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A
TREATISE
ON
ADULTERATIONS OF FOOD,
AND CULINARY POISONS.
EXHIBITING
The Fraudulent Sophistications of
BREAD, BEER, WINE, SPIRITOUS LIQUORS, TEA, COFFEE, CREAM, CONFECTIONERY, VINEGAR, MUSTARD, PEPPER, CHEESE, OLIVE OIL, PICKLES,
AND OTHER ARTICLES EMPLOYED IN DOMESTIC ECONOMY.
AND
METHODS OF DETECTING THEM.
By Fredrick Accum,
OPERATIVE CHEMIST, AND MEMBER OF THE PRINCIPAL ACADEMIES AND SOCIETIES OF ARTS AND SCIENCES IN EUROPE.
Philadelphia: PRINTED AND PUBLISHED BY AB'M SMALL 1820.
PREFACE.
This Treatise, as its title expresses, is intended to exhibit easy methods of detecting the fraudulent adulterations of food, and of other articles, classed either among the necessaries or luxuries of the table; and to put the unwary on their guard against the use of such commodities as are contaminated with substances deleterious to health.
Every person is aware that bread, beer, wine, and other substances employed in domestic economy, are frequently met with in an adulterated state: and the late convictions of numerous individuals for counterfeiting and adulterating tea, coffee, bread, beer, pepper, and other articles of diet, are still fresh in the memory of the public.
To such perfection of ingenuity has the system of counterfeiting and adulterating various commodities of life arrived in this country, that spurious articles are every where to be found in the market, made up so skilfully, as to elude the discrimination of the most experienced judges.
But of all possible nefarious traffic and deception, practised by mercenary dealers, that of adulterating the articles intended for human food with ingredients deleterious to health, is the most criminal, and, in the mind of every honest man, must excite feelings of regret and disgust. Numerous facts are on record, of human food, contaminated with poisonous ingredients, having been vended to the public; and the annals of medicine record tragical events ensuing from the use of such food.
The eager and insatiable thirst for gain, is proof against prohibitions and penalties; and the possible sacrifice of a fellow-creature's life, is a secondary consideration among unprincipled dealers.
However invidious the office may appear, and however painful the duty may be, of exposing the names of individuals, who have been convicted of adulterating food; yet it was necessary, for the verification of my statement, that cases should be adduced in their support; and I have carefully avoided citing any, except those which are authenticated in Parliamentary documents and other public records.
To render this Treatise still more useful, I have also animadverted on certain material errors, sometimes unconsciously committed through accident or ignorance, in private families, during the preparation of various articles of food, and of delicacies for the table.
In stating the experimental proceedings necessary for the detection of the frauds which it has been my object to expose, I have confined myself to the task of pointing out such operations only as may be performed by persons unacquainted with chemical science; and it has been my purpose to express all necessary rules and instructions in the plainest language, divested of those recondite terms of science, which would be out of place in a work intended for general perusal.
The design of the Treatise will be fully answered, if the views here given should induce a single reader to pursue the object for which it is published; or if it should tend to impress on the mind of the Public the magnitude of an evil, which, in many cases, prevails to an extent so alarming, that we may exclaim with the sons of the Prophet,
"THERE IS DEATH IN THE POT."
For the abolition of such nefarious practices, it is the interest of all classes of the community to co-operate.
FREDRICK ACCUM.
LONDON. 1820.
CONTENTS.
PRELIMINARY OBSERVATIONS ON THE ADULTERATION OF FOOD Page 13
EFFECT OF DIFFERENT KINDS OF WATER EMPLOYED IN DOMESTIC ECONOMY 33
Characters of Good Water 37
Chemical Constitution of the Waters used in Domestic Economy and the Arts 40
Rain Water 40 Snow Water 41 Spring Water 42 River Water 44
Substances usually contained in Common Water, and Tests by which they are detected 48
Method of ascertaining the Quantity of each of the different Substances usually contained in Common Water 54
Deleterious Effects of keeping Water for Domestic Economy, in Leaden Reservoirs 60
Method of detecting Lead, when contained in common Water 69
ADULTERATION OF WINE 74
Method of detecting the Deleterious Adulterations of Wine 86
Specific Differences, and Component Parts of Wine 89
Easy process of ascertaining the Quantity of Brandy contained in various sorts of Wine 92
Tabular View, exhibiting the Per Centage of Brandy or Alcohol contained in various kinds of Wine and other fermented Liquors 94
Constitution of Home-made Wines 96
ADULTERATION OF BREAD 98
Method of detecting the Presence of Alum in Bread 108
Easy Method of judging of the Goodness of Bread-Corn and Bread-Flour 110
ADULTERATION OF BEER 113
List of Druggists and Grocers, prosecuted and convicted for supplying illegal Ingredients to Brewers for Adulterating Beer 119
Porter 121
Strength and Specific Differences of different kinds of Porter 125
List of Publicans prosecuted and convicted for adulterating Beer with illegal Ingredients, and for mixing Table Beer with their Strong Beer 129
Illegal Substances used for adulterating Beer 131
Ingredients seized at various Breweries and Brewers' Druggists, for adulterating Beer 136
List of Brewers prosecuted and convicted for adulterating Strong Beer with Table Beer 143
Old, or Entire Beer; and New or Mild Beer 144
List of Brewers prosecuted and convicted for receiving and using illegal Ingredients in their Brewings 151
Method of detecting the Adulteration of Beer 158
Method of ascertaining the Quantity of Spirit contained in Porter, Ale, &c. 160
Per Centage of Alcohol contained in Porter, and other kinds of Malt Liquors 162
COUNTERFEIT TEA-LEAVES 163
Methods of detecting the Adulterations of Tea-Leaves 171
COUNTERFEIT COFFEE 176
ADULTERATION OF BRANDY, RUM, AND GIN 187
Method of detecting the Adulterations of Brandy, Rum, and Malt Spirit 195
Method of detecting the Presence of Lead in Spiritous Liquors 202
Method of ascertaining the Quantity of Alcohol contained in different kinds of Spiritous Liquors 203
Table exhibiting the Per Centage of Alcohol contained in various kinds of Spiritous Liquors 205
POISONOUS CHEESE, and method of detecting it 206
COUNTERFEIT PEPPER, and Method of detecting it 211
White Pepper, and method of manufacturing it 213
POISONOUS CAYENNE PEPPER, and method of detecting it 215
POISONOUS PICKLES, and method of detecting them 217
ADULTERATION OF VINEGAR, and method of detecting it 220
Distilled Vinegar 221
ADULTERATION OF CREAM, and method of detecting it 222
POISONOUS CONFECTIONERY, and method of detecting it 224
POISONOUS CATSUP, and method of detecting it 227
POISONOUS CUSTARDS 231
POISONOUS ANCHOVY SAUCE, and method of detecting it 234
ADULTERATION OF LOZENGES, and method of detecting them 236
POISONOUS OLIVE OIL, and method of detecting it 239
ADULTERATION OF MUSTARD 241
ADULTERATION OF LEMON ACID, and method of detecting it 243
POISONOUS MUSHROOMS 246
Mushroom catsup 250
POISONOUS SODA WATER, and method of detecting it 251
FOOD POISONED BY COPPER VESSELS, and method of detecting it 252
FOOD POISONED BY LEADEN VESSELS, and method of detecting it 257
INDEX 261
A
TREATISE
ON
ADULTERATIONS OF FOOD,
AND
CULINARY POISONS.
PRELIMINARY OBSERVATIONS.
Of all the frauds practised by mercenary dealers, there is none more reprehensible, and at the same time more prevalent, than the sophistication of the various articles of food.
This unprincipled and nefarious practice, increasing in degree as it has been found difficult of detection, is now applied to almost every commodity which can be classed among either the necessaries or the luxuries of life, and is carried on to a most alarming extent in every part of the United Kingdom.
It has been pursued by men, who, from the magnitude and apparent respectability of their concerns, would be the least obnoxious to public suspicion; and their successful example has called forth, from among the retail dealers, a multitude of competitors in the same iniquitous course.
To such perfection of ingenuity has this system of adulterating food arrived, that spurious articles of various kinds are every where to be found, made up so skilfully as to baffle the discrimination of the most experienced judges.
Among the number of substances used in domestic economy which are now very generally found sophisticated, may be distinguished—tea, coffee, bread, beer, wine, spiritous liquors, salad oil, pepper, vinegar, mustard, cream, and other articles of subsistence.
Indeed, it would be difficult to mention a single article of food which is not to be met with in an adulterated state; and there are some substances which are scarcely ever to be procured genuine.
