Twinings London – photo by Elisa.rolle

Is the tea in your cup genuine?

The fact is, had one been living in the early 19^th Century, one might occasionally encounter a counterfeit cup of tea.  Food adulterations to include added poisonings and suspect substitutions were a common problem in Europe at the time.

Here are a few facts from:

 A Treastise on Adulrations of Food and Culinary Poisons, Exhibiting The Fruadulent Sophistications of Bread, Beer, Wine, Spirituous Liquors, Tea, Coffee, Cream, Confectionary, Vinegar, Mustard, Pepper, Cheese, Olive Oil, Pickles, and Other Articles Employe in Domestic Economy and Mehods of Detecting Them by Fredrick Accum, Operative Chemist, Lecturer on Practical Chemistry, Mineralogy, and on  Chemistry applied to the Arts and Manufactures; Member of the Royal Irish Academy; Fellow of the Linneaen Society; Member of the Royal Academy of Sciences, and of the Royal Society of Arts of Berlin, &c, &c. 

London: Printed by J. Mallet, 59, Wardour Street, Soho. 

Sold by Longman, Hurst, Rees, Orme, and Brown, Paternaoster Row. 

1820

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The late detections that have been made respecting the illicit establishments for the manufacture of imitation tea leaves, arrested, not long ago, the attention of the public; and the parties by whom these manufactories were conducted, together with the numerous vender of factitious tea, did not escape the hand of justice.  In proof of this statement, it is only necessary to consult the London newspapers (the Times and the Courier) from March to July 1818; which show to what extent this nefarious traffic has been carried on; and they report also the prosecutions and convictions of numerous individuals who have been guilty of the fraud.  The following are some of those prosecutions and convictions.

Hatton Garden * (Courier, June 22, 1818)—On Saturday an information came to be heard at this office, before Thomas Leach, Esq. the sitting magistrate, against a man of the name of Edmund Rhodes, charged with having, on the 12^th of August last, dyed fabricated, and manufacture, divers large quantities, viz, one hundred weight of sloe leaves, one hundred weight of ash leaves, one hundred weight of elder leaves, and one hundred weight of the leaves of a certain other tree, in imitation of tea, contrary to the statue of the 17^th of Geo. III.* (Also, 2 Geo. I, c.30, §5; and 4 Geo. II, c. 14, §11.) whereby the said Edmund Rhodes had, for every pound of such leaves so manufactured, forfeited the sum of 5l. making the total of the penalties amount to 2,000l.  The second count in the information charged the said Rhodes with having in his possessions the above quantity of sloe, ash, elder, and other leaves, under the like penalty of 2,000l.  The third count charged him with having, on the said 12^th of August last, in his possession, divers quantities, exceeding six pounds weight of each respective kind of leaves; viz. fifty pounds weight of green sloe leaves, fifty pounds weight of green leaves of ash, fifty pounds of weight of green leaves of elder, and fifty pound weight of the green leaves of a certain other tree; not having proved that such leaves were gathered with the consent of the owners of the trees and shrubs from which they were taken, and that such leaves were gathered for some other use, and not for the purpose of manufacturing the same in imitation of teas; whereby he had forfeited for each pound weight, the sum of 5£. Amounting in the whole to 1,000£.; and, in default of payment, in each case, subjected himself to be committed to the house of correction for not more that twelve months, nor less than six months.

Mr. Denton, who appeared for the defendant, who was absent, said that he was a very poor man, with a family of five children, and was only the servant of the real manufacturer, and an ignorant man from the country, put into the premises to carry on the business, without knowing what the leaves were intended for.  By direction of Mr. Mayo, who conducted the prosecution, several barrels and bags, filled with the imitation tea, were then brought into the office, and a sample from each handed round.  To the eye they seemed a good imitation of tea.

The defendant was convicted in the penalty of £500 on the second count.

The Attorney-General against Palmer*. (The Times, May 18, 1818)—This was an action by the Attorney-General against the defendant, Palmer, charging him with having in this possession a quantity of sloe-leaves and white-thorn leaves, fabricated into an imitation of tea.

