In this video/lesson series we will explore the sense of smell. We profile 21st Century Chemist Nate Lewis, who's working to develop an artificial "nose" that can help detect odors, including hazardous gases and chemicals. A story on the carvone molecule adds information on how the nose distinguishes odors. Also in this collection: news stories from the archives of NBC News and Scientific American on air testing, sense of smell (human and canine) - and a Periodic Table of "Smellements.