"I want you to leave me alone," reiterated the old professor.
"I will—when I am done with you. How do you like that, old man?" And then Nat Poole gave a brutal laugh.
"Oh! oh! Don't smother me!" spluttered Caspar Potts. "Please leave me alone! You have ruined my clothes!"
"I wonder what's up?" said Dave to his chums, and ran through the barn to the rear. There he beheld Caspar Potts in a corner. In front of him stood Nat Poole, holding a big garden syringe in his hands. The syringe had been filled with a preparation for spraying peach trees, and the son of the money-lender had discharged the chalk-like fluid all over the aged professor.
"Nat Poole, what are you up to!" cried Dave, indignantly, and, leaping forward, he caught the other youth by the shoulder and whirled him around. "You let Professor Potts alone!"
"Dave!" cried the professor, and his voice showed his joy. "Oh, I am glad you came. That young man has been teasing me for over a quarter of an hour, and he just covered me with that spray for the peach-tree scale."
"What do you mean by doing such a thing?" demanded Dave. "Give me that syringe." And he wrenched the article from the other youth's
