In the original edition of The Hobbit, Gollum was willing to give up the ring; before 1994 the American and British editions of The Voyage of the Dawn Treader were different; Madame Mim was removed from The Sword and the Stone for its 1958 reissue.
Internet Archive Book Images, No restrictions, via Wikimedia Commons
J. R. R. Tolkien, C. S. Lewis, and T. H. White were three giants of early 20th century fantasy fiction. And each of them at some time re-edited and altered their seminal works. The Hobbit, The Voyage of the Dawn Treader, and The Sword in the Stone all underwent some level of revision, in some cases making the versions most commonly read today very different from the originally published editions.
(Spoilers for these three books, obviously, coming up.)
First, The Hobbit. When it was originally published in 1937, the extended legendarium of The Lord of the Rings and The Silmarillion was just a twinkle in Tolkien’s eye. In particular, the particular history, weight, and importance of the Ring of Power had not yet taken shape. Because of this, the first edition of The Hobbit treats it much less seriously. It’s just a simple magical object, one of many scattered around the world:
a wonderful, beautiful ring, a ring that [Gollum] had been given for a birthday present, ages and ages before in the old days when such rings were less uncommon
The Hobbit, 1937 edition
In the chapter in which Bilbo trades riddles with Gollum, Gollum’s obsession with the ring is much weaker. He freely offers the ring as a prize if he loses the riddle contest. And when he does lose, he keeps his word and goes to fetch it:
“Must we give it the thing, preciouss? Yess, we must! We must fetch it, preciouss, and give it the present we promised.”
The Hobbit, 1937 edition
And when he cannot locate the ring, Gollum actually apologizes and offers to lead Bilbo to safety:
I don’t know how many times Gollum begged Bilbo’s pardon. He kept on saying: “We are ssorry; we didn’t mean to cheat, we meant to give it our only only pressent, if it won the competition.” He even offered to catch Bilbo some nice juicy fish to eat as a consolation.
The Hobbit, 1937 edition
Now, all of this is a far cry from the threatening and menacing Gollum of editions you can buy today. (I mean, he still threatens to eat Bilbo, but the two still part on good terms.) When Tolkien wrote The Lord of the Rings, the idea of Gollum – or anyone – willingly giving up the ring became a problem. If Gollum could escape the ring’s possessive pull, was it truly as powerful and evil as the later work portrayed it? So, Tolkien rewrote that chapter. Gollum was no longer willing to part with the ring. He mourns its loss, tries to track down the invisible hobbit, and in the end swears revenge (“we hates it for ever!”). And that’s the version that survives in every new edition today.
On to The Voyage of the Dawn Treader. This one is a relatively small change. When C. S. Lewis was looking over the drafts for the first American edition of the book, he made a few key changes to the chapter about the Dark Island. This is an island that brings your dreams to life. Not your aspirations, mind you, but your actual dreams and nightmares.
In the original (and most recent) versions, Aslan in the form of an albatross rescues the ship and its crew, and the island disappears forever:
“Grant me a boon.”
The Voyage of the Dawn Treader, 1952 edition
“What is it?” asked Caspian.
“Never to bring me back there,” he said. He pointed astern. They all looked. But they saw only bright blue sea and bright blue sky. The Dark Island and the darkness had vanished for ever.
“Why!” cried Lord Rhoop. “You have destroyed it!”
“I don’t think it was us,” said Lucy.
When C. S. Lewis reviewed the proofs for the American edition of the book, for some reason he made the Dark Island just a little bit more sinister. In this version, the island does not disappear. Instead, it persists as a marine hazard for all others who may pass by:
“Grant me a boon.”
The Voyage of the Dawn Treader, pre-1994 American edition
“What is it?” asked Caspian.
“Never to ask me, nor to let any other ask me, what I have seen during my years on the Dark Island.”
“An easy boon, my Lord,” answered Caspian, and added with a shudder. “Ask you: I should think not. I would give all my treasure not to hear it.
This difference persisted in the American editions of the book until 1994, when a new publisher reverted to the original British text. Personally, I prefer the sinister American one.
Finally, T. H. White’s The Sword in the Stone underwent some pretty significant revisions in 1958. It’s a bit of a sad story, actually. T. H. White wrote five books in the Once and Future King series. The first three were published in 1938, 1939, and 1940. As the Second World War descended on Europe, he wrote two concluding stories with a pretty explicit (and melancholy) anti-war message… and also revised the earlier books to also speak to that theme.
But White’s publisher refused to print the new texts. Ostensibly this was because there was a wartime paper shortage, but really anything anti-war inevitably bumps up against the fervent patriotism of the time. The first four books were eventually re-issued as a single volume (The Once and Future King) in 1958. At that time, White cannibalised parts of the (still not to be published) fifth book and wove it into the earlier narrative.
The changes were extensive. One of the larger revisions was a surprising one: White deleted the section in which Merlyn has a magical battle with Madame Mim. I don’t know exactly why he trimmed that part. Disney had owned the film rights to the novel since 1939, and when they finally released The Sword in the Stone in 1964 that shape-changing duel is one of the highlights. But by then the whole scene was missing from the latest edition.
(Fortunately, the original texts are still in print today as well, and in 1977 the fifth part was finally published too.)
The Generalist Academy 
_(14801002423).jpg){kind=link}
This is pretty surprising. Now I’m trying to remember which version of The Hobbit I read but I’m thinking that it was the revision with the more sinister Gollum, and now I feel like I was cheated out of the original experience. On the other hand, I can’t really blame authors for revising or rewriting their older works. I always wondered how people can truly decide when a creative piece is finished since there’s always room for improvement. Some musicians recorded several versions of the same composition in what I assume was an effort to find the version that worked best. I guess it’s only fair that authors exercise the right to edit their old works as they see fit.
You almost certainly read the revised version, seeing as that has been the only one in print for decades. But you can see the original in the second link at the end of the article (“Riddles in the dark: The Lost version”) – I think the revision is an improvement.
I cannot remember who said it, but I’ve always liked the quote “No great work of art is ever finished, it is only ever abandoned.”