"Take any formula and transpose the symbols all the way through, and see what you get. Trinitrocresol, for instance. The formula is C7H5N3O7. Transpose it all the way through, and you have 7O3N5H7C. In that particular case, it wouldn't even make sense. But when our red-headed spy said he was a chemist and hadn't had any trouble compounding this new explosive, I figured the formula must be one that would be at least half-way logical, no matter which way you wrote it. Only the odds were a million to one that one way it would equal an explosive; the other, nothing at all. So I didn't hesitate to attack him."
"Joe," said Major Coggleston admiringly, "that's a lot faster thinking than I've ever done. And I don't need to tell you how grateful the Army will be."
"Really, Joseph, it was awfully clever!" Henry chimed in. "I'd never have thought of it—"
And then, changing thought in mid-sentence:
"Look! There's that pretty blonde girl with the—"
"Henry!" exploded Professor Paulsen. "You're old enough to behave like a grown man, not an inspectionistic schoolboy!" His hand shot out to grip his little partner's goatee and jerk his eyes from the luscious creature now parading her charms before them.
"Ouch!" squealed Henry, his face screwing up with pain. "Joseph, you're hurting!"
"Then will you be good? Will you behave yourself?"
"Of course, Joseph. Just let me go!" Then, sulkily, as the tall scientist released him: "Though I still think you're mighty finicky, Joseph Paulsen. After all, what's wrong with my liking the cute way that girl wears the bangs across her forehead?"