BLASTING-BLAYE.

BLAZON-BLEACHING.

rocky eminence crowned with a strong citadel. The was necessarily tedious and occupied much valuable town is further defended by the two forts of Paté land, and for this reason a large quantity of the and Médoc, which command the passage of the river. The port of B. is a very busy one, all inward vessels being required to anchor and deliver the manifests of their cargoes; and many outwardbound vessels lay in their provisions here. B. has manufactures of linen and woollen, glass and earthenware; a considerable export-trade in corn, wine, brandy, oil, fruits, soap, &c., and tribunals of jurisdiction and of commerce. Pop., exclusive of garrison (1876), 3801.

on the shield.

cloth required to be bleached was sent to Holland for that purpose. A particular kind of linen, which was regularly sent to Holland, received on that account the name of Hollands; and another variety of linen, which, from its fineness, was generally spread on the better grass-fields or lawns, received the title of lawn. An improvement in the preceding process was to dip the cloth occasionally in a weak alkaline lye, or solution of an alkali, such as soda in water, which step was called bucking; after BLA'ZON, BLA'ZONRY (Ger. Blasen, to blow, which, the cloth was spread out on the grass for as with a horn). These heraldic terms originated this stage being styled crofting; the cloth was then some weeks, and regularly moistened with water, in the custom of blowing a trumpet to announce the arrival of a knight, or his entrance into the soaked in sour milk and water, which was called souring, and again exposed on grass to the action of lists at a joust or tournament. The blast was answered by the heralds, who described aloud and air and sun-light. By repeating the bucking, croftexplained the arms borne by the knight. B. and ing, and souring operations several times, the bleachB. thus came to signify the art of describing, ing was very much hastened, and the amount of technical terms, the objects (or charges, as they next improvement was the introduction of dilute land occupied in bleaching-greens lessened. The are called) borne in arms-their position, gestures, tinctures, &c., and the manner of arranging them sulphuric acid instead of sour milk, as the souring agent; and this was so effectual, that it lessened the time required for B. from about eight months, Rules of Blazoning.—As heraldry, though an entirely arbitrary, is a very accurate science, the which was the original time, to about four mouths. rules of blazoning are observed on all occasions with in this natural mode of B. was entirely resident in Till very recently, it was thought that the agent the most rigid precision. The following are the the sun's rays, but the discovery of the substance most important: 1. In blazoning or describing called Ozone (q. v.), which possesses very powerful a coat of arms, it is necessary to begin with the B. properties, and which in greater or less quantity field, mentioning the lines by which it is divided-exists in the air of country districts at all times, has per pale, per fess, &c., if such there be-and noticing led to the opinion, now held by chemists, that the if they are indented, engrailed, or the like, it being B. which takes place when cloth is moistened and taken for granted that they are straight, unless the contrary be mentioned. 2. There must be no unnecessary repetition in blazoning; thus, where the field is blue, and the charges yellow, we should say, azure, a crescent between three stars, or, thereby implying that both the crescent and the stars are or. 3. For the same reason, where a colour has been already mentioned, and it is necessary, in order to avoid ambiguity, to repeat it in describing a subsequent charge, we say, of the first, or of the second, as the case may be. Thus, we should say, azure, on a saltire argent, three water bougets of the first, thus avoiding the repetition of the word azure. 4. Again, recurring to our first example, it would be an error to say, three stars with a crescent employed, and being diffused in the atmosphere of between them, because we must always begin with the charge which lies nearest the centre of the shield. 5. Where the charges are of the natural colour of the objects or animals represented, in place of describing the colour, you simply say proper -i. e., of the proper or natural colour. 6. Another general rule in blazoning, or rather in marshalling coat-armour, is, that metal shall never be placed upon metal, nor colour upon colour.

The rules for blazoning separate charges, whether animate or inanimate, are indicated in the descriptions which will be found of them under their respective heads. See ORDINARIES; also BAR, BEND, &c.