Some of these spurious compounds are comparatively harmless when used as food; and as in these cases merely substances of inferior value are substituted for more costly and genuine ingredients, the sophistication, though it may affect our purse, does not injure our health. Of this kind are the manufacture of factitious pepper, the adulterations of mustard, vinegar, cream, &c. Others, however, are highly deleterious; and to this class belong the adulterations of beer, wines, spiritous liquors, pickles, salad oil, and many others.
There are particular chemists who make it a regular trade to supply drugs or nefarious preparations to the unprincipled brewer of porter or ale; others perform the same office to the wine and spirit merchant; and others again to the grocer and the oilman. The operators carry on their processes chiefly in secresy, and under some delusive firm, with the ostensible denotements of a fair and lawful establishment.
These illicit pursuits have assumed all the order and method of a regular trade; they may severally claim to be distinguished as an art and mystery; for the workmen employed in them are often wholly ignorant of the nature of the substances which pass through their hands, and of the purposes to which they are ultimately applied.
To elude the vigilance of the inquisitive, to defeat the scrutiny of the revenue officer, and to ensure the secresy of these mysteries, the processes are very ingeniously divided and subdivided among individual operators, and the manufacture is purposely carried on in separate establishments. The task of proportioning the ingredients for use is assigned to one individual, while the composition and preparation of them may be said to form a distinct part of the business, and is entrusted to another workman. Most of the articles are transmitted to the consumer in a disguised state, or in such a form that their real nature cannot possibly be detected by the unwary. Thus the extract of coculus indicus, employed by fraudulent manufacturers of malt-liquors to impart an intoxicating quality to porter or ales, is known in the market by the name of black extract, ostensibly destined for the use of tanners and dyers. It is obtained by boiling the berries of the coculus indicus in water, and converting, by a subsequent evaporation, this decoction into a stiff black tenacious mass, possessing, in a high degree, the narcotic and intoxicating quality of the poisonous berry from which it is prepared. Another substance, composed of extract of quassia and liquorice juice, used by fraudulent brewers to economise both malt and hops, is technically called multum.[1]
The quantities of coculus indicus berries, as well as of black extract, imported into this country for adulterating malt liquors, are enormous. It forms a considerable branch of commerce in the hands of a few brokers: yet, singular as it may seem, no inquiry appears to have been hitherto made by the officers of the revenue respecting its application. Many other substances employed in the adulteration of beer, ale, and spiritous liquors, are in a similar manner intentionally disguised; and of the persons by whom they are purchased, a great number are totally unacquainted with their nature or composition.
An extract, said to be innocent, sold in casks, containing from half a cwt. to five cwt. by the brewers' druggists, under the name of bittern, is composed of calcined sulphate of iron (copperas), extract of coculus indicus berries, extract of quassia, and Spanish liquorice.
It would be very easy to adduce, in support of these remarks, the testimony of numerous individuals, by whom I have been professionally engaged to examine certain mixtures, said to be perfectly innocent, which are used in very extensive manufactories of the above description. Indeed, during the long period devoted to the practice of my profession, I have had abundant reason to be convinced that a vast number of dealers, of the highest respectability, have vended to their customers articles absolutely poisonous, which they themselves considered as harmless, and which they would not have offered for sale, had they been apprised of the spurious and pernicious nature of the compounds, and of the purposes to which they were destined.
For instance, I have known cases in which brandy merchants were not aware that the substance which they frequently purchase under the delusive name of flash, for strengthening and clarifying spiritous liquors, and which is held out as consisting of burnt sugar and isinglass only, in the form of an extract, is in reality a compound of sugar, with extract of capsicum; and that to the acrid and pungent qualities of the capsicum is to be ascribed the heightened flavour of brandy and rum, when coloured with the above-mentioned matter.
In other cases the ale-brewer has been supplied with ready-ground coriander seeds, previously mixed with a portion of nux vomica and quassia, to give a bitter taste and narcotic property to the beverage.
The retail venders of mustard do not appear to be aware that mustard seed alone cannot produce, when ground, a powder of so intense and brilliant a colour as that of the common mustard of commerce. Nor would the powder of real mustard, when mixed with salt and water, without the addition of a portion of pulverised capsicum, keep for so long a time as the mustard usually offered for sale.
Many other instances of unconscious deceptions might be mentioned, which were practised by persons of upright and honourable minds.
It is a painful reflection, that the division of labour which has been so instrumental in bringing the manufactures of this country to their present flourishing state, should have also tended to conceal and facilitate the fraudulent practices in question; and that from a correspondent ramification of commerce into a multitude of distinct branches, particularly in the metropolis and the large towns of the empire, the traffic in adulterated commodities should find its way through so many circuitous channels, as to defy the most scrutinising endeavour to trace it to its source.
It is not less lamentable that the extensive application of chemistry to the useful purposes of life, should have been perverted into an auxiliary to this nefarious traffic. But, happily for the science, it may, without difficulty, be converted into a means of detecting the abuse; to effect which, very little chemical skill is required; and the course to be pursued forms the object of the following pages.
The baker asserts that he does not put alum into bread; but he is well aware that, in purchasing a certain quantity of flour, he must take a sack of sharp whites (a term given to flour contaminated with a quantity of alum), without which it would be impossible for him to produce light, white, and porous bread, from a half-spoiled material.
The wholesale mealman frequently purchases this spurious commodity, (which forms a separate branch of business in the hands of certain individuals,) in order to enable himself to sell his decayed and half-spoiled flour.
Other individuals furnish the baker with alum mixed up with salt, under the obscure denomination of stuff. There are wholesale manufacturing chemists, whose sole business is to crystallise alum, in such a form as will adapt this salt to the purpose of being mixed in a crystalline state with the crystals of common salt, to disguise the character of the compound. The mixture called stuff, is composed of one part of alum, in minute crystals, and three of common salt. In many other trades a similar mode of proceeding prevails. Potatoes are soaked in water to augment their weight.
The practice of sophisticating the necessaries of life, being reduced to systematic regularity, is ranked by public opinion among other mercantile pursuits; and is not only regarded with less disgust than formerly, but is almost generally esteemed as a justifiable way to wealth.
It is really astonishing that the penal law is not more effectually enforced against practices so inimical to the public welfare. The man who robs a fellow subject of a few shillings on the high-way, is sentenced to death; while he who distributes a slow poison to a whole community, escapes unpunished.
It has been urged by some, that, under so vast a system of finance as that of Great Britain, it is expedient that the revenue should be collected in large amounts; and therefore that the severity of the law should be relaxed in favour of all mercantile concerns in proportion to their extent: encouragement must be given to large capitalists; and where an extensive brewery or distillery yields an important contribution to the revenue, no strict scrutiny need be adopted in regard to the quality of the article from which such contribution is raised, provided the excise do not suffer by the fraud.
But the principles of the constitution afford no sanction to this preference, and the true interests of the country require that it should be abolished; for a tax dependent upon deception must be at best precarious, and must be, sooner or later, diminished by the irresistible diffusion of knowledge. Sound policy requires that the law should be impartially enforced in all cases; and if its penalties were extended to abuses of which it does not now take cognisance, there is no doubt that the revenue would be abundantly benefited.
Another species of fraud, to which I shall at present but briefly advert, and which has increased to so alarming an extent, that it loudly calls for the interference of government, is the adulteration of drugs and medicines.
Nine-tenths of the most potent drugs and chemical preparations used in pharmacy, are vended in a sophisticated state by dealers who would be the last to be suspected. It is well known, that of the article Peruvian bark, there is a variety of species inferior to the genuine; that too little discrimination is exercised by the collectors of this precious medicament; that it is carelessly assorted, and is frequently packed in green hides; that much of it arrives in Spain in a half-decayed state, mixed with fragments of other vegetables and various extraneous substances; and in this state is distributed throughout Europe.
But as if this were not a sufficient deterioration, the public are often served with a spurious compound of mahogany saw-dust and oak wood, ground into powder mixed with a proportion of good quinquina, and sold as genuine bark powder.
Every chemist knows that there are mills constantly at work in this metropolis, which furnish bark powder at a much cheaper rate than the substance can be procured for in its natural state. The price of the best genuine bark, upon an average, is not lower than twelve shillings the pound; but immense quantities of powder bark are supplied to the apothecaries at three or four shillings a pound.
It is also notorious that there are manufacturers of spurious rhubarb powder, ipecacuanha powder,[2] James's powder; and other simple and compound medicines of great potency, who carry on their diabolical trade on an amazingly large scale. Indeed, the quantity of medical preparations thus sophisticated exceeds belief. Cheapness, and not genuineness and excellence, is the grand desideratum with the unprincipled dealers in drugs and medicines.
