Part 36

As he walked up from the pretty little Williston station Kennedy asked: “One more question, Mr. Whitney. How did Marian take the engagement?”

The district attorney hesitated. “I will be perfectly frank, Mr. Kennedy,” he answered. “The country-club people tell me that the girls were very cool toward each other. That was why I got that statement from Mrs. Wainwright. I wish to be perfectly fair to everyone concerned in this case.”

We found the coroner quite willing to talk, in spite of the fact that the hour was late. “My friend, Mr. Whitney, here, still holds the poison theory,” began the coroner, “in spite of the fact that everything points absolutely toward asphyxiation. If I had been able to discover the slightest trace of illuminating-gas in the room I should have pronounced it asphyxia at once. All the symptoms accorded with it. But the asphyxia was not caused by escaping illuminating-gas.

“There was an antique charcoal-brazier in the room, and I have ascertained that it was lighted. Now, anything like a brazier will, unless there is proper ventilation, give rise to carbonic oxide or carbon monoxide gas, which is always present in the products of combustion, often to the extent of from five to ten per cent. A very slight quantity of this gas, insufficient even to cause an odour in a room, will give a severe headache, and a case is recorded where a whole family in Glasgow was poisoned without knowing it by the escape of this gas. A little over one per cent of it in the atmosphere is fatal, if breathed for any length of time. You know, it is a product of combustion, and is very deadly--it is the much-dreaded white damp or afterdamp of a mine explosion.

“I'm going to tell you a secret which I have not given out to the press yet. I tried an experiment in a closed room today, lighting the brazier. Some distance from it I placed a cat confined in a cage so it could not escape. In an hour and a half the cat was asphyxiated.”

The coroner concluded with an air of triumph that quite squelched the district attorney.

Kennedy was all attention. “Have you preserved samples of the blood of Mr. Templeton and Miss Wainwright?” he asked.

“Certainly. I have them in my office.”

The coroner, who was also a local physician, led us back into his private office.

“And the cat?” added Craig.

Doctor Nott produced it in a covered basket.

Quickly Kennedy drew off a little of the blood of the cat and held it up to the light along with the human samples. The difference was apparent.

“You see,” he explained, “carbon monoxide combines firmly with the blood, destroying the red colouring matter of the red corpuscles. No, Doctor, I'm afraid it wasn't carbonic oxide that killed the lovers, although it certainly killed the cat.”

Doctor Nott was crestfallen, but still unconvinced. “If my whole medical reputation were at stake,” he repeated, “I should still be compelled to swear to asphyxia. I've seen it too often, to make a mistake. Carbonic oxide or not, Templeton and Miss Wainwright were asphyxiated.”

It was now Whitney's chance to air his theory.

“I have always inclined toward the cyanide-of-potassium theory, either that it was administered in a drink or perhaps injected by a needle,” he said. “One of the chemists has reported that there was a possibility of slight traces of cyanide in the mouths.”

“If it had been cyanide,” replied Craig, looking reflectively at the two jars before him on the table, “these blood specimens would be blue in colour and clotted. But they are not. Then, too, there is a substance in the saliva which is used in the process of digestion. It gives a reaction which might very easily be mistaken for a slight trace of cyanide. I think that explains what the chemist discovered; no more, no less. The cyanide theory does not fit.”

“One chemist hinted at nux vomica,” volunteered the coroner. “He said it wasn't nux vomica, but that the blood test showed something very much like it. Oh, we've looked for morphine chloroform, ether, all the ordinary poisons, besides some of the little known alkaloids. Believe me, Professor Kennedy, it was asphyxia.”

I could tell by the look that crossed Kennedy's face that at last a ray of light had pierced the darkness. “Have you any spirits of turpentine in the office?” he asked.

The coroner shook his head and took a step toward the telephone as if to call the drug-store in town.

“Or ether?” interrupted Craig. “Ether will do.”

“Oh, yes, plenty of ether.”

Craig poured a little of one of the blood samples from the jar into a tube and added a few drops of ether. A cloudy dark precipitate formed. He smiled quietly and said, half to himself, “I thought so.”

“What is it?” asked the coroner eagerly. “Nux vomica?”

Craig shook his head as he stared at the black precipitate. “You were perfectly right about the asphyxiation, Doctor,” he remarked slowly, “but wrong as to the cause. It wasn't carbon monoxide or illuminating-gas. And you, Mr. Whitney, were right about the poison, too. Only it is a poison neither of you ever heard of.”

“What is it?” we asked simultaneously.

“Let me take these samples and make some further tests. I am sure of it, but it is new to me. Wait till to-morrow night, when my chain of evidence is completed. Then you are all cordially invited to attend at my laboratory at the university. I'll ask you, Mr. Whitney, to come armed with a warrant for John or Jane Doe. Please see that the Wainwrights, particularly Marian, are present. You can tell Inspector O'Connor that Mr. Vanderdyke and Mrs. Ralston are required as material witnesses--anything so long as you are sure that these five persons are present. Good night, gentlemen.”

We rode back to the city in silence, but as we neared the station, Kennedy remarked: “You see, Walter, these people are like the newspapers. They are floundering around in a sea of unrelated facts. There is more than they think back of this crime. I've been revolving in my mind how it will be possible to get some inkling about this concession of Vanderdyke's, the mining claim of Mrs. Ralston, and the exact itinerary of the Wainwright trip in the Far East. Do you think you can get that information for me? I think it will take me all day to-morrow to isolate this poison and get things in convincing shape on that score. Meanwhile if you can see Vanderdyke and Mrs. Ralston you can help me a great deal. I am sure you will find them very interesting people.”