“I know Captain Putnam is greatly pleased. I am sure he will have something to say to the boys when he gets back.” And Mr. Strong was right, the master of the Hall complimented all on their appearance and deportment, and said he was sure the visitors had been unusually impressed.

“I knew you would all do well,” said the captain. “But it has surpassed my expectations.”

The only fellows who were not happy were Reff Ritter and his cronies. They could not understand how it was that Jack and his chums had come forth looking so spotless and bright.

“That druggist must have humbugged you, Reff,” said Gus Coulter. “I guess he gave you water instead of those chemicals.”

“I don’t understand it at all,” answered Ritter. “But if the druggist did really humbug me I’ll fix him some time, see if I don’t!”

“Let us look at the stuff left in the bottles,” suggested Coulter. “Must be a few drops at least.”

The two passed into the school. On the stairs they met Pepper and Dale.

“It was beastly stuff,” said Pepper, in a loud tone. “I’d like to know who used it. If we hadn’t had that patent preparation to take out the stains we would have been in a pickle, I can tell you, Jack especially,” and then the Imp and Dale passed on.

“I see it all,” groaned Ritter, when he and Coulter were alone. “No need to look for those bottles now. The stuff worked too quickly, and those chaps got some other preparation and cleaned up with it.”

“Yes, that must be it,” said Coulter. “Well, better luck next time.”