Those who are familiar with chemistry may easily convince themselves of the existence of the fraud, by subjecting to a chemical examination either spirits of hartshorn, magnesia, calcined magnesia, calomel, or any other chemical preparation in general demand.
Spirit of hartshorn is counterfeited by mixing liquid caustic ammonia with the distilled spirit of hartshorn, to increase the pungency of its odour, and to enable it to bear an addition of water.
The fraud is detected by adding spirit of wine to the sophisticated spirit; for, if no considerable coagulation ensues, the adulteration is proved. It may also be discovered by the hartshorn spirit not producing a brisk effervescence when mixed with muriatic or nitric acid.
Magnesia usually contains a portion of lime, originating from hard water being used instead of soft, in the preparation of this medicine.
To ascertain the purity of magnesia, add to a portion of it a little sulphuric acid, diluted with ten times its bulk of water. If the magnesia be completely soluble, and the solution remains transparent, it may be pronounced pure; but not otherwise. Or, dissolve a portion of the magnesia in muriatic acid, and add a solution of sub-carbonate of ammonia. If any lime be present, it will form a precipitate; whereas pure magnesia will remain in solution.
Calcined magnesia is seldom met with in a pure state. It may be assayed by the same tests as the common magnesia. It ought not to effervesce at all, with dilute sulphuric acid; and, if the magnesia and acid be put together into one scale of a balance, no diminution of weight should ensue on mixing them together. Calcined magnesia, however, is very seldom so pure as to be totally dissolved by diluted sulphuric acid; for a small insoluble residue generally remains, consisting chiefly of silicious earth, derived from the alkali employed in the preparation of it. The solution in sulphuric acid, when largely diluted, ought not to afford any precipitation by the addition of oxalate of ammonia.
The genuineness of calomel may be ascertained by boiling, for a few minutes, one part, with 1/32 part of muriate of ammonia in ten parts of distilled water. When carbonate of potash is added to the filtered solution, no precipitation will ensue if the calomel be pure.
Indeed, some of the most common and cheap drugs do not escape the adulterating hand of the unprincipled druggist. Syrup of buckthorn, for example, instead of being prepared from the juice of buckthorn berries, (rhamnus catharticus,) is made from the fruit of the blackberry bearing alder, and the dogberry tree. A mixture of the berries of the buckthorn and blackberry bearing alder, and of the dogberry tree, may be seen publicly exposed for sale by some of the venders of medicinal herbs. This abuse may be discovered by opening the berries: those of buckthorn have almost always four seeds; of the alder, two; and of the dogberry, only one. Buckthorn berries, bruised on white paper, stain it of a green colour, which the others do not.
Instead of worm-seed (artemisia santonica,) the seeds of tansy are frequently offered for sale, or a mixture of both.
A great many of the essential oils obtained from the more expensive spices, are frequently so much adulterated, that it is not easy to meet with such as are at all fit for use: nor are these adulterations easily discoverable. The grosser abuses, indeed, may be readily detected. Thus, if the oil be adulterated with alcohol, it will turn milky on the addition of water; if with expressed oils, alcohol will dissolve the volatile, and leave the other behind; if with oil of turpentine, on dipping a piece of paper in the mixture, and drying it with a gentle heat, the turpentine will be betrayed by its smell. The more subtile artists, however, have contrived other methods of sophistication, which elude all trials. And as all volatile oils agree in the general properties of solubility in spirit of wine, and volatility in the heat of boiling water, &c. it is plain that they may be variously mixed with each other, or the dearer sophisticated with the cheaper, without any possibility of discovering the abuse by any of the before-mentioned trials. Perfumers assert that the smell and taste are the only certain tests of which the nature of the thing will admit. For example, if a bark should have in every respect the appearance of good cinnamon, and should be proved indisputably to be the genuine bark of the cinnamon tree; yet if it want the cinnamon flavour, or has it but in a low degree, we reject it: and the case is the same with the essential oil of cinnamon. It is only from use and habit, or comparisons with specimens of known quality, that we can judge of the goodness, either of the drugs themselves, or of their oils.
Most of the arrow-root, the fecula of the Maranta arudinacea, sold by druggists, is a mixture of potatoe starch and arrow-root.
The same system of adulteration extends to articles used in various trades and manufactures. For instance, linen tape, and various other household commodities of that kind, instead of being manufactured of linen thread only, are made up of linen and cotton. Colours for painting, not only those used by artists, such as ultramarine,[3] carmine,[4] and lake;[5] Antwerp blue,[6] chrome yellow,[7] and Indian ink;[8] but also the coarser colours used by the common house-painter are more or less adulterated. Thus, of the latter kind, white lead[9] is mixed with carbonate or sulphate of barytes; vermilion[10] with red lead.
Soap used in house-keeping is frequently adulterated with a considerable portion of fine white clay, brought from St. Stephens, in Cornwall. In the manufacture of printing paper, a large quantity of plaster of Paris is added to the paper stuff, to increase the weight of the manufactured article. The selvage of cloth is often dyed with a permanent colour, and artfully stitched to the edge of cloth dyed with a fugitive dye. The frauds committed in the tanning of skins, and in the manufacture of cutlery and jewelry, exceed belief.
The object of all unprincipled modern manufacturers seems to be the sparing of their time and labour as much as possible, and to increase the quantity of the articles they produce, without much regard to their quality. The ingenuity and perseverance of self-interest is proof against prohibitions, and contrives to elude the vigilance of the most active government.
The eager and insatiable thirst for gain, which seems to be a leading characteristic of the times, calls into action every human faculty, and gives an irresistible impulse to the power of invention; and where lucre becomes the reigning principle, the possible sacrifice of even a fellow creature's life is a secondary consideration. In reference to the deterioration of almost all the necessaries and comforts of existence, it may be justly observed, in a civil as well as a religious sense, that "in the midst of life we are in death."
FOOTNOTES:
[1] The Times, May 18, 1818. The King v. Richard Bowman. The defendant was a brewer, living in Wapping-street, Wapping, and was charged with having in his possession a drug called multum, and a quantity of copperas.
The articles were produced by Thomas Gates, an excise officer, who had, after a search, found them on the defendant's premises. The Court sentenced the defendant to pay a fine of 200l.
The King v. Luke Lyons. The defendant is a brewer, and was brought up under an indictment charging him with having made use of various deleterious drugs in his brewery, among which were capsicum, copperas, &c. The defendant was ordered to pay the fines of 20l. upon the first count, 200l. upon the third, and 200l. upon the seventh count in the indictment.
The King v. Thomas Evans. The charge against this defendant was, that he had in his possession forty-seven barrels of stale unpalatable beer. On, the 11th of March, John Wilson, an excise officer, went to the storehouse, and found forty-seven casks containing forty-three barrels and a half of sour unwholesome beer. Several samples of the beer were produced, all of them of a different colour, and filled with sediment. A fine of 30l. was ordered to be paid by the defendant.
[2] Of this root, several varieties are imported. The white sort, which has no wrinkles, and no perceptible bitterness in taste, and which, though taken in a large dose, has scarcely any effect at all, after being pulverised by fraudulent druggists, and mixed with a portion of emetic tartar, is sold, at a low price, for the powder of genuine ipecacuanha root.
[3] Genuine ultramarine should become deprived of its colour when thrown into concentrated nitric acid.
[4] Genuine carmine should be totally soluble in liquid ammonia.
[5] Genuine madder and carmine lakes should be totally soluble by boiling in a concentrated solution of soda or potash.
[6] Genuine Antwerp blue should not become deprived of its colour when thrown into liquid chlorine.
[7] Genuine chrome yellow should not effervesce with nitric acid.
[8] The best Indian ink breaks, splintery, with a smooth glossy fracture, and feels soft, and not gritty, when rubbed against the teeth.
[9] Genuine white lead should be completely soluble in nitric acid, and the solution should remain transparent when mingled with a solution of sulphate of soda.
[10] Genuine vermilion should become totally volatilised on being exposed to a red heat; and it should not impart a red colour to spirit of wine, when digested with it.
REMARKS
ON THE
Effect of different Kinds of Waters
IN THEIR APPLICATION TO
DOMESTIC ECONOMY AND THE ARTS;
AND
METHODS OF ASCERTAINING THEIR PURITY.
It requires not much reflection to become convinced that the waters which issue from the recesses of the earth, and form springs, wells, rivers, or lakes, often materially differ from each other in their taste and other obvious properties. There are few people who have not observed a difference in the waters used for domestic purposes and in the arts; and the distinctions of hard and soft water are familiar to every body.
