Adulteration

Adulteration. The crime of food adulteration is a very old one. Pliny tells us of one article which was so extensively adulterated in his time, that even the wealthier members of the community could not obtain it in a state of purity. In England during the 11th century, drugs, as well as several different articles of food, were subjected to various processes of sophistication. In those early days, the means of detection of adulteration were, as may be imagined, neither so refined nor certain as those which we now possess, and in consequence—notwithstanding the greater punishments which were then enforced—the practice not only became very common, but it was carried out in a most unblushing fashion. In 1843 Mr Phillips, of the Inland Revenue, stated that it was supposed that there were no less than eight manufactories for the purpose of re-drying exhausted tea-leaves in London alone. People were employed to go about and buy up used tea-leaves at hotels, coffee-houses, and the like, which they did at the rate of twopence halfpenny a pound. The leaves gathered in this way were then taken to the manufactories, where they were immersed in a solution of gum, and dried. If the leaves, thus manufactured so far, were intended to be sold as ordinary black tea, they were finished by being mixed with rose-pink and black-lead. But not only was exhausted tea made use of; such things as the leaves of the sycamore, horse-chestnut, and sloe were freely employed, and these not alone, but in conjunction with catechu, green vitriol, and indigo. In a notice of Accum's book on food adulteration, published in 1820, the following passage occurs: 'Devoted to disease by baker, butcher, grocer, wine-merchant, spirit-dealer, cheesemonger, pastry-cook, and confectioner, we call in the physician to our assistance. But here again the pernicious system of fraud, as it has given the blow, steps in to defeat the remedy. The unprincipled dealer in drugs and medicines exerts the most potent and diabolical ingenuity in sophisticating the most potent and necessary drugs—Peruvian bark, rhubarb, ipecacuanha, magnesia, calomel, castor-oil, spirits of hartshorn, and almost every other medical commodity in general demand, and chemical preparation used in pharmacy.'

Sixty years of general advancement has no doubt produced a great change in the purity of our food; but the quarterly reports of the public analysts continually remind us that we have not yet finally banished the demon of food adulteration from our midst. The excuses which have at different times been urged in extenuation of adulteration are numerous, and in some cases even plausible. Thus we are told again and again that many articles of food are prepared and sold in an adulterated form in obedience to the public taste. Preserved vegetables must, it is said, possess a bright, permanent green hue, in order to be appreciated by the public. Peas do not retain their natural colour when preserved, and therefore the manufacturers of these articles colour them with verdigris or some similar salt of copper. Sauces and preserved meats must, it is alleged, be made, for similar reasons, to assume a red tint; butter and cheese must be yellow, and bread white; while confections must needs possess all the colours of the rainbow. Again, it is asserted that some forms of adulteration, or, as it is more euphoniously put, admixture, are quite allowable, seeing that they are undoubted improvements. Thus, it is maintained that to mix chicory with coffee is not only perfectly allowable, but commendable, seeing that the compound is by many considered to be superior to the pure coffee. So with the admixture of such things as flour and turmeric with mustard. As a third form of excuse, we have it openly asserted that certain things must be mixed with others in order to insure their preservation. With such energy, indeed, was this insisted on, that the legislature was actually constrained to legalise an admixture of a certain amount of oil of vitriol with vinegar, in order that thereby there might be conferred upon the latter certain keeping powers, which apparently it was supposed it did not of itself possess. Another excuse frequently made use of is, that it is perfectly impossible to supply pure articles at the current price. Finally, we have frequently the plea advanced that, after all, in many cases it does no harm—as in the addition of water to milk or whisky; therefore thus diluting these substances cannot be regarded as a criminal act.

