After that, in the early months of 1916, Cynthia was no more thought of, and even the delightful companionship with Gratia ceased for a while. He had sought girls as instinctively as a metal seeks the most abundant of the elements, and found them all slightly intoxicating, but none had crumbled him into white sparks. His love was lead. He was less enchanted by carbon than by her sister, who had sung Moseley to sleep to prevent him from revealing her music to the world. But Marvin, listening in, began to recover that music, thrill on thrill. It seemed to him to advance in close chords like those in which Cynthia had so happily died to him. To put it less figuratively, he began to suspect that no fewer than ten substances may pass as lead. They are what Soddy had called isotopes, or equals in place. The Moseley number for lead is 82, and Soddy had made it clear that at least one radioactive substance deserves that number, and that at least one inactive lead is lighter than ordinary lead. Marvin now conceived at least three inactive and three active leads, weighing 206, 207, 208, 210, 212, 214. This was maddeningly close to transmuting inactive into active, but he saw no hope of turning the trick. He had to content himself with proving that there really is an inactive lead as light as 206, and after much search and labor he discovered it in a certain Norwegian mineral. This was getting on, but not fast enough to stop any Germans. They were steadily advancing, preceded by hot lead of weight 207. Well, there was plenty of that sort in Missouri, and he concluded that America ought to do more than sell it to the Allies. She ought to project a little of it, hardened with antimony, herself. Chapter 9. Fluorine The Riches began the winter cozily, in blissful lack of chemical consciousness. It would not greatly have interested Dr. Rich to be told that his teeth contained fluorine, or that the steel of his ax had been smelted by fluorspar, or even that fluorspar had revealed a world beyond the violet rays. He had a chemistry which answered all his purposes. He got it from a person named Democritus, who, four centuries before Christ, had been so heretical as to believe that all things are made of atoms. Dr. Rich secretly regarded himself as pretty liberal not to wish that the books of Democritus had been burned up. He courageously admitted the general atomicity of things, though of course all atoms were massy, hard, and round. Only one thing did the old doctor reserve from granularity, and that was souls.