h in the hall and another halfway up the
stairs. He found the bedroom door locked, and turned the key from
outside with a bent wire. He entered, lit the candle, placed the box and
hassock, murdered his victim, washed his hands and knife, took the
candle-end from the socket and went downstairs, where he blew out the
candle and dropped it into the tray.

"The next clue is furnished by the sand on the pillow. I took a little
of it, and examined it under the microscope, when it turned out to be
deep-sea sand from the Eastern Mediterranean. It was full of the minute
shells called 'Foraminifera,' and as one of these happened to belong to
a species which is found only in the Levant, I was able to fix the
locality."

"But this is very remarkable," said the coroner. "How on earth could
deep-sea sand have got on to this woman's pillow?"

"The explanation," replied Thorndyke, "is really quite simple. Sand of
this kind is contained in considerable quantities in Turkey sponges. The
warehouses in which the sponges are unpacked are often strewn with it
ankle deep; the men who unpack the cases become dusted over with it,
their clothes saturated and their pockets filled with it. If such a
person, with his clothes and pockets full of sand, had committed this
murder, it is pretty certain that in leaning over the head of the bed in
a partly inverted position he would have let fall a certain quantity of
the sand from his pockets and the interstices of his clothing. Now, as
soon as I had examined this sand and ascertained its nature, I sent a
message to Mr. Goldstein asking him for a list of the persons who were
acquainted with the deceased, with their addresses and occupations. He
sent me the list by return, and among the persons mentioned was a man
who was engaged as a packer in a wholesale sponge warehouse in the
Minories. I further ascertained that the new season's crop of Turkey
sponges had arrived a few days before the murder.

"The question that now arose was, whether this sponge-packer was the
person whose fingerprints I had found on the candle-end. To settle this
point, I prepared two mounted photographs, and having contrived to meet
the man at his door on his return from work, I induced him to look at
them and compare them. He took them from me, holding each one between a
forefinger and thumb. When he returned them to me, I took them home and
carefully dusted each on both sides with a certain surgical
dusting-powder. The powder