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.
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
Green Paints are for the most part compounds of copper and of chromium. The best known greens are the following: Bremen green, or verditer, consisting mainly of a basic carbonate of copper. Brunswick green, a hydrated oxychloride of copper; but the name is sometimes given to a hydrated basic carbonate, also known as mountain green. Chrome and emerald green are oxide of chromium. Emerald green is also used as synonymous with Schweinfurt green. English green is a mixture of Scheele's green with gypsum. Guignets green is oxide of chromium prepared in a peculiar way. Hungary green is a kind of malachite found in Hungary. Rinman's green is obtained by heating zincoxide with a cobaltcompound. Saxony green is an indigo colour used in printing. Scheele's green is arsenite of copper, and Schweinfurt green, Veronese green, and Vienna green, are also compounds of arsenic and copper. Verdigris is a hydrated basic carbonate of copper, often seen in copper coins. Besides these are green colours derived from plants. Of these may be mentioned chlorophyll, the green colour of leaves: sap green, the juice of Rhamnus catharticus or buckthorn, made into a green lake with alumina; Chinese indigo-green, etc. Research Green Paint
The Characeae are a family of cryptogamous plants, nearly related to the Algae, composed of an axis consisting of parallel tubes which are either transparent or incrusted with limecarbonate. Research Characeae
Characese is an order of cryptogamous plants, nearly related to the Algae, composed of an axis consisting of parallel tubes, which are either transparent or encrusted with carbonate of lime, inhabiting stagnant water, both fresh and salt, beneath which they are always submersed. They are most common in the temperate zone, and emit an unhealthy fetid odour. Research Characese
Coral is a vast commune made up of tiny marine organisms called polyps, which are related to sea anemones.
Corals are of two types: perforate and imperforate. Perforate corals have porous skeletons with connections between the polyps through the skeleton. Imperforate corals have solid skeletons. Many corals have different growth forms. They can be plocoid as in Tubastrea coccinea (orangecup coral) and Favia fragum (golf ball coral). They can also be meandroid in which corallites form a series within the same walls, as in the species Dendrogyra cylindrus (pillar coral). Other growth forms include cocoid, spherical shaped and phalecoid, as in Eusmilia fastigiata.
Corals can obtain food in a variety of ways. Reef-building corals rely on the photosynthetic products of zooxanthellae for the majority of their nutrients. However, corals also capture zooplankton for food using their tentacles.
Coral is essential to the world's eco-system as it absorbs vast quantities of carbon dioxide from the water and converts it into calcium carbonate. More carbon dioxide is absorbed by the world's coral reefs than by the rain- forests on land. In 1998 70% of the world's coral was destroyed by a freak weather system, leading to fears that global warming could increase. Research Coral
Foraminifera is an order of animals of low type belonging to the class Rhizopoda, of the Phylum Protozoa, furnished with a shell or test, simple or complex, usually perforated by pores called foramina from which the animals get their name.
The shell may be composed of horny matter, or of carbonate of lime, secreted from the water in which they live. Owing to the resemblance of their convoluted chambered shells to those of the nautilus, they were at first reckoned among the most highly organized molluscs. In reality they are among the simplest of the protozoa. The body of the animal is composed of granular, gelatinous, highly elastic sarcode, which not only fills the shell, but passes through the perforations to the exterior, there giving off long thread - like processes called pseudopodia interlacing each other so as to form a net like a spider's web. Internally the sarcode-body exhibits no structure or definite organs of any kind.
Foraminifera appear very early in the geological formations. The great formation known as white chalk is largely composed of foraminiferous shells, while another remarkable formation known as Nummulitic Limestone receives its name from the presence of coin-shaped foraminifera, generally about 25 mm diameter. Research Foraminifera
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Adulteration
