Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/186

Rh 170 ADULTERATION Nuisances Removal Acts are almost insurmountable ; for, in the first place, the local sanitary authorities have no means of obtaining direct information of the existence of unsound or spurious tea, or other article of food or drink in bonded warehouses ; and secondly, if such information reaches them indirectly, they have no legal right of entry for the purpose of examining the tea and taking samples. But supposing both of these difficulties have been sur mounted, and the tea has been found on analysis to be spurious, there yet remain the difficulties of obtaining a justice s order for its condemnation, an order from the customs for its removal, and an order which will satisfy the requirements of the wharfinger in whose custody it has been placed. But besides these, there are the difficulties of proving the ownership of the article, and the guilty knowledge of the broker who sells it. In illustration of this, we may refer to the proceedings of the sanitary authorities of the city of London in their endeavour to suppress the importation and sale of spurious tea. In the month of March 1870, Dr Letheby, the food analyst for the city, reported that a large quantity of spurious tea had arrived in London from China, and was lodged in the bonded warehouses of the city. It was described as &quot; Fine Moning Congou&quot; from Shanghai ; and it consisted of the redried leaves of exhausted tea, much of which had become putrid before drying. It appears to have been called in China &quot; Ma-loo mixture&quot; Maloo being the name of the street where it was prepared, and along the sides of which heaps of this trash might often be seen drying in the sun, with dogs and pigs walking over it. Proceedings were taken under the Nuisance Removal Amendment Act (26 and 27 Viet. c. 117), for the purpose of obtaining an order for the condemnation and destruction of the tea ; but it was argued for the defence 1st, That &quot;tea&quot; was not named in the Act of Parliament ; 2d, That it was not included under the term &quot;vegetable;&quot; 3&amp;lt;/, That it was not &quot; food ;&quot; and 4th, That being in a bonded warehouse, it was not &quot; exposed for sale.&quot; The case, however, was so glaring that, after two days hearing, an order was given by the justice for its destruction ; but as a case was granted for the opinion of the Court of Queen s Bench, the order was suspended ; and as the application to the Court was never made, the order is still in abeyance. In another case, where many chests of spurious &quot; scented orange Pekoe siftings&quot; were in bond, the order for its condemnation was refuted on the ground that there was not sufficient evidence of the so-called tea being unwholesome, notwith standing that it was not above one-sixth its proper strength ; that it had little or none of the active principles of tea ; that it had an unpleasant odour and an acrid taste ; that a great portion of it was not tea at all, and that the rest of it was composed of exhausted tea leaves, with just enough good tea to give it a flavour. A like failure of justice occurred in the city in 1866, when measures were taken by the sanitary authorities to prevent the sale of about 350,000 Ibs. of rotten and charred tea which had been saved from a fire at Beal s wharf. The adulterations practised by the Chinese are numerous ; exhausted tea is redried and glazed in a very deceptive manner. Millions of pounds of leaves of different plants, other than tea, are gathered and mixed with it. Mineral matter too, in the form of china clay, fine sand, and iron filings, are ingeniously incorporated with the leaf before curling, so that as much as from 20 to 40 per cent, of impurity is thus mixed with it. The tests, however, for these adulterations are very simple. In the first place, there is the usual trade test of infusion : a quantity of tea, amounting to the weight of a sixpence, is put into a small covered cup, and infused with about four ounces of boiling water for ten minutes. The infusion is then poured off from the leaves, and is examined for colour, taste, and odour all of which are characteristic. The leaves, too, are examined for soundness, for colour, for size, and for special botanical properties. Impurities like iron filings, sand, or dirt, are easily seen among the leaves, or at the bottom of the cup ; and when these are placed upon a coarse sieve and washed with water, the impurities pal through, and may be collected for examination. The leaves, too, betray by their coarseness and botanical characters, the nature and quality of the tea ; for although the leaves of genuine tea differ much in size and form, yet their venation and general structure are very distinctive. Very young leaves are narrow, convoluted, and downy ; those next in size and age have their edges delicately serrated, and the venation is scarcely perceptible ; while those of larger size have the venation well marked, there being a series of loops along each side of the leaf extending from the mid-rib to the edge : the serrations also are stronger and deeper, beginning a short distance from the stem and running up the side of the leaf to the apex. In addition to this, the microscopic characters of the surface of the leaf are very characteristic. Further investigations of a chemical nature are sometimes needed to determine the question of adulteration ; and these depend on the well-known com position of good tea. In different cases, according to the age of the leaf and its mode of treatment, the proportions of its chief constituents may vary ; but in a general way it may be said that the average composition of tea is as follows : Moisture from 6 to 10 per cent. ; astringent matter (tannin), from 25 to 35 ; gum, from 6 to 7 ; albuminous matters, from 2 to 3 ; thein, from 2 to 3 ; mineral matters (ash), from 5 to 6 ; and ligneous or woody tissue, from 50 to GO per cent. Green tea, which is generally made out of young leaves, contains the largest quantity of soluble matters; and these, when fully exhausted from the leaves by successive boiling in water, amount to from 25 to 35 per cent, of the weight of the tea. In ordinary cases, when the tea is merely infused in boiling water, it does not yield above 25 per cent, of extractive. Again, the ash of tea is very characteristic of its quality old and spurious leaves, as well as tea adulterated with mineral matter, yielding more than 6 per cent, of ash. The chief constituents of the ash of good tea are potash and phosphoric acid, with a little lime, silica, and oxide of iron there being but a trace of chlorine and sulphuric acid ; whereas the ash of old and exhausted leaves contains but little potash and phosphoric acid, in proportion to the lime and silica ; and in those cases where tea has been damaged by sea water, the amount of chloride is considerable. Iron filings in tea are easily discovered by means of a magnet, there being in some cases as much as 20 or 30 per cent, of this impiirity. Even when incorporated with the leaf before rolling and glazing, the fraud is detected by the attraction of the tea to the magnet. 4. Cocoa in its natural state contains so much fatty matter (amounting to rather more than half its weight), that it has long been the practice to reduce it by means of sugar or farinaceous substances. The first of these pre parations is called chocolate, and the latter is known by such names as granulated, flake, rock, soluble cocoa, &c. In some cases the mixture is adulterated with mineral matters, as oxide of iron, to give colour. These adulterations are recognised by the appearance and taste of the preparation, by its microscopic characters, by the colour and reaction of its solution, and by the proportions of fat and mineral matters in it. 5. Bread. Especial care has been taken at all times to protect the public from the dishonest dealing of bakers. The assize of bread, for example, is a very ancient institu tion ; for it was the subject of a proclamation in 1202, and it was the chief matter referred to in the notable statute of