These excuses are found to be all perfectly invalid. It is possible that one who was unacquainted with the subject, might prefer such things as bright green peas or pickles to those which were more of a yellow tint. If, however, he were informed—as he certainly should be—that the bright, fresh-looking article owed its taking appearance to the presence in it of a poisonous copper salt, it is impossible to suppose that he would still elect to be supplied with it. As to admixtures being improvements, this is of course largely a matter of opinion, but it is worthy of consideration in this connection that the articles which are added by way of improvement are always very much cheaper than the articles which are supposed to have been improved. Thus coffee costs about two shillings per pound, while chicory costs about fourpence. Mustard costs also about two shillings per pound, while flour, by the agency of which the mustard is improved, costs about one penny. With reference to the statement that admixture is necessary for the preservation of certain articles, if this is true at all, it is true of very few articles indeed. That it does not apply to vinegar is abundantly proved by the fact that the vinegar now made by most if not all of the better manufacturers does not contain a drop of sulphuric acid. The statement that adulteration is rendered necessary because the public refuse to pay a fair price for pure articles, is manifestly absurd, for it is the traders and not the public who fix the price; and if a trader were only mindful to inform his patrons that, while the purity of the less costly articles sold by himself and his brethren in trade could by no means be guaranteed, that of those which were a little higher in price was undoubted, he would not have reason long to complain of a want of demand for unadulterated wares. As to such an adulteration as the admixture of water with milk doing no harm, as well might it be said that selling milk by means of a measure which only holds half as much as it is represented to hold, does no harm. We are not thereby poisoned, but we are certainly defrauded as much in one case as in the other.

The objects of employing different materials in the adulteration of food may be said to be three in number. First, for the purpose of increasing the bulk or weight of the dearer article; as, for example, when water is added to milk or whisky, or when chicory is added to coffee, or flour to mustard, or butcher fat to butter. Second, to brighten its colour, or to alter or improve its appearance; as in the case of the addition of certain metallic compounds to preserved fruits or vegetables, or the addition of barley-meal to oatmeal, or of alum to bread. Third, to increase its pungency or alter its flavour; as, for example, when pepper is added to ginger, artificial flavourings to wine or to alcohol, as is done in the manufacture of spurious liquors, such as imitation brandy, &c.

As to the means which the public possesses of preventing the sale of adulterated food, it may be said that before this crime against society can effectually be put an end to, we must be able to do two things. First, we must be able satisfactorily to detect adulteration, however skilfully it may have been done; and second, we must be able to inflict on those proved to have been guilty of the crime such penalties as will render the practice of it unprofitable.

As the detection of the fraud and the consequent exposure often forms in itself the most salutary form of punishment, the subject of the detection of food adulteration becomes a most important one. It is effected mainly by two agencies, chemical analysis and microscopical examination. They are employed for this purpose by a body of well-educated, highly trained men, known as public analysts, one of whom is to be found in almost every town of any importance. The duties of these officials, as well as the mode in which they are appointed, will be described in the article ANALYST. Public analysts have not as yet been very long in existence, but the amount of work which they have already done in the way of checking adulteration of food is very great.

It was not until the year 1860 that any general act of parliament dealing with food adulteration was passed into law in Great Britain. Previous to that date, special statutes applying to certain specified articles, such as tea, coffee, bread, and wine, were in force; but the main object of these enactments was to prevent the defrauding of the revenue, the health and protection of the purchaser being apparently a matter of secondary importance. The Act of 1860 did not seem to produce much result, although it remained in force for twelve years. In 1872 another act was passed, which, however, as it was supposed to have been the means of inflicting many real hardships on retail dealers, was superseded by the 'Sale of Food and Drugs Acts' of 1875 and 1879. It is these acts which constitute the existing law on the subject of food adulteration. They are, no doubt, in many respects better than the previous acts, but they are still far from being perfect. One of their most glaring and palpable defects is, that though they lay down with commendable minuteness of detail the mode of proving adulteration, together with the penalties to be inflicted when adulteration is proved, they do not, except in the case of one or two descriptions of spirituous liquors, say what adulteration is. It is really therefore left to the analyst to define (except in a certain general sense) what constitutes adulteration. Analysts, it so happens, are not all at one on this point, so that it is not by any means an impossible circumstance that a substance which might be found to be adulterated, and for the sale of which a man might be fined or imprisoned in one county, would be decided in the adjacent county to be quite pure. What is obviously required in order that the act may be more workable and useful, is that adulteration should be defined in exact and precise terms. The act should set forth exactly what is to be considered as constituting adulteration in each separate article of food, so that when an analysis is obtained, there will be no doubt as to whether the article is pure.

