1. Qualities from good to super-excellent may be made from any of the
preceding formulæ, by simply omitting the final dilution with the vinegar,
sour beer, or water, therein ordered at the end of the process.
2. (Bryant and James's INDIA-RUBBER PASTE BLACKING.--Patent dated 1836.)
Of india-rubber oil, ivory black, treacle, and gum-arabic, the same as for
their liquid blacking (see I, 4, _above_), but dissolving the last in only
12 _lbs._ (say 5 quarts), instead of 20 galls. of vinegar; grinding to a
smooth paste in a colour-mill, and then adding of oil of vitriol, 12 lbs.
as before. The mass is to be stirred daily for a week, when it will be fit
for use, or potting.[196] Excellent.
[Footnote 196: The final addition of the 3 _lbs._ of powdered gum, ordered
in the formula of their liquid blacking, is not mentioned by the
patentees; and we therefore presume they do not intend it to be made. If
made, it should be at the end of the week, and the daily stirring must
then be continued for another week. This addition, or omission, enables us
to produce two qualities from the same formula.]
3. Ivory-black, 1 cwt.; treacle, 28 lbs.; rape oil (or other cheap oil), 1
gall.; mix, as before; then add of oil of vitriol, 21 _lbs._; (diluted
with) water, 2 _galls._; mix them quickly and thoroughly by forcible
stirring with a strong wooden spatula, and as soon as admixture is
complete, but whilst still fuming, put the cover on the tub, and leave it
till the next day, when (without further stirring) it will be fit for use
or sale.[197] Good ordinary. Used for packets and tins.
[Footnote 197: The object here is to make the product as spongy and light
as possible, so that the purchaser may fancy he has a great deal for his
money.]
4. As the last; but adding with the ivory-black, &c., 14 to 28 _lbs._ of
coal-soot[198] (sifted), omitting one half of the oil, and diluting the
vitriol with an extra gall. of water. Inferior. Chiefly used for 1_d._ and
1/2_d._ packets.[199]
[Footnote 198: This is also to give bulk.]
[Footnote 199: A still more common article is vended in the north of
England, and in Scotland, in which the oil is omitted altogether. The sale
of such blackings (?) is disreputable, when it is remembered that a really
good article may be made for 2_d._ to 2-1/2_d._ per _lb._]
5. (GERMAN BLACKING). Ivory-black, 1 part; treacle, 1/2 part; sweet oil,
1/8 part; mix, as before; then stir in a mixture of hydrochloric acid, 1/8
part; oil of vitriol, 1/4 part (each separately diluted with twice its
weight of water before mixing them). This forms the ordinary
paste-blacking of Germany, according to Liebig.
6. (_Without Vitriol._) As I, 5 (_antè_); but with the omission of the
last 1/2 gall. of 'vinegar.'
