I'm going to set you and Campbell at it.

You're a practical, wide-awake young feller, and Campbell's a mighty good chemist; I guess you two boys ought to make something happen." His guess was shrewd enough.

Working in a shed a little way outside the town, where their cheery employer visited them sometimes to study their malodorous stews, the two young men found what Lamb had set them to find.

But Campbell was thoughtful over the discovery.

"Look here," he said.