England's Tony Cragg is an alchemist of sorts. Looking at his art, one imagines him surrounded by furnaces and fires, by beakers and alembics. His sculptures speak of colored smokes and arcane incantations. They cast a kind of spell on the Corcoran Gallery of Art.

The museum once looked different every time you entered, its changing exhibitions once flowed into the atrium. But not in recent years. "Tony Cragg: Sculpture 1975-1990" activates that grand front hall, rattling its quietudes, unsettling its spaces. Cragg's pestles, flasks and flagons have challenged its tall columns. His unexpected colors -- the blues of lapis lazuli, the glints of antiqued bronze, the dull blacks of worn tires -- have prodded its old grayness. Moribund so long, the atrium seems again alive.

The sculptor's personality flickers in his show. But you seldom glimpse him clearly. Like the alchemists of old -- who struggled to transmute base metals into gold -- he's intent on transformations. He likes to make the tiny huge, and the new look ancient. The first work one encounters, the piece called "Generations" (1988), suggests slugs of white, primordial ooze turning into spaceships.

Cragg was born in Liverpool in 1949. His father was an aeronaut -- both pilot and engineer -- and young Tony made his living as a lab technician before he turned to sculpture. His knack for transformations was apparent from the start. He first made his reputation by transmuting street rubbish into art.

Walking through the city, his eyes upon the ground, he'd pick up useless bits of plastic detergent bottles, shards of toys, Bic lighters out of fuel, cheap pens out of ink. In time he must have picked up tons of such detritus, treasure for the artist but mere junk for the rest of us. His "Self-Portrait With Sack" (1980) -- in which scraps of colored plastic fastened to the wall fill in his cast shadow -- shows him at his work. He'd sometimes sort his finds by color. The floor piece he calls "Newton's Tones" (1982) includes a thousand bits of color -- a dark-blue toy machine gun, a light-blue plastic dinosaur, a broken turquoise squirt gun. It's a portrait of the spectrum. And a hymn to Isaac Newton. Sir Isaac, who discovered all the colors in white sunlight, was an alchemist as well.

The modern art of Britain, not so very long ago, was seen as hopelessly behind the curve, but that's no longer true. Britain has grand painters now (Bacon, Freud, Kitaj, Hodgkin, Gilbert and George, Auerbach and Hockney). It has fine young sculptors too -- Anish Kapoor, for instance, and witty Barry Flanagan, and Cragg's London art school colleagues, Richard Deacon, Bill Woodrow, Richard Long. Cragg ranks high among them now. That wasn't always so.

The trick that made him famous -- his fashioning of "pictures" out of scraps of street detritus -- seemed a little pat. The weakest of those pictures -- a supine map of England, or a junky Union Jack, or a Mercedes logo made of bricks and bottles -- were political in message, and familiarly tendentious. They finger-wagged, they nagged.

But the minor, rather preachy artist that they showed us -- Cragg the anti-Thatcherite, Cragg the foe of costly cars, or the exemplary recycler -- is no longer much in evidence. He has somehow been replaced by an artist far more generous, more subtle and more powerful. That's the strongest of his alchemies: Cragg's transformed himself.

Compare his first self-portrait here, which shows him scavenging the streets, with the later one called "Loco" (1988) in which his beak-nosed profile has expanded into hugeness. He seems suddenly enormous. Since 1985 or so, Cragg has taken on so many skills, so many complex thoughts and rich materials, that one gets the eerie feeling a dozen different sculptors made the new works in this show.

The materials they deploy could hardly be more various. Cragg now makes vast castings out of green-patinaed bronze. He pours plaster, molten glass and molten iron too. (The 1989 piece he calls "Condensor" makes you think that Jack's magic beans have somehow sprouted to produce the graceful spiral tubing of a 15-foot-high still.)

He's no longer just a scrap-picker. Included in this show are slender vessels of blown glass (so elegant and delicate you fear that they would shatter if you looked at them askance), and big cylinders of black rubber that a hammer couldn't dent. He carves huge trunks of eucalyptus now, and blocks of lapis too. And he does more than carve. He draws, he paints, he pours, he turns, he balances and stacks.

He also composes traditional still lifes. A key piece in his show is called "Five Bottles on a Shelf" (1982). It's as silent and suggestive as a vision of Morandi's, though the bottles it presents are cheap extruded plastic things picked up on the street. Focusing with fierceness on those sad, discarded objects, Cragg has since transformed them into ceremonial vessels of iron or of stone that are near as tall as you are. He loves such shifts of scale. He's made the meanest of small objects -- a soap bottle, an eye cup or a set of rubber stamps -- into grand and eerie things.

It is only when the viewer has examined the whole show that it starts to come together. It takes a while for Cragg's various skills and multiple materials to seem reflective of one mind.

"People say there's a great deal of variety in my work, but I'm not so sure that's true," he's said. "It's like making a complete landscape with all the parts in it: There's the urban world, architecture and so on, there's the organic world, there's the atmosphere, and the geological structure." Eventually you get it. Like those poets who could see infinities in flowers or those alchemists who knew that base metals and noble ones partake of the same substance, Cragg aims at an underlying unity. His art is not abstract. It's about the street, the landscape, his workshop, his society, his reasoning and dreams. That the macro and the micro coexist in all things, that the precious and the valueless, the tiny and the vast, the proved and the imagined, belong to one another is the central message of his increasingly ambitious, steadily improving, deeply English art.

The show, Cragg's first solo American museum exhibition, was organized by the Newport Harbor Art Museum of Newport Beach, Calif. It was assembled by Paul Schimmel, now chief curator of the Museum of Contemporary Art, Los Angeles. It was installed at the Corcoran by the sculptor and by curator Terrie Sultan -- who has three shows on display there now, and whose contemporary installations have given the old Corcoran a touch of the vitality it so badly needs. "Tony Cragg: Sculpture 1975-1990" will remain on view through March.