“Now, of course my first thought was that she might have taken several capsules at once and that it was a case of accidental morphine poisoning, or it might even be suicide.  But it cannot be either, to my mind, for only three of the six capsules are gone.  No doubt, also, you are acquainted with the fact that the one invariable symptom of morphine poisoning is the contraction of the pupils of the eyes to a pin-point—­often so that they are unrecognisable.  Moreover, the pupils are symmetrically contracted, and this symptom is the one invariably present in coma from morphine poisoning and distinguishes it from all other forms of death.

“On the other hand, in the coma of kidney disease one pupil is dilated and the other contracted—­they are unsymmetrical.  But in this case both the pupils are normal, or only a very little dilated, and they are symmetrical.  So far we have been able to find no other poison than the slight traces of morphine remaining in the stomach after so many hours.  I think you are enough of a chemist to know that no doctor would dare go on the stand and swear to death from morphine poisoning in the face of such evidence against him.  The veriest tyro of an expert toxicologist could too easily confute him.”

Kennedy nodded.  “Have you the pill-box and the prescription?”

“I have,” replied Dr. Hanson, placing them on the table.

Kennedy scrutinised them sharply.  “I shall need these,” he said.  “Of course you understand I will take very good care of them.  Is there anything else of importance?”

“Really, I don’t know,” said the physician dubiously.  “It’s rather out of my province, but perhaps you would think it important.  It’s mighty uncanny anyhow.  Henry Vandam, as you doubtless know, was much more deeply interested in the work of this medium than was his wife.  Perhaps Mrs. Vandam was a bit jealous—­I don’t know.  But she, too, had an interest in spiritualism, though he was much more deeply influenced by Mrs. Popper than she.

“Here’s the strange part of it.  The old man believes so thoroughly in rappings and materialisations that he constantly keeps a notebook in his pocket in which he records all the materialisations he thinks he sees and the rappings he hears, along with the time and place.  Now it so happened that on the night Mrs. Vandam was taken ill, he had retired—­I believe in another part of the house, where he has a regular seance-room.  According to his story, he was awakened from a profound sleep by a series of rappings.  As was his custom, he noted the time at which they occurred.  Something made him uneasy, and he said to his ’control’—­at least this is his story: 

“‘John, is it about Mary?’

“Three raps answered ‘yes,’ the usual code.

“‘What is the matter?  Is she ill?’

“The three answering raps were so vigorous that he sprang out of bed and called for his wife’s maid.  The maid replied that Mrs. Vandam had not gone to bed yet, but that there was a light in the library and she would go to her mistress immediately.  The next moment the house was awakened by the screams of the maid calling for help, that Mrs. Vandam was dying.