Positioned at the crossroads of the physical and biological sciences, chemistry deals with neither the infinitely small, nor the infinitely large, nor directly with life. So it is sometimes thought of as dull, the way things in the middle often are. But this middle ground is precisely where human beings exist. As Hoffmann shows in his inspired prose, the world observed at its molecular level is complex and agitated, as are the emotions of the supposedly dispassionate scientists who explore it. In The Same and Not the Same the vital tensions of chemistry are revealed; with down-to-earth...