But now, amazingly, absinthe is back--increasingly popular around the world, and currently invading Canada. For the first time in living memory, B.C. Liquor Stores, the provincial government distribution agency, is making absinthe available in caselots to bars and restaurants. Meanwhile, the Liquor Control Board of Ontario (LCBO) is going even further, importing absinthe for individual-bottle sale at a dozen or so of its stores.

Absinthe, a bitter emerald liquid meant to be taken with sugar, seems to have followed a curious, winding path back to general popularity. About 1912, a few cases of bizarre and occasionally murderous behaviour were attributed to "absinthism." "Absinthism," needless to say, looked much like our more familiar plague of "alcoholism." But writers and artists had encouraged the idea that absinthe was distinctive and dangerous, and so legislators hastened to ban it even in countries where temperance movements did not take hold. Since then, absinthe has rarely been mentioned except in connection with Post-Impressionist painters and authors of the Décadence.

Yet there were places where absinthe remained legal, one of them being Spain. (Hemingway developed the taste while watching bullfights.) And in the 1980s and 1990s, Spain became a hot, hedonist tourist destination for English and European youths stuffed with Ecstasy and/or lager. Gradually, mail-order businesses developed throughout Western Europe as absinthe--a "natural" and "herbal" concoction--became a touchstone for wannabe hipsters.

Those seeking the genuine, Rimbaud-Verlaine experience of absinthe are likely to be disappointed by the modern concoctions that go by the name. Absinthe is made with an extract of the herb wormwood, which releases a chemical called thujone. Thujone is a terpene, like camphor and menthol, and like its brother chemicals it gives off a distinctive, powerful aroma. But the thujone molecule is also shaped like another famous chemical--tetrahydrocannibinol, or THC, the active ingredient in marijuana. Its shape is so similar, in fact, that it is now suspected of stimulating the same receptors in the brain that THC itself does.

Old-time absinthe contained about 250 parts thujone per million. Compared to what Van Gogh drank, modern absinthe is near-beer. In the United States and the European Union, the import and sale of absinthe is now legal if the beverage contains less than 10 parts per million of thujone. The brand B.C. is importing--Hill's, made by a Czech family whose kin live in the province--contains no measurable amount of thujone at all. (One connoisseur's Web page sums up its taste in one word: "Windex.") The Ontarian brands contain small, lawful amounts of thujone--fewer than four ppm--but both contain just 45% alcohol.

None are likely to yield the buzz that brought Van Gogh's The Night Café at Arles into the world, although not too much is known about the effects of thujone. The legal concentration of 10 ppm has been fed to rats without causing any visible effect on their behaviour. Yet absinthe drinkers insist that even the low-powered present-day stuff creates a unique, almost hypnotic effect, one in which the ferocious amount of alcohol in the beverage is offset by a certain haunting "clarity" of perception. Clinical knowledge of thujone remains in a sort of limbo--no one wants to give large or chronic doses to humans, but as a consequence our understanding of the substance remains poor.

B.C. Liquor Stores will not put the product on store shelves until they know there is a market for it. And in Ontario, "we don't expect it to be one of the more popular products we sell," says LCBO spokesman Chris Layton. "There's a kind of trendiness associated with these products and we're responding to the existence of a potential niche market." Consumers beware: entering the niche will not be cheap at first. "Absenthe"-brand absinthe will sell in Ontario for $45 a bottle--but what price the pleasures of a forgotten age?