In "Dr. Heidegger's Experiment," what does he tell them about the rose?

Dr. Heidegger presents the rose to his guests at the
beginning of his proposed "experiment," the nature of which remains a mystery to his
friends who are just about to be experimented upon. As Dr. Heidegger takes out the
remains of a rose from his folio, he tells his guests its
origin:

"This
rose," said Dr. Heidegger, with a sigh, "this same withered and crumbling flower,
blossomed five and fifty years ago. It was given me by Sylvia Ward, whose portrait hangs
yonder; and I mean tot wear it in my bosom at our wedding. Five and fifty years it has
been treasured between the leaves of this old volume. Now, would you deem it possible
that this rose of half a century could ever bloom
again?"

Thus we are told that
the rose relates to Dr. Heidegger's only love of long ago, who, we have already been
told, was killed in a terrible accident when Sylvia Ward took a medicine prescribed to
her by her fiancé. Dr. Heidegger uses it as a demonstration of the power of the Water of
Youth, but also he uses it at the end to highlight the message of the story about the
value of old age.