"I hope I have given him something to do which will keep him from mussing things up again," remarked Kennedy, mindful of Reginald's former excursion into detective work.
Meanwhile Craig plunged furiously into his study of the substances he had isolated from the saline solution in which he had "washed" the blood of the little Pekinese.
"There's no use doing anything in the dark," he explained. "Until we know what it is we are fighting we can't very well fight."
For the moment I was overwhelmed by the impending tragedy that seemed to be hanging over Mrs. Blake. The more I thought of it, the more inexplicable became the discovery of the mold.
"That is all very well about the mold on the gelatine strip in the letter," I insisted at length. "But, Craig, there must be something wrong somewhere. Mere molds could not have made Buster so ill, and now the infection, or whatever it is, has spread to Mrs. Blake herself. What have you found out by studying Buster?"
He looked up from his close scrutiny of the material in one of the test tubes which contained something he had recovered from the saline solution of the diffusion apparatus.
I could read on his face that whatever it was, it was serious. "What is it?" I repeated almost breathlessly.
"I suppose I might coin a word to describe it," he answered slowly, measuring his phrases. "Perhaps it might be called hyper-amino-acidemia."
I puckered my eyes at the mouth-filling term Kennedy smiled. "It would mean," he explained, "a great quantity of the amino-acids, non-coagulable, nitrogenous compounds in the blood. You know the indols, the phenols, and the amins are produced both by putrefactive bacteria and by the process of metabolism, the burning up of the tissues in the process of utilizing the energy that means life. But under normal circumstances, the amins are not present in the blood in any such quantities as I have discovered by this new method of diffusion."
He paused a moment, as if in deference to my inability to follow him on such an abstruse topic, then resumed, "As far as I am able to determine, this poison or toxin is an amin similar to that secreted by certain cephalopods found in the neighborhood of Naples. It is an aromatic amin. Smell it."
I bent over and inhaled the peculiar odor.
"Those creatures," he continued, "catch their prey by this highly active poison secreted by the so-called salivary glands. Even a little bit will kill a crab easily."
I was following him now with intense interest, thinking of the astuteness of a mind capable of thinking of such a poison.
"Indeed, it is surprising," he resumed thoughtfully, "how many an innocent substance can be changed by bacteria into a virulent poison. In fact our poisons and our drugs are in many instances the close relations of harmless compounds that represent the intermediate steps in the daily process of metabolism."
"Then," I put in, "the toxin was produced by germs, after all?"
"I did not say that," he corrected. "It might have been. But I find no germs in the blood of Buster. Nor did Dr. Wilson find any in the blood smears which she took from Mrs. Blake."
He seemed to have thrown the whole thing back again into the limbo of the unexplainable, and I felt nonplussed.
"The writer of that letter," he went on, waving the piece of sterile platinum wire with which he had been transferring drops of liquid in his search for germs, "was a much more skillful bacteriologist than I thought, evidently. No, the trouble does not seem to be from germs breathed in, or from germs at all--it is from some kind of germ-free toxin that has been injected or otherwise introduced."
Vaguely now I began to appreciate the terrible significance of what he had discovered.
"But the letter?" I persisted mechanically.
"The writer of that was quite as shrewd a psychologist as bacteriologist," pursued Craig impressively. "He calculated the moral effect of the letter, then of Buster's illness, and finally of reaching Mrs. Blake herself."
"You think Dr. Rae Wilson knows nothing of it yet?" I queried.
Kennedy appeared to consider his answer carefully. Then he said slowly: "Almost any doctor with a microscope and the faintest trace of a scientific education could recognize disease germs either naturally or feloniously implanted. But when it comes to the detection of concentrated, filtered, germ-free toxins, almost any scientist might be baffled. Walter," he concluded, "this is not mere blackmail, although perhaps the visit of that woman to the Prince Henry--a desperate thing in itself, although she did get away by her quick thinking--perhaps that shows that these people are ready to stop at nothing. No, it goes deeper than blackmail."
I stood aghast at the discovery of this new method of scientific murder. The astute criminal, whoever he might be, had planned to leave not even the slender clue that might be afforded by disease germs. He was operating, not with disease itself, but with something showing the ultimate effects, perhaps, of disease with none of the preliminary symptoms, baffling even to the best of physicians.
I scarcely knew what to say. Before I realized it, however, Craig was at last ready for the promised visit to Mrs. Blake. We went together, carrying Buster, in his basket, not recovered, to be sure, but a very different little animal from the dying creature that had been sent to us at the laboratory.
Chapter XXI
The Poison Bracelet
We reached the Blake mansion and were promptly admitted. Miss Betty, bearing up bravely under Reginald's reassurances, greeted us before we were fairly inside the door, though she and her brother were not able to conceal the fact that their mother was no better. Miss Sears was out, for an airing, and the new nurse, Miss Rogers, was in charge of the patient.
"How do you feel, this morning?" inquired Kennedy as we entered the sun-parlor, where Mrs. Blake had first received us.
A single glance was enough to satisfy me of the seriousness of her condition. She seemed to be in almost a stupor from which she roused herself only with difficulty. It was as if some overpowering toxin were gradually undermining her already weakened constitution.
She nodded recognition, but nothing further.
Kennedy had set the dog basket down near her wheel-chair and she caught sight of it.
"Buster?" she murmured, raising her eyes. "Is--he--all right?"
For answer, Craig simply raised the lid of the basket. Buster already seemed to have recognized the voice of his mistress, and, with an almost human instinct, to realize that though he himself was still weak and ill, she needed encouragement.
As Mrs. Blake stretched out her slender hand, drawn with pain, to his silky head, he gave a little yelp of delight and his little red tongue eagerly caressed her hand.
It was as though the two understood each other. Although Mrs. Blake, as yet, had no more idea what had happened to her pet, she seemed to feel by some subtle means of thought transference that the intelligent little animal was conveying to her a message of hope. The caress, the sharp, joyous yelp, and the happy wagging of the bushy tail seemed to brighten her up, at least for the moment, almost as if she had received a new impetus.
"Buster!" she exclaimed, overjoyed to get her pet back again in so much improved condition.
"I wouldn't exert myself too much, Mrs. Blake," cautioned Kennedy.
"Were--were there any germs in the letter?" she asked, as Reginald and Betty stood on the other side of the chair, much encouraged, apparently, at this show of throwing off the lethargy that had seized her.
"Yes, but about as harmless as those would be on a piece of cheese," Kennedy hastened. "But I--I feel so weak, so played out-- and my head--"
Her voice trailed off, a too evident reminder that her improvement had been only momentary and prompted