"For five years Dr. Carrel has been studying the subject, applying various extracts to wounded tissues. All of them increased the growth of connective tissue. but the degree of acceleration varied greatly. In some cases it was as high as forty times the normal. Dr. Carrel's dream of ten times the normal was exceeded by himself."
Astounded as we were by this revelation, Kennedy did not seem to consider it as important as one that he was now hastening to show us. He took a few cubic centimetres of some culture which he had been preparing, placed it in a tube, and poured in eight or ten drops of sulphuric acid. He shook it.
"I have here a culture from some of the food that I found was being or had been prepared for Mr. Pitts. It was in the icebox."
Then he took another tube. "This," he remarked, "is a one-to-one-thousand solution of sodium nitrite."
He held it up carefully and poured three or four cubic centimetres of it into the first tube so that it ran carefully down the side in a manner such as to form a sharp line of contact between the heavier culture with the acid and the lighter nitrite solution.
"You see," he said, "the reaction is very clear cut if you do it this way. The ordinary method in the laboratory and the text-books is crude and uncertain."
"What is it?" asked Pitts eagerly, leaning forward with unwonted strength and noting the pink colour that appeared at the junction of the two liquids, contrasting sharply with the portions above and below.
"The ring or contact test for indol," Kennedy replied, with evident satisfaction. "When the acid and the nitrites are mixed the colour reaction is unsatisfactory. The natural yellow tint masks that pink tint, or sometimes causes it to disappear, if the tube is shaken. But this is simple, clear, delicate—unescapable. There was indol in that food of yours, Mr. Pitts."
"Indol?" repeated Pitts.
"Is," explained Kennedy, "a chemical compound—one of the toxins secreted by intestinal bacteria and responsible for many of the symptoms of senility. It used to be thought that large doses of indol might be consumed with little or no effect on normal man, but now we know that headache, insomnia, confusion, irritability, decreased activity of the cells, and intoxication are possible from it. Comparatively small doses over a long time produce changes in organs that lead to serious results.
"It is," went on Kennedy, as the full horror of the thing sank into our minds, "the indol- and phenol-producing bacteria which are the undesirable citizens of the body, while the lactic-acid producing germs check the production of indol and phenol. In my tests here to-day, I injected four one-hundredths of a grain of indol into a guinea-pig. The animal had sclerosis or hardening of the aorta. The liver, kidneys, and supra-renals were affected, and there was a hardening of the brain. In short, there were all the symptoms of old age."
We sat aghast. Indol! What black magic was this? Who put it in the food?
"It is present," continued Craig, "in much larger quantities than all the Metchnikoff germs could neutralise. What the chef was ordered to put into the food to benefit you, Mr. Pitts, was rendered valueless, and a deadly poison was added by what another—"
Minna Pitts had been clutching for support at the arms of her chair as Kennedy proceeded. She now threw herself at the feet of Emery Pitts.
"Forgive me," she sobbed. "I can stand it no longer. I had tried to keep this thing about Thornton from you. I have tried to make you happy and well—oh—tried so hard, so faithfully. Yet that old skeleton of my past which I thought was buried would not stay buried. I have bought Thornton off again and again, with money—my money—only to find him threatening again. But about this other thing, this poison, I am as innocent, and I believe Thornton is as—"
Craig laid a gentle hand on her lips. She rose wildly and faced him in passionate appeal.
"Who—who is this Thornton?" demanded Emery Pitts.
Quickly, delicately, sparing her as much as he could, Craig hurried over our experiences.
"He is in the next room," Craig went on, then facing Pitts added: "With you alive, Emery Pitts, this blackmail of your wife might have gone on, although there was always the danger that you might hear of it—and do as I see you have already done—forgive, and plan to right the unfortunate mistake. But with you dead, this Thornton, or rather some one using him, might take away from Minna Pitts her whole interest in your estate, at a word. The law, or your heirs at law, would never forgive as you would."
Pitts, long poisoned by the subtle microbic poison, stared at Kennedy as if dazed.
"Who was caught in your kitchen, Mr. Pitts, and, to escape detection, killed your faithful chef and covered his own traces so cleverly?" rapped out Kennedy. "Who would have known the new process of healing wounds? Who knew about the fatal properties of indol? Who was willing to forego a one-hundred-thousand-dollar prize in order to gain a fortune of many hundreds of thousands?"
Kennedy paused, then finished with irresistibly dramatic logic,
"Who else but the man who held the secret of Minna Pitts's past and power over her future so long as he could keep alive the unfortunate Thornton—the up-to-date doctor who substituted an elixir of death at night for the elixir of life prescribed for you by him in the daytime—Dr. Lord."
Kennedy had moved quietly toward the door. It was unnecessary. Dr. Lord was cornered and knew it. He made no fight. In fact, instantly his keen mind was busy outlining his battle in court, relying on the conflicting testimony of hired experts.
"Minna," murmured Pitts, falling back, exhausted by the excitement, on his pillows, "Minna—forgive? What is there to forgive? The only thing to do is to correct. I shall be well—soon now—my dear. Then all will be straightened out."
"Walter," whispered Kennedy to me, "while we are waiting, you can arrange to have Thornton cared for at Dr. Hodge's Sanitarium."
He handed me a card with the directions where to take the unfortunate man. When at last I had Thornton placed where no one else could do any harm through him, I hastened back to the laboratory.
Craig was still there, waiting alone.
"That Dr. Lord will be a tough customer," he remarked. "Of course you're not interested in what happens in a case after we have caught the criminal. But that often is really only the beginning of the fight. We've got him safely lodged in the Tombs now, however."
"I wish there was some elixir for fatigue," I remarked, as we closed the laboratory that night.
"There is," he replied. "A homeopathic remedy—more fatigue."
We started on our usual brisk roundabout walk to the apartment. But instead of going to bed, Kennedy drew a book from the bookcase.
"I shall read myself to sleep to-night," he explained, settling deeply in his chair.
As for me, I went directly to my room, planning that to-morrow I would take several hours off and catch up in my notes.
That morning Kennedy was summoned downtown and had to interrupt more important duties in order to appear before Dr. Leslie in the coroner's inquest over the death of the chef. Dr. Lord was held for the Grand Jury, but it was not until nearly noon that Craig returned.
We were just about to go out to luncheon, when the door buzzer sounded.
"A note for Mr. Kennedy," announced a man in a police uniform, with a blue anchor edged with white on his coat sleeve.
Craig tore open the envelope quickly with his forefinger. Headed "Harbour Police, Station No. 3, Staten Island," was an urgent message from our old friend Deputy Commissioner O'Connor.
"I have taken personal charge of a case here that is sufficiently out of the ordinary to interest you," I read when Kennedy tossed the note over to me and nodded to the man from the harbour squad to wait for us. "The Curtis family wish to retain a private detective to work in conjunction with the police in investigating the death of Bertha Curtis, whose body was found this morning in the waters of Kill van Kull."
Kennedy