The action Of the alkali extracts a good deal
more of the c0l0rinE matter, and changes
the pale green 10 yellow At the end of a
second period of four hours the liquor is al
lowed to settle, is drawn Of from the lees as
before. If pumped into the stills and is It
distilled, and Is again brought back to be
rut through the acid and alkali bleaching
process the result being Its assumption of
clear, pale, yellow color. When in this
stage of its preparation the oil contains the
elements Of no less than four different pro-
ducts, each valuable as articles Of commerce,
to separate which is the next care Of the
manufacturer.
The separation is effected merely by dis
tilling the oil at various temperatures. At
the lowest temperatures. At the lowest
temperature the lightest and most volatile
parts Of the oil pass of in the shape Of va
por Upon being cooled. by passing through
pipes, this yapor yields liquid which, upon
being distilled by itself, gives a light, trans
parent. inlammable fluid known by the name
of naphtha, the specific gravity of which is
considerably less thar that of the naphtha de-
rived from coal-tar This naphtha is largely
employed as a substitute for turpentine in in
dia-rubber works. where it is employed to
dissolve the materials used in that branch of
manufacture. At the temperature next to
the lowest, those parts Of the oil that are
next to naphtha in point Of volatility are
taken of, distilled, and condensed, and yield
paralIine or lamp oil. The processes of puri-
fcation and distillation are repeated with this
oil till it has assumed the requisite degree Of
purity, and become transparent and almost
free from smell \ gallon of this oil weighs
obont ei0bt and a quarter mounds. and Is. in