_Concluding Remarks._--To produce a first-rate article of blacking it is
absolutely necessary that the ingredients be of the best quality, and used
in the proper proportions; and that the order of their admixture, and the
general manipulations, be conducted under ordinary circumstances, in the
manner described in the first of the above formulæ. The proportions of the
treacle and the oil (the most expensive of the ingredients) should not be
stinted; and, indeed, that of the latter may be safely increased in
quantity, without materially affecting the polish, and with manifest
advantage as far as the softness and durability of the leather to which it
is applied is concerned. The manipulations required in the manufacture of
both paste-blacking and liquid blacking are essentially the same; the
difference between the two articles, when the same materials are used,
depending entirely on the quantity of liquid added. Thus, as noticed
before, by diluting paste-blacking with water, vinegar, or beer-bottoms,
it may be converted into liquid blacking of a nearly similar quality; and,
by using less fluid matter, the ingredients of liquid blacking will
produce paste blacking. One thing must, however, be observed, and that is,
that the ivory-black used for liquid blacking should be reduced to a much
finer powder than for paste blacking; as, if this is not attended to, it
is apt to settle at the bottom, and to be with difficulty again diffused
through the liquid. Persons who object to the use of blacking containing
oil of vitriol may employ formula I, 5, or II, 6 (_above_). The vitriol,
however, greatly contributes to promote the shining properties of the
blacking; and, in small quantities, or in the proper proportion, is not so
injurious to the leather as some persons have represented; as it wholly
unites itself to the lime of the bone-phosphate contained in the
ivory-black, and is thus neutralised, insoluble sulphate of lime, and an
acid phosphate or superphosphate, being formed. It is the latter that
gives the acidity to a well-made sample of blacking, and not the sulphuric
acid originally added to it. In this way the larger portion of the
ivory-black is reduced to a state of extremely minute division, and with
the other ingredients forms a strongly adhesive paste, which clings to the
surface of the leather, and is susceptible of receiving a high polish by
friction when in a scarcely dry state. This is the reason why lamp-black
should never be employed for blacking to the exclusion of the necessary
proportion of bone-black, as it has no earthy base to absorb or neutralise
the acid, which, if left in a free state, would prove very hurtful to the
leather. Oil of vitriol is now employed in the manufacture of all the more
celebrated and expensive blackings; and that simply because no other
substance is known so efficient, and so little injurious to the leather.
In the common blackings of Germany, hydrochloric acid is often used to the
entire exclusion of oil of vitriol; but blacking so prepared possesses
several disadvantages from which that of England is free. In the best
German blackings only a small portion of this acid is used, as may be seen
by reference to formula II, 5 (_above_). The addition of white-of-egg,
isinglass, and similar articles[200] to blacking, always proves injurious,
as they tend to stiffen the leather and to make it crack, without at all
improving its polishing properties. Even gum-arabic, in quantity, is on
this account objectionable. Oil has an opposite tendency, and, as already
stated, the quantity commonly used may be increased with advantage. Resin
oil should be particularly avoided.
[Footnote 200: In Scotland, flour-paste soured by keeping is often
substituted for part of the treacle in the common blackings; with the
effect, however, of greatly impairing their polishing qualities, and
causing the leather to rapidly become stiff and to crack. Further, such
blacking will not keep, often growing mouldy and hard in two or three
weeks.]
Dr Ure has recommended the use of a little copperas[201] in blacking; with
the object, we presume, of striking a black with the tan in the leather;
but except with new, or nearly new leather, this effect would not occur,
whilst its presence, if not objectionable, would otherwise be useless.
[Footnote 201: The proportion recommended by Dr Ure is 1/4 _oz._ to each
_lb._ of bone-black, dissolved in 10 parts of water, and to be added with
the vitriol.]
The only improvement that has been introduced in the manufacture of
blacking since the early days of the celebrated Day & Martin is, a few
hours after the conclusion of the mixture of the ingredients (but before
adding the vinegar, if any), to simmer the whole very gently, for about 8
or 10 minutes, observing to stir it assiduously all the time. The fire
must then be withdrawn, and the pan covered over until it is quite cold,
when half an hour's lusty stirring will finish the process.[202] In this
way a degree of maturity and brilliancy will be imparted to the product,
which, without the application of heat, it would take months to acquire,
if, indeed, it ever reached it.
[Footnote 202: A capacious enamelled cast-iron boiler, with a concave
bottom, should be used for this purpose; in which case the ingredients can
be mixed in it, and thus the trouble of removal avoided. If a common
copper or cast-iron boiler be employed, the blacking must not be allowed
to remain in it longer than necessary to give it the 'simmer,' at the
conclusion of which it should be turned out into a wooden tub or vat to
cool.]
