White soap 100 parts.
White wax of the best quality 100 --
Mutton suet 30 --
Shell-lac 50 --
Mastic 50 --
Lamp black 30 or 35 --
These materials are to be melted as above described for the lithographic
ink.
_Lithographic ink and paper._--The following recipes have been much
commended:
Virgin or white wax 8 parts
White soap 2 --
Shell-lac 2 --
Lamp black 3 table-spoonsful.
_Preparation._--The wax and soap are to be melted together, and before
they become so hot as to take fire, the lamp black is to be well stirred
in with a spatula, and then the mixture is to be allowed to burn for 30
seconds; the flame being extinguished, the lac is to be added by
degrees, carefully stirring all the time; the vessel is to be put upon
the fire once more in order to complete the combination, and till the
materials are either kindled or nearly so. After the flame is
extinguished, the ink must be suffered to cool a little, and then put
into the moulds.
With the ink crayons thus made, lines may be drawn as fine as with the
point of the graver, and as full as can be desired, without risk of its
spreading in the carriage. Its traces will remain unchanged on paper for
years before being transferred.
Some may think it strange that there is no suet in the above
composition, but it has been found that ink containing it is only good
when used soon after it is made, and when immediately transferred to
the stone, while traces drawn on paper with the suet ink become
defective after 4 or 5 days.
_Lithographic paper._--Lay on the paper,
3 successive coats of sheep-feet jelly,
1 layer of white starch,
1 layer of gamboge.
The first layer is applied with a sponge dipped in the solution of the
hot jelly, very equally over the whole surface, but thin; and if the
leaf be stretched upon a cord, the gelatine will be more uniform. The
next two coats are to be laid on, until each is dry. The layer of starch
is then to be applied with a sponge, and it will also be very thin and
equal. The coat of gamboge is lastly to be applied in the same way. When
the paper is dry, it must be smoothed by passing it through the
lithographic press; and the more polished it is, the better does it take
on the ink in fine lines.
_Transfer._--When the paper is moistened, the transfer of the ink from
the gamboge is perfect and infallible. The starch separates from the
gelatine, and if, after taking the paper off the stone, we place it on a
white slab of stone, and pour hot water over it, it will resume its
primitive state.
The coat of gamboge ought to be laid on the same day it is dissolved, as
by keeping, it becomes of an oily nature; in this state it does not
obstruct the transfer, but it gives a gloss to the paper which renders
the drawing or tracing more difficult, especially to persons little
habituated to lithography.
The starch paste can be employed only when cold, the day after it is
made, and after having the skin removed from its surface.
A leaf of such lithographic paper may be made in two minutes.
In transferring a writing, an ink drawing, or a lithographic crayon,
even the impression of a copper-plate, to the stone, it is necessary, 1.
that the impressions be made upon a thin and slender body like common
paper; 2. that they may be detached and fixed totally on the stone by
means of pressure; but as the ink of a drawing sinks to a certain depth
in paper, and adheres pretty strongly, it would be difficult to detach
all its parts, were there not previously put between the paper and the
traces, a body capable of being separated from the paper, and of losing
its adhesion to it by means of the water with which it is damped. In
order to produce this effect, the paper gets a certain preparation,
which consists in coating it over with a kind of paste ready to receive
every delineation without suffering it to penetrate into the paper.
There are different modes of communicating this property to paper.
Besides the above, the following may be tried. Take an unsized paper,
rather strong, and cover it with a varnish composed of:--
Starch 120 parts
Gum arabic 40 --
Alum 20 --
A paste of moderate consistence must be made with the starch and some
water, with the aid of heat, into which the gum and alum are to be
thrown, each previously dissolved in separate vessels. When the whole is
well mixed, it is to be applied, still hot, on the leaves of paper, with
a flat smooth brush. A tint of yellow colour may be given to the
varnish, with a decoction of the berries of Avignon, commonly called
French berries by our dyers. The paper is to be dried, and smoothed by
passing under the scraper of the lithographic press.
Steel pens are employed for writing and drawing with ink on the
lithographic stones.
LITMUS (_Tournesol_, Fr.; _Lackmus_, Germ.); is prepared in Holland from
the species of lichen called _Lecanora tartarea_, _Roccella tartarea_,
by a process which has been kept secret, but which is undoubtedly
analogous to that for making archil and cudbear. The ground lichens are
first treated with urine containing a little potash, and allowed to
ferment, whereby they produce a purple-red; the coloured liquor, treated
with quicklime and some more urine, is set again to ferment during two
or three weeks, then it is mixed with chalk or gypsum into a paste,
which is formed into small cubical pieces, and dried in the shade.
