Part 74

=VII. Straw, Straw-plait=, and articles made of them, are, on the large scale, usually bleached by (1) a hot steep or boil in a weak solution of caustic soda, or a stronger one of soda-ash, followed (2) by washing and (3) by exposure to the fumes of burning sulphur. To effect the last, the goods are suspended in a close chamber connected with a small stove, in which brimstone is kept burning. On the small scale, a large chest or box is commonly employed. A piece of brick, or an old box-iron heater, heated to dull redness, is placed at the bottom of an iron crock or earthen pan, a few fragments of roll sulphur thrown on, the lid instantly closed, and the whole left for some hours. Care should be taken to avoid inhaling the fumes, which are very deleterious as well as disagreeable and annoying. Straw goods are now also frequently bleached by the use of a weak solution of chloride of lime, or of water strongly soured with oxalic acid or even oil of vitriol, followed by very careful rinsing in clean water; but here, as in the former case, the natural varnish, dirt, grease, &c., must be first removed by alkalies or soap, to enable the chlorine or acid to act on the fibres.

=VIII. Wax.= Wax is bleached by first melting it at a low temperature in a cauldron, from whence it is allowed to run out by a pipe at the bottom into a capacious vessel filled with cold water.

This vessel is fitted with a large wooden cylinder, which turns upon its axis; and the melted wax falls upon this cylinder. The surface of the cylinder being always wet, the wax does not adhere to it, but becomes solid, assuming the form of ribbons as it does so, and in this shape becoming distributed through water in the tub. The wax is then removed and placed upon large frames stretched upon linen cloth, which are supported about 18 inches above the ground, and erected in a situation exposed to the air, dew, and sun. The several ribbons thus placed on the frame should not exceed an inch and a half, and they ought to be so moved about from time to time as that each part may be equally exposed. If the weather be favorable the wax will become white in a few days. It is again remelted, formed into ribbons, and exposed as before. These operations are continued in until the wax is completely bleached, after which it is melted and run into moulds.

_Concluding Remarks._ The theory of bleaching, notwithstanding the giant strides of chemistry during the last 20 years, remains still unsettled; and hence the processes employed are still, for the most part, empirical. It appears probable that chlorine acts by uniting with the hydrogen of the water, or of other compounds present, or probably with that of both, and that it is the oxygen thus liberated, and whilst in the nascent state, that is the true operative agent. Hence bleaching by chlorine, or by the hypochlorites, may be regarded as an oxidation of the colouring matter; but whether the chlorine or the oxygen effects this oxidation is of little practical importance--the result being the same--the destruction of the compound, and the removal of the colour that depends on its existence. It is doubtful whether the bleaching power of sulphurous acid is due to it as an oxidising or a deoxidising agent; but the last is probably the case, with a like destruction of the compound constituting the colouring matter. It may, however, be supposed that sulphurous acid acts as an oxidiser, as it appears to do when it decomposes sulphuretted hydrogen; or it may act by simply altering the compound by inserting itself, a view receiving some support from the fact that wool whitened by sulphuring may be restored to nearly its previous colour by merely treating it with soap or alkalies.

The bleaching power of light depends on its actinic or chemical rays, which, like chlorine, appear to act as an oxidising agent.

Chlorates, chromates, chromic acid, manganates, &c., have been proposed as bleaching agents for textile filaments and fabrics, but without success or practical advantage. Immersion in water more or less strongly impregnated with sulphurous acid has, however, been successfully substituted for the common sulphuring process, particularly for silk.

To avoid the injury of the goods by sparks, and by drops of water highly saturated with sulphurous acid falling from the roof, Mr Thom has invented a method of passing them rapidly through, or keeping them in constant motion in the sulphuring chamber. His apparatus is constructed on the principle of the washing-machine, the fumes of burning sulphur being used instead of water.

M. Tessie du Motay has proposed a new method for bleaching. He takes about equal parts of permanganate of soda and sulphate of magnesia, and dissolves them in lukewarm water. The tissues, previously freed from grease, are to be plunged into this bath until they are covered with a brown coating. They are then to be placed in a bath of sulphuric acid at 4 per cent., and rinsed after the brown matter is removed. They may be finally passed through sulphurous acid. Mr Ramsay's method consists in sprinkling with water equal parts of chloride of lime and sulphate of magnesia, when hydrochlorate of magnesia is formed. It may be remarked that none of the more modern methods of bleaching have been found, when reduced to practice, to be cheaper, better, or more advantageous to work than those sanctioned by long experience and use.

