THE FRENCH MEDICAL establishment took an instant dislike to it because it was foreign. Europeans started using it to counteract the effects of leaden diets and heavy drinking. Americans thought of ways to sidestep the preparation ritual and invented bags and instant versions.

Tea, the bracing beverage that has soothed Englishmen, tantalized fortunetellers and inflamed revolutionaries has undergone several metamorphoses during its long popularity.

In the beginning there were tea cakes. During the Tang dynasty (618 to 906 A.D.) the Chinese bound tea together with glutinous rice into bricks and roasted it. To prepare tea, they scraped it off the outside of the brick and boiled it with salt, onion, ginger and orange peel.

During the Sung period (960 to 1279) whipped tea became popular. Bricks were out. Instead, the leaves were ground to a powder and whipped in hot water with a bamboo whisk until a green foam appeared. No other flavorings were added. Ch'an (Zen) Buddhist monks made tea equipment into works of art, and the ceremony of making and drinking it became a celebration of their beliefs in simplicity and harmony.

Because the masses were also Buddhist, tea gained popularity among the lower classes. During the Ming Dynasty (1368 to 1644), the tea ceremony became commonplace and tea pottery was mass-produced. At the same time, the ritual was simplified to the steeping method of adding leaves to water.

The Japanese did not adopt tea as a beverage until their monks introduced the "Cha-no-yu" or "hot-water tea," their version of the tea ceremony. It was adopted by the middle and upper classes in all its complexity because the ceremony offered a chance for quiet and meditation in the midst of a rank-conscious society devoted to warfare and power politics.

But although there were many contacts between Europe and China and Japan during the 15th and 16th centuries, tea was not readily accepted in Europe. It took 200 years of travelers' accounts connecting the apparent good health of the Chinese and Japanese to their tea-drinking before European curiosity was piqued.

Owing to their heavy diets and drinking, Europeans had always been plagued by gout, gallstones, headaches and intestinal troubles. Their poor health thus set the stage for a light, stimulating beverage.

In Europe, any time a new food is introduced it's first found at the apothecary. The same was true of tea; it was sold, like sugar, spices, ginger, chocolate and coffee, over the counter.

But the suspicious French produced their own versions of herbal teas, using local plants, to counter the importation and use of foreign tea. Today, French pharmacies still sell chamomille, verveine and other herbal teas. Saint-Arroman summed up the feelings of the 19th-century French medical establishment: "The best tea of the Celestial Empire cannot bear a comparison with bordeaux, burgundy and champagne. The English drink tea because they have no wine and don't know how to eat."

It took the British most of the 17th century to wrestle some of the spice and tea trade away from the Dutch. But when they did, their East India Company and the Dutch East India Company became the first multinational corporations -- capable of ruling and protecting their territories.

By 1700 there were more than 500 tea houses in London, all of which excluded women. In 1706 Thomas Twining opened Tom's Coffee House, which also sold tea and just about everything else. It was so popular that he opened The Golden Lion, the first tea house to allow women. This initial blow for female equality made him a rich man. Business has not always been resistant to social change -- not when it opens new markets.

In addition to Twining's, three other names became big in the tea trade: Lipton, Lyons and Tetley. Thomas J. Lipton was a native of Scotland who came to America and earned enough money to start a small provisions shop in Glasgow. This was highly profitable; he bought a tea estate in Ceylon (now Sri Lanka) and then opened an American tea wholesale business. J. Lyons & Company started as a catering shop renowned for providing a good pot of tea for twopence instead of the usual threepence. (Hence the expression "tea for two" -- not a fabrication of Broadway.) Joseph Tetley & Company Ltd. started as a tea-packing house in Britain that expanded into the American market.

In Britain, there's teatime and then there's teatime. The custom of taking tea in the afternoon was invented by Anna, wife of the seventh Duke of Bedford, who, as was customary among aristocratic women in the 18th century, ate a prodigious breakfast and very small lunch. Consequently she had a "sinking feeling" in the early-evening hours before a late dinner, so she ordered tea and small cakes. This was termed a low tea.

High tea, on the other hand, had bourgeois beginnings.Because, at the time, working people ate only one large meal -- at midday -- they ate whatever was left over for dinner. And they washed it down with tea.

