"Well, he is sure to keep an eye on the papers, since, to a poor man, the loss was a heavy one. He was clearly so scared by his mischance in breaking the window and by the approach of Peterson that he thought of nothing but flight, but since then he must have bitterly regretted the impulse which caused him to drop his bird. Then, again, the introduction of his name will cause him to see it, for everyone who knows him will direct his attention to it. Here you are, Peterson, run down to the advertising agency and have this put in the evening papers."

"In which, sir?"

"Oh, in the Globe, Star, Pall Mall, St. James's, Evening News, Standard, Echo, and any others that occur to you."

"Very well, sir. And this stone?"

"Ah, yes, I shall keep the stone. Thank you. And, I say, Peterson, just buy a goose on your way back and leave it here with me, for we must have one to give to this gentleman in place of the one which your family is now devouring."

When the commissionaire had gone, Holmes took up the stone and held it against the light. "It's a bonny thing," said he. "Just see how it glints and sparkles. Of course it is a nucleus and focus of crime. Every good stone is. They are the devil's pet baits. In the larger and older jewels every facet may stand for a bloody deed. This stone is not yet twenty years old. It was found in the banks of the Amoy River in southern China and is remarkable in having every characteristic of the carbuncle, save that it is blue in shade instead of ruby red. In spite of its youth, it has already a sinister history. There have been two murders, a vitriol-throwing, a suicide, and several robberies brought about for the sake of this forty-grain weight of crystallised charcoal. Who would think that so pretty a toy would be a purveyor to the gallows and the prison? I'll lock it up in my strong box now and drop a line to the Countess to say that we have it."

"Do you think that this man Horner is innocent?"

"I cannot tell."

"Well, then, do you imagine that this other one, Henry Baker, had anything to do with the matter?"

"It is, I think, much more likely that Henry Baker is an absolutely innocent man, who had no idea that the bird which he was carrying was of considerably more value than if it were made of solid gold. That, however, I shall determine by a very simple test if we have an answer to our advertisement."

"And you can do nothing until then?"