BLEACHING (Ang.-Sax. blæcan, from blæc, pale, bleak) is generally understood to mean the process of whitening or decolorising cloth; but the term is also applied to the decolorising of such substances as the fixed oils, Irish moss, &c. Until about the close of the 18th c., B. depended upon the natural bleaching agencies present in the atmosphere and in the sun's rays. The usual plan was to spread out the cloth on a grass field, called a bleachinggreen, and to continue sprinkling it with water several times a day. After being thus exposed for several months to the action of air, light, and moisture, the cloth was rendered white. The process

exposed to the air is mainly due to the ozone present therein; though the chemical rays which in the B., and also aid in the formation of the ozone. accompany the luminous rays of the sun may assist That the ozone has very much to do in open-air B., is observable from the fact that in town districts, where little or no ozone exists in the air, cloth is

never bleached white.

French chemist, discovered the powerful B. pro-
In the year 1785, Berthollet, a distinguished
Perties of Chlorine (q. v.), and immediately there-
in the B. of cloth. At the first, the gas chlorine was

after it was suggested that chlorine would be useful

But

a vessel or small apartment, cloth hung therein was speedily bleached. It was found, however, that the chlorine, which bleaches, or destroys colour by uniting with the hydrogen of the colouring principle with the hydrogen of the fibre (see LIGNIN) and and thus decomposing the colour, could also unite destroy or render tender the textile fabric. So long as chlorine was employed in the gaseous state, it was very difficult to use it of such strength as only to destroy the colour, without also rotting the soluble in water, to the extent of two volumes of cloth. It was then suggested, that as chlorine was chlorine gas in one volume of cold water, the solution of chlorine might be employed. although chlorine water was found to act efficiently and safely when the solution was of the proper strength, it was very difficult always to make it of the same strength, and more so to preserve it when made; as the least exposure to light causes more or less of the chlorine to unite with the hydrogen of the water, forming hydrochloric acid, which does not possess B. properties. After attempts to fix the chlorine in alkaline solutions, it was found that dry slaked lime was an admirable absorber of chlorine gas. The material produced from the union of chlorine with dry slaked lime is known as the chloride of lime, or Bleaching powder (q. v.), and this is the substance which has continued from 1799 up

BLEACHING.

to the present time to be the great artificial bleacher of cotton and linen fabrics. It is not serviceable in the destruction of the colour of wool, silk, or the oils and fats; such materials being bleached by the employment of other agents, as will be afterwards noticed.

the condition best suited for the subsequent operations. The fifth stage is chemicking with B. liquor, obtained by dissolving B. powder (q. v.) in water, and allowing the impurities or insoluble matter to subside. The B. liquor is much diluted with water, and the cloth is steeped in it for about six hours, then taken out, and allowed to soak for other six hours in a second vat containing water, after which it is drawn out and exposed to the atmosphere, when the carbonic acid of the air sets free a portion of the chlorine from the B. powder, imbibed by the cloth. The sixth stage is another souring process, during which the cloth is immersed for about four hours in a steeping vat, containing dilute sulphuric acid of the strength ranging from 1 to 8 gallons of acid in 200 gallons of water. This acid liquid, as it soaks the cloth, encounters the B. liquid which previously saturated the fibre of the cloth, and the acid combining with the lime of the B. liquid, liberates the chlorine, which attacks the remaining traces of colour, and removes them from the cloth.

more

The cloth, on being removed from the souringvat, is boiled with soda lye, washed, and again treated with dilute sulphuric acid, which effectually removes the decomposed colouring matter. It is thereafter thoroughly washed, passed through rollers to remove some of the water; then introduced into the Hydro-extractor (q. v.), to get rid of the water more effectually; and lastly, the cloth is dried by being suspended in the air, or by being passed over a series of heated tin rollers, called Steam Cans (q. v.). In the ordinary course of B. cotton loses about onetwentieth of its weight, and linen about one-third.

