“Thank you.”
“Marvin, I notice that when we get an invitation and my wife just says thank you, we ain’t a-going.”
A faint smile appeared on Marvin’s lips.
“Young man,” said Asher Ferry sharply, “if my chemists can’t follow you. I’ll hire one that can. You and I had a pretty good talk on the boat, and you didn’t seem to think me such a damn fool then. I know you ain’t much interested in coal. What you want is to turn some substance into some other substance—change the atoms—and make use of the energy. But there’s one thing I’d like to know before we part. Why has most of the elements got fractional weights?”
“Because they are mixtures.”
“I don’t understand that.”
“Well, weight depends on the nucleus of an atom, and we don’t know much about the pattern of the nucleus yet. But take any atom, and all you need to keep it the same atom is the same balance between nucleus and moons. A nucleus having six positive charges bound by three negative will give lithium just as surely as seven positive bound by four negative. Ordinary lithium is a mixture of a lighter lithium and a heavier lithium.”
“Then what’s called pure elements ain’t really pure?”
“Probably not. I could tell you more about it if I knew what a chap named Aston has been doing recently in England.”
“Well, before you can change one element into another, you’ve got to get it pure, ain’t you?”