t, too, by the way,
the divisional surgeon told me a little, but a very useless little. The
mark was not properly dried, owing to its slightly greasy nature, and
although it was almost impossible to remove it wholly, it _was_ possible
to scrape off a little of the ink, or colour. Here is a little of it on
a paper--quite dried now, of course."

Plummer carefully took from his pocket a small folded paper, unfolded
it, and revealed a smaller paper within. On this were two little smears
of a bright red colour. "There--that's the stuff," he said. "The surgeon
examined it, and he reports it to be rather oddly constituted--so as to
bear some affinity of meaning, possibly, to the triangle. For the stuff
is a compound of three substances--animal, vegetable and mineral; there
is a fine vegetable oil, he says, some waxy preparation, certainly of
animal origin, and a mineral--cinnabar: vermilion, in fact. But though
there _may_ be some connection between the triangle and the substances
representing the three natural kingdoms, it gives nothing
practical--nothing to go on."

Martin Hewitt had been closely examining the marks on the paper, and now
he answered, "I'm not so sure of that, though, Plummer. I think at least
that it gives us another conjecture. I should guess that the man you
want, as well as being acquainted with the use of the tourniquet, has at
some time travelled in, or to, China."

"Why?"

"Unless I am wider of the mark than usual, this is the pigment used on
Chinese seals. A Chinaman's seal acts for his signature on all sorts of
documents; it is impressed or printed by hand pressure from a little
engraved stone die, precisely as this triangle seems to have been, and
the ink or colour is almost always red, compounded of vermilion, wax,
and oil of sesamum."

Plummer sat up with a whistle. "Phew! Then it may have been done by a
Chinaman!"

Hewitt shrugged his shoulders. "It's possible," he said; "of course,
though, the sign, the triangle, is not a Chinese character. As a
character, of course it is the Greek _Delta_. But it may be no character
at all. In the signs of the ancient Cabala, the triangle, apex upward as
it was in this case, was the symbol of fire; apex downward, it signified
water."

Plummer patted the side of his head distractedly. "Heavens!" he said,
"don't tell me I'm to search all China, and Greece, and--wherever the
cabalistic pundits come from!"

"Well, no," Hewitt answered with a smile. "I th