As it is generally more convenient to measure than to weigh liquids, it
may be useful to remind the reader that, in round numbers,
1 gal. of oil weighs 9-1/4 _lbs._
1 " sour beer " 10-1/4 "
1 " vinegar } " 10 "
1 " water }
We may here further remark that the blackings of different houses vary
considerably in some of their properties; as also do those of even the
same maker by age. Some blackings dry off rapidly and give a very
brilliant polish with very little labour; whilst others take a little
longer to 'dry off,' and somewhat more labour to polish them. The former
are best adapted to hasty use, and when a very brilliant surface is
desired; the latter when depth of polish, without extreme brilliancy,
satisfies the wearer. The first best meets the requirements of fashionable
life; the last those of the middle classes and pedestrians exposed to
dirt, mud, and the various vicissitudes of travelling and weather. To the
one belong the 'blackings' of Everett, Day & Martin, &c.; to the other,
those of Warren, Bryant & James, and most of the smaller manufacturers,
with nearly all the paste-blacking of the more respectable shops. Time,
however, equalises the qualities of these two classes. Blackings which are
crude, moist, and oily lose these properties, and become drier and more
brilliant by age. The practice of several of the first-class West-end boot
and shoe makers is never to use a blacking which they have not had in
their stock at least a twelvemonth.
Blacking, both liquid and paste, should be stored in a cool and moderately
dry cellar; and when in use should be kept corked or otherwise excluded
from the air. Exposure or desiccation destroys most of its best qualities.
The present annual value of the blacking consumed in the United Kingdom is
estimated at 562,500_l._, or about 4-1/2_d._ per head for the whole
population; while the collective yearly value of that exported is about
35,000_l._
[See BALLS, BLACKING, BONE-BLACK, BOOTS AND SHOES, LEATHER, SULPHURIC
ACID, &c.; also _below_.]
=Blacking, Automat'ic.= _Syn._ SELF-SHI''NING BLACKING, SPAN'ISH JAPAN,
&c. _Prep._ 1. Gum-arabic, 4 _oz._; treacle or coarse moist sugar,
1-1/2_oz._; good black ink, 1/4 pint; strong vinegar, 2 _oz._; rectified
spirit of wine and sweet oil, of each 1 _oz._; dissolve the gum in the
ink, add the oil, and rub them in a mortar or shake them together for some
time, until they are thoroughly united; then add the vinegar, and lastly
the spirit.
2. Lamp-black, 3/4 _oz._; indigo (in fine powder), 1 _dr._; put them in a
mortar, or basin, and rub them with sufficient mucilage (made by
dissolving 4 _oz._ of gum in 1/4 pint of strong vinegar) to form a thin
paste; add very gradually of sweet oil, 1 _oz._; and triturate until their
union is complete, adding toward the end the rest of the mucilage; then
further add of treacle, 1-1/2 _oz._; and afterwards, successively, of
strong vinegar, 2 _oz._; rectified spirit, 1 _oz._; lastly, bottle for
use.
3. Mix the whites of 2 eggs with a table-spoonful of spirit of wine, 2
large lumps of sugar (crushed), and sufficient finely powdered ivory-black
to give the required colour and thickness, avoiding excess.
_Obs._ The above are chiefly used for dress boots and shoes. The first two
are applied to the leather with the tip of the finger, or a sponge, and
then allowed to dry out of the dust. The third is commonly laid on with a
sponge or soft brush, and when almost dry or hard may have its polish
heightened with a brush or soft rubber, after which it is left for a few
hours to harden. It may also be used to revive the faded black leather
seats and backs of old chairs. They all possess great brilliancy for a
time; but are only adapted to clean, dry weather, or indoor use. They
should all be applied to the leather as thinly as possible, as otherwise
they soon crack off.
=Blacking, Har'ness.= Good glue or gelatine, 4 _oz._; gum-arabic, 3 _oz._;
water, 3/4 pint; dissolve by heat; add of treacle, 6 _oz._; ivory-black
(in very fine powder), 5 _oz._; and gently evaporate, with constant
trituration, until of a proper consistence when cold; when nearly cold put
it into bottles, and cork them down. For use, the bottle may be warmed a
little to thin it, if necessary. Does not resist the wet.
