WE Americans live on a vast patch of the earth, a sweep of scattered geography in which states tumble together around barely visible boundaries, and we have no idea who the hell we are. Of course, various people have tried to find out; we have drifted down the river with Huck Finn, poured across the highways with the Joads, maybe followed Kerouac through his woozy continental high-jinks. We somehow believe that there exists a sense, a spirit, something, that defines this tumbled vastness as distinctly American.

Jasmine

By Bharati Mukherjee

Grove Weidenfeld

241 pp., $17.95

Bharati Mukherjee has caught that something, and she portrays an America that actually exists, that exists now. Jasmine is the story of an Indian girl who emigrates to America, shedding selves as she moves to, and through, this country, eventually realizing herself as genuinely American. It's a book about disintegration and change, constant rebirth in the midst of bewildering opportunity: she is Jyoti, then Jasmine and later, in Iowa, Jane Ripplemeyer, though even this is not an endpoint.

Jyoti-Jasmine-Jane says at one point: "It is by now only a passing wave of nausea, this response to the speed of transformation, the fluidity of American character and the American landscape. I feel at times like a stone hurtling through diaphanous mist, unable to grab hold, unable to slow myself, yet unwilling to abandon the ride I'm on."

THE novel also vividly portrays the experience of a modern immigrant, dipping into the violent world of illegal documents, desperation and dark beaches in Florida. "There are national airlines flying the world that do not appear in any directory... we are refugees and mercenaries and guest workers; you watch us sleeping in airport lounges; you watch us unwrapping the last of our native foods..." Mukherjee gives us a strong sense of this under-world, and also of the Indian culture Jyoti is escaping.

This alien world we enter is shown as both merging into the American experience, and as illuminating its more familiar elements. In an Indian neighborhood of New York City, insulated with Hindi video stores and Punjabi fabric shops, Jasmine stifles in an atmosphere of Old World nostalgia. In Iowa, lonely Grandmother Ripplemeyer appreciates Jasmine's Indian sense of strong family ties.

It's a good book. Mukherjee moves easily from simple details to startling observations. She brings genuine hope out of painfully depicted loss.

Although reading dust-jacket review clips is a filthy habit which I wouldn't encourage in anyone, it was the back of this book which drew me in. (The front cover is incredibly ugly; don't let it deter you.) One of the best of English travel writers (who has also done some exploring of our America, in Old Glory, a fabulous journey down the Mississippi), Jonathan Raban, describes her earlier work as a "romance with America itself, its infinitely possible geography, its license, sexiness, and violence." The description clearly fits this new novel, and romance is a well-chosen word.

DESPITE the tragedies which pursue Jasmine--one character says to her, "you are a tornado. You're leaving a path of destruction behind you."--there is a lot of love and warmth coursing through this tale. As an undocumented au pair girl in New York, she adopts the name Jase and becomes part of her first American family--Wylie and Taylor and their daughter Duff.

At a crisis point in their relationship, we have this scene:

I put Duff to bed, which was something Wylie liked to do herself, and Taylor read Duff and me a paper he was writing on weak gravity, in a room that was dark except for the yellow glow of a table lamp and the purple glow of the fish tank. He made it funny, choosing neighborhood and household examples for anything technical. "Weak gravity is what keeps your dreams inside your head so they don't go flying out," he said. "It's what keeps Jase and Duff together," he said, smiling sweetly, "so they don't fly off the bed at night. When you look around, weak gravity is everywhere."

We didn't have our talk. We didn't have to. Fish rippled their phosphorescent stripes inside the tank. The water gurgled, always clean, always warm.

The next morning I put my arms around Wylie. She cried.

Weak gravity becomes a symbol for the way America holds together. It's used to explain why, despite the danger and chaos that snakes through us, we have some sense of a national character. We are loosely held, we fly off, reattach, reemerge, continue. This is what we are--which sounds like a strange kind of unity, but this behavior, this trait, whatever you want to call it, is what has always bound us together as Americans; has been ever since Huck Finn lit out for a new territory.

Bharati Mukherjee's Jasmine proves that America is still full of new territory, and that lighting out for it, into the unknown, into danger, into hope, will always make us Americans.