"I presume so."

"Thank you, Mrs. Morowitch," said Kennedy, when it was evident that she either could not or would not add anything to what she had said. "Pardon us for causing all this trouble."

"No trouble at all," she replied graciously, though I could see she was intent on every word and motion of Kennedy and Andrews.

Kennedy stopped the car at a drug-store a few blocks away and asked for the business telephone directory. In an instant, under chemists, he put his finger on the name of Poissan--"Henri Poissan, electric furnaces,--William St.," he read.

"I shall visit him to-morrow morning. Now for the doctor."

Doctor Thornton was an excellent specimen of the genus physician to the wealthy--polished, cool, suave. One of Mr. Andrews's men, as I have said, had seen him already, but the interview had been very unsatisfactory. Evidently, however, the doctor had been turning something over in his mind since then and had thought better of it. At any rate, his manner was cordial enough now.

As he closed the doors to his office, he began to pace the floor. "Mr.

Andrews," he said, "I am in some doubt whether I had better tell you or the coroner what I know. There are certain professional secrets that a doctor must, as a duty to his patients, conceal. That is professional ethics. But there are also cases when, as a matter of public policy, a doctor should speak out."

He stopped and faced us.

"I don't mind telling you that I dislike the publicity that would attend any statement I might make to the coroner."

"Exactly," said Andrews. "I appreciate your position exactly. Your other patients would not care to see you involved in a scandal--or at least you would not care to have them see you so involved, with all the newspaper notoriety such a thing brings."

Doctor Thornton shot a quick glance at Andrews, as if he would like to know just how much his visitor knew or suspected.

Andrews drew a paper from his pocket. "This is a copy of the death-certificate," he said. "The Board of Health has furnished it to us. Our physicians at the insurance company tell me it is rather extraordinarily vague. A word from us calling the attention of the proper authorities to it would be sufficient, I think. But, Doctor, that is just the point. We do not desire publicity any more than you do. We could have the body of Mr. Morowitch exhumed and examined, but I prefer to get the facts in the case without resorting to such extreme measures."

"It would do no good," interrupted the doctor hastily. "And if you'll save me the publicity, I'll tell you why."

Andrews nodded, but still held the death-certificate where the doctor was constantly reminded of it.

"In that certificate I have put down the cause of death as congestion of the lungs due to an acute attack of pneumonia. That is substantially correct, as far as it goes. When I was summoned to see Mr. Morowitch I found him in a semiconscious state and scarcely breathing. Mrs.

Morowitch told me that he had been brought home in a taxicab by a man who had picked him up on William Street. I'm frank to say that at first sight I thought it was a case of plain intoxication, for Mr. Morowitch sometimes indulged a little freely when he made a splendid deal. I smelled his breath, which was very feeble. It had a sickish sweet odour, but that did not impress me at the time. I applied my stethoscope to his lungs. There was a very marked congestion, and I made as my working diagnosis pneumonia. It was a case for quick and heroic action. In a very few minutes I had a tank of oxygen from the hospital.

"In the meantime I had thought over that sweetish odour, and it flashed on my mind that it might, after all, be a case of poisoning. When the oxygen arrived I administered it at once. As it happens, the Rockefeller Inst.i.tute has just published a report of experiments with a new antidote for various poisons, which consists simply in a new method of enforced breathing and throwing off the poison by oxidising it in that way. In either case--the pneumonia theory or the poison theory--this line of action was the best that I could have adopted on the spur of the moment.

I gave him some strychnine to strengthen his heart and by hard work I had him resting apparently a little easier. A nurse had been sent for, but had not arrived when a messenger came to me telling of a very sudden illness of Mrs. Morey, the wife of the steel-magnate. As the Morey home is only a half-block away, I left Mr. Morowitch, with very particular instructions to his wife 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 pota.s.sium 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 pota.s.sium is used in certain processes in photography."

"Who was interested in photography, Mr. or Mrs. Morowitch?"

"Both of them."

"Was Mrs. Morowitch?"

"Both of them," repeated the doctor hastily. It was evident how Andrews's questions were tending, and it was also evident that the doctor did not wish to commit himself or even to be misunderstood.

Kennedy had sat silently for some minutes, turning the thing over in his mind. Apparently disregarding Andrews entirely, he now asked, "Doctor, supposing it had been cyanogen gas which caused the congestion of the lungs, and supposing it had not been inhaled in quant.i.ties large enough to kill outright, do you nevertheless feel that Mr. Morowitch was in a weak enough condition to die as a result of the congestion produced by the gas after the traces of the cyanogen had been perhaps thrown off?"

"That is precisely the impression which I wished to convey."

"Might I ask whether in his semiconscious state he said anything that might at all serve as a clue?"

"He talked ramblingly, incoherently. As near as I can remember it, he seemed to believe himself to have become a millionaire, a billionaire.

He talked of diamonds, diamonds, diamonds. He seemed to be picking them up, running his fingers through them, and once I remember he seemed to want to send for Mr. Kahan and tell him something. 'I can make them, Kahan,' he said, 'the finest, the largest, the whitest--I can make them.'"

Kennedy was all attention as Dr. Thornton added this new evidence.

"You know," concluded the doctor, "that in cyanogen poisoning there might be hallucinations of the wildest kind. But then, too, in the delirium of pneumonia it might be the same."

I could see by the way Kennedy acted that for the first time a ray of light had dawned upon him in tracing out the case. As we rose to go, the doctor shook hands with us. His last words were said with an air of great relief, "Gentlemen, I have eased my conscience considerably."

As we parted for the night Kennedy faced Andrews. "You recall that you promised me one thing when I took up this case?" he asked.

Andrews nodded.

"Then take no steps until I tell you. Shadow Mrs. Morowitch and Mr.

Kahan, but do not let them know you suspect them of anything. Let me run down this Poissan clue. In other words, leave the case entirely in my hands in other respects. Let me know any new facts you may unearth, and some time to-morrow I shall call on you, and we will determine what the next step is to be. Good night. I want to thank you for putting me in the way of this case. I think we shall all be surprised at the outcome."

It was late the following afternoon before I saw Kennedy again. He was in his laboratory winding two strands of platinum wire carefully about a piece of porcelain and smearing on it some peculiar black gla.s.sy granular substance that came in a sort of pencil, like a stick of sealing-wax. I noticed that he was very particular to keep the two wires exactly the same distance from each other throughout the entire length of the piece of porcelain, but I said nothing to distract his attention, though a thousand questions about the progress of the case were at my tongue's end.

Instead I watched him intently. The black substance formed a sort of bridge connecting and covering the wires. When he had finished he said: "Now you can ask me your questions, while I heat and anneal this little contrivance. I see you are bursting with curiosity."

"Well, did you see Poissan?" I asked.

Kennedy continued to heat the wire-covered porcelain. "I did, and he is going to give me a demonstration of his discovery to-night."

"His discovery!"

"You remember Morowitch's 'hallucination,' as the doctor called it? That was no hallucination; that was a reality. This man Poissan says he has discovered a way to make diamonds artificially out of pure carbon in an electric furnace. Morowitch, I believe, was to buy his secret. His dream of millions was a reality--at least to him."

"And did Kahan and Mrs. Morowitch know it?" I asked quickly.

"I don't know yet," replied Craig, finishing the annealing.