ively again--"that through all
the tumult and noise next door Mademoiselle Cynthia slept. That admitted
of two possibilities. Either her sleep was feigned--which I did not
believe--or her unconsciousness was indeed by artificial means.

"With this latter idea in my mind, I examined all the coffee-cups
most carefully, remembering that it was Mrs. Cavendish who had brought
Mademoiselle Cynthia her coffee the night before. I took a sample from
each cup, and had them analysed--with no result. I had counted the cups
carefully, in the event of one having been removed. Six persons had
taken coffee, and six cups were duly found. I had to confess myself
mistaken.

"Then I discovered that I had been guilty of a very grave oversight.
Coffee had been brought in for seven persons, not six, for Dr.
Bauerstein had been there that evening. This changed the face of the
whole affair, for there was now one cup missing. The servants noticed
nothing, since Annie, the housemaid, who took in the coffee, brought
in seven cups, not knowing that Mr. Inglethorp never drank it, whereas
Dorcas, who cleared them away the following morning, found six as
usual--or strictly speaking she found five, the sixth being the one
found broken in Mrs. Inglethorp's room.

"I was confident that the missing cup was that of Mademoiselle Cynthia.
I had an additional reason for that belief in the fact that all the
cups found contained sugar, which Mademoiselle Cynthia never took in
her coffee. My attention was attracted by the story of Annie about
some 'salt' on the tray of coco which she took every night to Mrs.
Inglethorp's room. I accordingly secured a sample of that coco, and sent
it to be analysed."

"But that had already been done by Dr. Bauerstein," said Lawrence
quickly.

"Not exactly. The analyst was asked by him to report whether strychnine
was, or was not, present. He did not have it tested, as I did, for a
narcotic."

"For a narcotic?"

"Yes. Here is the analyst's report. Mrs. Cavendish administered a
safe, but effectual, narcotic to both Mrs. Inglethorp and Mademoiselle
Cynthia. And it is possible that she had a mauvais quart d'heure in
consequence! Imagine her feelings when her mother-in-law is suddenly
taken ill and dies, and immediately after she hears the word 'Poison'!
She has believed that the sleeping draught she administered was
perfectly harmless, but there is no doubt that for one terrible moment
she must have feared that Mrs. Ingleth