BLEACHING OF COTTON AND LINEN FABRICS. The substances requiring to be got rid of in the purification of cotton and linen cloth, are (1) the organic colouring matter naturally present in the fibre; (2) resinous and fatty bodies, also inherent in the fibre; (3) weavers' dressing and perspiration taken up during the process of spinning; and (4) certain saline or earthy substances. The first stage in the B. is the singeing of the cloth, which is accomplished by drawing the cloth rapidly over a red-hot iron cylinder, or a numerous series of gas jets, which burn off the minute particles of fibre, resembling in appearance short hairs or down, and leave the cloth perfectly smooth. The second stage is the washing or scouring of the cloth, which consists in rolling up the pieces of calico or linen into bundles like coils of rope, and throwing a number of pieces into a large vat among lukewarm water, and allowing them to lie till fermentation begins, and proceeds some length, when the cloth is taken out, and thoroughly washed in the dash-wheels; which are large horizontal cylinders divided into several compartments, into each of which a stream of water keeps running while the wheel is turning. The third stage is boiling with lime-water, or bucking. The apparatus employed is called the Bouking or Bucking Kier, and consists of two compartments. After the B. operations have been successfully The lower part is a boiler containing the lime-water, performed, it is customary to proceed to the finishing and the upper part is a capacious circular tank, into of the cloth, which consists in, firstly, passing it which the cloth in bundles, as it comes from the through a large mangle, where the crumpled piece dash-wheels, is placed. By an ingenious arrangement, of cloth becomes smooth; secondly, drawing the the lime-water is alternately forced up, by the com- cloth over rollers, which cause it to dip in a trough pression of the steam, through a pipe into the upper containing starch; thirdly, drying the starched compartment, and falls in a shower upon the cloth, cloth; and, fourthly, passing it through a large through which it percolates and sinks again through mangle or calender, consisting of a series of rollers, perforations into the boiler, to be again propelled alternately of polished cast iron and solid paper, into the upper compartment. Instead of using lime and which not only smooth out the cloth, but comalone, a mixture of lime and carbonate of soda municate a fine glazed surface, such as is generally (NaOCO,), is occasionally employed, which acts exhibited in bleached cloth when purchased. The by forming the inert carbonate of lime or chalk cloth intended to be printed upon or to be dyed is (CaOCO,), and caustic soda (NaO), which pos- not starched or calendered. The operations consesses high detergent properties. The chemical nected with the B. of cloth by chlorine exert no action which the boiling lye exerts on the cloth injurious effect on the health of men and women is in the formation of a soap with the resinous engaged in them. Some of the bleach-works near and fatty substances naturally inherent in the Glasgow are of long standing, and give regular cotton or linen fibre, or communicated to it in employment to several hundred women. The the process of weaving, the greater portion of rapidity with which the B. by chlorine can be which is detached by the lye in the bucking kier carried on, may be understood from the fact, that and ultimately removed by a subsequent washing when pressed for time, it is no uncommon thing to with water. This takes place either in the dash- bleach, finish, and return to town 1000 pieces of wheels, or in a more effectual washing arrange- cloth within 48 hours. Valuable in many respects, ment, consisting of a series of boxes or vats of however, as is the rapidity of B. by means of chemdifferent depths, placed side by side, into which the ical agents, it must be admitted that the process eloth is made to dip successively by passing over exerts a certain weakening effect on the cloth, and and under two sets of rollers. As the cloth moves that, after all, B. according to the old method on on from the lower vats to the higher, it is passing the grass is preferable. Grass-B. is therefore still from the soiled water to the more pure, as a stream in use where time admits, as also for clearing of pure water is kept constantly running through the vats from the higher to the lower. The fourth stage in B. is the souring or chemicking in dilute sulphuric acid, of the strength of one gallon of the acid to from 25 to 30 gallons of water. The weak acid liquid is put into a large stone vat, and the goods are steeped in it. The acid acts beneficially in removing the remaining traces of the Ene-soap which have adhered to the cloth, and a second washing in water, followed by bucking, or scouring in soda lye, and a third washing in water are generally found necessary to obtain the cloth in

linen and cotton apparel in domestic washing. See WASHING.

