So the British had more to do with Art Nouveau than perhaps we imagined - several of the artists and craftspeople involved originally came to the V&A to find inspiration in its collections, for instance, while proto-modern designers from earlier in the century such as E.W. Godwin and Christopher Dresser were there to indicate that radical aesthetic reappraisal was already well under way. If you want a starting point for Art Nouveau, then Beardsley's etiolated illustrations for Oscar Wilde's "Salome" in 1893 mark it just as much as the organically twining metalwork of architect Victor Horta's celebrated Tassel House in Brussels, the same year. Or Louis Sullivan's exotically-decorated Transportation Building at the Columbian Worlds Fair in Chicago, also 1893. Strange that it was Sullivan who coined what became the modernist mantra "form follows function". But his idea of form was as much organic as anything - something he taught his attentive pupil Frank Lloyd Wright, who was to provide an alternative to machine-aesthetic international modernism right up to 1959.

Although the style was big in Belgium, increasingly in America (and a subject of parody in London, where Gilbert and Sullivan had already satirised the Aesthetic Movement), it needed to take off in Paris - centre of art trade - in order to become an international force. An art dealer with an eye to the main chance, Siegfried Bing, duly opened a new gallery and shop in Paris in December 1895. He called his enterprise "L'Art Nouveau".

Et voila. By the time of the Paris Universal Exposition of 1900, Art Nouveau had swept the board. It was the contemporary style. The curators of the mighty V&A - in those days much more interested in current trends than it was later to become - went to the Expo and bought a lot of it. They probably regretted their spending spree for most of the 20th century. It turned out to be the century of ornament-free modernism, after all, and Art Nouveau came to be seen as irredeemably kitsch. Indeed, some of it is undoubtedly kitsch - take a look at the silver-and-ivory Belgian sculptures in the show, or a lavish ornamental piece by our very own Alfred Gilbert, creator of Eros in Piccadilly, and feel your stomach lurch. Art Nouveau always trod right along the edge of acceptable taste. Often it slipped over the edge.

Three objects define the exhibtion. The first appears on all the posters (and heads this piece): Rene Lalique's "Dragonfly Woman" brooch of 1898 - an absolutely exquisite if somewhat sinister piece of jewellery, its wings and body subtly articulated to drape fluidly over the chest of the wearer. It is the stuff of Ridley Scott science fantasy. The second, culturally dislocating when encountered in the middle of this London gallery, is a complete Hector Guimard Metro station entrance from Paris, of the type built all over the city from 1899 to 1913. Here the fragility of Lalique is transformed into cast-iron public architecture. Thus removed from its familiar context, its sinuous, organic form is astonishing. It is inconceivable that the British would ever have adopted such an extreme new style for the London Underground. It is totally feminine, and at the time, "feminine" was a perjorative term in British architecture. This would have been seen as pansy architecture all right, doubtless the sort of thing that the disgraced Wilde would have liked - and may even have seen, in his last year in Paris.