as to what to do.

"I had intended to return immediately, but before I got back Mr.
Morowitch was dead. Now I think I've told you all. You see, it
was nothing but a suspicion--hardly enough to warrant making a
fuss about. I made out the death-certificate, as you see.
Probably that would have been all there was to it if I hadn't
heard of this incomprehensible robbery. That set me thinking
again. There, I'm glad I've got it out of my system. I've thought
about it a good deal since your man was here to see me."

"What do you suspect was the cause of that sweetish odour?" asked
Kennedy.

The doctor hesitated. "Mind, it is only a suspicion. Cyanide of
potassium or cyanogen gas; either would give such an odour."

"Your treatment would have been just the same had you been
certain?"

"Practically the same, the Rockefeller treatment."

"Could it have been suicide" asked Andrews.

"There was no motive for it, I believe," replied the doctor.

"But was there any such poison in the Morowitch house?"

"I know that they were much interested in photography. Cyanide of
potassium is used in certain processes in photography."