BLEACHING OF WOOL is never accomplished by B. powder, but recourse is had to sulphurous acid, which disguises the colour of the wool by combining with it to form a colourless compound. Originally the wool is contaminated with a greasy substance called the yolk, which naturally exudes from the skin of the sheep, and this unctuous matter mainly consists of a kind of soap soluble in water. The first stage in the B. of W. is to get rid of the yolk, which can be done by long-continued washing

BLEACHING-BLEACHING POWDER.

(q. v.) of which hats or bonnets are made; but the details of the processes followed in these and other operations, will be described more properly under their respective headings.

chlorine and dry slaked lime (see BLEACHING), was BLEACHING POWDER, a combination of first manufactured on a large scale in Glasgow by Mr. Charles Tennant, who obtained a patent for its preparation in 1799. The substances employed in preparing the chlorine are common salt (chloride of acid. The operation may be conducted in one or in sodium), black oxide of manganese, and sulphuric two stages. The vessel used is a still. The whole apparatus is made of strong sheet led, or of cast iron, or of grooved stones fitting closely. The more general plan is to have the upper part of lead, and the under part of cast iron. The lower third of the still has usually a double jacket, or double walls, for heating the contents of the still. In using the between which steam is admitted through a pipe apparatus, 100 parts of black oxide of manganese introduced by an opening in the top, which is closed (MnO2) and 150 parts of common salt (NaCl) are of specific gravity 1600, are then poured in by by a water-joint; 185 parts of sulphuric acid (SOs),

in water; but as this is tedious, the general plan is to steep the wool in a vat containing one part of stale urine and five parts of water, then boil for some time, and ultimately strain the wool and wash well. The agent in the stale urine which acts upon the yolk is carbonate of ammonia, and this acting upon the oily matters forms a soap which can be readily washed away. When woollen cloth is to be bleached, it is customary to substitute carbonate of soda (washing soda) for the stale urine, and this forms an alkaline lye, which performs the same part as the carbonate of ammonia. Soap is sometimes used as an auxiliary. The second stage of bleaching wool is the sulphuring, which takes place in a small wooden apartment, in which the damp cloth is suspended in regular folds from the roof to the floor, and a small pan of ignited sulphur being introduced, the doors, &c., are firmly closed. There are little openings round the sides of the chamber, for the admission of air, which can be closed at pleasure. The sulphur (S) in burning takes up two atoms of oxygen from the air, forming sulphurous acid (SO2), which is the bleaching agent; and in about 24 hours the operation is finished, and the woollen material only requires to be thoroughly washed with water, which may contain a little potash or soda. Where the wool is naturally high-coloured, it is necessary to repeat a funnel, and on the admission of steam into the the various stages of the process several times jacket, chlorine is evolved, and issues by a tube before the bleaching is complete. Instead of applying at the head of the still. The theory of the changes sulphurous acid in the gaseous form, a solution of it that occur in the still is represented in the following in water is sometimes used. An economical method table, there being two equivalents or atomic weights of preparing the solution of sulphurous acid is to of sulphuric acid for one equivalent of each of the introduce a mixture of sulphate of iron and sublimed other ingredients: sulphur into an earthenware retort, and apply a low red heat, when sulphurous acid is disengaged, which is passed through a vessel containing some porous matter, such as moss, to retain mechanical impurities, and then transmitted through a series of bottles containing water, where it is dissolved to the extent of forty volumes of the gas for every one volume of the water. The bleaching of wool by sulphurous acid is not so complete as the bleaching of cotton or linen by chlorine. In the latter case, the colour is destroyed, but in the former, the sulphurous acid merely combines with the colouring matter to produce a colourless compound, from which the colour can again be revived, either by soaking the wool in a dilute acid, such as sulphuric acid, or a dilute alkali, such as soda. Hence it is that new woollen cloth or garments, such as flannel, blankets, and underclothing, though almost colourless when purchased, yet after being washed several times, return to their natural yellow; for the soda used, as well as the soap which contains potash or soda, destroys the colourless compound formed in the texture of the wool during the sulphuring, and resuscitates the original colour.

