The Secret of Scent is a book about science by way of art, in which the author's passion for perfume leads him to the scientific mystery of what makes one molecule smell of garlic while another smells of rose. Readers who know Luca Turin as the lively central figure in Chandler Burr's The Emperor of Scent will remember the ongoing debate between two competing theories of smell—one based on molecular shape, the other on molecular vibrations. Now Turin himself describes in detail the science, evidence, and long history of this debate, from the beginnings of organic chemistry to the present day, and pays homage to those before him who got it right. This fascinating and accessible account will appeal to anyone who has ever wondered about smell, still the most mysterious of the senses.