Litmus has a violet-blue colour, is easy to pulverize, is partially
soluble in water and dilute alcohol, leaving a residuum consisting of
carbonate of lime, of clay, silica, gypsum, and oxide of iron combined
with the dye. The colour of litmus is not altered by alkalis, but is
reddened by acids; and is therefore used in chemistry as a delicate test
of acidity, either in the state of solution or of unsized paper stained
with it. It is employed to dye marble blue.
LIXIVIATION (_Lessivage_, Fr.; _Auslagen_, Germ.); signifies the
abstraction by water of the soluble alkaline or saline matters present
in any earthy admixture; as from that of quicklime and potashes to make
potash lye, from that of effloresced alum schist to make aluminous
liquors, &c.
LOADSTONE, MAGNETIC IRON-STONE (_Fer oxydulé_, Fr.; _Magneteisenstein_,
Germ.); an iron ore consisting of the protoxide and peroxide of iron in
a state of combination.
LOAM (_Terre-limoneuse_, Fr.; _Lehm_, Germ.); a native clay mixed with
quartz sand and iron ochre, and occasionally with some carbonate of
lime.
LODE, is the name given by the Cornish miners to a vein, whether it be
filled with metallic or earthy matter.
LOGWOOD (_Bois de Campèche_, _Bois bleu_, Fr.; _Blauholz_, Germ.); is
the wood of the _Hæmatoxylon Campechianum_, a native tree of central
America, grown in Jamaica since 1715. It was first introduced into
England in the reign of Elizabeth, but as it afforded to the unskilful
dyers of her time a fugitive colour, it was not only prohibited from
being used, under severe penalties, but was ordered to be burned
wherever found, by a law passed in the 23d year of her reign. The same
prejudice existed, and the same law was enacted against indigo. At
length, after a century of absurd prohibition, these two most valuable
tinctorial matters, by which all our hats, and the greater part of our
woollen cloths, are dyed, were allowed to be used.
Old wood, with black bark and with little of the white alburnum, is
preferred. Logwood is denser than water, very hard, of a fine compact
grain, and almost indestructible by the atmospheric elements; it has a
sweet and astringent taste, and a peculiar not inoffensive smell.
For its chemical composition, see HEMATIN.
When chipped logwood is for some time exposed to the air, it loses a
portion of its dyeing power. Its decoction absorbs the oxygen of the
atmosphere, and then acquires the property of precipitating with
gelatine, which it had not before. The dry extract of logwood, made from
an old decoction, affords only a fugitive colour.
For its applications in dyeing, see BLACK DYE; BROWN DYE; CALICO
PRINTING; DYEING; HAT DYEING, &c.
The imports of logwood for home use, were, in 1836, 12,880 tons, 13
cwts.; in 1837, 14,677 tons, 13 cwts. And the amount of duty received
was, in 1836, 2,480_l._; in 1837, 2,552_l._
LOOM (_Metier a tisser_, Fr.; _Weberstuhl_, Germ.); is the ancient and
well-known machine for weaving cloth by the decussation of a series of
parallel threads, which run lengthwise, called the warp or chain, with
other threads thrown transversely with the shuttle, called the woof or
weft. See JACQUARD LOOM and WEAVING.
LUBRICATION. The following simple and efficacious plan of lubricating
the joints and bearings of machinery by capillary attraction, has been
kindly communicated to me, by its ingenious inventor, Edward Woolsey,
Esq.:--
[Illustration: 645, 646, 647]
_Fig._ 645. represents a tin cup, which has a small tin tube A, which
passes through the bottom, as shown by the dotted lines. It may have a
tin cover to keep out the dust.
_Fig._ 646. is a plan of the same.
_Fig._ 647. is a section of the same. Oil is poured into the cup, and
one end of a worsted or cotton thread is dipped into the oil, and the
other end passed through the tube. The capillary attraction causes the
oil to ascend and pass over the orifice of the tube, whence it gradually
descends, and drops slower or quicker, according to the length of the
thread, or its thickness, until every particle of oil is drawn over by
this capillary syphon. The tube is intended to be put into the bearings
of shafts, &c., and is made of any size that may be wished. If oil, or
other liquids, is desired to be dropped upon a grindstone or other
surface, this cup can have a handle to it, or be hung from the ceiling.
[Illustration: 648]
_Fig._ 648. It is frequently required to stop the capillary action when
the machinery is not going; and this has been effected by means of a
tightening screw, which passes through a screw boss in the cover of the
cup, and presses against the internal orifice of the tube, preventing
the oil from passing.