BLEACHING OF SILK is carried on in a manner very similar to that pursued in the bleaching of wool. The silk has naturally a good deal of wax, accompanied by oil and colouring matter, enveloping the fibre, and the silk stuffs are repeatedly boiled in water containing a little soap or carbonate of soda, the alkaline nature of the solution being occasionally tempered by the admixture of some bran, which contains an acid. When well scoured and washed, the silk is obtained white enough for many kinds of printing; but where it is desirable that a pure white be obtained, the silken stuffs are introduced into a very weak solution of sulphurous acid, and thereafter thoroughly washed.

Chloride of sodium (NaCl)..

Oxide of manganese (MnO2),

Sulphuric acid (50g), .
Sulphuric acid (SO3)

Cl, Chlorine escapes as gas.
Na

(9

Mn

NaOSO

MnOSO3, Sulphate of Sulphate manganese, of Soda,

left in still.

The pipe which carries away the chlorine gas is connected with a stone or leaden chamber, into which it enters at one or more points, and the chlorine entering, comes in contact with dry slaked lime in fine powder, with which the floor of the chamber is covered to the depth of some inches. The chlorine is rapidly absorbed by the lime, which, when the absorption flags, is stirred from time to time by wooden rakes. The process must not be allowed to proceed too quickly, as much heat is evolved during the combination of the chlorine with the lime; and if the temperature of the chamber rises beyond 110° F., the power of combination is very much lessened.

The material which is left in the still as a residuum, consisting of the sulphate of manganese and the sulphate of soda mixed together, is comparatively worthless, and accordingly it is found more economical in large chemical works to divide the process of the manufacture of B. P. into two stages, at each of which the residuum is of commercial use, and can be worked up into marketable products. The first stage is to heat the common salt and sulphuric acid together, when hydrochloric acid (q. v.) is disengaged in the gaseous state, and is received in proper vessels, and the sulphate of soda-from which common soda (q. v.) is prepared Other substances employed in the arts and manu--is left in the retort or still. The hydrochloric factures are subjected to a process of bleaching; as the rags which are being manufactured into PAPER (q. v.), the palm-oil which is being converted into CANDLES (q. v.) and night-lights, and the STRAW

acid thus obtained, is then placed along with the black oxide of manganese in the still, and on the steam-heat being applied, chlorine is evolved and is conducted to the lime chamber, while chloride of

BLEAK-BLEEDING.

Chlorine escapes as gas.

The eating; and a dish of well-cooked B. is scarcely
inferior to gudgeons. They should be cooked in
the same
manner as sprats, which they rather
resemble in shape and appearance. The best way
to catch B. is to angle for them with a single
gentle and a light quill-float, the bait being abou
a foot under water; they may be caught with very
small flies, and all the more easily, if the book be
pointed with a gentle. They are so active, that the
angler cannot strike too quickly, and where they
abound, they form good preliminary practice for the
young fly-fisher. The neighbourhood of running
drains are very favourite resorts for B., and the
angler can soon determine if there be any about,
casting on the water a handful of bran, when,
if there be any, they will immediately rise at it.

HO,
Chloride of Water, Water,

manganese,

left in the retort. The chloride of manganese can be returned to the condition of black oxide of manganese, and used again and again. See MANGANESE. The B. P., prepared either in one or two stages, contains, when freshly and fully manufactured, generally between 30 and 40 per cent. of chlorine, and the strength of any sample is determined by the process of Chlorimetry (q. v.). The composition of B. P. is expressed by the formula CaCl+CaOCIO, and it is regarded as a double salt of the chloride of calcium and hypochlorite of lime. For its employment as a decolorising agent, see BLEACHING,

