Elizabeth Enright, Gone-away Lake , New York, Harcourt, Brace & Co., 1957.

On the floor of the brook there many caddis cases made of twigs and micas-flakes. Julian collected a few, putting them into the thermos bottle with some brook water.
« We’ve done pretty well today, « he said. « We’ve got the Catocala and theses caddis worms and the tree fungus and the garnets. But the sensational thing is the philosopher’s stone!..