The Sale of Food and Drugs Act, 1899, is an amending act dealing principally with dairy produce. It simplifies previous acts, and generally prohibits the importation or sale of any adulterated or impoverished article of 'food' (which has a new and very wide interpretation) unless in a tin or case with a true description of the contents. It also provides for imported dairy produce being sampled at the port of entry, so that, when necessary, action may be taken against the adulterator through the importer, instead of against the retailer. Stringent changes are made with regard to milk, butter, and margarine (see subsections Milk, Butter). Penalties for offences under the acts are increased, and additional stringency introduced into their application. The penalty for a first offence is £20; second, £50; third and subsequent, £100, and three months' imprisonment may be added if culpable personal default is proved. The following list, includes the more important of the substances often sold in an impure condition.

Milk is not only a most important article of food, but is the one most frequently subjected to adulteration. That it should be so we can easily understand. To conduct the business of a milk-seller but little capital is required; the trade is therefore largely in the hands of the lower class of traders. Then again, the admixture of water with milk, or the abstraction of cream, is not only very easy to perform, but it is also, unless by chemical analysis, very difficult to detect. The two forms of sophistication just mentioned are the only ways in which milk is ever adulterated. All the sensational stories of sheep's brains and chalk being used for this purpose are purely apocryphal. But though seemingly simple, and as compared with adulteration of other substances, tolerably harmless, this practice of reducing the quality of milk is really a very serious affair. Of all forms of food, not even excepting bread, milk is the one most largely used. In London alone, very nearly one and a half millions of money are annually paid for milk; and of this sum—according to a recent government return—about one-twentieth part, or from £70,000 to £80,000, is paid for water sold as milk. Judging from official reports made by analysts in different parts of the country, the practice of adulterating milk is carried on extensively in most, if not all the large towns in the kingdom.

The detection of adulteration in milk, unless by means of chemical analysis, is a very difficult matter. It may be done in a rough way either by taking the specific gravity of the milk, or by ascertaining how much cream it will throw up. The former operation is carried out by plunging into the milk, at a temperature of 60° F., an instrument called a Hydrometer (q.v.), which sinks in the milk to a greater or less extent, according as the specific gravity is high or low. The second operation is carried out by placing a quantity of the milk to be tested in a long narrow glass tube, closed at one end, which stands in an upright position, and is graduated into a hundred divisions. Enough milk having been poured in to occupy a hundred divisions, it is allowed to repose in the tube for at least twelve hours. Under these circumstances, the milk will throw up a certain proportion of cream, the exact amount of which can be easily read off by means of the graduated divisions. Good pure milk will throw up a sufficient amount of cream to occupy from twelve to fourteen divisions of the scale, and such milk should have a specific gravity of from 1029 to 1032. Milk from which the cream has been removed will, on the other hand, throw up much less cream than fourteen per cent.; and milk which has been adulterated by being simply mixed with water, will show a lower specific gravity than that given above. The act of 1899, already referred to, increases the penalty for selling condensed, skimmed, or separated milk, not labelled as such, to £10.

Bread.—Bread and sugar are the purest forms of food with which the public are at present supplied. The only adulteration which we now occasionally find in bread is alum, and possibly occasionally an excessive amount of common salt. The former is added for the purpose of communicating an admired white appearance to the bread, and the latter in order that it may retain an undue proportion of water. The alum, it is alleged, is often added by the miller in order that his inferior produce may yield bread having the appearance of that made from flour of a higher class. Both of these forms of adulteration are to be severely reprobated. Alum, according to many authorities, has the effect of seriously impairing the digestibility of bread; and salt added knowingly in excess of what is necessary is a fraud, whether the allegation that it causes the bread to retain water be true or not.

Alum may be detected in bread by laying a piece about two inches square upon a saucer, and then pouring upon it a small quantity of tincture of logwood, which has previously been mixed with its own bulk of carbonate of ammonia solution. If alum be present, the bread will turn blue by this treatment, whereas, if it be free from any admixture of this kind, it will become pink. Other substances besides alum which might be present in bread, have the effect of producing a blue colour with logwood, so that all we can certainly say as the result of this test is, that if a blue colour is produced, the bread is not pure, and that the impurity most probably is alum.

Other substances said to be used for adulterating bread are rice-flour, bran-flour, potatoes, borax, sulphate of copper, sulphate of zinc, chalk, and carbonate of magnesia. These, however, if they are ever employed at all, are employed to a very limited extent only; and in England in recent times, no conviction has been obtained except for admixture of alum.

