Research Results For 'Salt'

ADULTERATION

Adulteration is a term not only applied in its proper sense to the fraudulent mixture of articles of commerce, food, drink, drugs, seeds, etc, with noxious or inferior ingredients, but also by magistrates and analysts to accidental impurity, and even in some cases to actual substitution.

The chief objects of adulteration are to increase the weight or volume of the article, to give a colour which either makes a good article more pleasing to the eye or else disguises an inferior one, to substitute a cheaper form of the article, or the same substance from which the strength has been extracted, or to give it a false strength.

Among the adulterations which were commonly practised around 1905 for the purpose of fraudulently increasing the weight or volume of an article are the following: Bread was adulterated with alum or sulphate of copper, which gives solidity to the gluten of damaged or inferior flour; with chalk or carbonate of soda to correct the acidity of such flour; and with boiled rice or potatoes, which enables the bread to carry more water, and thus to produce a larger number of loaves from a given quantity of flour. Wheat flour is adulterated with other inferior flours, as the flour from rice, bean, Indian-corn, potato, and with sulphate of lime, alum, etc. Milk was usually adulterated with water. The adulterations generally present in butter consisted of an undue proportion of salt and water, lard, tallow, and other fats; when of poor quality it was frequently coloured with a little annatto, and, at times, with the juice of carrots. Genuine butter should not contain less than 80 percent of butter-fat. Cheese was also coloured with annatto and other substances. Tea was adulterated chiefly in China with sand, iron-filings, chalk, gypsum, China clay, exhausted tea leaves, and the leaves of the sycamore, horse-chestnut, and plum, whilst colour and weight were added by black-lead, indigo, Prussian-blue (one of the deleterious ingredients used by the Chinese in converting the lowest qualities of black into green teas), gum, turmeric, soapstone, catechu, and other substances.

Coffee was mingled with chicory, roasted wheat, roasted beans, acorns, mangel-wurzel, rye-flour, and coloured with burned sugar and other materials. Chicory was adulterated with different flours, as rye, wheat, beans, etc, and coloured with ferruginous earths, burned sugar, Venetian red, etc. Cocoa and chocolate were mixed with the cheaper kinds of arrow-root, animal matter, corn, sago, tapioca, etc. Sugar was adulterated to some extent with flour. Tobacco was mixed with sugar and treacle, aloes, liquorice, oil, alum, etc, and such leaves as rhubarb, chicory, cabbage, burdock, coltsfoot, besides excess of salt and water. Snuffs were adulterated with carbonate of ammonia, glass, sand, colouring matter, etc.

Confections were adulterated with flour and sulphate of lime. Preserved vegetables were kept green and poisoned by salts of copper. The acridity of mustard is commonly reduced by flour, and the colour of the compound is improved by turmeric. Pepper was adulterated with linseed-meal, flour, mustard husks, etc. Colour was given to pickles by salts of copper, acetate of copper, etc. Ale was adulterated with common salt, Cocculus Indicus, grains of paradise, quassia, and other bitters, sulphate of iron, alum, etc. Porter and stout were mixed with sugar, treacle, salt, and an excess of water. Brandy was diluted with water, and burned sugar was added to improve the colour; sometimes bad whisky was flavoured and coloured so as to resemble brandy, and sold under its name.

Gin was mixed with excess of water, and flavouring matters of various kinds, with alum and tartar, were added. Rum was diluted with water, and the flavour and colour kept up by the addition of cayenne and burned sugar. For champagne gooseberry and other inferior wines were often substituted. Port was manufactured from red Cape and other inferior wines, the body, flavour, strength, and colour being produced by gum-dragon, the washings of brandy casks, and a preparation of German bilberries. Cheap brown sherry was mixed with Cape and other low-priced brandies, and was flavoured with the washings of brandy casks, sugar-candy, and bitter almonds. Pale sherries were produced by gypsum, by a process called plastering, which removes the natural acids as well as the colour of the wine. Other wines were adulterated with elderberry, logwood, Brazil-wood, cudbear, red beetroot, etc, for colour; with lime or carbonate of lime, carbonate of soda, carbonate of potash, and litharge, to correct acidity; with catechu, sloe-leaves, and oak-bark for astringency; with sulphate of lime and alum for removing colour; with cane-sugar for giving sweetness and body; with alcohol for fortifying; and with ether, especially acetic ether, for giving bouquet and flavour.

