“I have heard that some people find it only a narcotic, and it is said that in Siberia there are actually Amanita debauchees who go on prolonged tears by eating the thing.  It may be that it does not affect some people as it does others, but in most cases that beautiful gossamer veil which you see about the stem is really a shroud.

“The worst of it is,” he continued, “that this Amanita somewhat resembles the royal agaric, the Amanita caesarea.  It is, as you see, strikingly beautiful, and therefore all the more dangerous.”

He ceased a moment, while we looked in a sort of awe at the fatally beautiful thing.

“It is not with the fungus that I am so much interested just now, however,” Kennedy began again, “but with the poison.  Many years ago scientists analyzed its poisonous alkaloids and found what they called bulbosine.  Later it was named muscarin, and now is sometimes known as amanitin, since it is confined to the mushrooms of the Amanita genus.

“Amanitin is a wonderful and dangerous alkaloid, which is absorbed in the intestinal canal.  It is extremely violent.  Three to five one-thousandths of a gram, or six one-hundredths of a grain, are very dangerous.  More than that, the poisoning differs from most poisons in the long time that elapses between the taking of it and the first evidences of its effects.

“Muscarin,” Kennedy concluded, “has been chemically investigated more often than any other mushroom poison and a perfect antidote has been discovered.  Atropin, or belladonna, is such a drug.”

For a moment I looked about at the others in the room.  Had it been an accident, after all?  Perhaps, if any of the others had been attacked, one might have suspected that it was.  But they had not been affected at all, at least apparently.  Yet there could be no doubt that it was the poisonous muscarin that had affected Mansfield.

“Did you ever see anything like that?” asked Kennedy, suddenly, holding up the gilt spangle which he had found on the closet floor near the wall safe.

Though no one said a word, it was evident that they all recognized it.  Lewis was watching Madeline closely.  But she betrayed nothing except mild surprise at seeing the spangle from her dress.  Had it been deliberately placed there, it flashed over me, in order to compromise Madeline Hargrave and divert suspicion from some one else?

I turned to Mina.  Behind the defiance of her dark eyes I felt that there was something working.  Kennedy must have sensed it even before I did, for he suddenly bent down over the recording needle and the ruled paper on the table.

“This,” he shot out, “is a pneumograph which shows the actual intensity of the emotions by recording their effects on the heart and lungs together.  The truth can literally be tapped, even where no confession can be extracted.  A moment’s glance at this line, traced here by each of you, can tell the expert more than words.”