Water perfectly pure is scarcely ever met with in nature.
It must also be obvious, that the health and comfort of families, and the conveniences of domestic life, are materially affected by the supply of good and wholesome water. Hence a knowledge of the quality and salubrity of the different kinds of waters employed in the common concerns of life, on account of the abundant daily use we make of them in the preparation of food, is unquestionably an object of considerable importance, and demands our attention.
The effects produced by the foreign matters which water may contain, are more considerable, and of greater importance, than might at first be imagined. It cannot be denied, that such waters as are hard, or loaded with earthy matter, have a decided effect upon some important functions of the human body. They increase the distressing symptoms under which those persons labour who are afflicted with what is commonly called gravel complaints; and many other ailments might be named, that are always aggravated by the use of waters abounding in saline and earthy substances.
The purity of the waters employed in some of the arts and manufactures, is an object of not less consequence. In the process of brewing malt liquors, soft water is preferable to hard. Every brewer knows that the largest possible quantity of the extractive matter of the malt is obtained in the least possible time, and at the smallest cost, by means of soft water.
In the art of the dyer, hard water not only opposes the solution of several dye stuffs, but it also alters the natural tints of some delicate colours; whilst in others again it precipitates the earthy and saline matters with which it is impregnated, into the delicate fibres of the stuff, and thus impedes the softness and brilliancy of the dye.
The bleacher cannot use with advantage waters impregnated with earthy salts; and a minute portion of iron imparts to the cloth a yellowish hue.
To the manufacturer of painters' colours, water as pure as possible is absolutely essential for the successful preparation of several delicate pigments. Carmine, madder lake, ultramarine, and Indian yellow, cannot be prepared without perfectly pure water.
For the steeping or raiting of flax, soft water is absolutely necessary; in hard water the flax may be immersed for months, till its texture be injured, and still the ligneous matter will not be decomposed, and the fibres properly separated.
In the culinary art, the effects of water more or less pure are likewise obvious. Good and pure water softens the fibres of animal and vegetable matters more readily than such as is called hard. Every cook knows that dry or ripe pease, and other farinaceous seeds, cannot readily be boiled soft in hard water; because the farina of the seed is not perfectly soluble in water loaded with earthy salts.
Green esculent vegetable substances are more tender when boiled in soft water than in hard water; although hard water imparts to them a better colour. The effects of hard and soft water may be easily shown in the following manner.
EXPERIMENT.
Let two separate portions of tea-leaves be macerated, by precisely the same processes, in circumstances all alike, in similar and separate vessels, the one containing hard and the other soft water, either hot or cold, the infusion made with the soft water will have by far the strongest taste, although it possesses less colour than the infusion made with the hard water. It will strike a more intense black with a solution of sulphate of iron, and afford a more abundant precipitate, with a solution of animal jelly, which at once shews that soft water has extracted more tanning matter, and more gallic acid, from the tea-leaves, than could be obtained from them under like circumstances by means of hard water.
Many animals which are accustomed to drink soft water, refuse hard water. Horses in particular prefer the former. Pigeons refuse hard water when they have been accustomed to soft water.
CHARACTERS OF GOOD WATER.
A good criterion of the purity of water fit for domestic purposes, is its softness. This quality is at once obvious by the touch, if we only wash our hands in it with soap. Good water should be beautifully transparent; a slight opacity indicates extraneous matter. To judge of the perfect transparency of water, a quantity of it should be put into a deep glass vessel, the larger the better, so that we can look down perpendicularly into a considerable mass of the fluid; we may then readily discover the slightest degree of muddiness much better than if the water be viewed through the glass placed between the eye and the light. It should be perfectly colourless, devoid of odour, and its taste soft and agreeable. It should send out air-bubbles when poured from one vessel into another; it should boil pulse soft, and form with soap an uniform opaline fluid, which does not separate after standing for several hours.
It is to the presence of common air and carbonic acid gas that common water owes its taste, and many of the good effects which it produces on animals and vegetables. Spring water, which contains more air, has a more lively taste than river water.
Hence the insipid or vapid taste of newly boiled water, from which these gases are expelled: fish cannot live in water deprived of those elastic fluids.
100 cubic inches of the New River water, with which part of this metropolis is supplied, contains 2,25 of carbonic acid, and 1,25 of common air. The water of the river Thames contains rather a larger quantity of common air, and a smaller portion of carbonic acid.
If water not fully saturated with common air be agitated with this elastic fluid, a portion of the air is absorbed; but the two chief constituent gases of the atmosphere, the oxygen and nitrogen, are not equally affected, the former being absorbed in preference to the latter.
According to Mr. Dalton, in agitating water with atmospheric air, consisting of 79 of nitrogen, and 21 of oxygen, the water absorbs 1/64 of 79/100 nitrogen gas = 1,234, and 1/27 of 21/100 oxygen gas = 778, amounting in all to 2,012.
Water is freed from foreign matter by distillation: and for any chemical process in which accuracy is requisite, distilled water must be used.
Hard waters may, in general, be cured in part, by dropping into them a solution of sub-carbonate of potash; or, if the hardness be owing only to the presence of super-carbonate of lime, mere boiling will greatly remedy the defect; part of the carbonic acid flies off, and a neutral carbonate of lime falls down to the bottom; it may then be used for washing, scarcely curdling soap. But if the hardness be owing in part to sulphate of lime, boiling does not soften it at all.
When spring water is used for washing, it is advantageous to leave it for some time exposed to the open air in a reservoir with a large surface. Part of the carbonic acid becomes thus dissipated, and part of the carbonate of lime falls to the bottom. Mr. Dalton[11] has observed that the more any spring is drawn from, the softer the water becomes.
CHEMICAL CONSTITUTION OF THE WATERS USED IN DOMESTIC ECONOMY AND THE ARTS.
Rain Water,
Collected with every precaution as it descends from the clouds, and at a distance from large towns, or any other object capable of impregnating the atmosphere with foreign matters, approaches more nearly to a state of purity than perhaps any other natural water. Even collected under these circumstances, however, it invariably contains a portion of common air and carbonic acid gas. The specific gravity of rain water scarcely differs from that of distilled water; and from the minute portions of the foreign ingredients which it generally contains, it is very soft, and admirably adapted for many culinary purposes, and various processes in different manufactures and the arts.
Fresh-fallen snow, melted without the contact of air, appears to be nearly free from air. Gay-Lussac and Humboldt, however, affirm, that it contains nearly the usual proportion of air.
Water from melted ice does not contain so much air. Dew has been supposed to be saturated with air.
Snow water has long laid under the imputation of occasioning those strumous swellings in the neck which deform the inhabitants of many of the Alpine vallies; but this opinion is not supported by any well-authenticated indisputable facts, and is rendered still more improbable, if not entirely overturned, by the frequency of the disease in Sumatra[12], where ice and snow are never seen.
In high northern latitudes, thawed snow forms the constant drink of the inhabitants during winter; and the vast masses of ice which float on the polar seas, afford an abundant supply of fresh water to the mariner.
Spring Water,
Includes well-water and all others that arise from some depth below the surface of the earth, and which are used at the fountain-head, or at least before they have run any considerable distance exposed to the air. Indeed, springs may be considered as rain water which has passed through the fissures of the earth, and, having accumulated at the bottom of declivities, rises again to the surface forming springs and wells. As wells take their origin at some depth from the surface, and below the influence of the external atmosphere, their temperature is in general pretty uniform during every vicissitude of season, and always several degrees lower than the atmosphere. They differ from one another according to the nature of the strata through which they issue; for though the ingredients usually existing in them are in such minute quantities as to impart to the water no striking properties, and do not render it unfit for common purposes, yet they modify its nature very considerably. Hence the water of some springs is said to be hard, of others soft, some sweet, others brackish, according to the nature and degree of the inpregnating ingredients.
Common springs are insensibly changed into mineral or medicinal springs, as their foreign contents become larger or more unusual; or, in some instances, they derive medicinal celebrity from the absence of those ingredients usually occurring in spring-water; as, for example, is the case with the Malvern spring, which is nearly pure water.
Almost all spring-waters possess the property termed hardness in a greater or less degree; a property which depends chiefly upon the presence of super-carbonate, or of sulphate of lime, or of both; and the quantity of these earthy salts varies very considerably in different instances. Mr. Dalton[13] has shewn that one grain of sulphate of lime, contained in 2000 grains of water, converts it into the hardest spring water that is commonly met with.
