Pig swill, brothels and corpses to darken lazy river days of Huck Finn

A DARKER, more uncomfortable reading of Mark Twain's Huckleberry Finn will be available in the Spring, giving readers the chance to compare the original text of the seminal American novel with the final draft that Twain sent to the printers several years later. When a Hollywood librarian discovered the missing manuscript in a trunk in her attic more than five years ago, jubilant scholars called the 665 pages, in Twain's fading handwriting, the literary find of the 20th century.

In the book that Ernest Hemingway famously called the source of "all modern American literature", narrated in 12-year-old Huck's backwoods Missouri vernacular, the boy and the runaway slave Jim share a raft drifting down the Mississippi river. The first words of the sunrise scene in Chapter 19 celebrate their lazy days on the water. "Two or three days and nights went by," Huck recounts. "I reckon I might say they swum by, they slid along so quiet and smooth and lovely.'' But in Twain's first telling, Huck eats pig swill and his father, a drunk, dies in a one-woman brothel.

In an episode from a religious revival meeting excised by the author, a black woman, carried away in the spiritual fervour, is shoved away by white worshippers she tries to embrace. Some scholars hope this "astonishing" scene may help to defend Twain against charges of racism that led to some schools banning his book.

Though Huckleberry Finn is centred round the companionship of a Southern boy and a former slave, the word "nigger" appears more than 200 times. But it appears he considered it too risque for contemporary readers. In Life on the Mississippi, Twain compares the unfettered life of the river pilots with writers, whom he calls the "manacled servants of the public. We write frankly and fearlessly, but then we 'modify' before we print."

He removed in its entirety another passage that could have offended: a story told by Jim , in which he is sent to warm up a frozen corpse for dissection. As he manhandles the cadaver in front of the fire, it falls on him.

This macabre interlude, titled "The Ghost Story" was published for the first time in the New Yorker magazine last year. The Adventures of Huckleberry Finn appeared in 1884, in an edition personally corrected by Twain, who was adamant in defending Huck's language against proof-readers who sought to correct his grammar.

In 1885 James Gluck, a lawyer in Buffalo, New York, wrote to Twain enclosing a photograph of his local library's new fire-proof building, and asked him to donate an original manuscript. Twain sent the second half of the novel, explaining that the rest had been lost. Twain, in fact, found and sent on the first half in 1887, but it was more than a century later that Gluck's granddaughter, slowly weeding through trunks of his private papers that she had inherited, turned it up.

Within days, the document was on its way to Sotheby's in New York in an armoured truck. After legal negotiations between the Gluck family, the Buffalo library and the foundation that owns the copyright to his works, excerpts from the find are being incorporated in a new edition to be published by Random House in the US and Bloomsbury in Britain in late April or June.

Twain, whose real name was Samuel Clemens, wrote the book in fits and starts over seven years. He was in his 40s, living as a full-time writer at the height of his powers after a life as a steamboat pilot, gold prospector and journalist. It was originally intended as a companion volume to Tom Sawyer, but the novel took Tom's sidekick Huck on a picaresque adventure through the American frontier, setting the free life of Huck and Jim on the river against a travelling circus of treacherous adults on shore.

Twain wrote the first half between 1876 and 1880. Victor Fischer, a Huck Finn expert at the Mark Twain Centre in Berkeley, California, said that one sees Twain returning to the work and finding Huck's voice. In Huck's first description of the sunrise, for example, he says , "You would see the lightest and whitest mist curling up from the water". The final version has lost the conventional flourish: "You see the mist curl up off of the water".

Until the manuscript was found, it was assumed that Twain broke off writing for three years when he ploughed a Mississippi steamboat through Huck and Jim's raft.In fact he kept going at this point for a further 12 pages.

The new edition will contain 30 pages of other excerpts and commentary. According to Victor Doyno, the Buffalo professor editing the text, there is nothing to support a recent theory that Twain enjoyed romantic relationships with men.