Medicines, such as jalap, opium, rhubarb, cinchona bark, scammony, aloes, sarsaparilla, squills, etc, were mixed with various foreign substances. Castor-oil has been adulterated with other oils; and inferior oils were often. mixed with cod-liver oil. Cantharides were often mixed with golden-beetle and also artificially-coloured glass.

The adulteration of seeds was largely practised also, the seed which forms the adulterant being of course of the most worthless kind that can be had. Thus turnip-seed was mixed with rape, wild mustard, or charlock, which are steamed and kiln-dried to destroy their vitality, so as to evade detection in the progress of growth; old and useless turnip-seed was also used fraudulently mixed with fresh seeds. Clover was also much mixed with plantain and mere weeds.

Acts against adulteration have been passed in various countries and at various times. In Britain there was a law against it as early as 1267.
Research Adulteration

AMBER

Research Amber

ASSAYING

Assaying is the estimation of the amount of pure metal, and especially of the precious metals, in an ore or alloy. In the case of silver the assay is either by the dry or by the wet process. The dry process is called eupellation from the use of a small and very porous cup, called a cupel, which is usually made of well-burned and finely-ground bone-ash or of magnesia. The cupel, being thoroughly dried, is placed in a fire-clay oven about the size of a drain-tile, with a flat sole and arched roof, and with slits at the sides to admit air. This oven, called a muffle, is set in a furnace, and when it is at a red heat the assay, consisting of a small weighed portion of the alloy wrapped in sheet-lead, is laid upon the cupel. The heat causes the lead to volatilize or combine with the other metals, and to sink with them into the cupel, leaving a bright globule of pure metallic silver, which gives the amount of silver in the alloy operated on. In the wet process the alloy is dissolved in nitric acid, and to the solution are added measured quantities of a solution of common salt of known strength, which precipitates chloride of silver. The operation is concluded when no further precipitate is obtained on the addition of the salt solution, and the quantity of silver is calculated from the amount of salt solution used.

An alloy of gold is first cupelled with lead as above, with the addition of three parts of silver for every one of gold. After the cupellation is finished the alloy of gold and silver is beaten and rolled out into a thin plate, which is curled up by the fingers into a little spiral or cornet. This is put into a flask with nitric acid, which dissolves away the silver and leaves the cornet dark and brittle. After washing with water the cornet is boiled with stronger nitric acid to remove the last traces of silver, well washed, and then allowed to drop into a small crucible, in which it is heated, and then it is weighed. The assay of gold, therefore, consists of two parts: cupellation, by which inferior metals (except silver) are removed; and quartation, by which the added silver and any silver originally present are got rid of. The quantity of silver added has to be regulated to about three times that of the gold. If it be more the cornet breaks up, if it be less the gold protects small quantities of the silver from the action of the acid. Where, as in some gold manufactured articles, these methods of assay cannot be applied, a streak is drawn With the article upon a touchstone consisting of coarse-grained Lydian quartz saturated with bituminous matter, or of black basalt. The practised assayer will detect approximately the richness of the gold from the colour of the streak, which may be further subjected to an acid test. The Goldsmith's Company of London is the statutory assay-master of all England.
Research Assaying

BAY-SALT

Bay-salt is a general term for coarse grained salt, but properly it is applied to salt obtained by spontaneous or natural evaporation of sea-water in large shallow tanks or bays.
Research Bay-salt

DYEING

Dyeing is the art of giving colour to textile and other articles in such a way that the colours are more or less permanent, and not readily affected by the action of light, washing, etc. Like spinning and weaving it was originally a home industry, as it still is in many places. Until about 1850 natural dye-stuffs alone were employed, but the discovery of dyes of all colours that can be obtained from coal-tar products revolutionized dyeing as an industry, and the vegetable dye-stuffs were gradually superseded by the newer colours.

Before dyeing, the materials have generally to be cleansed or bleached to get rid of undesirable colouring matters or impurities; and frequently a textile material is subjected to some subsidiary treatment in order to obtain special effects. For example, cotton yarn may be subjected to the action of strong caustic soda ('mercerizing' process) while in a state of great tension, in order to give it a permanent silky lustre.

Dyeing is not only an art, it is also a branch of applied chemistry. One fundamental principle is, that the colouring matter and other necessary substances must be applied in a state of solution, and while in direct contact with the fibre they must be rendered insoluble, so that they are precipitated within or upon the fibre and thus permanently fixed. The method of effecting this varies greatly according to the fibre and the colouring matter employed. As a rule the vegetable and the animal fibres are dyed by very different methods. The affinity of the animal fibres for certain colouring matters is often so great that they are readily dyed by simple immersion in hot colour solutions;
but this simple process is not generally sufficient. According to the method of their application in dyeing the following groups: of dye-stuffs may be distinguished: Avid Colours, Basic Colours, Direct Colours, Developed Colours, Mordant Colours, Miscellaneous Colours, Reactive Colours.