Mr. Dauncey stated the case to the jury, and observed that the defendant, Mr. Palmer, was a grocer.  It would appear that a regular manufactory was established in Goldstone-street.  The parties by whom the manufactory was conducted, was a person of the name of Proctor, and another person named J. Malins.  They engaged others to furnish them with leaves, which, after undergoing a certain process, were sold to and drank by the public as tea.  The leaves in order to be converted into an article resembling black tea, were first boiled, then baked upon an iron plate; and when dry, rubbed with the hand, in order to produce that curl which the genuine tea had.  This was the most wholesome part of the operation; for the colour, which was yet to b given to it was produced by logwood.  The green tea was manufactured in a manner more destructive to the constitution of those by whom it was drank.  The leaves, being pressed and dried, were laid upon sheets of copper, where they received their colour from an article known by the name of Dutch pink.  The article used in producing the appearance of the fine green bloom, observable on the China tea, was however, decidedly a dead poison!  He alluded to the verdigrise, which was added to the Dutch pink in order to complete the operation.  This was the case which he had to bring before the jury; and hence it would appear, that, at the moment they were supposing they were drinking a pleasant and nutritious beverage, they were, in fact, in all probability, drinking the produce of the hedges round the metropolis, prepared for the purposes of deception in the most noxious manner.   He trusted he should be enabled to trace to the possession of the defendant eighty pounds weight of the commodity he had been describing.

Thomas Jones deposed, that he knew Proctor, and was employed by him at the latter end of April, 1817, to gather black and white thorn leaves.  Sloe leaves were the black thorn.  Witness also knows John Malins, the son of William Malins, a coffee roaster; he did not at first know the purpose for which the leaves were gathered,  but afterwords learnt they were to make imitation tea.  Witness did not gather more than one hundred and a half weight of these leaves; but he employed another person, of the name of John Bagster, to gather them.  He had two-pence per pound for them.  They were first boiled, and the water squeezed from them in a press.   They were afterwards placed over a slow fire upon sheets of copper to dry; while on the copper they were rubbed with the hand to curl them.  At the time of boiling there was a little verdigris put into the water (this applied to green tea only.)  After the leaves were dried, they were sifted, to separate the thorns and stalks.  After they were sifted, more verdigris and some Dutch pink were added.   The verdigris gave the leaves that green bloom observable on genuine tea.

The black tea went through a similar course as the green, except the application of Dutch pink: a little verdigris was put in the boiling, and to this was added a small quantity of logwood to dye it, and thus the manufacture was complete.  The drying operation took place on sheets of iron.  Witness knew the defendant, Edward Palmer; he took some of the mixture he had been describing to his shop.  The first time he took some was in May 1817.  In the course of that month, or beginning of June, he took four or five seven-pound parcels; when he took it there, it was taken up to the top of the house.   Witness afterwards carried some to Russell-street, which was taken to the top of the house, about one hundred weight and three quarters; from this quantity he carried fifty-three pounds weight to the house of the defendant’s porter, by the desire of Mr. Malins; it was in paper parcels of seven pounds each.

John Bagster proved that he had been employed by Malins and Proctor, to gather sloe and whitethorn leaves:  they were taken to Jones’s house, and from thence to Malin’s coffee roasting premises; witness received two-pence per pound from them; he saw the manufacturing going  on, but did not know much about it: witness saw the leaves on sheets of copper, Goldstone-street.  The was the case for the Crown.—Verdict for the Crown, £840.

The Attorney-General against John Prentice*.—(The Time, May 18, 1818. Ibid) This was an information similar to the last, in which the defendant submitted to a verdict for the Crown.

The Attorney-General against Lawson Holmes.—In this case the defendant submitted to a verdict for the Crown.

The Attorney-General against John Orkney.—Thomas Jones proved that the defendant was grocer, and in the months of May last he carried to his shop seven pounds of imitation tea, by the order of John Malins for which he received the money, viz. 15s. 9d. or 2s. 3d. per pound.  The jury found a verdict for the Crown —Penalties £70.

The Attorney-General against James Gray*.—(The Times, May 18, 1818. +Ibid. ++Ibid. §Ibid. II Ibid.  The defendant submitted to a verdict for the Crown. —Penalties £120.

The Attorney-General against H.Gilbert, and Powel+.—These defendants submitted to a verdict. Penalties £140.