2. Mutton suet, 2 _oz._; bees-wax (pure), 6 _oz._; melt, add of sugar
candy (in fine powder), 6 _oz._; soft soap, 2 _oz._; lamp-black, 2-1/2
_oz._; indigo (in fine powder), 1/2 _oz._; when thoroughly incorporated,
further add of oil of turpentine, 1/4 pint; and pour it into pots or tins.
3. Bees'-wax, 1 _lb._; soft soap, 6 _oz._; ivory-black, 1/4 _lb._;
Prussian blue, 1 _oz._; (ground in) linseed oil, 2 _oz._; oil of
turpentine, 1/2 pint; to be mixed, &c., as before.
_Obs._ The above are used by laying a very little of them on the leather,
evenly spreading it over the surface, and then polishing it by gentle
friction with a brush, or a soft-rubber. The last two are waterproof.
Numerous compositions of the class are vended by the saddlers and oilmen,
but the mass of them are unchemical mixtures, badly prepared, and cause
disappointment to those who use them. Such is not the case with the
products of the above formulæ, if we may rely on the statements of those
who have employed them for years. The last two are suitable for both
harness and carriage leather. See BALLS, HEEL, &c.
=BLADD'ER.= _Syn._ VES'ICA, L.; VESSIE, Fr.; BLASE, BLATTER, Ger. In
_anatomy_, &c., a thin membranous sac or bag, in an animal, serving as a
receptacle for some secreted fluid; appr., the urinary bladder. See
CALCULUS, INFLAMMATION, RUPTURE, &c.
=Bladd'ers.= (In _commerce_.) The better qualities of these articles are
prepared by cutting off the fat and loose membranes attached to them, and
washing them first in a weak solution of chloride of lime, and afterwards
in clear water; they are then blown out and submitted to strong pressure
by rolling them under the arm, by which they become considerably larger;
they are next blown quite tight, dried, and tied up in dozens. Commoner
qualities are merely emptied, the loose fat removed, and then blown out,
and strung up to dry. Used chiefly by druggists and oilmen to tie over
pots, bottles, and jars, and to contain pill-masses, hard extracts, and
other similar substances; also in surgery, to cover wounds, sore heads,
&c.--_Obs._ Bladders should never be purchased unless perfectly dry and
air-tight; as, if the reverse be the case, they will neither keep nor
prove useful, but will rapidly become rotten and evolve a most offensive
odour. If purchased whilst damp, they should be at once hung up in a
current of air, so as to dry as soon as possible.
=BLAIN*= (bl[=a]ne). A boil; a sore; a pustule.
=BLANC= (bl[)o]ng). [Fr.] In _cookery_, a dish which, according to Mrs
Rundell, is formed of grated bacon and suet, of each 1 _lb._; butter, 1/2
_lb._; 2 lemons; 3 or 4 carrots (cut into dice); 3 or 4 onions; and a
little water; the whole being simmered for a short time, with or without
the addition of a glass of sherry or marsala, before serving.
=BLANCH'ING.= _Syn._ CANDICA'TIO, DEALBA'TIO, &c., L.; BLANCHIMENT, &c.,
Fr.; BLEICHEN, &c., Ger. A whitening, or making white; a growing white. In
some cases it means decortication. See ALMONDS, BLEACHING, DECOLORATION,
&c.
=Blanching.= In _cookery_, an operation intended to impart whiteness,
plumpness, and softness, to joints of meats, poultry, tongues, palates,
&c. It is usually performed by putting the articles into cold water, which
is then gradually raised to the boiling point, when they are at once taken
out, plunged into cold water, and left there until quite cold. They are
subsequently removed and wiped dry, ready for being dressed.
