This last chapter is a full testament written by Jekyll concerning his history and his character. Jekyll describes himself as
a proud man who wanted a reputation as a serious person. Early on he hid his natural high spirits and developed a double
character. His scientific studies focused on the mystical and transcendental as he searched out these aspects of man,
especially in the moral dimension. He wanted to learn how these two sides could be disconnected. At the same time he
was studying drugs and discovered a potion that could transform his flesh and turn him into a creature that represented
his baser nature. When he tries the drug on himself, he feels himself to be extremely wicked but at the time he was
exhilarated by this sensation. He begins to live this dual life, one as the respectable gentleman and the other as a person
who gives into every impulse. Jekyll continues to metamorphose back and forth between his two halves until one day the
reversal occurs spontaneously. He realizes that the evil side of his nature is growing and is in danger of taking control of
his life. He tries to resist the temptation but once again he gives in. This time he kills Sir Carew. He is penitent and tries
to maintain a good and sober life until he forgets his terror. Now his evil side begins to take over even without the drug.
He must use stronger and stronger doses of the potion to return to his original self. When he runs out of the salt he uses
in the compound, he finds that the fresh supply he orders does not have the power to transform him.
As he writes this testament he knows he has limited time before his evil nature takes over. He wonders if Hyde will die
on the scaffold or commit suicide. This is the end of the unhappy life of Henry Jekyll.