The acid colours are so called because they are of an acid character and are applied in an acid dye-bath. As a rule, they are only suitable for dyeing the animal fibres, e.g. wool and silk, also leather, horn, feathers, etc. Only a few vegetable dye-stuffs belong to this class, for example, the purple colour orchil and the blue colour indigo extract. On the other hand, the acid colours derived from coal-tar - and increasingly petroleum - are very numerous and yield a great variety of hues - red, orange, yellow, green, blue, violet, brown, and black, each with its particular name.

The basic colours are so called because their essential constituents, to which they owe their dyeing power, are organic bases. The bases themselves are colourless and too insoluble in water to be of use, hence they are employed in the form of their soluble coloured salts, usually the hydrochlorides of the colour-bases. Their solutions are precipitated by tannic acid, because it combines with the colour-bases to form insoluble tannates. Wool, silk, and animal substances generally have a direct attraction for colour-bases, and hence these fibres are readily dyed by simple immersion in hot aqueous solutions of the basic colours. Cotton and linen, on the other hand, are not dyed so readily; they need first to be prepared or impregnated with tannic acid, and thus prepared are said to be mordanted, the tannic acid in this connection being styled the mordant. Most of the colours of this class are fugitive to light, and all but one, barberry root, are derived from coal-tar products.

The direct colours are so called because they dye cotton direct, that is, without the aid of any mordanting process. The first of this class derived from coal-tar was congo red, discovered in 1884; this group includes a very great variety of fast colours, and forms, indeed, one of the most important and valuable series of dye-stuffs employed. Cotton, linen, and the vegetable fibres generally are dyed in the simplest possible manner by merely boiling them in a solution of the dye-stuff, with or without the addition of a little soap, carbonate or sulphate of soda, etc. Wool and silk are frequently dyed in the same manner as cotton. Very few vegetable dye-stuffs belong to the direct colours, e.g. Safflower, Turmeric, Saffron, Annatto. They are all fugitive, and have been of little or no importance to the dyer since the end of the 19th century. The coal-tar colours of this class, on the other hand, are extremely numerous.

The developed colours include a variety of colours which are formed in situ upon the fibre by the successive application of two or more substances. These colours are all of coal-tar origin. A number of them belong to the so-called azo colours, derived from compounds containing nitrogen.

The mordant colours form one of the most important classes of colouring matters, for they include not only most of the vegetable dye-stuffs, e.g. madder, logwood, fustic, etc, but also many valuable fast coal-tar colours, commonly known as the alizarin colours, after their typical representative, alizarin. These mordant colours have by themselves very little colouring power, as a rule, and if employed alone in dyeing give little or no result. If applied, however, in conjunction with metallic salts, notably those of chromium, aluminium, iron, tin, and copper, they each yield a variety of colours, according to the metallic salt employed. In employing them usually two distinct operations are involved: first, that of applying the metallic salt or mordant, called the mordanting process ; and second, that of dyeing proper, in which the mordanted material is boiled in a solution or decoction of the dye-stuff. During the dyeing operation the colouring principle of the dye-stuff combines with the metallic salt already upon the material, and the colour is thus produced and fixed upon the fibre. The method of mordanting varies with the fibre and the metallic salt employed. The vegetable dye-stuffs of this class include Madder, Sapanwood, Camwood, Barwood, Old Fustic, Young Fustic, Quercitron Bark, Persian Berries, Weld, Logwood. Madder was formerly the most important and highly valued of the dye-stuffs of this class, being especially employed to produce the fine 'Turkey-red' dye; but was entirely superseded by the coal-tar colour alizarin towards the end of the 19th century.

Reactive colours combine directly with the fibre being dyed through a chemical reaction and result in a fast colour. The first ranges of reactive dyes for cellulose fibres were introduced in the mid-1950s.

Similarly, the employment of cochineal (an insect dye) has also greatly diminished through the introduction of the cheaper colours. Camwood and barwood are almost entirely used in wool-dyeing, either in conjunction with the indigo-vat or for the purpose of dyeing various shades of brown. Old fustic is the most important of the yellow mordant dye-stuffs, and the colours are fast although not very brilliant. Young fustic yields fugitive colours, and has been little used since 1900. Quercitron bark is an excellent dye-stuff employed by wool-dyers for the production of bright orange and yellow colours. Persian berries and weld, a species of wild mignonette, are both excellent dye-stuffs, but their employment is now limited. Logwood is largely employed by wool, silk, and cotton dyers for dyeing black and dark-blues, which, although fast to washing, are only moderately so towards light. During the 20th century dyewoods were gradually replaced by coal-tar colours.

