ce it for me to tell
you, that this colorless liquid is practically the Elixir of Life, for
which the ancients sought in vain."

"The Elixir of Life? Why, that is a myth!" Leon almost smiled. But he
did not quite, because the expression on the Doctor's face was too
serious.

"I said that it is practically the magic fluid. It has the property of
supplying the body in twenty-four hours, with the vital energy which
it would otherwise need several days of rest and recreation to
recover. That is why I prescribe it to you, while you are engaged so
arduously upon your studies. Do you not find that you are less easily
fatigued?"

"I do, indeed. It is certainly a wonderful invigorator!"

"Leon," said the Doctor, after a slight pause, "I believe that I have
your confidence and trust?"

"Absolutely, Doctor!"

"Would you take any drug that I might administer, without knowing its
effects, and without questioning my motive, so long as I assure you
that you would be benefited?"

"I would!"

"I will put you to the test, but, in exchange for your trust, I will
tell you in part what I mean to do." He took a small phial from his
pocket, a tiny tube containing less than five minims of a clear
colorless liquid. "In this little bottle, Leon, there is a medicine of
frightful potency. One drop would suffice to destroy a human life. But
mixed with your nightly draught, a new chemical compound is produced,
which, though harmless, will so energize the brain-cells that the
powers of recollection will be more than trebled. By this means, your
progress can be very much enhanced, for instead of receiving what I
offer to you each night, and assimilating a part of it, you will find
in the future that all my words will be indelibly imprinted upon your
mind."

"I would have taken the drug without your explanation, Doctor, but now
I am eager for the experiment."

"This is no experiment, Leon. Beware of operating upon a human being
when your knowledge is so meagre that you must resort to experimental
tests." There was a touch of deep feeling in the Doctor's tones, as
though he might at some time have made the error against which he
admonished the lad. Leon, however, did not observe anything out of the
common. He was intent upon what the Doctor was about to do. Dr.
Medjora carefully removed the tiny glass stopper from the phial, and,
holding it in his left hand, took up the glass from the table with his
right. Pausing a moment he exclaimed: