Mrs.
Armitage alone; and to this idiotic hallucination she has, I fear, fallen
a sacrifice. Judging from the emaciated appearance of the body, and other
phenomena communicated to me by her ordinary medical attendant--a
blundering ignoramus, who ought to have called in assistance long
before--she has been poisoned with _iodine_, which, administered in
certain quantities, would produce precisely the same symptoms. Happily
there is no mode of destroying human life which so surely leads to the
detection of the murderer as the use of such agents; and of this truth
the post mortem examination of the body, which takes place to-morrow
morning, will, if I am not grossly mistaken, supply another vivid
illustration. Legal assistance will no doubt be necessary, and I am sure
I do not err in expecting that _you_ will aid me in bringing to justice
the murderer of Mary Rawdon?"

A pressure of his hand was my only answer. "I shall call for you at ten
o'clock" said he, as he put me down at my own door. I bowed, and the
carriage drove off.

"Well!" said I, as Dr. Curteis and Mr. ---- the eminent surgeon entered
the library at Mount Place the following morning after a long absence.

"As I anticipated," replied the doctor with a choking voice: "she has
been poisoned!"

I started to my feet. "And the murderer?"

"Our suspicions still point to young Bourdon; but the persons of both
mother and son have been secured."

"Apart?"

"Yes; and I have despatched a servant to request the presence of a
neighbor--a county magistrate. I expect him momently."

After a brief consultation, we all three directed our steps to the
summer-house which contained young Bourdon's laboratory. In the room
itself nothing of importance was discovered; but in an enclosed recess,
which we broke open, we found a curiously-fashioned glass bottle half
full of iodine.

"This is it!" said Mr. ----; "and in a powdered state too--just ready
for mixing with brandy or any other available dissolvent." The powder had
somewhat the appearance of fine black lead. Nothing further of any
consequence being observed, we returned to the house, where the
magistrate had already arrived.

Alfred Bourdon was first brought in; and he having been duly cautioned
that he was not obliged to answer any question, and that what he did say
would be taken down, and, if necessary, used against him, I proposed the
following questions:--

"Have you the key of your laboratory?"

"No; the