The waters of deep wells are usually much harder than those of springs which overflow the mouth of the well; but there are some exceptions to this rule.
The purest springs are those which occur in primitive rocks, or beds of gravel, or filter through sand or silicious strata. In general, large springs are purer than small ones: and our old wells contain finer water than those that are new, as the soluble parts through which the water filters in channels under ground become gradually washed away.
River Water,
Is a term applied to every running stream or rivulet exposed to the air, and always flowing in an open channel. It is formed of spring water, which, by exposure, becomes more pure, and of running land or surface water, which, although turbid from particles of the alluvial soil suspended in it, is otherwise very pure. It is purest when it runs over a gravelly or rocky bed, and when its course is swift. It is generally soft, and more free from earthy salts than spring water; but it usually contains less common air and carbonic acid gas; for, by the agitation of a long current, and exposed to the temperature of the atmosphere, part of its carbonic acid gas is disengaged, and the lime held in solution by it is in part precipitated, the loss of which contributes to the softness of the water. Its specific gravity thereby becomes less, the taste not so harsh, but less fresh and agreeable; and out of a hard spring is often made a stream of sufficient purity for most of the purposes where a soft water is required.
The water called in this metropolis New River Water, contains a minute portion of muriate of lime, carbonate of lime, and muriate of soda.
Some streams, however, that arise from clean silicious beds, and flow in a sandy or stony channel, are from the outset remarkably pure; such as the mountain lakes and rivulets in the rocky districts of Wales, the source of the beautiful waters of the Dee, and numberless other rivers that flow through the hollow of every valley. Switzerland has long been celebrated for the purity and excellence of its waters, which pour in copious streams from the mountains, and give rise to the finest rivers in Europe.
Some rivers, however, that do not take their rise from a rocky soil, and are indeed at first considerably charged with foreign matter, during a long course, even over a richly cultivated plain, become remarkably pure as to saline contents; but often fouled with mud containing much animal and vegetable matter, which are rather suspended than held in true solution. Such is the water of the river Thames, which, taken up at London at low water mark, is very soft and good; and, after rest, it contains but a very small portion of any thing that could prove pernicious, or impede any manufacture. It is also excellently fitted for sea-store; but it then undergoes a remarkable spontaneous change, when preserved in wooden casks. No water carried to sea becomes putrid sooner than that of the Thames. But the mode now adopted in the navy of substituting iron tanks for wooden casks, tends greatly to obviate this disadvantage.
Whoever will consider the situation of the Thames, and the immense population along its banks for so many miles, must at once perceive the prodigious accumulation of animal matters of all kinds, which by means of the common sewers constantly make their way into it. These matters are, no doubt, in part the cause of the putrefaction which it is well known to undergo at sea, and of the carburetted and sulphuretted hydrogen gases which are evolved from it. When a wooden cask is opened, after being kept a month or two, a quantity of carburetted and sulphuretted hydrogen escapes, and the water is so black and offensive as scarcely to be borne. Upon racking it off, however, into large earthen vessels, and exposing it to the air, it gradually deposits a quantity of black slimy mud, becomes clear as crystal, and remarkably sweet and palatable.
It might, at first sight, be expected that the water of the Thames, after having received all the contents of the sewers, drains, and water courses, of a large town, should acquire thereby such impregnation with foreign matters, as to become very impure; but it appears, from the most accurate experiments that have been made, that those kinds of impurities have no perceptible influence on the salubrious quality of a mass of water so immense, and constantly kept in motion by the action of the tides.
Some traces of animal matter may, however, be detected in the water of the Thames; for if nitrate of lead be dropped into it,[14] "you will find that it becomes milky, and that a white powder falls to the bottom, which dissolves without effervescence in nitric acid. It is, therefore, (says Dr. Thomson) a combination of oxide of lead with some animal matter."
SUBSTANCES USUALLY CONTAINED IN COMMON WATER, AND TESTS BY WHICH THEY ARE DETECTED.
To acquire a knowledge of the general nature of common water, it is only necessary to add to it a few chemical tests, which will quickly indicate the presence or absence of the substances that may be expected.
Almost the only salts contained in common waters are the carbonates, sulphates, and muriates of soda, lime, and magnesia; and sometimes a very minute portion of iron may also be detected in them.
EXPERIMENT.
Fill a wine-glass with distilled water, and add to it a few drops of a solution of soap in alcohol, the water will remain transparent.
This test is employed for ascertaining the presence of earthy salts in waters. Hence it produces no change when mingled with distilled or perfectly pure water; but when added to water containing earthy salts, a white flocculent matter becomes separated, which speedily collects on the surface of the fluid. Now, from the quantity of flocculent matter produced, in equal quantities of water submitted to the test, a tolerable notion may be formed of the degrees of hardness of different kinds of water, at least so far as regards the fitness of the water for the ordinary purposes of domestic economy. This may be rendered obvious in the following manner.
EXPERIMENT.
Fill a number of wine-glasses with different kinds of pump or well water, and let fall into each glass a few drops of the solution of soap in alcohol. A turbidness will instantly ensue, and a flocculent matter collect on the surface of the fluid, if the mixture be left undisturbed. The quantity of flocculent matter will be in the ratio of the quantity of earthy salts contained in the water.
It is obvious that the action of this test is not discriminative, with regard to the chemical nature of the earthy salt present in the water. It serves only to indicate the presence or absence of those kinds of substances which occasion that quality in water which is usually called hardness, and which is always owing to salts with an earthy base.
If we wish to know the nature of the different acids and earths contained in the water, the following test may be employed.[15]
EXPERIMENT.
Add about twenty drops of a solution of oxalate of ammonia, to half a wine-glass of the water; if a white precipitate ensues, we conclude that the water contains lime.
By means of this test, one grain of lime may be detected in 24,250 of water.
If this test occasion a white precipitate in water taken fresh from the pump or spring, and not after the water has been boiled and suffered to grow cold, the lime is dissolved in the water by an excess of carbonic acid; and if it continues to produce a precipitate in the water which has been concentrated by boiling, we then are sure that the lime is combined with a fixed acid.
EXPERIMENT.
To detect the presence of iron, add to a wine-glassful of the water a few drops of an infusion of nut-galls; or better, suffer a nut-gall to be suspended in it for twenty-four hours, which will cause the water to acquire a blueish black colour, if iron be present.
EXPERIMENT.
Add a few grains of muriate of barytes, to half a wine-glass of the water to be examined; if it produces a turbidness which does not disappear by the admixture of a few drops of muriatic acid, the presence of sulphuric acid is rendered obvious.
EXPERIMENT.
If a few drops of a solution of nitrate of silver occasions a milkiness with the water, which vanishes again by the copious addition of liquid ammonia, we have reason to believe that the water contains a salt, one of the constituent parts of which is muriatic acid.
EXPERIMENT.
If lime water or barytic water occasions a precipitate which again vanishes by the admixture of muriatic acid, then carbonic acid is present in the water.
EXPERIMENT.
If a solution of phosphate of soda produces a milkiness with the water, after a previous addition to it of a similar quantity of neutral carbonate of ammonia, we may then expect magnesia. The application of this test is best made in the following manner:
Concentrate a quantity of the water to be examined to about 1/20 part of its bulk, and drop into about half a wine-glassful, about five grains of neutral carbonate of ammonia. No magnesia becomes yet precipitated if this earth be present; but on adding a like quantity of phosphate of soda, the magnesia falls down, as an insoluble salt. It is essential that the carbonate of ammonia be neutral.
This test was first pointed out by Dr. Wollaston.
The presence of oxygen gas loosely combined in water may readily be discovered in the following manner.
EXPERIMENT.
Fill a vial with water, and add to it a small quantity of green sulphate of iron. If the water be entirely free of oxygen, and if the vessel be well stopped and completely filled, the solution is transparent; but if otherwise, it soon becomes slightly turbid, from the oxide of iron attracting the oxygen, and a small portion of it, in this more highly oxidated state, leaving the acid and being precipitated. Or, according to a method pointed out by Driessen, the water is to be boiled for two hours in a flask filled with it, and immersed in a vessel of water kept boiling, with the mouth of the flask under the surface of the water: it is to be inverted in quicksilver, taking care that no air-bubble adheres to the side of the flask, and being tinged with infusion of litmus, a little nitrous gas is to be introduced: if the oxygen gas has been sufficiently expelled from the water, the purple colour of the litmus does not change; while, if oxygen be present, it immediately becomes red.[16]
If we examine the different waters which are used for the ordinary purposes of life, and judge of them by the above tests, we shall find them to differ considerably from each other. Some contain a large quantity of saline and earthy matters, whilst others are nearly pure. The differences are produced by the great solvent power which water exercises upon most substances. Wells should never be lined with bricks, which render soft water hard; or, if bricks be employed, they should be bedded in and covered with cement.
