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. Wheatflour 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, Chinaclay, 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.
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 champagnegooseberry 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, cinchonabark, 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
Blue is one of the seven colours into which the rays of light divide themselves when refracted through a glassprism, seen in nature in the clear expanse of the heavens; the term is also applied to a dye or pigment of this hue.
The substances used as blue pigments are of very different natures, and derived from various sources; they are all compound bodies, some being natural and others artificial. They are derived almost entirely from the vegetable and mineral kingdoms. The principal blues used in painting are ultramarine, which was originally prepared from lapis-lazuli or azure-stone - a mineral found in China and other oriental countries - but, as now prepared, it is an artificial compound of china-clay, carbonate of soda, sulphur, and charcoal; Prussian or Berlin blue, which is a compound of cyanogen and iron; blue bice, prepared from carbonate of copper; indigo blue, from the indigo plant. Besides these, there are numerous other blues used in art, as blue-verditer, smalt- and cobalt-blue, from cobalt, lacmus or litmus, etc.
Before the discovery of aniline or coal-tar colours dyers chiefly depended for their blues on woad, archil, indigo, and Prussian blue, but now a series of brilliant blues are obtained from coal-tar, possessing great tinctorial power and various degrees of durability.
Blue as a colour ranges from green-blue (turquoise) through to purple-blue (indigo).
Alice blue - A very light greenish-blue colour.
Aquamarine - A bluish-green colour.
Azure - A deep blue colour reminiscent of the sky.
Aquamarine - A pale greenish-blue colour.
Bice blue - A medium blue colour
Cambridge blue - A light blue colour.
Cobalt blue - A deep blue colour with a greenish-tint. The colour of old blue glass.
Cologne yellow is a pigment consisting of two parts yellow chromate of lead, one of sulphate of lead, and seven of sulphate of lime or gypsum. It is prepared by precipitating a mixture of nitrate of lead and nitrate of lime with sulphate of soda and chromate of potash. Research Cologne Yellow
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, cottonyarn may be subjected to the action of strong causticsoda ('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 organicbases. 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, barberryroot, are derived from coal-tar products.
The direct colours are so called because they dyecotton 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 alkalipresent, 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
Glasswort are plants of the genus Salicornia, family Chenopodiaceae. They are succulent marine herbs growing abundantly on the coasts of southern Europe and north Africa. When burnt their ashes yield soda which was once used in making glass, hence the name glasswort. Research Glasswort
Grass-wrack (Sea-Grass, Zostera marina) is a phanerogamous plant belonging to the Naiadeae, forming green beds at the bottom of the sea where it is shallow. The ash contains soda. Research Grass-wrack
Ludwig Mond was a German chemist. He was born in 1838 at Cassel and died in 1909. Educated at Marburg and Heidelburg universities he went to England in 1862 to introduce a process for the recovery of sulphur from alkali waste and in 1873 partnered John Brunner to invent a process for creating soda - the Silvay or ammonia process - erecting a works near Norwich for the manufacture of soda. Research Ludwig Mond
Gunpowder is an explosive mixture of potassium nitrate, charcoal and sulphur in the proportions of 75, 15 and 10 - although alternative proportions are also used. The three ingredients must be very finely ground and mixed, and ordinary charcoal is not very suitable. Rather charcoal from dogwood, alder or willow is used. The wood is cut in spring and stored for between two and three years before being cut into small pieces and packed into thick iron containers with holes at one end to allow gases to escape, and heated for four hours.
The crude pottassium nitrate is dissolved in boiling water, filtered, and then allowed to cool and crystallize in a trough in order to purify it from nitrates of soda and lime, chlorides of potassium and sodium, etc, the liquid being continually agitated, so that the crystals may be formed small and pure. They are then washed and allowed to drain. The sulphur is purified and ground. The charcoal is obtained from alder or willow wood, or from dogwood for the finest powder. These ingredients are first roughly mixed, then sprinkled with water and incorporated under rollers in a mill, and formed into a cake termed 'mill cake'. This is broken up under grooved rollers, and brought by pressure into 'press cake'. After this it is granulated, by being passed between toothed rollers, and separated into classes by sieves of different sizes of mesh. Around the end of the 19th century a very large grain was adopted for the heaviest ordnance; this was termed pellet or pebble powder. 'Pellet' powder was made by filling the cylindrical holes in a thick gun-metal plate with mealed powder, and by means of pistons under a hydraulic press, forming them into short cylinders or 'pellets', with a small cavity at one end to catch a flame the more readily. 'Pebble' powder was made by cutting or pressing edges which divide the press cake into small cubes; these, like pebbles, have their corners rubbed off and rounded by friction. The largest pebble powder consisted of cubes of 1.5 inches.