[Further information in connection with bleaching will be found under the heads ACTINISM, BLANCHING, CALICO-PRINTING, CHARCOAL, CHLORIDES (Bleaching), CHROMATES, CHROMIC ACID, HYPOCHLORITES, HYPOCHLOROUS ACID, LIGHT, RINSING, SPOTS and STAINS, SULPHURATION, WASHING, &c.; also under BONES, ENGRAVINGS, FAT, FEATHERS, HORN, IVORY, OIL, PAPER, PRINTED BOOKS, RAGS, SPONGE, STRAW-PLAIT, TALLOW, WAX, &c.[225]]

[Footnote 225: An accurate description of the apparatus and machinery employed in bleach-works, with numerous engravings, will be found in Ure's 'Dict. of Arts, Manuf. & Mines,' 5th ed., i, 318-351, &c.]

=Bleaching Liq'uid.= Solution of chloride of lime.

=Bleaching Pow'der.= Chloride of lime.

=Bleaching Salts.= The commercial hypochlorites.

=BLEAR'-EYE= (bl[=e]re'-[=i]). _Syn._ LIPPITU'DO, L.; CHASSIE, LIPPITUDE, Fr. An exudation of a puriform matter from the margins of the eyelids, which are red, tumid, and painful; and frequently, during the night, glued together by the discharge.

_Treatm._ Mild astringent collyria, as those of sulphate of zinc or alum (6 or 8 gr. to 1 oz. of water). An ointment formed of 1 part of the ointment of nitrate of mercury (Ph. L.), diluted with 11 parts of sweet washed lard, may be advantageously applied nightly, by means of a camel-hair pencil, the smallest quantity possible only being used. Excess in eating and drinking should be avoided, and some aperient medicine taken.

=BLEAK= (bl[=e]ke). _Syn._ BLAY[double-dagger], BLEY[double-dagger], (bl[=a]). The _cypri'nus albur'nus_ (Linn.), a small river-fish, the scales of which are used in making artificial pearls (which _see_).

=BLEB.= A vesicle or blister. In some states of general derangement of health this arises spontaneously. It should be treated in the same way as scalds.

=BLEED'ING= (bl[=e]de'-). In the sense of a flow or loss of blood, see HÆMORRHAGE; in that of bloodletting, see CUPPING, LEECHING, VENESECTION, &c.

=Bleeding Piles.= Take every morning aperient doses of milk of sulphur, then a small teaspoonful of confection of black pepper every day. Wash externally with a sponge and cold water. Apply compound gall. ointment to the piles if external.

=Bleeding from the Air Passages and Lungs.= Let the patient at once go to bed, and keep perfectly quiet, avoiding movement of any kind as much as possible. Administer dilute acids in frequently repeated doses, with five drops of tincture of digitalis. The bowels should be kept open by means of Epsom salts in infusion of roses. Give iced drinks and let solid ice be sucked. Mustard plasters may be applied to the chest. A morphia lozenge may now and then be sucked gradually away, as well as a small piece of sal prunella. The cough must be allayed by the administration of small doses of morphia in gum water or barley water. All food should be taken cold.

The treatment that we have indicated in the last two forms of hæmorrhage is intended for the exclusive guidance of emigrants or of others so placed as to be unable to summon prompt medical aid. Wherever this can be obtained no time should be lost in at once seeking it.

=Bleeding from the Nose.= Apply cold water containing ice, if obtainable. It should be so applied to the nose as to cause a shock. A cold piece of metal, such as a key, placed on the naked back sometimes stops the hæmorrhage. If neither of the above means succeed inject with a syringe a solution of alum or sulphate of zinc (ten grains to the ounce), or snuff up the nostrils some gallic acid, powder of pomegranate, kino, or catechu, mixed with starch. A plug of lint may also be dipped in either of the above solutions, or rolled in the powders, and pushed up the nostrils, or some tincture of perchloride of iron, properly diluted and applied on a piece of lint, may be tried.

