Read "The Alien Intelligence" by Jack Williamson online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
Just before daylight Austen completed his calculations, and stated the result. He was very tired, and his eyes were red. He had worked for a day and two nights since we had found him. He gave his conclusion in a colorless monotone.
"You know," he said, "that there are several rare gases in the air, in addition to oxygen and nitrogen. The inert gas argon comprises nearly one per cent of the atmosphere, and there are, in addition, smaller quantities of helium, neon, xenon, and krypton, not to mention the carbon dioxide and water vapor. Those gases are monatomic and do not ordinarily enter into any compounds at all.