Attorney-General against William Clark.++. —This defendant also submitted to a verdict. Penalties £140.

The Attorney-General against George David Bellis§. —This defendant  submitted to a verdict for the Crown

The Attorney-General against John Horner II. —The defendant in this case was a grocer; it was proved by Jones that he received twenty pound of imitation tea.—Verdict for the Crown.—Penalties £210.

The Attorney-General against William Dowling*. —This was a grocer.  Jones proved that he delivered seven pounds of imitation tea to Mr. Dowling’s house, and received the money for it, namely 15s. 9d. Penalties £70.

Method of Detecting the Adulterations of Tea

The adulteration of tea may be evinced by comparing the botanical characters of the leaves of the two respective trees, and by submitting them to the action of a few chemical tests.

The shape of the tea-leaf is slender and narrow, as shown in this sketch, the edges are deeply serrated, and the end or extremity is acutely pointed.  The texture of the leaf is very delicate, its surface smooth and glossy, and its colour is a lively pale green.

The sloe- leaf ( and also the white-thorn leaf), as shewn in this sketch, is more rounded, and the leaf is obtusely pointed.  The serratures or jags on the edges are not

so deep, the surface of the leaf is more uneven, the texture not so delicate, and colour is a dark olive green.

These characters of course can be observed only are the dried leaves have been suffered to macerate in water for about twenty-four hours.

The leaves of some sorts of tea may differ in size, but the shape is the same in all of them; because all the different kinds of tea imported from China, are the produce of one species of plant, and the difference between the green and souchong, or black tea, depends chiefly upon the climate, soil, culture, age, and mode of drying the leaves.

Spurious black tea*(The examination of twenty-seven samples of imitation tea of different qualities, from the most costly, to the most common, which it fell to my lot to undertake, induces me to point out the marks of sophistications here detailed, as the most simple and expeditious.) slightly moistened, when rubbed on a sheet of white paper, immediately produces a blueish-black stain; and speedily afford, when thrown into cold water, a blueish-black tincture, which instantly becomes reddened by letting fall into it, a drop or two, of sulphuric acid.

Two ounces of the suspected leaves should be infused in half-a-pint of cold, soft water, and suffered to stand for about an hour.  Genuine tea produces an amber-coloured infusion, which does not become reddened by sulphuric acid.

All the samples of spurious green tea(nineteen in number) which I have examined, were coloured with carbonate of copper (a  poisonous substance), and not by means of verdigrise, or copperas*.  (Mr. Twining, an eminent tea-merchant, asserts, that “the leaves of spurious tea are boiled in a copper, with copperas and sheep’s dung.—See Encyclop. Britan.  vol.xviii. p. 331. 1797.  See alo the History of the Tea Plant, p. 48; and p. 22 and 231 of this Treatise.) The latter substances would instantly turn the tea black; because both these metallic salts being  soluble in water, are acted on by the astringent matter of the leaves, whether genuine or spurious, and convert the infusion into ink.

Tea, rendered poisonous by carbonate of copper, speedily imparts to liquid ammonia a fine sapphire blue tinge.  It is only necessary to shake up in a stopped vial, for a few minutes, a tea-spoonful of the suspected leaves, with about two table-spoonsful of liquid ammonia, diluted with half its bulk of water.  The supernatant liquid will exhibit a fine blue colour, if the minutest quantity of copper be present.

Green tea, coloured with carbonate of copper, when thrown into water impregnated with sulphuretted hydrogen gas, immediately acquires a black colour.  Genuine green tea suffers no change from the action of these tests.

The presence of copper may be further rendered obvious, by mixing one part of the suspected tea-leaves, reduced to powder, with two or three parts of nitrate of potash, (or with two parts of chlorate of potash,) and projecting this mixture by small portions at a time, into a platina, or porcelain-ware crucible, kept red-hot in a coal fire;  the whole vegetable matter of the tea leaves will thus become destroyed, and the oxide of copper left behind, in combination with the potash, of the nitrate of potash(or salt petre), or with the muriate of potash, if chlorate of potash has been employed.

If water, acidulated with nitric acid, be then poured into the crucible to dissolve the mass, the presence of the copper may be rendered manifest by adding to the solution, liquid ammonia, in such quantity that the pungent odour of it predominates.