“I wonder,” he said reflectively, “if I ever reach the mature age of one hundred, if I will carry in my head as many odds and ends of information as you have at thirty!”

“I?”

“You. How in the world did you know, for instance, about those tongs?”

“It was quite simple. I’d seen something like them in the laboratory here. Of course I didn’t know what animals he’d used, but the grayish brown hair looked like rats. The laboratory must be the cellar room. I knew it had been fumigated—it was sealed with paper, even over the keyhole.”

So, sitting there beside me, Mr. Patton told me the story as he had got it from Mr. Reed—a tale of the offer in an English scientific journal of a large reward from some plague-ridden country of the East for an anti-plague serum. Mr. Reed had been working along bacteriological lines in his basement laboratory, mostly with guinea pigs and tuberculosis. He was in debt; the offer loomed large.

“He seems to think he was on the right track,” Mr. Patton said. “He had twenty of the creatures in deep zinc cans with perforated lids. He says the disease is spread by fleas that infest the rats. So he had muslin as well over the lids. One can had infected rats, six of them. Then one day the Frenchwoman tried to give the dog a bath in a laundry tub and the dog bolted. The laboratory door was open in some way and he ran between the cans, upsetting them. Every rat was out in an instant. The Frenchwoman was frantic. She shut the door and tried to drive the things back. One bit her on the foot. The dog was not bitten, but there was the question of fleas.

“Well, the rats got away, and Mademoiselle retired to her room to die of plague. She was a loyal old soul; she wouldn’t let them call a doctor. It would mean exposure, and after all what could the doctors do? Reed used his serum and she’s alive.

“Reed was frantic. His wife would not leave. There was the Frenchwoman to look after, and I think she was afraid he would do something desperate. They did the best they could, under the circumstances, for the children. They burned most of the carpets for fear of fleas, and put poison everywhere. Of course he had traps too.