Throwing away the scroll

Jeremiah 51:60-63 - Jeremiah had written on a scroll about all the disasters that would come upon Babylon—all that had been recorded concerning Babylon. He said to Seraiah, "When you get to Babylon, see that you read all these words aloud. Then say, 'O LORD, you have said you will destroy this place, so that neither man nor animal will live in it; it will be desolate forever.' When you finish reading this scroll, tie a stone to it and throw it into the Euphrates...."

I wonder how many copies of the prophecy against Babylon were made. There must have been at least two. There was the one that Seraiah was to throw into the Euphrates -- presumably lost forever. And there was the one that has been passed down through the ages here in the book of Jeremiah. Or did the one that was thrown into the river survive? Did it ever actually get thrown away?