There is also a gunpowder known as 'prismatic', the grains forming large hexagonal prisms with a hole through the centre. 'Cocoa' powders are made with other kinds of carbon than wood charcoal. The greatest precautions must be taken to prevent fire or water from coming into contact with gunpowder. Hence it was usually kept in magazines which were of great strength in defensive works, although lighter and well-ventilated buildings sufficed under other conditions. In the transportation of gunpowder, the casks should be dust-proof, and the carriages and vessels containing it should be water-tight. As iron vessels are dangerous, gunpowder was usually packed in copper-hooped barrels made with coppernails.
The explosive power of gunpowder is very great. It is, however, necessary to place it within a confined space, as, when it is heaped up in the open air, it explodes without report or much effect. As the result of experiments it appears that the weight of the gases produced by inflaming gunpowder is about three-fifths of that of the powder, and their volume 288 times its bulk, when they have attained an elasticity equal to that of the air. If the effect of heat evolved during the combustion be added, the elastic force is increased to 1000 atmospheres in round numbers, i.e. a pressure of about 6.5 tons to the square inch.
Gunpowder is thought to have been invented by the Chinese and Marcus Graecus, who lived about the 9th century, describes its composition, which was also known to Roger Bacon, who refers to it in 1267. It was also apparently known to the Arabs at an early period. In 1342 the Moors employed it in the siege of Algeciras. According to the common story the discovery of its propulsive power was due to the German monk Barthold Schwartz between 1290 and 1320.
Guns are said to have been employed by Edward III in 1327, on his invasion of Scotland. It is also asserted that gunpowder was employed in 1346 by the English at Crecy. It was not, however, until the 16th century that its use in warfare became general.
Alcohol, or ethyl alcohol,( CaHgO), is the intoxicating part of all liquids that have undergone vinous fermentation, may be extracted by distillation, and is a limpid colourless liquid, with an agreeable smell and a strong pungent taste. When brandy, whisky, and other spirituous liquors, themselves distilled from cruder materials, are redistilled, highly volatile alcohol is the first product to pass off. The alcohol thus obtained contains much extraneous matter, including water, from the first as much as 20 or 25 percent, and increasing greatly as the process continues. Charcoal and carbonate of soda put in the brandy or other liquor, partly retain the fusel-oil and acetic acid it contains. The product thus obtained by distillation is called rectified spirits or spirits of wine, and contains from 55 to 85 percent of alcohol, the rest being water. By distilling rectified spirits over carbonate of potassium, powdered quicklime, or chloride of calcium, the greater part of the water is retained, and nearly pure alcohol passes over. It is only, however, by repeated digestion with desiccating agents and subsequent distillation that the last traces of water can be removed.
The specific gravity of alcohol varies with its purity, decreasing as the quantity of water it contains decreases. This property is a convenient test of the alcoholic strength of liquors that contain only alcohol and water; but on account of the condensation that invariably takes place on the mixture of these two liquids, it can be applied only in connection with special tables of reference, or by means of an instrument specially adapted for the purpose (known as an alcoholometer.) By simple distillation the specific gravity of alcohol can scarcely be reduced below .825 at 60 degrees Fahrenheit; by rectification over chloride of calcium it may be reduced to .794; as it usually occurs it is about .820. Alcohol is composed of carbon, hydrogen, and oxygen, in the proportions expressed by the formula CaHgO. Under a barometric pressure of 29.5 inches it boils at 173 degrees Fahrenheit or 78.4 degrees Centigrade; in the exhausted receiver of an air-pump it boils at ordinary temperatures. The freezing of alcohol is effected only at the very low temperature of -203 degrees Fahrenheit. Its very low freezing-point renders it valuable for use in thermometers suited for very low temperatures.
Alcohol vapour is extremely inflammable, and burns with a pale-blue flame, scarcely visible in bright daylight. It occasions no carbonaceous deposit upon substances held over it, and the products of its combustion are carbon dioxide and water. The steady and uniform heat which it produces during combustion makes it a valuable material for lamps. It dissolves the vegetable acids, the volatile oils, the resins, extractive matters, and many of the soaps; the greater number of the fixed oils are taken up by it in small quantities only, but some are dissolved largely. When alcohol is submitted to distillation with certain acids a peculiar compound is formed, called ether. It is alcohol which gives all intoxicating liquors the property whence they are so called. Alcohol acts strongly on the nervous system, and though in small doses it is stimulating and exhilarating, in large doses it acts as a poison. In medicine it is often of great service.
The name alcohol is also applied in chemistry to a large group of compounds of carbon, hydrogen, and oxygen, whose chemical properties are analogous to those of common or ethylic alcohol. Research Alcohol
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Adulteration