_Obs._ The operation of blanching meat, although it renders it more
sightly according to the notions of fashionable life, at the same time
lessens its nutritive qualities, by abstracting a portion of the soluble
saline matter which it contains, especially the phosphates, and thus
deprives it of one of the principal features which distinguish fresh meat
from salted meat. Animal food, before being dressed, may be washed or
rinsed in cold water without injury, provided it be quickly done; but it
cannot be soaked in water at any temperature much below the boiling-point
without the surface, and the parts near it, being rendered less
nutritious. Washing meat when first received from the butcher is, indeed,
a necessary act of cleanliness; but soaking it for some time in water is
unnecessary, and for the reasons stated should be avoided.
Strong acetic acid (concentrated vinegar) poured on or rubbed over hard
lean meat gradually renders it soft and gelatinous. Ordinary household
vinegar has the same effect, but in a less degree. Tough meat thus treated
for a short time before dressing it becomes more tender and digestible,
though somewhat less nutritious; whilst the taste and flavour of the
vinegar is removed by the heat subsequently employed in dressing it.
=BLANCMANGE'.= (blo-m[)o]n_g_zh'[double-dagger].) _Syn._ BLANCMANGER
(bl[)o]n_g_-m[)o]n_g_-zh[=a]), Fr. _Literally_, white food; in _cookery_,
a confected white jelly. It is commonly prepared by simmering 1 _oz._ of
isinglass, 2 or 3 _oz._ of lump sugar, and a little flavouring,[203] in
about a pint of milk, until the first is dissolved, when the whole is
thrown into a jelly-bag, and the strained liquor is allowed to cool and
solidify; it is next remelted by a gentle heat, and, when nearly cold,
poured into moulds, which have been previously rubbed with a little salad
oil and then wiped out again.
[Footnote 203: This may be 5 or 6 bitter almonds (grated), or a little
cinnamon, orange, or lemon peel, &c., at will. Sometimes these are
omitted, and a little orange-flower water, rose-water, or essence of
vanilla, added to the remelted jelly.]
_Obs._ Good gelatine, or strong calves' feet jelly, is often substituted
for the isinglass. At other times the jelly is made with about 1/2 pint of
water (instead of milk), when 1/2 pint of almond-milk, or of cream, is
added to the remelted jelly. Sometimes ground rice or arrow-root is
employed in lieu of isinglass, when the product is called RICE-BLANCMANGE,
or WEST-INDIAN B., as the case may be. TRANSPA''RENT BLANCMANGE[204] is
merely clarified isinglass-jelly, flavoured. See CREAM (Stone), ISINGLASS,
and JELLY.
[Footnote 204: A misnomer of the confectioners and cooks.]
=BLANQUETTE'= (blan_g_-ket'). [Fr.] In _cookery_, a species of white
fricasee. It is also the name of a delicate species of white wine, and of
a particular sort of pear.
=BLAST'ING.= In _civil_ and _military engineering_, the disruption of
rocks, &c., by the explosion of gunpowder, or other like material.
=BLAST'ING POWDERS= (Melville and Callow's). _Prep._ 1. (POWDER NO. 1.)
Chlorate of potassa, 2 parts; red sulphuret of arsenic, 1 part; to be
separately carefully reduced to powder, and lightly mixed together,
scrupulously avoiding the use of iron instruments, percussion, much
friction, the slightest contact with acids, or exposure to heat.
2. (POWDER NO. 2.) Chlorate of potassa, 5 parts; red sulphuret of arsenic,
2 parts; ferrocyanide of potassium (prussiate of potash), 1 part; as No.
1.
3. (POWDER NO. 3.) Chlorate of potassa and ferrocyanide of potassium,
equal parts.
_Obs._ These compounds are not permanently injured by either salt or fresh
water, merely requiring to be dried to regain their explosive character.
They possess fully eight times the force of ordinary powder. One of their
advantages, especially to the underground miner, is the very trifling
amount of smoke produced by their explosion. On the other hand, the
extreme facility with which they explode by attrition, contact with a
strong acid, and a slight elevation of temperature, render them unsuited
to most of the purposes of ordinary gunpowder. On this account they should
only be prepared in small quantities at a time, and with the utmost
caution. Mr Callow, the inventor of them, lost several of his fingers, and
was rendered a cripple for life, by an explosion of the kind referred to,
which occurred only a few weeks after the sealing of his patent. A straw,
or small strip of wood, only slightly wetted with oil of vitriol, and
applied to a small heap of the powder, produces instantaneous explosion.
