tung by the thought which they conveyed. Mr. Barnes merely
nodded assent.

"Then the end is at hand!" muttered the Doctor, softly. "All is ready
for the final experiment!" Mr. Barnes did not comprehend the meaning
of what he heard, but, as the Doctor walked about the room, back and
forth, like a caged animal, seemingly oblivious of the fact that he
was not alone, the detective thought it wise to observe him closely
lest he might attack him unawares.

Presently the Doctor stopped before the detective, and thus addressed
him, in calm tones:

"Mr. Barnes, you are shrewd and you are clever. You have guessed a
part of the truth, and I have decided to tell you everything."

"I warn you," said Mr. Barnes, quickly, "that what you say will be
used against you."

"I will take that risk!" The Doctor smiled, and an expression akin to
weariness passed over his countenance. "You have said that, in your
belief, as early as 1873, I knew of the bacillus of diphtheria, and
that I inoculated my wife with it. You are right, but, nevertheless,
you are mistaken when you say that she died from that malady. I must
go further back, and tell you that the main source of my knowledge has
been some very ancient hieroglyphical writings, which recorded what
was known upon the subject by the priests of centuries ago. Much that
is novel to-day, was very well understood in those times. The germ
theory of disease was thoroughly worked out to a point far in advance
of what has yet been accomplished in this era. The study required to
translate and comprehend the cabalistic and hieroglyphical records has
been very great, and it was essential that I should test each step
experimentally. About the time of Mabel's death I had discovered the
germ of diphtheria, but I found that my experiments with the lower
animals were very unsatisfactory, owing to the fact that it does not
affect them and human beings in a precisely similar manner. I
therefore risked inoculating my wife."

"That was a hideous thing to do," ventured Mr. Barnes.

"From your standpoint, perhaps you are right. But I am a unique man,
occupying a unique position in the world. To me alone was it given to
resurrect the buried wisdom of the past. Even if I had known that the
experiment might be attended by the death of my wife, whom I loved
dearer than myself, I still would not have been deterred. Science
transcended everything in my mind. Death must come to us all, and a
few years difference