"What!" they all exclaimed with looks of horror on their faces, "do you really mean that Pierre did the dastardly act?"
"Certainly. Do you remember, Dr. Roux, when you called on me this afternoon and asked me to help you to draw up your report as you were uncertain whether Delapine was dead or not?"
"I do, perfectly."
"Well, you recollect that I searched in my text-books to find some drug which would cause a person to lapse into a state of apparent death for a long period, and failing to discover it, I suddenly thought of something, and climbed up a ladder and took a bottle from the top shelf, and to my horror and amazement discovered it to be half empty?"
"I do, and what's more you seemed to have lost your senses for a moment, you were so agitated," said Roux.
"Now, I suddenly remembered that two or three weeks ago, Pierre, whom I have not seen for two or more years, unexpectedly called and cross-questioned me as to the action of certain secret poisons which science has been unable to detect, and I showed him a Japanese poison which had recently arrived from Tokio. I took the bottle down and showed it to him, and I then replaced it on the shelf. The liquid was a thick, highly refractive dichromic liquid, which had a very unusual appearance something like quinine only much more highly refractive, besides being far heavier. When we left the room we waited in the passage of the house for a cab, when suddenly Pierre asked for the loan of the key of the room as he had forgotten his cigarette case. Not suspecting anything, I gave it to him, and waited there until he returned. To the best of my recollection, no one except my servant has ever had access to the room since, and when I discovered the bottle half empty to-day I knew it must have been Pierre who had opened it."
"Yes," said Riche, "and I remember at the séance last week I noticed Pierre quietly slip out of the room and disappear. Well, less than half an hour afterwards we all noticed the smoke of the fire."
"A strange coincidence that the two events should follow one another so soon," said Villebois, who had been listening intently. "Not only that, but your daughter called my attention to the fact that Pierre tampered with Delapine's coffee when we had the race on the lawn, and I think we all noticed how cleverly Delapine excused himself from drinking it, and killed a plant with a few drops of the liquid. You see how all these facts fit in together and render the evidence of his guilt convincing. Lastly, here is the liquid which I emptied out of the syringe I found on the floor of the séance-room after the person inside had escaped."
Paul took the bottle out of Riche's hand and examined it carefully.
"Yes," he replied, as he placed it on the table for the others to look at. "That is the Japanese liquid which was stolen from my laboratory."