Humorist Mark Twain wasn’t averse to a “golly” or two in some of the dialogue in his books, but for anyone who dared to interfere with his punctuation, he had stronger words. “The damned half-developed foetus!” Twain raged to his U.K. publishers Chatto & Windus. Once again, Twain was excoriating a proofreader, a professional figure who frequently met with his wrath.

