"Yes," he said, "the doctors think it's due to a germ of some sort." He made a sort of effort and continued. "It is funny, some of these germs being invisible through microscopes. Measles and chickenpox and common things like that. They've never seen the germs that cause them, that's what the papers say. It seems odd—having something you can't see." He turned his head, and looked for his hat that hung on a peg behind him.
"One moment," I said. I took out my card-case. "I want you to read this card. Don't think I'm mad. I want to talk to you for a particular reason which I'll explain in a moment." He took the card hesitatingly and read it. Then he looked at me. "The reason why I am speaking to you is this," I said. "I want to find out what a decent citizen like yourself will think of something I know. It concerns the Blue Disease and its origin."
He seemed disturbed, and took out his watch.
"I ought to get home. My wife——"
"Is your wife ill?"
"Yes."
"What's the matter with her?"
He frowned.
"Dr. Sykes thinks it's lung trouble."
"Consumption?"