Among miscellaneous colours are several dye-stuffs applied in a distinct manner. Indigo is a dark-blue powder quite insoluble in water, but can be rendered soluble for dyeing purposes by two methods. The first method converts the indigo into so-called indigo extract, which is sold as a blue paste and applied as an acid colour in dyeing wool and silk. In the second method the indigo-blue is converted into indigo-white, which readily dissolves in the alkali present, the solution thus obtained being called an indigo-vat. If cotton, wool, or silk is steeped for some time in the clear yellow solution of such a vat, and then exposed to the oxidizing influence of the air, they are dyed a permanent blue. The indigo-white absorbed by the fibre loses its acquired hydrogen, and thus insoluble indigo-blue is regenerated within and upon the fibre. Aniline black is a valuable colour, produced direct upon the fibre by the oxidation of aniline, and remarkable for its extreme permanency.

Catechu is a vegetable dye-stuff used in dyeing cotton and woollen brown. On wool, catechu yields khaki browns in single bath by using copper sulphate as the mordant. On silk it is largely employed for weighting purposes in the process of dyeing black. Chrome Yellow, Iron Buff, Prussian Blue, and Manganese Brown, employed in cotton dyeing, are frequently classed as mineral colours. Chrome yellow is obtained by immersing cotton successively in solutions of acetate of lead and bichromate of potash, whereby the yellow precipitate of chromate of lead is fixed upon the fibre. Iron buff is obtained in a similar manner by the successive application of iron sulphate and carbonate of soda, and finally developing the full colour by washing with water and exposure to air. The buff colour is really due to the precipitation of oxide of iron on the cotton. Prussian blue is at once developed by passing the buff-dyed cotton through an acidified solution of potassium ferrocyanide. The production of manganese brown on cotton is similar to that of iron buff. The brown colour ultimately produced upon the fibre is an oxide of manganese. The mineral colours are very useful for certain purposes, and are to be regarded as very fast to light.
Research Dyeing

GILDING

Gilding is the art of applying gold-leaf or gold in a finely-divided state to surfaces of wood, stone, or metals. It is a very ancient art, being practised among the Egyptians, Greeks, Romans, and Ancient Persians. The processes employed through more modern times have been very varied. Metals are gilded either by what is called chemical gilding, mercurial gilding, by electro-gilding (electro-plating), or by the application of gold-leaf. Copper and brass, for instance, may be gilded by the process called wash or water gilding, with an amalgam of gold and mercury. The surface of the copper, freed from oxide, is covered with the amalgam, and afterwards exposed to heat until the mercury is driven off, leaving a thin coat of gold.

Gilding is also performed by dipping a linen rag in a saturated solution of gold, and burning it to tinder, the black powder thus obtained being rubbed on the metal to be gilded, with a cork dipped in salt water, until the gilding appears. Iron or steel is often gilded by applying gold-leaf, after the surface has been well cleaned, and heated until it has acquired the blue colour which at a certain temperature it assumes. Several leaves of gold are thus applied in succession, and the last is burnished down cold.

One process of chemical gilding was by dipping the article into a solution of gold, what is termed Elkington's solution being composed as follows: 5 oz. (troy) of fine gold; nitro-muriatic acid, 52 oz. (avoirdupois); dissolve by heat, and continue the heat until the cessation of red or yellow vapours; decant the clear liquid; add 4 gallons of distilled water, 20 lbs of pure bicarbonate of potassa and boiling for two hours.

Gilding on wood, plaster, leather, parchment, or paper, is performed by different processes of mechanical gilding. The first of these is oil-gilding, in which gold-leaf is cemented to the work by means of oil-size. In the case of paper or vellum the parts to be gilt receive a coat of gum-water or fine size, and the gold-leaf is applied before the parts are dry. They are afterwards burnished with agate. Lettering and other gilding on bound books are applied without size. The gold-leaf is laid on the leather and imprinted with hot brass types. Brass rollers with thin edges are employed in the same way for lines, and similar tools for other ornaments. When the edges of the leaves of books are to be gilt they are first cut smooth in the press, after which a solution of isinglass in spirits is laid on, and the gold-leaf is applied when the edges are in a proper state of dryness.

