How we cite our quotes: Citations follow this format: (Paragraph)
Quote #4
There, in fact, stood the four glasses, brimful of this wonderful water, the delicate spray of which, as it effervesced from the surface, resembled the tremulous glitter of diamonds. It was now so nearly sunset that the chamber had grown duskier than ever; but a mild and moonlike splendor gleamed from within the vase, and rested alike on the four guests and on the doctor's venerable figure. (32)
It's probably not a coincidence that, as the evening's events transpire, the sun sets. There is a much bigger transformation in the setting which accompanies the transformation taking place inside the Doctor's study.
Quote #5
He sat in a high-backed, elaborately-carved, oaken arm-chair, with a gray dignity of aspect that might have well befitted that very Father Time, whose power had never been disputed, save by this fortunate company. Even while quaffing the third draught of the Fountain of Youth, they were almost awed by the expression of his mysterious visage. (32)
Dr. Heidegger, too, has been transformed in the course of the evening. His "visage" has certainly changed, though whether this change is manifested only in the eyes of his guests is subject to debate.
Quote #6
The fresh gloss of the soul, so early lost, and without which the world's successive scenes had been but a gallery of faded pictures, again threw its enchantment over all their prospects. They felt like new-created beings in a new-created universe. (33)
Lines like this one support the theory that Dr. Heidegger is a godly figure. If the guests are newly-created beings, then it is Dr. Heidegger who has created them. If the world is a newly-created world, then, again, Dr. Heidegger is its creator.