Which two sentences in this excerpt from Nathaniel Hawthorne's "Dr. Heidegger's Experiment" most closely reflects the central theme of the passage? His guests shivered again. A strange chillness, whether of the body or spirit they could not tell, was creeping gradually over them all. They gazed at one another, and fancied that each fleeting moment snatched away a charm, and left a deepening furrow where none had been before. Was it an illusion? Had the changes of a lifetime been crowded into so brief a space, and were they now four aged people, sitting with their old friend, Dr. Heidegger?

"Are we grown old again, so soon?" cried they, dolefully.

In truth they had. The Water of Youth possessed merely a virtue more transient than that of wine. The delirium which it created had effervesced away. Yes! they were old again. With a shuddering impulse, that showed her a woman still, the widow clasped her skinny hands before her face, and wished that the coffin-lid were over it, since it could be no longer beautiful.

"Yes, friends, ye are old again," said Dr. Heidegger, "and lo! the Water of Youth is all lavished on the ground. Well, I bemoan it not; for if the fountain gushed at my very doorstep, I would not stoop to bathe my lips in it; no, though its delirium were for years instead of moments. Such is the lesson ye have taught me!"

But the doctor's four friends had taught no such lesson to themselves. They resolved forthwith to make a pilgrimage to Florida, and quaff at morning, noon, and night, from the Fountain of Youth.