e old man puckered up his eyebrows, as if genuinely anxious to
remember something that would please the man who had shown him so
much sympathy.

"I can't think of anything, sir," he said at length, apologetically,
"only the marmalade, and that, of course, wouldn't----"

"The marmalade?" Malcolm Sage turned quickly.

"It was nothing, sir," said the old man. "Perhaps I oughtn't to have
mentioned it; but the morning before we found him, the master had
not eaten any marmalade, and him so fond of it. I was rather worried,
and I asked Mrs. Graham if it was a new brand, thinking perhaps he
didn't like it; but I found it was the same he always had."

For fully a minute Malcolm Sage was silent, gazing straight before
him.

"He never smoked?" he asked at length.

"Never, sir, not during the whole thirty years I've been with him."

"Who cleaned the laboratory? It did not look as if it had been
unswept for a week."

"No, indeed, sir," was the reply, "the professor was very particular.
He always swept it up himself each morning. It was cleaned by one of
the servants once a month."

"You're sure about the sweeping-up?" Malcolm Sage enquired with a
keen glance that with him always meant an important point.

"Quite certain, sir."

"That, I think, will be all."

"Thank you, sir," said the butler, rising. "Thank you for being so
kind, and--and understanding, sir," and he walked a little
unsteadily from the room.

"I was afraid you wouldn't get anything out of him, Mr. Sage," said
Inspector Carfon, with just a suspicion of relief in his voice.

"No," remarked Malcolm Sage quietly, "nothing new; but an important
corroboration of the doctor's evidence."

"What was that?"

"That it was the murderer and not Professor McMurray who ate
Wednesday's breakfast, luncheon and dinner."

"Good Lord!" The inspector's jaw dropped in his astonishment.

"I suspect that for some reason or other he returned to
the laboratory; that accounts for the rough marks upon the
door-fastenings as if someone had first torn them off and then sought
to replace them. After his second visit the murderer evidently stayed
too long, and was afraid of being seen leaving the laboratory. He
therefore remained until the following night, eating the professor's
meals. Incidentally he knew all about his habits."

"Well, I'm blowed if he isn't a cool un!" gasped the inspector.

Malcolm Sage rose with the air of one who has concluded the business
on hand.