It is a truth universally acknowledged — as Jane Austen might put it — that a publisher in possession of a work in the public domain must be in want of a new way to make a quick buck from it. First, it was with zombies: Authors cashed in on the current mania for the undead by adding zombie hordes to out-of-copyright classics like “Pride and Prejudice.” Now a British e-book publisher, hoping to capitalize on the popularity of “mommy porn,” is releasing “sexed-up” rewrites of Austen, Jules Verne, Arthur Conan Doyle, and other writers.

The raunchy version of “Pride and Prejudice,” for instance, casts the delightful intercourse of Mr. Darcy and Elizabeth Bennet in an entirely new light. And readers of the Sherlock Holmes rewrite will learn that Dr. Watson was dearer to the detective than they might have realized.

As the rewriters point out, 19th-century fiction is rife with sexual euphemisms and allusive naughtiness, and to modern readers the delicate language of more prudish eras can seem ridiculous. Arguably, the X-rated rewrites are just restoring material the authors might have wished to include, had they been allowed to loosen the proverbial corset.

But in a backhanded way, the rewrites should also draw attention to how skillful the original authors were to convey so much steam under such constraints. Ambiguity and imprecision can be powerful tools, and generations of readers have already filled in certain details with their own saucy imaginations.