METHOD OF ASCERTAINING THE RELATIVE QUANTITY OF EACH OF THE DIFFERENT SUBSTANCES USUALLY CONTAINED IN COMMON WATER.
To ascertain the quantity of earthy and saline matter contained in water, the following is the most simple and easy method.
EXPERIMENT.
Put any measured quantity of the water into a platina, or silver evaporating basin, the weight of which is known, and evaporate the water upon a steam bath, at a temperature of about 180 deg., nearly to dryness; and, lastly, remove the basin to a sand bath, and let the mass be evaporated to perfect dryness. The weight of the platina basin being already known, we have only to weigh it carefully. When the solid saline contents of the water is attached to it, the increase of weight gives the quantity of solid matter contained in a given quantity of the water.
EXPERIMENT.
Pour upon the saline contents a quantity of distilled water equal to that in which the obtained salts were originally dissolved. If the whole saline matter become dissolved in this water, there is reason to believe that the saline matter has not been altered during the evaporation of the water. But if a portion remain undissolved, as is usually the case, then we may conclude that some of the salts have mutually decomposed each other, when brought into a concentrated state by the evaporation, and that salts have been formed which did not originally exist in the water before its evaporation.
We have already mentioned that almost the only salts contained in common waters, are the carbonates, sulphates, and muriates, of soda, lime, and magnesia; and sometimes a very minute portion of iron. Having determined the different acids and bases present, in the manner stated at p. 49, we may easily ascertain the relative weight of each.
The following formula suggested by Dr. Murray,[17] is fully as accurate a means of analysing waters as any other, and it is easy of execution. The weight of the saline ingredients of a given quantity of water being determined, we may proceed to the accurate analysis of it in the following manner.
EXPERIMENT.
Measure out a determinate volume of the water (as 500 or 1000 cubic inches,) and evaporate it gradually, in an unglazed open vessel defended from dust, to one third of its original bulk; then divide this evaporated liquid into three equal portions.
EXPERIMENT.
Drop into the first portion, muriate of barytes; wash the precipitate, collect it, dry it at a red heat upon platina foil, and weigh it; digest it in nitric acid, dry it, and weigh it again. The loss of weight indicates the quantity of carbonate of barytes which the precipitate contained. The residual weight is sulphate of barytes; the carbonic acid in the water is equivalent to 0,22 of the weight of the carbonate of barytes; the sulphuric acid to 0,339 of the weight of the sulphate of barytes.
EXPERIMENT.
Precipitate the second portion of the concentrated water, by the addition of nitrate of silver; wash the precipitate, dry it, and fuse it on a piece of foil platina, previously weighed. By weighing the foil containing the fused chloride of silver, the weight of the precipitate may be ascertained. The fourth part of this weight is equivalent to the weight of the muriatic acid contained in the portion of water precipitated.
EXPERIMENT.
Precipitate the third portion of the water by the addition of oxalate of ammonia; wash and dry the precipitate; expose it to a red heat, on a platina foil, or in a capsule of platina; pour on it some dilute sulphuric acid; digest for some time, then evaporate to dryness, expose the capsule to a pretty strong heat, and, lastly, weigh the sulphate of lime thus produced: 0.453 of its weight indicate the quantity of lime in the portion of water precipitated.
EXPERIMENT.
Add to the same third portion of the water thus freed from lime, a portion of a solution of neutral carbonate of ammonia, and then add phosphoric acid, drop by drop, as long as any precipitate falls down. Wash the precipitate, dry it, and expose it to a red heat in a platina capsule: it is phosphate of magnesia. 0.357 of the weight of this salt is equivalent to the weight of the magnesia contained in the water.
EXPERIMENT.
If the water contain a minute portion of iron, a quantity of it equal to one of the three preceding portions, must be taken and mixed with a solution of benzoate of ammonia. The precipitate being washed, dried, and exposed to a red heat, and weighed, nine-tenths of its weight indicate the weight of protoxide of iron contained in the water.
In this manner the quantity of all the substances contained in the water will be ascertained, except there be any soda. To know the amount of it, the following method, pointed out by Dr. Murray, answers very well.
EXPERIMENT.
Evaporate a portion of the water to one third of its bulk. Precipitate the carbonic and sulphuric acids by the addition of muriate of barytes, taking care not to add any excess of the tests.
Precipitate the lime by oxalate of ammonia, and the magnesia by carbonate of ammonia and phosphoric acid. (Page 52.) Then evaporate the liquid thus treated to dryness. A quantity of common salt will remain: let this be exposed to a red heat; 0.4 of its weight indicate the sodium contained in the bulk of water employed; and 0.4 sodium are equivalent to 0.53 of soda.
It seems hardly requisite to mention some other substances that occasionally make their appearance in the waters used for domestic purposes. A fine divided sand is a common constituent, which is easily obtained in a separate state. We have only to evaporate a portion of the water to dryness, and redissolve the saline residue in distilled water. The silicious sand remains undissolved, and betrays itself by its insolubility in acids, and its easy fusibility into a transparant glass, with soda, before the blow-pipe.
DELETERIOUS EFFECTS OF KEEPING WATER FOR DOMESTIC ECONOMY IN LEADEN RESERVOIRS.
The deleterious effect of lead, when taken into the stomach, is at present so universally known, that it is quite unnecessary to adduce any argument in proof of its dangerous tendency.
The ancients were, upwards of 2000 years ago, as well aware of the pernicious quality of this metal as we are at the present day; and indeed they appeared to have been much more apprehensive of its effects, and scrupulous in the application of it to purposes of domestic economy.
Their precautions may have been occasionally carried to an unnecessary length. This was the natural consequence of the imperfect state of experimental knowledge at that period. When men were unable to detect the poisonous matters—to be over scrupulous in the use of such water, was an error on the right side.
The moderns, on the other hand, in part, perhaps, from an ill-founded confidence, and inattention to a careful and continued examination of its effects, have fallen into an opposite error.
There can be no doubt that the mode of preserving water intended for food or drink in leaden reservoirs, is exceedingly improper; and although pure water exercises no sensible action upon metallic lead, provided air be excluded, the metal is certainly acted on by the water when air is admitted: this effect is so obvious, that it cannot escape the notice of the least attentive observer.
The white line which may be seen at the surface of the water preserved in leaden cisterns, where the metal touches the water and where the air is admitted, is a carbonate of lead, formed at the expense of the metal. This substance, when taken into the stomach, is highly deleterious to health. This was the reason which induced the ancients to condemn leaden pipes for the conveyance of water; it having been remarked that persons who swallowed the sediment of such water, became affected with disorders of the bowels.[18]
Leaden water reservoirs were condemned in ancient times by Hyppocrates, Galen, and Vitruvius, as dangerous: in addition to which, we may depend on the observations of Van Swieten, Tronchin, and others, who have quoted numerous unhappy examples of whole families poisoned by water which had remained in reservoirs of lead. Dr. Johnston, Dr. Percival, Sir George Baker, and Dr. Lamb, have likewise recorded numerous instances where dangerous diseases ensued from the use of water impregnated with lead.
Different potable waters have unequal solvent powers on this metal. In some places the use of leaden pumps has been discontinued, from the expense entailed upon the proprietors by the constant want of repair. Dr. Lamb[19] states an instance where the proprietor of a well ordered his plumber to make the lead of a pump of double the thickness of the metal usually employed for pumps, to save the charge of repairs; because he had observed that the water was so hard, as he called it, that it corroded the lead very soon.
The following instance is related by Sir George Baker:[20]
"A gentleman was the father of a numerous offspring, having had one-and-twenty children, of whom eight died young, and thirteen survived their parents. During their infancy, and indeed until they had quitted the place of their usual residence, they were all remarkably unhealthy; being particularly subject to disorders of the stomach and bowels. The father, during many years, was paralytic; the mother, for a long time, was subject to colics and bilious obstructions.
"After the death of the parents, the family sold the house which they had so long inhabited. The purchaser found it necessary to repair the pump. This was made of lead; which, upon examination was found to be so corroded, that several perforations were observed in the cylinder, in which the bucket plays; and the cistern in the upper part was reduced to the thinness of common brown paper, and was full of holes, like a sieve."
I have myself seen numerous instances where leaden cisterns have been completely corroded by the action of water with which they were in contact: and there is, perhaps, not a plumber who cannot give testimony of having experienced numerous similar instances in the practice of his trade.
