"What about the radiator?" asked Average Jones, getting down on his
knees beside that antiquated contrivance. "It seems to have been
the center of disturbance."

"If you're thinking of fumes," replied the chemist. "I tested for
that. It isn't possible."

"No; I suppose not. And yet, there's the curious feature that the
fatal influence seems to have emanated from the corner which is the
most remote from both windows and door. Are your windows left open
at night?"

"The windows, sometimes. The transom is kept double-bolted."

"Do they face any other windows near by?"

"You can see for yourself that they don't."

"There's no fire-escape and it's too far up for anything to come in
from the street." Average examined the walls with attention and
returned to the big keyhole, through which he peeped.

"Do you ever chew gum?" he asked suddenly.

The Chemist stared at him. "It isn't a habit of mine to," he said.

"But you wouldn't have any objection to my sending for some, in
satisfaction of a sudden irresistible craving?"

"Any particular brand? I'll phone the corner drug store."