here is no branch of detective science which
is so important and so much neglected as the art of tracing footsteps.
Happily, I have always laid great stress upon it, and much practice
has made it second nature to me. I saw the heavy footmarks of the
constables, but I saw also the track of the two men who had first passed
through the garden. It was easy to tell that they had been before the
others, because in places their marks had been entirely obliterated by
the others coming upon the top of them. In this way my second link was
formed, which told me that the nocturnal visitors were two in number,
one remarkable for his height (as I calculated from the length of his
stride), and the other fashionably dressed, to judge from the small and
elegant impression left by his boots.

"On entering the house this last inference was confirmed. My well-booted
man lay before me. The tall one, then, had done the murder, if murder
there was. There was no wound upon the dead man's person, but the
agitated expression upon his face assured me that he had foreseen his
fate before it came upon him. Men who die from heart disease, or any
sudden natural cause, never by any chance exhibit agitation upon their
features. Having sniffed the dead man's lips I detected a slightly sour
smell, and I came to the conclusion that he had had poison forced upon
him. Again, I argued that it had been forced upon him from the hatred
and fear expressed upon his face. By the method of exclusion, I had
arrived at this result, for no other hypothesis would meet the facts.
Do not imagine that it was a very unheard of idea. The forcible
administration of poison is by no means a new thing in criminal annals.
The cases of Dolsky in Odessa, and of Leturier in Montpellier, will
occur at once to any toxicologist.

"And now came the great question as to the reason why. Robbery had not
been the object of the murder, for nothing was taken. Was it politics,
then, or was it a woman? That was the question which confronted me.
I was inclined from the first to the latter supposition. Political
assassins are only too glad to do their work and to fly. This murder
had, on the contrary, been done most deliberately, and the perpetrator
had left his tracks all over the room, showing that he had been there
all the time. It must have been a private wrong, and not a political
one, which called for such a methodical revenge. When the inscription
was discovered upon the wall I was more