“Oh, no,” Anne protested. “At one time the formula actually existed and it was an excellent piece of research—I know that. I’m confident it is here in the house somewhere. Probably in the most out of the way place. Since Father took pains to write it out in code, I’m sure he secreted it where one would never think of searching.”

“Then our work is cut out for us,” Madge laughed. “If we ever do find the formula we’ll still have the code to unravel.”

“And it will be a real one too! Father made a hobby of codes. Years ago he did work along that line for the government.”

Madge’s interest in the missing formula had somewhat cheered Anne and the girls began their search of the house with high hope. They spent the better part of an hour browsing about Mr. Fairaday’s laboratory on the second floor, hunting through old ledgers and desk drawers. Satisfied that the lost paper was not to be found there they made a similar inspection of the old chemist’s bedroom, examining discarded letters and even searching behind pictures which hung on the walls.

“We might try the library,” Anne suggested at length. “I’ve looked there of course, but I’ve never gone carefully through the book shelves.”

They returned to the first floor and undaunted by the vast array of volumes lining the walls, attacked the stacks, working on opposite sides of the room. They went about the task methodically, removing each book from the shelf and shaking it carefully to see that nothing had been hidden between the pages.

Madge experienced a genuine thrill when an envelope, yellow with age, dropped from a volume of Keats’ poems. The girls seized upon it only to be bitterly disappointed when it turned out to be of no value.

“How provoking!” Anne cried impatiently. “I guess you’ve wasted your morning, Madge.”

“Oh, I don’t consider it wasted,” the other corrected without glancing up from the volume she was examining. “Say, this book looks interesting.”

“What is it? Kipling? That particular volume was Father’s favorite. It’s a real good story too. Take it home if you like.”