[Illustration: 649 650 651 652]
_Fig._ 649. As I find when these screw cups (_fig._ 648.) are used upon
beams of engines and moving bearings, that the screw is apt to be
tightened by the motion; and also, as I think the action of the screw is
uncertain, from the workman neglecting to screw it down sufficiently, it
answers best to take out the capillary thread when the lubrication is
not required; and to effect this easily, I have a tin top to the cup,
with a round pipe soldered to it: this pipe has a slit in it, like a
pencil case, and allows a bolt B to slide easily in it. In _fig._ 650.
the bolt is down; in _fig._ 651., the bolt, which is a piece of brass
wire, is drawn up, and there is no capillary action between the thread
and the oil. In _fig._ 651. it will be observed, that the bolt is kept
in its place by its head C, resting in a lateral slit in the pipe, and
it cannot be drawn out on account of the pin E. One end of the thread is
fastened to the eye-hole at the bottom of the bolt, and the other end is
tied to a small wire which crosses the lower orifice of the tube at D
and which is shown in plan _fig._ 652.
By this simple contrivance the capillary action can be stopped or
renewed in a second, without removing the top of the lubricator.
The saving by this plan, instead of pouring oil into the bearings, is 2
gallons out of 3, while the bearings are better oiled.
“I send you the drawings of the lubricators, with a detailed
explanation. I have omitted to state, that the saving in labour is
considerable where there are many joints to keep oiled three or four
times a day; and that the workman does not, with this apparatus, run
the risk of being caught by the machinery. Perhaps your friends may be
at a loss how to tie on the cotton or worsted thread. I pass a long
thread through the eye-hole E of the bolt, and then draw the two ends
through the tube by a fine wire with a hook to it, one end on one side
of the cross wire D, and the other end on the other side. I then put
the cover on, and the bolt in the position shown in _fig._ 651.; when
by drawing the two ends of the thread, and tying them across the wire
D, you have the exact length required. When you wish to see the
quantity of oil remaining in the lubricator, the bolt must be dropped
as in _fig._ 650., and you can then lift the cover a little way off,
without breaking the thread, and replenish with oil. The cost of
_fig._ 650. in tin plate is 9_d._ The figures in the wood cuts are one
third of the full size.
“Believe me to be yours sincerely,
“E. J. WOOLSEY.”
LUPININE, is a substance of a gummy appearance, so named by M. Cussola,
because it was obtained from Lupines.
LUPULINE, from _Humulus Lupulus_; is the peculiar bitter aromatic
principle of the hop. See BEER.
LUTE (from _lutum_, clay; _Lut_, Fr.; _Kitte_, _Beschläge_, Germ.); is a
pasty or loamy matter employed to close the joints of chemical
apparatus, or to coat their surfaces, and protect them from the direct
action of flame. Lutes differ according to the nature of the vapours
which they are destined to confine, and the degree of heat which they
are to be exposed to.
1. _Lute of linseed meal_, made into a soft plastic dough with water,
and immediately applied pretty thick to junctions of glass, or
stone-ware, makes them perfectly tight, hardens speedily, resists acid
and ammoniacal vapours, as also a moderate degree of heat. It becomes
stronger when the meal is kneaded with milk, lime-water, or solution of
glue.
2. Lute of thick gum-water, kneaded with clay, and iron filings, serves
well for permanent junctions, as it becomes extremely solid.
3. By softening in water a piece of thick brown paper, kneading it first
with rye-flour paste, and then with some potter’s clay, till it acquire
the proper consistence, a lute is formed which does not readily crack or
scale off.
4. Lute, consisting of a strong solution of glue kneaded into a dough
with new slaked lime, is a powerful cement, and with the addition of
white of egg, forms the _lut d’ane_;--a composition adapted to mend
broken vessels of porcelain and stone-ware.
5. Skim-milk cheese, boiled for some time in water, and then triturated
into paste with fresh-slaked lime, forms also a good lute.
6. Calcined gypsum, diffused through milk, solution of glue or starch,
is a valuable lute, in many cases.
7. A lute made with linseed, melted caoutchouc, and pipe-clay,
incorporated into a smooth dough, may be kept long soft when covered in
a cellar, and serves admirably to confine acid vapours. As it does not
harden, it may therefore be applied and taken off as often as we please.
8. Caoutchouc itself, after being melted in a spoon, may be
advantageously used for securing joints against chlorine and acid
vapours, in emergencies when nothing else would be effectual. It bears
the heat at which sulphuric acid boils.
9. The best lute for joining crucibles inverted into each other, is a
dough made with a mixture of fresh fire-clay, and ground fire-bricks,
worked with water. That cement if made with solution of borax answers
still better, upon some occasions, as it becomes a compact vitreous mass
in the fire. See CEMENTS.
LUTEOLINE, is a yellow colouring matter discovered by Chevreul in weld.
When sublimed, it crystallizes in needles.
LYCOPODIUM CLAVATUM. The seeds of the lycopodium ripen in September.
They are employed, on account of their great combustibility, in
theatres, to imitate the sudden flash of lightning, by throwing a
quantity of them from a powder puff, or bellows, across the flame of a
candle.
LYDIAN STONE, is flint-slate.