I have been frequently called upon to examine leaden cisterns, which had become leaky on account of the action of the water which they contained; and I could adduce an instance of a legal controversy having taken place to settle the disputes between the proprietors of an estate and a plumber, originating from a similar cause—the plumber being accused of having furnished a faulty reservoir; whereas the case was proved to be owing to the chemical action of the water on the lead. Water containing a large quantity of common air and carbonic acid gas, always acts very sensibly on metallic lead.
Water, which has no sensible action, in its natural state, upon lead, may acquire the capability of acting on it by heterogeneous matter, which it may accidentally receive. Numerous instances have shewn that vegetable matter, such as leaves, falling into leaden cisterns filled with water, imparted to the water a considerable solvent power of action on the lead, which, in its natural state it did not possess. Hence the necessity of keeping leaden cisterns clean; and this is the more necessary, as their situations expose them to accidental impurities. The noted saturnine colic of Amsterdam, described by Tronchin, originated from such a circumstance; as also the case related by Van Swieten,[21] of a whole family afflicted with the same complaint, from such a cistern. And it is highly probable that the case of disease recorded by Dr. Duncan,[22] proceeded more from some foulness in the cistern, than from the solvent power of the water. In this instance the officers of the packet boat used water for their drink and cooking out of a leaden cistern, whilst the sailors used the water taken from the same source, except that theirs was kept in wooden vessels. The consequence was, that all the officers were seized with the colic, and all the men continued healthy.
The carelessness of the bulk of mankind, Dr. Lambe very justly observes, to these things, "is so great, that to repeat them again and again cannot be wholly useless."
Although the great majority of persons who daily use water kept in leaden cisterns receive no sensible injury, yet the apparent salubrity must be ascribed to the great slowness of its operation, and the minuteness of the dose taken, the effects of which become modified by different causes and different constitutions, and according to the predisposition to diseases inherent in different individuals. The supposed security of the multitude who use the water with impunity, amounts to no more than presumption, in favour of any individual, which may or may not be confirmed by experience.
Independent of the morbid susceptibility of impressions which distinguish certain habits, there is, besides, much variety in the original constitution of the human frame, of which we are totally ignorant.
"The susceptibility or proneness to disease of each individual, must be esteemed peculiar to himself. Confiding to the experience of others is a ground of security which may prove fallacious; and the danger can with certainty be obviated only by avoiding its source. And considering the various and complicated changes of the human frame, under different circumstances and at different ages, it is neither impossible nor improbable that the substances taken into the system at one period, and even for a series of years, with apparent impunity may, notwithstanding, at another period, be eventually the occasion of disease and of death.
"The experience of a single person, or of many persons, however numerous, is quite incompetent to the decision of a question of this nature.
"The pernicious effects of an intemperate use of spiritous liquors is not less certain because we often see habitual drunkards enjoy a state of good health, and arrive at old age: and the same may be said of individuals who indulge in vices of all kinds, evidently destructive to life; many of whom, in spite of their bad habits, attain to a vigorous old age."[23]
In confirmation of these remarks, we adduce the following account of the effect of water contaminated by lead, given by Sir G. Baker:
"The most remarkable case on the subject that now occurs to my memory, is that of Lord Ashburnham's family, in Sussex; to which, spring water was supplied, from a considerable distance, in leaden pipes. In consequence, his Lordship's servants were every year tormented with colic, and some of them died. An eminent physician, of Battle, who corresponded with me on the subject, sent up some gallons of that water, which were analysed by Dr. Higgins, who reported that the water had contained more than the common quantity of carbonic acid; and that he found in it lead in solution, which he attributed to the carbonic acid. In consequence of this, Lord Ashburnham substituted wooden for leaden pipes; and from that time his family have had no particular complaints in their bowels."
Richmond, Sept. 27, 1802.
METHOD OF DETECTING LEAD, WHEN CONTAINED IN WATER.
One of the most delicate tests for detecting lead, is water impregnated with sulphuretted hydrogen gas, which instantly imparts to the fluid containing the minutest quantity of lead, a brown or blackish tinge.
This test is so delicate that distilled water, when condensed by a leaden pipe in a still tub, is affected by it. To shew the action of this test, the following experiments will serve.
EXPERIMENT.
Pour into a wine-glass containing distilled water, an equal quantity of water impregnated with sulphuretted hydrogen gas: no change will take place; but if a 1/4 of a grain of acetate of lead (sugar of lead of commerce), or any other preparation of lead, be added, the mixture will instantly turn brown and dark-coloured.
To apply this test, one part of the suspected water need merely to be mingled with a like quantity of water impregnated with sulphuretted hydrogen. Or better, a larger quantity, a gallon for example, of the water may be concentrated by evaporation to about half a pint, and then submitted to the action of the test.
Another and more efficient mode of applying this test, is, to pass a current of sulphuretted hydrogen gas through the suspected water in the following manner.
EXPERIMENT.
Take a bottle (a) or Florence flask, adapt to the mouth of it a cork furnished with a glass tube (b), bent at right angles; let one leg of the tube be immersed in the vial (c) containing the water to be examined; as shewn in the following sketch. Then take one part of sulphuret of antimony of commerce, break it into pieces of half the size of split pease, put it into the flask, and pour upon it four parts of common concentrated muriatic acid (spirit of salt of commerce). Sulphuretted hydrogen gas will become disengaged from the materials in abundance, and pass through the water in the vial (c). Let the extrication of the gas be continued for about five minutes; and if the minutest quantity of lead be present, the water will acquire a dark-brown or blackish tinge. The extrication of the gas is facilitated by the application of a gentle heat.
The action of the sulphuretted hydrogen test, when applied in this manner, is astonishingly great; for one part of acetate of lead may be detected by means of it, in 20000 parts of water.[24]
Another test for readily detecting lead in water, is sulphuretted chyazate of potash, first pointed out as such by Mr. Porret. A few drops of this re-agent, added to water containing lead, occasion a white precipitate, consisting of small brilliant scales of a considerable lustre.
Sulphate of potash, or sulphate of soda, is likewise a very delicate test for detecting minute portions of lead. Dr. Thomson[25] discovered, by means of it, one part of lead in 100000 parts of water; and this acute Philosopher considers it as the most unequivocal test of lead that we possess. Dr. Thomson remarks that "no other precipitate can well be confounded with it, except sulphate of barytes; and there is no probability of the presence of barytes existing in common water."
Carbonate of potash, or carbonate of soda, may also be used as agents to detect the presence of lead. By means of these salts Dr. Thomson was enabled to detect the presence of a smaller quantity of lead in distilled water, than by the action of sulphuretted hydrogen. But the reader must here be told, that the use of these tests cannot be entrusted to an unskilful hand; because the alkaline carbonates throw down also lime and magnesia, two substances which are frequently found in common water; the former tests, namely, water impregnated with sulphuretted hydrogen gas, and nascent sulphuretted hydrogen, are therefore preferable.
It is absolutely essential that the water impregnated with sulphuretted hydrogen, when employed as a test for detecting very minute quantities of lead, be fresh prepared; and if sulphate of potash, or sulphate of soda, be used as tests, they should be perfectly pure. Sulphate of potash is preferable to sulphate of soda. It is likewise advisable to act with these tests upon water concentrated by boiling. The water to which the test has been added does sometimes appear not to undergo any change, at first; it is therefore necessary to suffer the mixture to stand for a few hours; after which time the action of the test will be more evident. Mr. Silvester[26] has proposed gallic acid as a delicate test for detecting lead.
FOOTNOTES:
[11] Dalton, Manchester Memoirs, vol. iv. p. 55.
[12] Marsden's History of Sumatra.
[13] Manchester Memoirs vol. x. 1819.
[14] Observations on the Water with which Tunbridge Wells is chiefly supplied for Domestic Purposes, by Dr. Thomson; forming an Appendix to an Analysis of the Mineral Waters of Tunbridge Wells, by Dr. Scudamore.
[15] It is absolutely essential that the tests should be pure.
[16] Philosophical Magazine, vol. xv. p. 252.
[17] Transactions of the Royal Society of Edinburgh, vol. viii. p. 259.
[18] Sir G. Baker, Med. Trans. vol. i. p. 280.
[19] Lamb on Spring Water.
[20] Medical Trans. vol. i. p. 420.
[21] Van Swieten ad Boerhaave, Aphorisms, 1060. Comment.
[22] Medical Comment. Dec. 2, 1794.
[23] Lambe on Spring Water.
