ght, one desire, to get a breath of fresh air. The
window in the west wall, directly opposite the bed, attracted us. In Mr.
Ashton's case, no doubt, the face of Li Min, peering in from without,
increased his terror. Like myself, he sprang up and dashed toward the
window, placing his right foot, as I did, upon the low stool beside the
bed. His first dash forward and upward, to a standing position, like my
own, brought his head, elevated by the height of the stool, in contact
with the spike upon the lower end of the chandelier with great force.
The spike entered his head, fracturing the skull. He was a taller and
heavier man than myself, and the force of the contact as he sprang
forward and upward must have been terrific. In my case, owing to my
having jumped from the bed at a slightly different point, I struck the
spike only a glancing blow, which was sufficient however to render me
unconscious for several minutes. I fell to the floor, senseless, but in
a short time I struggled to my knees and managed, by crawling painfully
to the door, to escape from the room. The interval, from the time I
first fell to the time I reached the hall and again became unconscious,
must have been very short."

"Why?" asked McQuade, who, like the others, followed my every word with
intense interest.

"Because, had the time been very long, I, like Mr. Ashton, should never
have risen at all. You would have found me here this morning, as he was
found."

"But why?" asked Major Temple.

For answer I took a box of wax tapers from my pocket and lighted one.
"Have you ever heard of the Cave of Dogs, near Naples?" I inquired.

"Carbon dioxide," gasped the Major with a look of comprehension.

Sergeant McQuade looked blank, and I saw that to him neither my question
nor the Major's answer had conveyed any definite meaning. "Look," I
cried, as I held the match out before me, where it burned with a bright,
clear flame.

McQuade's mystification increased. I think he wondered if I were trying
to play some practical joke upon him. But, when I slowly lowered the
taper until it reached a point a few inches above my knee, and its
flame faded away and then suddenly went out, as though the match had
been plunged into a basin of water, his expression slowly cleared, and
he gave a significant grunt. "Carbonic-acid gas," he said. "I
understand. But where does it come from?"

"That I do not know, at the moment," I said, "but I think there should
be no great