=Bleeding from the Stomach.= _Syn._ HEMATEMESIS. In this case the blood is vomited usually in clots of a dark colour. It should be noticed whether it comes from the back of the nose or throat. The treatment consists in perfect repose in bed, and in the administration of dilute sulphuric acid in infusion of roses, with saline aperients. If these fail to give relief, tannin and krameria may be tried, and small doses of laudanum or five grains of alum may be given every four hours. If in pain, add to it 1/4 grain of acetate of morphia. All food and drinks should be taken cold, the latter iced. Pernitrate of iron in from 10 to 30 minim doses is a valuable remedy.

=BLENDE= (bl[)e]nd). A name applied to several minerals; appr., zinc-blend, or native sulphuret of zinc--the black jack of miners.

=BLIGHT= (bl[=i]te). See MILDEW, and PLANTS (Diseases of).

=BLIND'NESS= (bl[=i]nd'-). _Syn._ ABLEP'SIA, CÆ'CITAS, &c., L.; AVEUGLEMENT, CÉCITÉ, Fr.; BLINDHEIT, Ger. Deprivation or want of sight.

Blindness may be congenital, or born with a person; or it may arise from accident, external violence, or disease. In the latter it may frequently be relieved by medical and surgical treatment. See AMAUROSIS, CATARACT, EYES, OPHTHALMIA, VISION, &c.

=Blindness, Day.= _Syn._ NIGHT'-SIGHT; N[)Y]CTALO'PIA, L. A disease of the eye in which vision is painfully acute or more or less extinct in a strong light, as that of day; but clear and pleasant in the dusk of evening and at night. Its chief causes are excessive exposure of the eyes to the direct influence of very strong or glaring light, or to heat, or both of them together; and is often one of the sequelæ of ophthalmia (which _see_).

=Blindness, Night.= _Syn._ DAY'-SIGHT; HEMERALO'PIA, L. An affection of the eye, the reverse of the preceding, in which objects are clearly seen only in broad daylight. In the beginning of the complaint the patient continues to be able to see, though less clearly, for a short time after sunset, and even by moonlight, and perhaps distinctly by bright candle light; but after a short time this power is lost. It most frequently occurs in hot climates, and low latitudes at sea. Its chief causes are fatigue and exposure of the eyes to the glare of the tropical sun, probably coupled with gastric derangement. In some cases it is congenital, and is then generally incurable. The treatment consists in avoiding exciting causes, and endeavouring to restore the tone of the stomach, and the general health, by the usual methods. The eyes at the same time should be topically medicated by the frequent use of cold water, or mild astringent collyria. See OPHTHALMIA (Chronic).

=BLIS'TER.= _Syn._ PAP'ULA, PUS'TULA, L.; PUSTULE, VESSIE, &c., Fr.; BLASE, BLATTER, Ger. A bladder or vesicle caused by the deposition of serous fluid between the cuticle and the derma or true skin, occasioned by the application of a vesicant, or by a burn, scald, or friction.

=Blister.= _Syn._ VESICATO''RIUM, L.; EPISPASTIQUE, VESICATOIRE, Fr.; BLASEN-PFLASTER, B.-STOFF, Ger. A substance which vesicates or raises blisters; in pop. lang., a vesicating plaster or similar application.

The use of blisters is very ancient, and appears to date back long prior to the time of Hippocrates. Indeed, their value as cutaneous stimulants and counter-irritants appears to have been recognised by the medical faculty of all nations down to the present time. It is a principle sufficiently established with regard to the living system, that where a morbid action exists, it may often be removed by inducing an action of a different kind, as a state of excitement or irritation, in the same or a neighbouring part. In this way is explained the utility of blisters in local inflammation and spasmodic action, and it is this principle which regulates their application in pneumonia, gastritis, hepatitis, phrenitis, angina, rheumatism, colic, spasmodic affections of the stomach, &c.--diseases in which they are employed with the most marked advantage. A similar principle exists with respect to pain; exciting one pain often relieves another. Hence blisters frequently give relief in neuralgia, toothache, and other like painful affections. Lastly, blisters, by their operation, communicate a stimulus to the whole system, and raise the vigour of the circulation. Hence, in part, their utility in fevers of the typhoid kind, though in such cases they are used with still more advantage to obviate or remove local inflammation.

