It might be Mark Twain or O.Henry.
It discusses the shortcomings of that era's novels and short stories. Specifically, it parodies authors' remarks qualifying dialogue. The author of the essay claims that those remarks have become so mindless and mechanical that no one, neither authors no readers, pay attention to the actual meaning of the words those remarks contain: as if there existed a barrel of words and stock phrases specifically for this purpose, and each time an author needed to qualify a character's dialogue line, he or she would just dip his or her hand into the barrel and select some words and phrases at random. As in:
"I have no idea," said the policeman and wept. "You might be right," said the dog, flicking cigar ashes on the floor. "You should have told me earlier," said the woman and tugged thoughtfully at her beard.
Something like that.