you obtained
such perfect reprints that, in your hasty examination, you can be
certain of identifying them with those of the persons who will pass
through your office to undergo the test?"

Bertillon smiled:

"Oh, my dear fellow, you are of those who do not put much faith in the
results of my tests for police purposes! That, let me tell you, is
because you are not acquainted with our procedure. The impressions I
obtained are distinct--precise as can be; if an arrest is made before
long it will be made on sure grounds."

Fandor bowed:

"I accept your statement, dear master!... But, do be kind enough to tell
me what happened after my departure?"

"Oh, nothing very extraordinary.... Of course you know about the
affair--how the Princess Sonia Danidoff was discovered?..."

"What I know is that Thomery found one of his guests, Princess Sonia
Danidoff, in a dead faint in a small drawing-room; that Dr. Du Marvier
declared she had been rendered unconscious; that the theft of a pearl
necklace worn by the victim had been the motive of this criminal
attempt; that Monsieur Havard, called in at once, first made sure that
no one had left the house, and then had everyone on the premises
searched ... and that is really all I know about it!"

"Well, Havard did not find anything!"

"No one was caught with compromising jewels in their possession. The
last guest gone, the house searched from top to bottom, not a single
pearl had been found.... I arrived just when the investigations had
terminated: at the moment when they were about to take the Princess
home. She had regained consciousness by this time and declared she knew
nothing except that she had fallen asleep after using a perfume sprayer.
This has been seized and chloroform has been found in it; but no one
seems to know who filled the sprayer with this stupefying perfume."

"Did Monsieur Havard send for you?"

"Yes, he telephoned. You know, of course, that I am always asked to
intervene now in any ticklish affair!... Well Dr. Du Marvier, an expert
in his way, noticed that the Princess had been half strangled by the
thief in his haste to secure the pearl collar, and he wished me to
search for finger prints on the nape of the victim's neck--to discover
the assassin's signature in fact."

"And there were some?"

"A quantity. The Princess had been slightly wounded in the nape of the
neck ... blood had been pressed on to the skin of her neck, and it was
easy to take a cast