“If they’re so rare, maybe the stuff is not so important for life after all.” Ken looked at Drai to see if he were serious.
“In the first place,” he pointed out, seeing that the other had not been joking, “mere rarity doesn’t prove that life doesn’t need it. We use quite respectable quantities of fluorine in our bodies, not to mention zinc, arsenic and copper. This other form of life may well do the same. In the second place, just because an element is rare on Sarr doesn’t prove it would be so on Planet Three — it’s a much bigger world, and could easily have held considerable quantities of the lighter elements during its original formation, even if they had been there as uncombined gases.” The group had been walking toward Ken’s room, where he had stored most of his apparatus, as they talked. Reaching it at this point, they entered. Ken draped himself without apology on the only rack, and began to flip through the pages of the chemical handbook, in the section devoted to inorganic compounds. He realized that his mysterious substance could contain carbon, but it certainly could not contain more than one atom per molecule, so there was no danger of its being a really complex organic material.
There were, in fact, just eight elements likely to be present; and the laws of chemistry would put considerable restriction on the possible combinations of those eight. The lightest of these was hydrogen, of course; and to the hydrogen compounds Ken turned, since they came first in that section of the handbook.
Drai had moved to a position from which he could oversee the pages that Ken was reading; the less interested or less excitable Lee stayed near the door and waited silently. He was more prepared than his employer for a long wait while the scientist made his search; and he was correspondingly more surprised when Ken, almost as soon as he began reading, suddenly stiffened in a fashion which indicated he had found something of interest. Drai saw the action as well.
“What is it?” he asked at once. Both Ken and Lee realized that the “it” referred to the substance, not the cause of Ken’s interest; Drai assumed without thought that his scientist had found what he was seeking.
“Just a moment. There’s something that doesn’t quite agree — but the rest is too perfect — wait a minute—” Ken’s voice trailed off for a moment; then, “Of course. This is under normal pressure.” He looked up from the book.
“This appears to be the stuff — it’s almost completely unknown on Sarr, because of its low molecular weight— most of it must have escaped from the atmosphere eons ago, if it ever was present. According to this handbook, it should be liquid through quite a temperature range, but that’s under our atmospheric pressure. It’s quite reasonable that it should sublime the way it did in this vacuum.”
“But what is it?”
“One of the oxides of hydrogen — H2O, apparently. If it proves to be essential for the form of growth you’re interested in, we’re going to have a very interesting time handling it.”
“We have cargo shells that can be kept at outside conditions, and towed outside the ship,” Drai pointed out.