This past week’s mail brought a couple of interesting items. First off, while I was anticipating the arrival of a new gas cap for my wife’s Jeep Compass to correct an emissions issue, the package that arrived felt more like a hardcover book than a Jeep gas cap. Much to my surprise, I received a copy of Dr. Robert T. Sharp’s new book, “The Bull in the Darkness and the One-Eyed Dog,” a followup to his well-received classic, “No Dogs in Heaven? Scenes from the Life of a Country Veterinarian.”