By Taylor RayneSmell is our most primal and, arguably, most emotionally potent sense. It summons memories, shapes taste, and influences behavior: the aroma of coffee is capable of enhancing alertness well before caffeine ever reaches the bloodstream. A hint of sunscreen collapses decades, taking us back to youth; but, pinch the nose, and suddenly a slice of apple is hard to distinguish from a piece of raw potato.Despite its significance, scent remains the most mysterious of our senses. Unlike vi...