"Sit on the sofa," he advised. "The chairs are a job lot bought at the sale after the suppression of the Holy Inquisition in Spain. This is a pretty good negative," he went on, holding it up to the light with his head at the angle of discriminating judgment. "Washed enough now, I think. Let us leave it to dry, and get rid of all this mess."
Mr. Cupples, as the other busily cleared the table of a confusion of basins, dishes, racks, boxes and bottles, picked up first one and then another of the objects and studied them with innocent curiosity.
"That is called hypo-eliminator," said Trent as Mr. Cupples uncorked and smelled at one of the bottles. "Very useful when you're in a hurry with a negative. I shouldn't drink it, though, all the same. It eliminates sodium hypophosphite, but I shouldn't wonder if it would eliminate human beings too." He found a place for the last of the litter on the crowded mantel-shelf, and came to sit before Mr. Cupples on the table. "The great thing about a hotel sitting-room is that its beauty does not distract the mind from work. It is no place for the May-fly pleasures of a mind at ease. Have you ever been in this room before, Cupples? I have, hundreds of times. It has pursued me all over England for years. I should feel lost without it if, in some fantastic, far-off hotel, they were to give me some other sitting-room. Look at this table-cover; there is the ink I spilled on it when I had this room in Halifax. I burnt that hole in the carpet when I had it in Ipswich. But I see they have mended the glass over the picture of 'Silent Sympathy,' which I threw a boot at in Banbury. I do all my best work here. This afternoon, for instance, since the inquest, I have finished several excellent negatives. There is a very good dark-room downstairs."
"The inquest—that reminds me," said Mr. Cupples, who knew that this sort of talk in Trent meant the excitement of action, and was wondering what he could be about. "I came in to thank you, my dear fellow, for looking after Mabel this morning. I had no idea she was going to feel ill after leaving the box; she seemed quite unmoved, and really she is a woman of such extraordinary self-command, I thought I could leave her to her own devices and hear out the evidence, which I thought it important I should do. It was a very fortunate thing she found a friend to assist her, and she is most grateful. She is quite herself again now."
Trent, with his hands in his pockets and a slight frown on his brow, made no reply to this. "I tell you what," he said after a short pause, "I was just getting to the really interesting part of the job when you came in. Come: would you like to see a little bit of high-class police work? It's the very same kind of work that old Murch ought to be doing at this moment. Perhaps he is; but I hope to glory he isn't." He sprang off the table and disappeared into his bedroom. Presently he came out with a large drawing-board on which a number of heterogeneous objects was ranged.
"First I must introduce you to these little things," he said, setting them out on the table. "Here is a big ivory paper-knife; here are two leaves cut out of a diary—my own diary; here is a bottle containing dentifrice; here is a little case of polished walnut. Some of these things have to be put back where they belong in somebody's bedroom at White Gables before night. That's the sort of man I am—nothing stops me. I borrowed them this very morning when everyone was down at the inquest, and I dare say some people would think it rather an odd proceeding if they knew. Now there remains one object on the board. Can you tell me, without touching it, what it is?"
"Certainly I can," said Mr. Cupples, peering at it with great interest. "It is an ordinary glass bowl. It looks like a finger-bowl. I see nothing odd about it," he added after some moments of close scrutiny.
"That," replied Trent, "is exactly where the fun comes in. Now take this little fat bottle, Cupples, and pull out the cork. Do you recognize that powder inside it? You have swallowed pounds of it in your time, I expect. They give it to babies. Gray powder is its ordinary name—mercury and chalk. It is great stuff. Now while I hold the basin side-ways over this sheet of paper, I want you to pour a little powder out of the bottle over this part of the bowl—just here.... Perfect! Sir Edward Henry himself could not have handled the powder better. You have done this before, Cupples, I can see. You are an old hand."
"I really am not," said Mr. Cupples seriously, as Trent returned the fallen powder to the bottle. "I assure you it is all a complete mystery to me. What did I do then?"
"I brush the powdered part of the bowl lightly with this camel-hair brush. Now look at it again. You saw nothing odd about it before. Do you see anything now?"