Captain Wynand's 'Saxifragine' is composed of nitrate of baryta, 76 parts;
charcoal, 22 parts; and nitre, 2 parts. Schultze's wood-gunpowder is
composed of granulated wood treated with a mixture of nitric and sulphuric
acid, afterwards impregnated with a solution of nitre. M. Bäudish has
invented a method by which this wood-gunpowder may be compressed into a
solid substance, exerting great power and free from danger by transport.
Lithofracteur, a white blasting powder used in Belgium, is a substance
similar to gun-cotton.
Messrs Nenmayer and Fehleisen's haloxylin is composed of charcoal, nitre,
and yellow prussiate of potash. See GUN-COTTON, GUNPOWDER, MINING, &c.
=BLATTA ORIENTALIS.= The common cockroach, originally imported from the
East, belongs to the family of orthopterous insects; and may be classed
amongst the most offensive and objectionable of domestic pests. It is
extremely voracious, not only devouring all kinds of provisions, but
attacking and consequently destroying silk, flannel, and even cotton
fabrics, in the absence of anything more eatable. The cockroach is
nocturnal in its habits, and exceedingly active and swift of movement. Its
flattened form enables it to insinuate itself easily into crevices, and so
to escape detection. The American cockroach (_Blatta Americana_) is larger
than the above. A still larger species (_Blatta gigantea_) is found in the
West Indies where it is known by the name of the drummer. It is so called
from the tapping noise it makes on wood, the sound so produced, when
joined in by several of the creatures (as it usually is) being sufficient
to destroy the slumbers of a household.
Cockroaches may be poisoned by means of wafers made of red lead, or caught
by smearing a piece of wood with treacle, and floating it on a broad basin
of water. When the fires and lights are extinguished they issue from their
holes, and fall into the basin in their efforts to reach the bait. The
chinks and holes from which they come should also be filled up with
unslaked lime, and some lime should also be sprinkled about the ground.
Old Gerrard says they avoid any place in which the leaves of the mullein
are strewn about.
The _Blatta Orientalis_, which was formerly supposed to possess remedial
powers, and was hence employed in medicine by the more ancient
therapeutists, has lately found advocates for his readmission into the
animal materia medica. He is reported, when made into a tincture, to act
as a diuretic, and to yield a crystalline body possessed of similar
properties, but in a more concentrated form. Some of the American journals
report that he may be given in the form of powder or infusion (from 15 to
30 gr.) 3 or 4 times a day, in dropsy, and to increase the secretion of
urine as well as of perspiration.
=BLEACH'ING=, (bl[=e]che'-). _Syn._ DEÄLBA'TIO (-sh'o), INSOLA'TIO,[205]
&c., L.; BLANCHIMENT, BLANCHISSAGE, Fr.; BLEICHEN, Ger. The process by
which the colour of bodies, natural or acquired, is removed, and by which
they are rendered white or colourless. It is more particularly applied to
the decolorisation of textile filaments, and of cloths made of them.
[Footnote 205: Bleaching by exposure in the sun.]