Coffee is now extensively adulterated, insomuch that it is becoming a difficult matter to obtain it free from admixture. The material most commonly used for adulterating coffee is ground chicory-root. It is used for this purpose in enormous quantities, 40 or 50 per cent. being no unusual amount to find in coffee as frequently sold; and occasionally as much as 70, 80, or even 90 per cent. has been shown to be present. Coffee costs about two shillings per pound and chicory about fourpence, so that the temptation to sell a mixture of the two as coffee is very strong. As already mentioned, it is legal to sell the mixture if labelled as such. Chicory may be detected in coffee by allowing a few grains of the suspected article to fall into a glass of cold water. If the coffee is pure, almost all the little particles will, after one or two minutes, remain hard, and will continue to float on the surface, communicating very little colour to the water. If, on the other hand, chicory or any similar foreign substance be present, many of the little particles will become quite soft, and they will sink to the bottom, colouring the water more or less brown.

Cocoa is largely adulterated with sugar, arrow-root, and other starchy matters, with the view of concealing the cocoa-fat and enabling the powder to mix easily with boiling water.

Butter used to be extensively adulterated, and occasionally materials were sold as butter which contained very little or no butter at all. The original article called butterine was a poor compound of animal fats, manipulated with salt and milk, with or without a mixture of real butter, and was too often sold as butter. Owing to the stringency of the acts dealing with food adulteration, and particularly of the act of 1899, already referred to, this is no longer possible. The substance called margarine, which has superseded butterine, is, owing to greatly improved manufacture, a much superior article, and is really what it professes to be—a cheap substitute for butter, and, properly prepared, not an injurious substitute. By the act of 1899 the Margarine Act of 1887 is extended to include margarine-cheese and other products, and further and very stringent precautions are taken against their being imported or sold unless properly labelled as such. As a further precaution against its being sold as butter, margarine must not have more than 10 per cent. of real butter in its composition. The only adulterations now found in butter are boric preservatives and colouring matter.

Sugar is usually sold in a state of great purity; it should not have a damp appearance; it should have a pure, sweet taste; it should dissolve completely in cold water; and it should leave only a very small residue or ash when it is burned.

Tea was formerly much more extensively adulterated than it is at present. The only form of adulteration which we encounter in these days is in the so-called faced tea. This is nothing more than black tea, possibly not of a very high class, to which a fictitious appearance has been communicated by means of such things as indigo, Prussian blue, French chalk, plumbago, and lime being made to adhere to the surface of the leaf. This certainly is not a very serious form of adulteration, and it is very rapidly decreasing. When tea is heavily faced, the facing material may be detected by removing a portion of it either by friction on a soft piece of white cloth, or by digesting the leaves for a few minutes in a small quantity of warm water.

Oatmeal.—The only adulteration of oatmeal is barley-flour, added, it is said, for the purpose of giving the oatmeal a whiter appearance—to make, indeed, the meal produced from damaged or poor oats look as if it had been made from grain of a better quality. The presence of barley or any other similar substance in oatmeal is ascertained by means of the microscope. The starch granules of barley are large and somewhat oval; those of oats are smaller and angular.

Whisky is generally supposed to be extensively adulterated. This, however, is a mistaken belief. It is frequently sold when it is too new and not properly matured, and it is occasionally rather freely watered by some of the smaller retailers. Any other form of adulteration is, however, extremely rare. The strength can be ascertained by means of the hydrometer.

Brandy is a preparation resulting from the distillation of wine. There can be little doubt, however, that most of the brandy made in this country is simply a mixture of spirit with various flavouring materials, including, possibly, a small quantity of genuine brandy.

Wine.—The stronger wines, before they are imported, are generally 'fortified' by the addition of a certain amount of spirit. It is also alleged that wines are frequently coloured with various colouring matters. While this may be true of some of the very low-priced wines, it seems that, on the whole, wine for which a fair price has been paid, and which has been obtained at a respectable establishment, is fairly pure. A satisfactory test of the purity and quality of wine, and of similar spirituous liquors, cannot be made without employing somewhat complicated chemical processes.

