articles of food and drink are described with especial reference to their chemical relations and the ordinary adulterations to which they are exposed. It should be added, that many of the methods of examination given are quoted in a condensed form from the more extensive works on food-analysis.

TEA.

THE early history of tea is probably contemporary with that of China, although, in that country, the first authentic mention of the plant was as late as A.D. 350; while, in European literature, its earliest notice occurs in the year 1550. The first important consignment of tea into England took place in 1657. Chinese tea made its appearance in the United States in 1711; in 1858, the importation of Japan tea began. During the season of 1883-1884, the importation of tea into this country* was-from China, 30 millions of pounds; from Japan, 32 millions of pounds. Recently, numerous shipments of Indian tea have been placed upon our markets, the quality of which compares very favourably with the older and better known varieties. During the past four years the consumption of tea in this country has materially decreased; whilst that of coffee has undergone an almost corresponding increase. The per capita consumption of tea and coffee in the United States as compared with that of Great Britain is as follows:-United States, tea, 1.16; coffee, 9.50; Great Britain, tea, 462; coffee, o 89. In the year 1885 our importation of tea approximated 82 millions of pounds, that of coffee being nearly 455 millions of pounds.

Genuine tea is the prepared leaf of Thea sinensis. The growth of the tea shrub is usually restricted by artificial means to a height of from three to five feet. It is ready for picking at the end of the third year, the average life of the plant being about ten years. The first picking is made in the middle of April, the second on the 1st of May, the third in the middle of July, and occasionally a fourth during

* I.e. the United States.

the month of August. The first pickings, which obviously consist of the young and more tender leaves, furnish the finer grades of tea. After sorting, the natural moisture of the leaves is partially removed by pressing and rolling; they are next more thoroughly dried by gently roasting in iron pans for a few minutes. The leaves are then rolled on bamboo tables and again roasted, occasionally re-rolled and re-fired, and finally separated into the various kinds, such as twankay, hyson, young hyson, gunpowder, etc., by passing through sieves. The difference between green and black tea is mainly due to the fact that the former is dried shortly after gathering, and then rolled and carefully fired, whereas black tea is first made up into heaps, which are exposed to the air for some time before firing and allowed to undergo a species of fermentation, resulting in the conversion of its original olive-green into a black colour. The methods employed in the preparation of the tea are somewhat modified in their details in the different tea districts of China and Japan. In Japan two varieties of the leaf are used, which are termed "otoko" (male), and "ona" (female), the former being larger and coarser than the latter. After picking, the leaves are steamed by placing them in a wooden tray suspended over boiling water, in which they are allowed to remain for about half a minute. They are next thrown upon a tough paper membrane attached to the top of an oven, which is heated by burning charcoal covered with ashes, where they are constantly manipulated by the hand until the light-green colour turns to a dark olive, and the leaves have become spirally twisted. After this "firing," the tea is dried at a low temperature for from four to eight hours; it is next sorted by passing through sieves, and is then turned over to the "go-downs," or warehouses of the foreigners, where the facing process is carried on by placing the tea in large metallic bowls, heated by means of a furnace, and gradually adding the various pigments used, the mixture being continually stirred. The

tea is finally again sorted by means of large fans, and is now ready for packing and shipment.

The sophistications to which tea is exposed have received the careful attention of chemists, but not to a greater extent than the importance of the subject merits; indeed, it is safe to assert that no article among alimentary substances has been, at least in past years, more subjected to adulteration. The falsifications which are practised to no inconsiderable extent may be conveniently divided into three classes.

Ist. Additions made for the purpose of giving increased weight and bulk, which include foreign leaves and spent tea leaves, and also certain mineral substances, such as metallic iron, sand, brick-dust, etc.

2nd. Substances added in order to produce an artificial appearance of strength to the tea decoction, catechu and other bodies rich in tannin being mainly resorted to for this purpose.

3rd. The imparting of a bright and shining appearance to an inferior tea by means of various colouring mixtures or "facings," which operation, while sometimes practised upon black tea, is far more common with the green variety. This adulteration involves the use of soap-stone, gypsum, China clay, Prussian blue, indigo, turmeric, and graphite. The author lately received from Japan several samples of the preparations employed for facing the tea in that country, the composition of which was shown by analysis to be essentially as follows:

1. Magnesium silicate (soap-stone).

2. Calcium sulphate (gypsum).

3. Turmeric.

4. Indigo.

5. Ferric ferrocyanide (Prussian blue).

6. Soap-stone, 47 5 per cent.; gypsum, 47'5 per cent.; Prussian blue, 5 per cent.

7. Soap-stone, 45 per cent.; gypsum, 45 per cent.; Prussian blue, 10 per cent.

8. Soap-stone, 75 per cent.; indigo, 25 per cent. 9. Soap-stone, 60 per cent; indigo, 40 per cent.

The "facing" or "blooming" of tea is often accomplished by simply placing it in an iron pan, heated by a fire, and rapidly incorporating with it one of the preceding mixtures (Nos. 6, 7, 8, or 9), in the proportion of about half a dram to seven or eight pounds of the tea, a brisk stirring being maintained until the desired shade of colour is produced.

Some of the above forms of sophistication usually go together; thus exhausted tea is restored by facing. The collection of the spent leaves takes place in China. Much of the facing was, until about three years since, done in New York city, and constituted a regular branch of business, which included among its operations such metamorphoses as the conversion of a green tea into a black, and vice verså.

According to James Bell,* the composition of genuine tea is as follows:

The ash of samples of uncoloured and unfaced tea, and of spent tea analysed by the author, had the following composition:

*Chemistry of Foods.'