The earliest humans understood matter on a very basic, practical level. Through trial and error they determined which rocks could make good spearheads and good pounding or grinding stones. The Bronze Age began about 2000 BCE when rocks containing copper and tin were heated together. The combination of the two metals yielded the alloy bronze. Metals played a significant role in the growth of chemical knowledge. Important questions were posed—what exactly was happening to individual material objects when they were mixed together and transformed into a different substance? The search for answers would lead to generations of the greatest thinkers, philosophers, and scientists on the quest to discover the most basic building block of matter—the atom. This beautiful and engaging narrative presents the fascinating story of the atom's discovery, which is full of bizarre theories, false starts, dead ends, and inspiring intellectual insight and vision.