We hear excerpts from the perfume reviews of Luca Turin, voiced by Doug Gordon. Then, Steve Paulson talks with Chandler Burr, author of “The Emperor of Scent: A Story of Perfume, Obsession, and the Last Mystery of the Senses.” The book explains Luca Turin’s theory of how we smell and recounts his amazing ability to recognize the odor of particular molecules. And we hear some excerpts from the book.