_Hist._ Bleaching is a very ancient art, as passages referring to it in
the earlier sacred and profane writers fully testify. It had probably
reached a high degree of excellence among the inhabitants of the first
Assyrian empire, and was certainly practised in Egypt long before the
commencement of written history. We may fairly assume that fine white
linen formed part of the "raiment," which, together with "jewels of gold,
and jewels of silver," and "precious things," Abraham sent as presents to
the beautiful Rebekah and her family,[206] fully three centuries and a
half before the Exodus. Subsequently, in Scripture, we have special
mention of "fine linen, white and clean." Herodotus, the earliest Greek
historian, tells us, that the Babylonians wore "white cloaks;"[207] and in
Athenæus we read of "shining fine linen," as opposed to that which was
"raw" or unbleached.[208] At this early period, and for many centuries
afterwards, the operations of washing, fulling, and bleaching were not
distinctly separated. The common system of washing followed by drying in
the sun, adopted by the ancients, is a process which of itself, by
frequent repetition, decolorises the raw materials of textile fabrics, and
thus must inevitably have taught them the art of 'natural bleaching' of a
character similar to that practised in Europe up to a comparatively very
recent period. And this appears, according to the authority of ancient
authors, to have been the case. Washing or steeping in alkaline and
ammoniacal lyes, or in milk of lime, followed by exposure in the sun,
formed the chief basis of their system; whilst woollens, then as now, were
treated with soap and fuller's earth, or with potter's clay, marl,
Cimolian earth, or other like mineral. Urine was highly esteemed among
them; and we are told that in the time of the emperor Vespasian,[209] and
undoubtedly long before it, cloths were sulphured. Indeed, according to
Pliny, sulphuring was often had recourse to in ordinary washing, as well
as in the bleaching process.[210]
[Footnote 206: Gen. xxiv, 53; B.C. 1857.]
[Footnote 207: Herod., i, 195.]
[Footnote 208: Athen., ix, 77.]
[Footnote 209: 'Hist. Nat.,' xxv, 57, &c.]
[Footnote 210: {Transcriber's note: Footnote omitted by publisher.}]
Bleaching continued to be practised with no essential change of its
principles until the discovery of chlorine, to which we shall presently
refer. In the last century Holland obtained the best name for bleaching.
The process passed then to Ireland and Scotland, and thence into England.
It was even customary to send goods from this country to be bleached in
Holland. The first attempt to vie with Holland was made, in Scotland, in
1749.
The first steps towards the modern or chemical system of bleaching were
the investigations of Berthollet on chlorine, in 1784, but which were not
communicated to the French Academy until the year 1787. The knowledge of
the use of chlorine as a bleacher was soon afterwards brought to this
country by the Duke of Gordon, and by Prof. Copeland of Aberdeen, and
through them was practically applied by Messrs Milnes of that place. About
the same time James Watt, a correspondent of Berthollet, successfully
introduced its use in the neighbourhood of Glasgow, and then generously
laid a statement of the results before the Manchester manufacturers. In
enforcing the importance of the new substance and process on these
gentlemen, he was ably followed and seconded by Dr Henry. In 1798, Mr
Charles Tennant, of Glasgow, obtained a patent for a new bleaching liquor
prepared by saturating lime water with chlorine; and another, in 1799, for
dry chloride of lime, a substance which is still preferred as a bleacher
to all other preparations of chlorine. The new or continuous process of
bleaching, as it is called, and that which is at present in general use in
all the chief bleach-works of Lancashire, was introduced by Mr David
Bentley, of Pendleton, and patented by him in 1828.
_Proc._ Bleaching is commonly said to be natural when exposure to light,
air, and moisture forms the leading part of the process; and to be
chemical when chlorine, chloride of lime, sulphurous acid, or other like
substances are employed. In some cases, as with linen, the two processes
are combined. The subject requires to be noticed under separate heads,
depending on the material operated on:--
I. BLEACHING of =Cotton=:--Cotton is more easily bleached, and appears to
suffer less from the process than most other textile substances. On the
old plan it was first (1) thoroughly washed in warm water, to remove the
weaver's paste or dressing; then (2) 'bucked' or 'bowked' (boiled) in a
weak alkaline lye, or in milk of lime, to remove colouring, fatty, and
resinous matters, insoluble in simple water; and after being (3) again
well washed, was (4) spread out upon the grass, or bleaching ground, and
freely exposed to the joint action of light, air, and moisture
(technically called 'crofting'). The operation of 'bucking' in an alkaline
lye, washing, and exposure was repeated as often as necessary, when the
goods were (5) 'soured' or immersed in water acidulated with sulphuric
acid, after which they (6) received a final thorough washing in clean
water, and were (7) dried, finished, and folded for the market. From the
length of the exposure upon the bleaching ground this method is apt to
injure the texture of the cloth; and from the number of operations
required is necessarily expensive and tedious. It is therefore now very
generally superseded by the system of chemical bleaching briefly described
below.
