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 think I should, at any rate, begin in this country. I rather think you might make a beginning at Denson. That is what I should do if the case were mine. See if anything can be ascertained of his previous life—probably under another name or names. He may have been in China. Yes, certainly, as we stand at present, I should begin at Denson."
"I think I will," the inspector replied, "though there's precious little to begin on there. I'd like to have you with me on this job, but, of course, that's impossible, since it's purely a police matter. But something, some information, may come your way, and in that case you'll let me know at once, of course."
"Of course I shall—it's a serious matter, as well as a strange one. I wish you all luck!"