We have impatient Americans to thank for tea bags and instant tea. In 1908 Thomas Sullivan, a parsimonious New York City importer, sent out tea samples to his retailers in little silk bags instead of tin cans. Not knowing otherwise, the shopkeepers assumed they were to dip the bags directly into the cup or pot. This custom was at first limited to hotels but soon captured the American love for convenience.

Iced tea was invented in 1904 at the St. Louis World's Fair. Richard Blechynden, who was promoting Indian and Ceylonese teas, found it impossible to interest passing, sweltering spectators in cups of hot tea. So he dumped some ice in it and peddled the new drink with more success.

Instant tea was never really invented: It crept onto the market. The India Tea Bureau of New York devised a liquid concentrate in the 1930s. It wasn't until the development of the spray drier, however, that instant tea became a commercial reality. The spray drier is a stainless steel, inverted cone used in converting liquid tea to a powdered concentrate. Hot air is blown in from the bottom, where the dry particles fall and are collected. Both Nestle''s and Standard Brands developed a 50-percent tea, 50-percent carbohydrate product. The carbohydrate is not used to increase profits but to enable the processors to use cooler air, thus retaining more of the tea's aroma and flavor.

The names of teas often seem mysterious. In some cases, as with Earl Grey tea, they refer to a blend. In others, as with Darjeeling, they refer to tea districts (the foot of the Himalayas), and in still others (such as Formosa Oolong) they refer to both place and type of processing.

Leaves are handpicked from a medium-size bush. This is because the only parts of the tea bush that are used are the first, second, third and sometimes fourth leaves. This shoot is called a flush. The most aromatic and flavorful tea grows at higher elevations (to 6,000 feet), where the flushes grow most slowly.

There are two varieties of tea bush, the Assam or Indian plant and the Bohea or Chinese plant. But the basic differences among teas are not related to the variety, geographical area or climate; it's what happens to the flushes once they are picked.

In general, green tea, preferred by the Chinese and Japanese, is unfermented; oolong, once popular in the United States, is partially fermented, and black tea, the most popular tea in the West, is completely fermented.

Confused? Wait, it gets worse. The word fermentation, though used extensively by the tea industry, is misleading. What happens to oolong and black teas has nothing to do with any microbial growth. Instead, it is a chemical discoloration of the tea leaf caused by an enzyme (catechol oxidase), on a group of compounds called tannins (now referred to as polyphenols).

Once picked, green tea is either steamed or fired (heat-dried) to inactivate this enzyme. Consequently the leaves remain green. The tea is then dried and packaged.

Oolong, called a "flavory tea" by the industry because of its bright character, is really the rose of teas. It has the brightness -- aromatic character -- of black tea. The flushes are first dried to remove 9 to 12 percent of their moisture. This makes the leaves more flexible to rolling, a mechanical agitation that disrupts cell walls, allowing catechol oxidase to come in contact with the polyphenols. The tea leaves are then fired at a high temperature before packaging.

Black tea undergoes the same process as oolong, except fermentation takes three hours instead of minutes. After firing, the leaves are very black.

To further complicate things, each country adopts its own naming and grading system. Here are a few names and what they mean:

* Orange pekoe (pronounced pekko): Originally part of the Sri Lankan grading system, this name has been adopted by many tea exporters to the United States because of its sales appeal. It means large, unbroken leaves. Other pekoe grades (in decreasing leaf size): pekoe souchong, souchong, broken orange pekoe, broken pekoe, broken tea, fannings and dust. Broken orange pekoe is frequently used in tea bags because less time is needed for infusion. Orange pekoe is always made with black tea.

* Lapsang souchong: Lapsang is the name of a district in China and souchong is the general name for the black teas of South China. This is a very smoky, heavy tea.

* Earl Grey: This is called a scented tea. Scented teas may be flavored with dried flowers (jasmine tea) or with extracts, in this case oil of bergamot (a Turkish, pear-shaped orange). This tea is made with a souchong leaf.

* English breakfast: This is one of the blended teas. It, like Queen Anne and ceylonese, started with one tea importer and has become an industry standard.

* Darjeeling: This is among the highest-priced tea, some fetching $100 a pound. It is grown along the slopes of the Himalayas in the province of Bengal, India. It is a full-bodied tea with a unique, nutty flavor.

* Gunpowder: This is the fanciest grade of green teas. As the green teas dry, they tend to curl. If the leaves are rolled properly -- by hand or machine -- they form tight, little gray balls.