A signed copy of Karl Marx's Das Kapital has sold for a record £218,500 ($309,808) at an auction in London.
The book was originally valued at £120,000 ($170,146), a figure it exceeded by an impressive 82% at Bonhams on June 15.
Marx has inscribed the book to his old friend Johann Georg Eccarius
It's inscribed to Johann Georg Eccarius, chairman of the workers' union First International, and is dated 1867.
Eccarius was a close friend of Marx, but the pair fell out in the 1870s after Eccarius appeared to take the credit for some of Marx's ideas in an article in the Telegraph.
Bonhams' Simon Roberts says: "This was a very important copy of one of the world's most influential books and not surprisingly the bidding was extremely keen - presentation copies are extremely scarce.
"I suspect the irony that a devastating criticism of capitalism should sell for such a huge sum would have caused Marx a wry smile".
Meanwhile, a handwritten page from a tract by Isaac Newton titled "The Question Stated about Abstaining from Blood" made £58,750 ($83,225).
After much wrangling with biblical sources, Newton eventually comes to the conclusion that eating blood is morally wrong.
It was for this reason that he avoided both black pudding and rabbits, as their meat tended to be bloody.
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