In "A Short Drink from a Certain Fountain," the experimental youth serum alludes to what famous spring?
A Short Drink from a Certain Fountain:  In this episode, a scientist gives his brother an experimental youth serum in order to save his marriage to a much younger woman. Fountain of Youth: The Fountain of Youth is a spring that supposedly restores the youth of anyone who drinks or bathes in its waters.
i don't know