Malt Liquors.—These vary in strength very considerably, from Scotch ale containing nearly 9 per cent. of alcohol, to table-beer containing sometimes as little as 2 per cent. Now that the use of other bitter principles than that derived from hops has been legalised, only such bitter substances as are deleterious can be regarded as adulterations. Picric acid is certainly a poison, and it has been detected in beer. Picrotoxin, the poisonous principle of Cocculus indicus, is another objectionable bitter substance, the presence of which in beer has been at least strongly suspected. It is supposed that other bitter substances, such as those existing in wormwood, in aloes, in gentian, and in quassia, are occasionally used in the manufacture of beer. These, however, if they are employed at all, are made use of very seldom. It was alleged on one occasion that large quantities of strychnine were habitually used by English brewers in the production of their famous bitter beer. This absurd statement was conclusively shown to be utterly destitute of foundation. The addition of undue quantities of salt to beer is an offence for which several persons have been prosecuted. The object of adulterating beer with salt is not very apparent, unless it is done with the intention of creating thirst. Salicylic acid has also occasionally been found in beer. The salicylic acid is a powerful preservative agent, and it is added with the view of conferring special keeping properties upon the beer. Sulphuric acid, sulphate of iron, and alum were at one time added to beer or porter by the London publicans, for the purpose of giving the liquor a 'smack of age,' and producing a head. This offence seems now to be of rare occurrence. An extensive epidemic of a form of neuritis in many of the midland towns of England in 1900 was traced to the presence of arsenic in beer, which in its turn was traced to 'inverted' sugar used in the manufacture, improperly prepared with impure sulphuric acid, causing the formation of arsenic.

Honey.—Much of the material sold as honey is really not honey at all. It is composed largely of starch—sugar or glucose, and contains a small quantity of real honey in order to communicate a little of the true flavour. The raw material from which this spurious mixture is made, is prepared by acting on potato starch with oil of vitriol. The result of this action is then mixed with a small proportion of real honey; it is then packed in neat jars and sent into the market. Unfortunately, there is no simple reliable test which can be applied by people outside of a chemical laboratory to detect this fraud, so skilfully are the materials chosen and the mixture made.

Pickles are now sold in a much purer condition than formerly. At one time it was apparently thought necessary that certain varieties of pickles should always possess a bright green colour. As the vegetables themselves did not exhibit this in a degree sufficiently pronounced, the requisite tint was produced by the agency of verdigris or of some other salt of copper. When such an adulteration as this does exist to any considerable extent, it may be detected by introducing the blade of a steel knife, which has been recently polished by means of fine sand-paper, into the vinegar in which the pickles are preserved. The presence of copper will be proclaimed by the appearance of a coating of metallic copper on the part of the knife immersed, after that has stood in contact with the liquid for a few minutes.

Mustard is at present adulterated to an enormous extent; indeed, it is only by the exercise of care that pure mustard can be obtained. The materials which are principally used for adulterating mustard are flour and the yellow dye-stuff, turmeric. It is alleged, on good authority, that cayenne pepper, ginger, and charlock are also employed; these, however, are not nearly in such common use. As in the case of honey, no simple test can be given by which the adulterations may, with certainty, be detected. The professional analyst employs for this purpose certain re-agents, which he adds to the mustard when it is arranged for observation under the microscope.

Pepper is frequently mixed with sand, occasionally with linseed-meal and other vegetable substances, and sometimes with starchy matters, such as wheat-flour, rice-flour, sago, &c. The most common adulteration, the sand, may be detected by burning the suspected pepper until all the vegetable matter is consumed, and making an examination of the ash. If sand is present, the ash will be rough and gritty; whereas if the pepper is pure, the ash will be fine, and few or no rough siliceous particles will be discernible in it.

Vinegar.—The substances employed for the adulteration of vinegar are few in number. The chief of them are water and sulphuric acid. It is stated that such things as chillies and grains of paradise are occasionally made use of for the same purpose. Adulteration by water is best detected by estimating the amount of real vinegar acid which is present. This, however, can only be done by means of a properly conducted chemical analysis. A rough test, however, may be made by means of the hydrometer. According to Hassall, vinegar which shows less than 1015 on the hydrometer scale is unquestionably adulterated with water. Sulphuric acid and other mineral acids may be detected by adding to the suspected vinegar a few drops of methyl aniline violet. If the vinegar be pure, no colour will result; but if it be mixed with sulphuric or any similar acid, a blue or green coloration will be developed.

Drugs.—Food adulteration, as of most interest and importance to the community generally, has been somewhat fully treated; in the other two main groups, drugs and miscellaneous articles used in the arts and manufactures, lists of the chief substances adulterated and of the most usual adulterants must here suffice; fuller information will be found under the articles on these various substances.

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