He twirled the cat carelessly.
"Oh, the examination papers are on various subjects. One is chemistry."
"Chemistry?"
"Yes—that part of organic chemistry which includes the scientific preparation of—er—food."
Her eyes flashed; he twirled the cat absently.
"Yes," he said, "chemistry is one of the subjects. Physics is another—physical phenomena."
"What kind?"
"Oh, the—the proposition that nature abhors a vacuum. You're to prove it—you're given a certain area—say a bed-room full of dust. Then you apply to it——"
"I see," she said; "you mean we apply to it a vacuum cleaner, don't you?"