BLEAK (Leuciscus Alburnus), a small fresh-water fish of the family of Cyprinidae (q. v.), of the same genus with the Roach, Dace, Minnow, &c. See LEUCISCUS. It is seldom more than six or seven inches long; in general form it resembles the dace, but is more elongated; the dorsal fin is placed further back, and the base of the anal fin is longer; the nose is pointed, the under jaw the longest; the scales are of moderate size, and beautifully striated; the back is of an olivaceous green colour; the sides, belly, cheeks, and gill-covers, shining silvery white; all the fins nearly white. The tail is forked for half its length. The B. is found in

Bleak (Leuciscus Alburnus).

many of the rivers of Europe. On the inner surface of the scales of the B., as of white bait, roach, dace, &c., a silvery substance, from which they derive their beautiful lustre, is found in such abundance as to be much used for making artificial pearls (q. v.), the white beads so common in ladies' head-dresses, and similar ornaments. That obtained from the scales of the B. is preferred to that of the roach and dace, but is inferior to that of the whitebait. It readily separates from the scales when they are soaked for a time in water, and settles to the bottom of the vessel. Small glass tubes are then dipped in it, and it is injected into thin hollow glass beads of the requisite forms and sizes, which are placed in a current of air to dry, and are sometimes further filled with wax.-The B. is singularly liable to be infested by a species of tape

worm.

BLEBS (allied to bulb-Lat. bulla, a bubble) are transparent bladders or blisters of the cuticle, which make their appearance in some forms of fever, in erysipelas, and in disorders of the digestive apparatus. There are three varieties of B. recognised by physicians: 1. The mild B., which vary in size from a pea to a hazel-nut, occur on the face, neck or arms, and legs of teething infants, and of young persons who have indulged in unripe fruit. They generally burst, discharge the clear fluid they contain, and heal up again in three or four days. 2. The tedious B., which most commonly affect aged and weakly persons, are seen as an eruption of numerous red elevations, which enlarge to the size of a pea, containing pale yellow serous fluid. These vesicles multiply to such an extent that the sufferer is disturbed at night from the irritation, and slight febrile attacks further debilitate him. 3. The solitary bleb generally selects old women for its victims, and appears, after much tingling of the skin, as one large vesication, and bursts in 48 hours, leaving a superficial sore.

The treatment consists in correcting the secretions, limiting the diet to what is farinaceous and easy of digestion, cooling drinks and tonics. For local treatment, the irritated surfaces are to be soothed by poultices and water-dressings.

BLEEDING (hemorrhage) is one of the most serious accidents which can happen to an animal, and constitutes the most anxious complication in surgica operations. As there is but a limited quantity of blood in the body, and as the sudden escape of a large portion of it is sufficient to cause death, every one should be instructed as to the measures which experience has shown to be the most efficient for preventing a dangerous loss of blood.

B. may be either from a wounded artery or vein, or from a raw surface; and it may be in the form of a general oozing from the surface of a sore or a mucous membrane. We shall consider these varieties separately.

Arterial B. is recognised by the florid redness of the blood, and by its issuing from the cut vessel per saltum or by jerks. There are exceptions to this, however. When an artery has been tied, and bleeding occurs from below the ligature, the flow of blood is continuous, and of a dark colour.

If a large artery be wounded, the first gush of blood may prove fatal, but in general the patient faints, and nature takes advantage of the respite to place the cut artery in circumstances as favourable The B. is an inhabitant of most of the English as possible to the preservation of life; viz., the rivers which contain roach and dace. It is a very artery draws up within its sheath (see ARTERY); restless, active, little fish, constantly playing about the blood, no longer impelled vigorously by the heart, the top of the water, in search of small flies or clots between the cut end and the cellular tissue other food. A small piece of bread cast into the surrounding it; the inner and middle coats not only water becomes speedily surrounded by a shoal of retract but contract, and another clot forms within them, and it is amusing to watch them darting to the arterial tube. These clots-which, with the and fro at it with increasing pertinacity. It is not faintness and the contraction and retraction of the only a pretty little fish, but is, withal, delicate | artery, are termed natural hæmostatics (blood