[24] See An Analysis of the Mineral Waters of Tunbridge Wells, by Dr. Scudamore, p. 55.
The application of the sulphuretted hydrogen test requires some precautions in those cases where other metals besides lead may be expected; because silver, quicksilver, tin, copper, and several other metals, are affected by it, as well as lead; but there is no chance of these metals being met with in common water.—See Chemical Tests, third edition, p. 207.
[25] Analysis of Tunbridge Wells Water, by Dr. Scudamore, p. 55.
[26] Nicholson's Journal, p. 33, 310.
Adulteration of Wine.
It is sufficiently obvious, that few of those commodities, which are the objects of commerce, are adulterated to a greater extent than wine. All persons moderately conversant with the subject, are aware, that a portion of alum is added to young and meagre red wines, for the purpose of brightening their colour; that Brazil wood, or the husks of elderberries and bilberries,[27] are employed to impart a deep rich purple tint to red Port of a pale, faint colour; that gypsum is used to render cloudy white wines transparent;[28] that an additional astringency is imparted to immature red wines by means of oak-wood sawdust,[29] and the husks of filberts; and that a mixture of spoiled foreign and home-made wines is converted into the wretched compound frequently sold in this town by the name of genuine old Port.
Various expedients are resorted to for the purpose of communicating particular flavours to insipid wines. Thus a nutty flavour is produced by bitter almonds; factitious Port wine is flavoured with a tincture drawn from the seeds of raisins; and the ingredients employed to form the bouquet of high-flavoured wines, are sweet-brier, oris-root, clary, cherry laurel water, and elder-flowers.
The flavouring ingredients used by manufacturers, may all be purchased by those dealers in wine who are initiated in the mysteries of the trade; and even a manuscript recipe book for preparing them, and the whole mystery of managing all sorts of wines, may be obtained on payment of a considerable fee.
The sophistication of wine with substances not absolutely noxious to health, is carried to an enormous extent in this metropolis. Many thousand pipes of spoiled cyder are annually brought hither from the country, for the purpose of being converted into factitious Port wine. The art of manufacturing spurious wine is a regular trade of great extent in this metropolis.
"There is, in this city, a certain fraternity of chemical operators, who work underground in holes, caverns, and dark retirements, to conceal their mysteries from the eyes and observation of mankind. These subterraneous philosophers are daily employed in the transmutation of liquors; and by the power of magical drugs and incantations, raising under the streets of London the choicest products of the hills and valleys of France. They can squeeze Bourdeaux out of the sloe, and draw Champagne from an apple. Virgil, in that remarkable prophecy,
Incultisque ruhens pendebit sentibus uva.
Virg. Ecl. iv. 29.
The ripening grape shall hang on every thorn.
seems to have hinted at this art, which can turn a plantation of northern hedges into a vineyard. These adepts are known among one another by the name of Wine-brewers; and, I am afraid, do great injury, not only to her Majesty's customs, but to the bodies of many of her good subjects."[30]
The following are a few of the recipes employed in the manufacture of spurious wine:
To make British Port Wine.[31]—"Take of British grape wine, or good cyder, 4 gallons; of the juice of red beet root two quarts; brandy, two quarts; logwood 4 ounces; rhatany root, bruised, half a pound: first infuse the logwood and rhatany root in brandy, and a gallon of grape wine or cyder for one week; then strain off the liquor, and mix it with the other ingredients; keep it in a cask for a month, when it will be fit to bottle."
British Champagne.—"Take of white sugar, 8 pounds; the whitest brown sugar, 7 pounds, crystalline lemon acid, or tartaric acid, 1 ounce and a quarter, pure water, 8 gallons; white grape wine, two quarts, or perry, 4 quarts; of French brandy, 3 pints."
"Put the sugar in the water, skimming it occasionally for two hours, then pour it into a tub and dissolve in it the acid; before it is cold, add some yeast and ferment. Put it into a clean cask and add the other ingredients. The cask is then to be well bunged, and kept in a cool place for two or three months; then bottle it and keep it cool for a month longer, when it will be fit for use. If it should not be perfectly clear after standing in the cask two or three months, it should be rendered so by the use of isinglass. By adding 1 lb. of fresh or preserved strawberries, and 2 ounces of powdered cochineal, the PINK Champagne may be made."
Southampton Port.[32]—"Take cyder, 36 gallons; elder wine, 11 gallons; brandy, 5 gallons; damson wine, 11 gallons; mix."
The particular and separate department in this factitious wine trade, called crusting, consists in lining the interior surface of empty wine-bottles, in part, with a red crust of super-tartrate of potash, by suffering a saturated hot solution of this salt, coloured red with a decoction of Brazil-wood, to crystallize within them; and after this simulation of maturity is perfected, they are filled with the compound called Port wine.
Other artisans are regularly employed in staining the lower extremities of bottle-corks with a fine red colour, to appear, on being drawn, as if they had been long in contact with the wine.
The preparation of an astringent extract, to produce, from spoiled home-made and foreign wines, a "genuine old Port," by mere admixture; or to impart to a weak wine a rough austere taste, a fine colour, and a peculiar flavour; forms one branch of the business of particular wine-coopers: while the mellowing and restoring of spoiled white wines, is the sole occupation of men who are called refiners of wine.
We have stated that a crystalline crust is formed on the interior surface of bottles, for the purpose of misleading the unwary into a belief that the wine contained in them is of a certain age. A correspondent operation is performed on the wooden cask; the whole interior of which is stained artificially with a crystalline crust of super-tartrate of potash, artfully affixed in a manner precisely similar to that before stated. Thus the wine-merchant, after bottling off a pipe of wine, is enabled to impose on the understanding of his customers, by taking to pieces the cask, and exhibiting the beautiful dark coloured and fine crystalline crust, as an indubitable proof of the age of the wine; a practice by no means uncommon, to flatter the vanity of those who pride themselves in their acute discrimination of wines.
These and many other sophistications, which have long been practised with impunity, are considered as legitimate by those who pride themselves for their skill in the art of managing, or, according to the familiar phrase, doctoring wines. The plea alleged in exculpation of them, is, that, though deceptive, they are harmless: but even admitting this as a palliation, yet they form only one department of an art which includes other processes of a tendency absolutely criminal.
Several well-authenticated facts have convinced me that the adulteration of wine with substances deleterious to health, is certainly practised oftener than is, perhaps, suspected; and it would be easy to give some instances of very serious effects having arisen from wines contaminated with deleterious substances, were this a subject on which I meant to speak. The following statement is copied from the Monthly Magazine for March 1811, p. 188.
"On the 17th of January, the passengers by the Highflyer coach, from the north, dined, as usual, at Newark. A bottle of Port wine was ordered; on tasting which, one of the passengers observed that it had an unpleasant flavour, and begged that it might be changed. The waiter took away the bottle, poured into a fresh decanter half the wine which had been objected to, and filled it up from another bottle. This he took into the room, and the greater part was drank by the passengers, who, after the coach had set out towards Grantham, were seized with extreme sickness; one gentleman in particular, who had taken more of the wine than the others, it was thought would have died, but has since recovered. The half of the bottle of wine sent out of the passengers' room, was put aside for the purpose of mixing negus. In the evening, Mr. Bland, of Newark, went into the hotel, and drank a glass or two of wine and water. He returned home at his usual hour, and went to bed; in the middle of the night he was taken so ill, as to induce Mrs. Bland to send for his brother, an apothecary in the town; but before that gentleman arrived, he was dead. An inquest was held, and the jury, after the fullest enquiry, and the examination of the surgeons by whom the body was opened, returned a verdict of—Died by Poison."
The most dangerous adulteration of wine is by some preparations of lead, which possess the property of stopping the progress of acescence of wine, and also of rendering white wines, when muddy, transparent. I have good reason to state that lead is certainly employed for this purpose. The effect is very rapid; and there appears to be no other method known, of rapidly recovering ropy wines. Wine merchants persuade themselves that the minute quantity of lead employed for that purpose is perfectly harmless, and that no atom of lead remains in the wine. Chemical analysis proves the contrary; and the practice of clarifying spoiled white wines by means of lead, must be pronounced as highly deleterious.
Lead, in whatever state it be taken into the stomach, occasions terrible diseases; and wine, adulterated with the minutest quantity of it, becomes a slow poison. The merchant or dealer who practises this dangerous sophistication, adds the crime of murder to that of fraud, and deliberately scatters the seeds of disease and death among those consumers who contribute to his emolument. If to debase the current coin of the realm be denounced as a capital offence, what punishment should be awarded against a practice which converts into poison a liquor used for sacred purposes. |
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