Hermann Kopp (1817-1892) is best remembered today as a historian of chemistry, but during his lifetime he was one of the most eminent chemists of his day, and one of the earliest pioneers of physical chemistry. Late in his career he wrote an endearing fantasy about personified molecules. Published in 1882, Aus der Molecular-Welt (From the Molecular World) portrayed the intimate details of what might actually be happening in the sub-microscopic world; the atoms and molecules we meet there have agency, personalities, sometimes even dialog. Filled with appealing tropes, humor, and whimsical...