He entered into explanations, for which there was no need, as to why he had been led to believe that a robbery had been committed, which included the simultaneous discovery he had made in the lavatory, and the empty precious cabinet in the laboratory.

The first thing that had struck him, he said, was the unusual form of that piece of furniture.

It was very strongly built of fire-proof iron, clearly showing that it was intended for the keeping of most valuable objects.

Then he noticed that the key had been left in the lock.

"One does not ordinarily have a safe and leave it open!" he had said to himself.