othing to dissect--"

"I've got a knot now for you."

"Good! good! I trust it is a good complication--I love them so--there
is such a satisfaction when the end is reached. But not yet--no, not
yet. A glass of wine first--something prime--I imported it myself, so
that I would know what I am getting."

The wine was soon forthcoming and then a cigar for the detective and a
pipe for the doctor. At last the latter threw himself into an old easy
chair and gazed at his caller expectantly.

"I am ready to untie the knot," he said. "What is it?"

CHAPTER X

AN AFFAIR OF THE HEART

There was a moment of silence.

"Briefly put, doctor, the case is this," said Adam Adams. "I want to
know if there is anything known to the medical world, a powder or
something of that sort, strong enough to kill a person if he should
breathe of it."

"A powder strong enough to kill a person?" The brow of the old
physician contracted. "It would have to be very powerful to do that.
You mean if a person was boxed up with it--like one killed by gas?"

"No, not at all. I mean a powder that could be held to a person's nose
and mouth in the open, when it would make that person sick and give him
cramps perhaps."

"And kill him?"

"Yes."

The old doctor rubbed his hands in thought. "That is a subject for
speculation. Certain cyanide compounds might be powerful enough to do
so under certain conditions. Any real dry powder would choke a person
if he got a big dose of it. I heard of a boy who came near dying as
the result of breathing in a quantity of extra dry licorice powder.
But he was smothered and did not have cramps."

"Nothing in the shape of any foreign compound? You once showed me a
Turkish liquid that burnt when water was poured on it, and dyed
everything blood red."

"Ah, yes, the _fozeska_, something truly dangerous. But I know of
nothing-- But hold!" The doctor clapped his hands together. "Yes!
yes! That would do it, that and that only."

"What?"

"I had a sample of it given to me some six months ago. It was called
_yamlang-peholo_, and was made in China, from the roots of the
_yamlang_ bush--a rare growth found only in the western part of the
country. By many Chinamen the _yamlang_ bush is supposed to be
accursed, and whenever they come near one they utter a prayer for
deliverance from its evils. If you sleep near the _yamlang_ bush it
will make you very sick."

"And that powder, what did it look