Blisters are commonly prepared with cantharides plaster, or with some other preparation of cantharides; and, in the former case, usually have their surface sprinkled over with powdered Spanish fly; whilst the blistering surface is surrounded with a margin spread with common adhesive plaster, for the purpose of causing them to adhere to the part to which they are applied. In order to prevent the action of the cantharides upon the mucous membrane of the bladder, or urinary organs, they are also often sprinkled with a little powdered camphor, or better still, are moistened with camphorated ether, which, on its evaporation, leaves a thin layer of camphor on the surface; but care must be taken that the layer be not too thick, as in that case the plaster would not take effect. With a like object, a piece of thin book-muslin or tissue-paper (silver-paper) is frequently placed between the blistering surface of the plaster and the skin; the efficacy of which may be still further heightened by first soaking the muslin or paper in olive or almond oil.

The usual time an ordinary blister of cantharides plaster is allowed to remain in contact with the skin is from 10 to 12 hours. It is then gently removed. The subsequent treatment depends on the object in view. When it is not wished to maintain a discharge from the blistered surface, the vesicle is cut with the point of a pair of scissors at its most depending part, to let out the fluid which it contains, followed by a dressing of spermaceti or other simple ointment; but when the case requires the blister to be kept open, or to be converted into a perpetual blister, as it is sometimes called, the whole of the detached cuticle is carefully removed with the scissors, and the part is dressed with either the ointment of cantharides or of savine, at first more or less diluted with lard or simple ointment, with an occasional dressing of resin cerate. According to Mr Crowther, the blistered surface is best kept clean by daily fomentation with warm water.

Of late years, to obviate the unpleasant effects occasionally arising from the common blister, various compounds having cantharides for their base, as well as fabrics spread with them, have been brought before the public. These are noticed hereafter. See PLASTER, VESICANTS, &c.

=Blisters, Extempora''neous.= Among the best of these may be mentioned the following:--

1. A piece of lint dipped in the strongest vinegar of cantharides, and immediately after its application to the skin, covered over with a piece of strapping, or preferably a piece of sheet gutta percha or oiled silk, to prevent evaporation. Raises a blister in from 5 to 8 minutes.

2. Concentrated acetic acid, applied in the same way, has a similar effect.

3. (Dr Darcq.) Into a flat watch glass pour from 8 to 10 drops of highly concentrated liquor of ammonia; cover the liquid with a small piece of linen of rather less diameter than that of the glass, and at once apply this little apparatus to the previously shaved skin. The whole must be kept in its place by means of moderate pressure with the fingers, until a red ring, about 2 centimètres in breadth, is observed round the glass, when it is certain that vesication is effected. Sometimes scarcely 30 seconds are necessary for obtaining the result. The apparatus may then be removed, and the blistered part treated in the usual manner; the dressing being according to the object in view.

4. (Trousseau.) Bibulous paper slightly wetted with a little of the ethereal extract of cancharides, and instantly applied to the skin, the whole being covered with a piece of common adhesive plaster to prevent evaporation.

5. Boiling water applied by means of a suitably shaped tube, the adjacent parts being at the same time protected from injury. Instantaneous.

=Blister, Horse.= See VETERINARY MEDICINES.

=Blister*, Perpet'ual.= See BLISTER (_antè_).

=BLIS'TERING.= _Syn._ VES'ICANS, VESICATO''RIUS, L.; EPISPASTIQUE, VÉSICANT, VÉSICATOIRE, Fr.; BLASENZIEHEND, &c., Ger. In _medicine_, &c., that vesicates or raises blisters when applied to the skin.

=Blistering Pa'per, Plas'ter, Tis''sue= (t[)i]sh-[=u]), &c. See PLASTERS, VESICANTS, &c.

=BLOAT'ER.= See BLOTE.

=BLONDE.= [Fr.] _Syn._ BLOND'-LACE. Silk-lace. The name is now also applied to cotton-lace edged with silk. For the mode of cleaning it and getting it up, see LACE and MUSLIN.