In the CHEMICAL SYSTEM of bleaching the goods are 'washed' and 'bucked' as
on the old plan, then submitted to the action of a weak solution of
chloride of lime, and afterwards passed through water soured with
hydrochloric or sulphuric acid, when they have only to be thoroughly
washed, and to be dried and finished, for the entire completion of the
process.
The new or continuous process, before referred to,[211] is the method of
chemical bleaching at present in the most general use; and, indeed, it has
nearly superseded all other methods. In this system the pieces, previously
tacked together endwise so as to form a chain, are drawn, by the motion of
rollers, in any direction, and any number of times, through every solution
to the action of which it is desired to expose them, and this entirely and
completely under the control of the operator.
[Footnote 211: See 'Hist.' (_antè_).]
The following _Table_ exhibits an outline of the several operations in the
improved form of the continuous process as practised by Messrs McNaughten,
Barton, and Thom, at Chorley, and in most other large bleach-works:--
1. Preliminary operations:--_a_. The 'pieces'[212] are separately stamped
with the printer's name, a solution of silver, or sometimes coal-tar,
being employed for the purpose.
[Footnote 212: Usually about 30 yards each.]
_b._ They are tacked together endwise either by hand or a machine, so as
to form one continuous piece of 300 to 350 yards in length, according to
the weight of the cloth.
_c._ They are singed.[213]
[Footnote 213: Generally on one side only; but for goods to be
subsequently finely printed, on both sides. For very fine printing the nap
is sometimes removed by shearing instead of 'singeing,' an ingenious and
effective machine being employed for the purpose.]
_d._ They are crushed into a rope-like form by drawing them through a
smooth aperture,[214] the surface of which is generally of glass or
porcelain--the rope-form being given them to enable the water and other
liquids to penetrate the goods more easily, and to allow them to be laid
in loose coils in the kiers.
[Footnote 214: Such apertures are also used instead of pulleys, in the
transfer of the rope from place to place.]
2. The pieces are bucked or boiled in milk of lime[215] for 12 to 14
hours,[216] followed by rinsing or cleansing in the washing-machine.
[Footnote 215: The common proportions are about 1 lb. of quick-lime slaked
and reduced to milk, with 2 galls. of water, for every 14 or 15 lbs. of
cloth.]
[Footnote 216: This is done in a large iron boiler furnished with a
perforated false bottom of wood, and technically termed a 'kier.']
3. They are soured in water acidulated with hydrochloric acid,[217] and
again washed; similar machines being employed for each.
[Footnote 217: This dilute acid or acidulated water has usually the sp.
gr. 1·010 or 2° Twaddle.]
4. They are bucked or boiled for 15 or 16 hours in a solution of resinate
of soda,[218] and then washed as before.
[Footnote 218: Made with about 17 _lbs._ of soda-ash and 3 _lbs._ of
resin, with water, 50 galls., to every 20 or 21 _lbs._ of cloth.]
5. They are chemicked by being laid in a wooden, stone, or slate cistern,
when a solution of chloride of lime[219] is pumped over them, so as to run
through the 'goods' into a vessel below, from which it is returned on them
by continued pumping, so that the cloth lies in it for 1 or 2 hours; it is
then washed.
[Footnote 219: Technically called 'chemick.' The strength of the solution
is usually of the sp. gr. 1·0025, or 1/2° Twaddle.]
6. They are bucked or boiled, for 4 or 5 hours, in a solution of 1 _lb._
of crystallised carbonate of soda, dissolved in 5 galls. of water, to
every 35 _lbs._ of cloth; and washed.