"I saw you eating something when you met us and you put part of it in
your pocket. What was it?"
"A sandwich. My wife always makes me one when I go out on night-duty,"
the man explained.
"Have you any of it left?"
For answer he drew from his pocket a portion of an uneaten sandwich and
placed it upon the table. Boyd, with his pocket-knife, cut off a piece
of the meat, upon it sprinkled a grain or so of the mysterious powder,
and threw it down to the hungry cat, which was mewing loudly, and
purring round our legs.
The thin creature, ravenously hungry, devoured it, but ere ten seconds
had passed, and while we all three were watching attentively, it
staggered, with a faint cry, and almost without a struggle rolled over,
dead.
"As I suspected," Boyd observed, turning to me. "This is the powder
from the herbalist's."