Japanner's gilding is another kind of mechanical gilding, which is performed in the same way as oil-gilding, except that instead of gold-leaf a gold dust or powder is employed. Frames of pictures and mirrors, mouldings, etc, are gilt by the application of gold-leaf, or by the cheaper process of 'German gilding,' that is, by tin-foil or silver-leaf, with a yellow varnish above.

Porcelain and other kinds of earthenware, as well as glass, may be gilt by fixing a layer of gold in a powdered state by the action of fire. The gold-dust or powder required in this operation may be obtained by precipitating it from a solution in aqua regia, either by means of iron sulphate or proto-nitrate of mercury. In order that the gold powder may be applied to the surface of the article to be gilt it must be well mixed with some viscous vehicle, such as strongly-gummed water. It is then laid on with a fine camel's-hair brush.
Research Gilding

LAGOON

A lagoon is a shallow stretch of salt water partly or wholly separated from the sea by a narrow strip of land or a low sand-bank or coral reef.
Research Lagoon

LAKES

Lakes are accumulations of water in hollows on the earth's surface. When they are drained by rivers their waters are fresh, but when they have no outlet they are salty, e.g. the Dead Sea, Sea of Aral, etc.
Lakes may owe their origin to:

1. The formation of a barrier across a river.


2. Earth movements.


3. Ice erosion.


4. Volcanic action.

The nehrungs of East Prussia are sand-spits which enclose the shallow salt-water lagoons or halls, such as Kurische Haff. Earth movements cause lake formation when subsidence occurs. This is most easily seen in rift valleys. Examples of rift valley lakes are the Dead Sea, Lakes Nyasa and Tanganyika in Africa, and Lake Torrens in Australia. These are all long, narrow, and very deep lakes.
In Cheshire, the removal of underground beds of salt has caused subsidence resulting in the 'meres' of the Weaver Valley. The 'folding' of the earth across the line of a river valley may partially block a river and help to form a lake. The study of a good physical map will reveal the connection between mountain building and the formation of Lake Geneva and Lake Constance in Switzerland. Where there are large areas of depressed lowland wide and shallow lakes are formed in the lowest part of the depression, for example the Sea of Aral in Asiatic Russia, Lake Balaton in Hungary, and Lake Eyre in Australia. Ice sheets and valley glaciers may scoop out hollows to form 'rock basins'. Mountain tarns and corrie lakes in North Wales and Scotland have been formed in this way. Water also accumulates in the hollows of unevenly- distributed glacial drift. Such are the lakes of East Prussia, and also those of the Cheshire-Shropshire borders near Ellesmere. Subsidence of the land surface and consequent lake formation may be directly related to volcanic action. Lough Neagh in Northern Ireland is a shallow lake formed by subsidence of this type. Lakes are often formed by the accumulation of water in the craters of extinct volcanoes, for example the Laachersee in the Eifel region of Germany.
Research Lakes

MARINE SOAP

Marine soap was a former variety of soap made from coconut oil and intended to be used with salt water.
Research Marine Soap

MARKET TOWNS

Most British boroughs came into being through the action of the King or some great noble or bishop in selecting a strong point, primarily as a centre of defence, in late Anglo-Saxon or early Norman times. In the more peaceful days, the twelfth and thirteenth centuries, town burgesses began to increase their freedom to control markets and trade by purchasing charters, or documents setting out the town's right to the status of borough, free to conduct its own affairs in return for an annual payment to the King. The wording of the charter often included the right to hold a weekly market and an annual fair. The market was the most important weekly event in the life of a mediaeval town, and the essential nucleus of the town became the market square. This was the place where agricultural produce from the surrounding countryside could be sold, and where the town craftsmen could display their wares. Stalls and booths, at first temporary and later permanent, began to be erected in the centre of the market place, and outlying parts of the
market were set aside for the sale of livestock. Later, many towns acquired a market hall, or town hall, with a meeting hall for the transaction of business on the upper floor and open arches at ground level where goods might be displayed out of the rain. The market was concerned with supplying local needs; a similar form of business held in certain towns was the fair which had a wider significance because they attracted traders from other parts of England and even from the Continent. At fairs one might buy the specialised products of certain parts of England, such as Sussex iron, Worcestershire salt, Derbyshire lead or Cornish tin, or spectacle lenses ground at Augsburg in Germany, beaten copperware from Dinant in modern Belgium or cutlery from Solingen in Germany.
Research Market Towns

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