He went on, beginning to relish the lecture. “On the other hand, the lighter elements are also better distributed. The ocean solids aren’t predominantly sodium chloride as on Earth. Junior’s oceans contain a respectable helping of magnesium salts. And take what they call the ‘rare lights.’ Those are the elements lithium, beryllium, and boron. They’re lighter than carbon, all of them, but they are of very rare occurrence on Earth, and in fact, on all planets. Junior, on the other hand, is quite rich in them. The three of them total almost four-tenths of a per cent of the crust as compared to about four-thousands on Earth.”
Mark plucked at the other’s sleeve. “Do you have a list of figures on all the elements? May I see?”
“I suppose so.” He took a folded piece of paper out of his hip-pocket.
He grinned as Mark took the sheet and said, “Don’t publish those figures before I do.”
Mark glanced at them once and returned the paper.
“Are you through?” asked Vernadsky in surprise.
“Oh, yes,” said Mark, thoughtfully, “I have it all.” He turned on his heel and walked away with no word of parting.
The last glimmer of Lagrange I faded below the horizon.
Vernadsky gazed after Mark and shrugged. He plucked his nucleometer out of the ground, and followed after, walking back toward the tents.
Sheffield was moderately pleased.. Mark had been doing better than expected. To be sure, he scarcely talked but that was not very serious. At least, he showed interest and didn’t sulk. And he threw no tantrums.