"The final addition of silicon. It will not enter the compound, but forces something less active from the combination."
"Making it useless?"
"Right."
"You've tried it?"
"And it works," nodded Orfall.
"And knowing that you of Terra have some wonders in science, we would like to know—"
"You see," interrupted Orfall, "they've figured that the catalyst would be less than sixty-one percent efficient, if we could combine the silicon with it and let it replace into the other compound. That would work. But again we are stuck. The catalyst is stable as it is. What has Terra done to assist in forcing combination in unstable compounds?"
"Must be something," said Sandra, thoughtfully. "May I have a moment to think?"
"Certainly."
"And one thing more. Haven't you anything that even resembles tobacco on this sterile planet?"