=BLOOD= (bl[)u]d). _Syn._ SAN''GUIS, L.; SANG, Fr.; BLUT, Ger. The general circulating fluid of animals, and that on which the nourishment and growth of their bodies depend, and from which all the secretions are formed. It is warm and red in vertebrated animals; and, for the most part, cold and white in the invertebrata. In man and all other mammals, and in birds--the two highest classes of the animal kingdom--the blood, though collectively forming but one circulating stream, varies considerably in appearance according to the part or vessels in which it is found. That contained in the left side of the heart, and in the arteries, possesses a very brilliant scarlet colour, and is called arte''rial blood; whilst that found in the right side of the heart, and in the veins, has a darkish purple colour, and is called ve'nous blood. The two, however, differ little from each other in their chemical properties and composition; the most marked point of difference being that venous blood holds carbonic acid in solution, whilst oxygen predominates in the blood of the arteries. The fibrine of venous blood is also soluble in a solution of nitrate of potassa; whilst that of arterial blood is insoluble in that menstruum.

_Comp._ Blood consists of a transparent and nearly colourless fluid (plas'ma, se''rum, s[)e]ralbu'men), in which float about a countless multitude of microscopic round red bodies (blood-discs, blood-corpuscles), to which its colour is due, accompanied by a few colourless globules (white blood-corpuscles) of a somewhat larger size. The red corpuscles are found, on more minute examination, to consist of an envelope containing a solution of hæmatosin.

_Prop._ These are, for the most part, well known. It has an alkaline reaction, a saline and rather disagreeable sweetish taste, and when newly drawn evolves a peculiar odour or halitus, which almost immediately disappears. As it cools and on repose it coagulates, owing, according to some, to the spontaneous solidification of the fibrine.

The following table, based upon the observations of Schmidt and the analysis of Lehmann, is given by the latter, as representing the average quantitative relation of the principal constituents of normal blood. It will be noticed that the blood is here regarded as composed of two portions, one consisting solely of the red particles, and the other of the liquid, in which these red corpuscles are suspended, termed the _liquor sanguinis_, which consists of the serum holding fibre in solution:--

_Sp. gr. of Blood-corpuscles, 1·0885._

1000 parts blood-corpuscles contain--

Water 688·00 Solid constituents 312·00 consisting of-- Hæmatin (with iron) 16·75 Globulin and cell membrane 282·22 Fat 2·31 Extractive matters 2·60 Mineral substances (without iron) 8·12 Chlorine 1·686 Sulphuric anhydride (SO_{3}) 0·066 Phosphoric anhydride (P_{2}O_{5}) 1·134 Potassium 3·328 Sodium 1·052 Oxygen 0·667 Calcium phosphate 0·114 Magnesium phosphate 0·073

_Sp. gr. of Liquor Sanguinis, 1·028._

1000 parts of liquor sanguinis contain--

Water 902·90 Solid constituents 97·10 consisting of-- Fibrin 4·05 Albumen 78·84 Fat 1·72 Extractive matters 3·94 Mineral substances 8·55 Chlorine 3·644 Sulphuric anhydride (SO_{3}) 0·115 Phosphoric anhydride (P_{2}O_{5}) 0·191 Potassium 0·323 Sodium 3·341 Oxygen 0·403 Calcium phosphate 0·311 Magnesium phosphate 0·222

The ash of blood contains about 6·84 per cent. of ferric oxide. (Lehmann.)

The following table gives the results of the average composition of human blood in man and woman, according to the analyses of Becquerel and Rodie:

Male. Female. Specific gravity of defibrinated blood 1·0600 1·0575 " " of serum 1·0280 1·0274 Water 779·00 791·00 Fibrin 2·20 2·20 { Serolin } { 0·02 } { 0·02 { Phosphorised fat } { 0·49 } { 0·46 Fatty Matters { } 1·60 { } 1·62 { { Cholesterin } { 0·09 } { 0·09 { Saponified fat } { 1·00 } { 1·05 Albumen 69·40 70·50 Blood-corpuscles 141·10 127·20 Extractive matters 6·80 7·40 ------- ------- 1000·10 1000·02 ------- ------- { Sodium chloride 3·10 3·90 Salts { Other soluble salts 2·50 2·90 { Earthy phosphates 0·33 0·35 Metallic iron 0·57 0·54 ----- ----- 6·50 7·69

The blood also contains, in solution, oxygen, nitrogen, carbonic acid, as well as a free alkaline carbonate, urea, and small traces of alcohol have also been detected in normal blood.