"None yet. I'm not worrying. It was insured."
"Who is this arch criminal, Dr. Hopf?" I mused as we retraced our steps to the laboratory. "Is Mrs. Blake stricken now by the same trouble that seems to have affected Buster?"
"Only my examination will show," he said. "I shall let nothing interfere with that now. It must be the starting point for any work that I may do in the case."
We arrived at Kennedy's workshop of scientific crime and he immediately plunged into work. Looking up he caught sight of me standing helplessly idle.
"Walter," he remarked thoughtfully adjusting a microscope, "suppose you run down and see Garwood. Perhaps he has something to report. And by the way, while you are out, make inquiries about the Blakes, young Baldwin, Miss Sears and this Dr. Wilson. I have heard of her before, at least by name. Perhaps you may find something interesting."
Glad to have a chance to seem to be doing something whether it amounted to anything or not, I dropped in to see Garwood. So far he had nothing to report except the usual number of false alarms. From his office I went up to the Star where fortunately I found one of the reporters who wrote society notes.
The Blakes, I found, as we already knew, to be well known and moving in the highest social circles. As far as known they had no particular enemies, other than those common to all people of great wealth. Dr. Wilson had a large practice, built up in recent years, and was one of the best known society physicians for women. Miss Sears was unknown, as far as I could determine. As for Duncan Baldwin, I found that he had become acquainted with Reginald Blake in college, that he came of no particular family and seemed to have no great means, although he was very popular in the best circles. In fact he had had, thanks to his friend, a rather meteoric rise in society, though it was reported that he was somewhat involved in debt as a result.
I returned to the laboratory to find that Craig had taken out of a cabinet a peculiar looking arrangement. It consisted of thirty-two tubes, each about sixteen inches long, with S-turns, like a minute radiator. It was altogether not over a cubic foot in size, and enclosed in a glass cylinder. There were in it, perhaps, fifty feet of tubes, a perfectly-closed tubular system which I noticed Kennedy was keeping absolutely sterile in a germicidal solution of some kind.
Inside the tubes and surrounding them was a saline solution which was kept at a uniform temperature by a special heating apparatus.
Kennedy had placed the apparatus on the laboratory table and then gently took the little dog from his basket and laid him beside it. A few minutes later the poor little suffering Buster was mercifully under the influence of an anesthetic.
Quickly Craig worked. First he attached the end of one of the tubes by means of a little cannula to the carotid artery of the dog. Then the other was attached to the jugular vein.
As he released the clamp which held the artery, the little dog's feverishly beating heart spurted the arterial blood from the carotid into the tubes holding the normal salt solution and that pressure, in turn, pumped the salt solution which filled the tubes into the jugular vein, thus replacing the arterial blood that had poured into the tubes from the other end and maintaining the normal hydrostatic conditions in the body circulation. The dog was being kept alive, although perhaps a third of his blood was out of his body.
"You see," he said at length, after we had watched the process a few minutes, "what I have here is in reality an artificial kidney. It is a system that has been devised by several doctors at Johns Hopkins.
"If there is any toxin in the blood of this dog, the kidneys are naturally endeavoring to eliminate it. Perhaps it is being eliminated too slowly. In that case this arrangement which I have here will aid them. We call it vividiffusion and it depends for its action on the physical principle of osmosis, the passage of substances of a certain kind through a porous membrane, such as these tubes of celloidin.
"Thus any substance, any poison that is dialyzable is diffused into the surrounding salt solution and the blood is passed back into the body, with no air in it, no infection, and without alteration. Clotting is prevented by the injection of a harmless substance derived from leeches, known as hirudin. I prevent the loss of anything in the blood which I want retained by placing in the salt solution around the tubes an amount of that substance equal to that held in solution by the blood. Of course that does not apply to the colloidal substances in the blood which would not pass by osmosis under any circumstances. But by such adjustments I can remove and study any desired substance in the blood, provided it is capable of diffusion. In fact this little apparatus has been found in practice to compare favorably with the kidneys themselves in removing even a lethal dose of poison."
I watched in amazement. He was actually cleaning the blood of the dog and putting it back again, purified, into the little body. Far from being cruel, as perhaps it might seem, it was in reality probably the only method by which the animal could be saved, and at the same time it was giving us a clue as to some elusive, subtle substance used in the case.
"Indeed," Kennedy went on reflectively, "this process can be kept up for several hours without injury to the dog, though I do not think that will be necessary to relieve the unwonted strain that has been put upon his natural organs. Finally, at the close of the operation, serious loss of blood is overcome by driving back the greater part of it into his body, closing up the artery and vein, and taking good care of the animal so that he will make a quick recovery."
For a long time I watched the fascinating process of seeing the life blood coursing through the porous tubes in the salt solution, while Kennedy gave his undivided attention to the success of the delicate experiment. It was late when I left him, still at work over Buster, and went up to our apartment to turn in, convinced that nothing more would happen that night.
The next morning, with characteristic energy, Craig was at work early, examining the cultures he had made from the black spots on the gelatine.
By the look of perplexity on his face, I knew that he had discovered something that instead of clearing the mystery up, further deepened it.
"What do you find?" I asked anxiously.
"Walter," he exclaimed, laying aside the last of the slides which he had been staining and looking at intently through the microscope, "that stuff on the gelatine is entirely harmless. There was nothing in it except common mold."
For the moment I did not comprehend. "Mold?" I repeated.
"Yes," he replied, "just common, ordinary mold such as grows on the top of a jar of fruit or preserves when it is exposed to the air."
I stifled an exclamation of incredulity. It seemed impossible that the deadly germ note should be harmless, in view of the events that had followed its receipt.
Just then the laboratory door was flung open and Reginald Blake, pale and excited, entered. He had every mark of having been up all night.
"What's the matter?" asked Craig.
"It's about my mother," he blurted out. "She seems to be getting worse all the time. Miss Sears is alarmed, and Betty is almost ill herself with worry. Dr. Wilson doesn't seem to know what it is that affects her, and neither does the new nurse. Can you DO something?"
There was a tone of appeal in his voice that was not like the self-sufficient Reginald of the day before.
"Does there seem to be any immediate danger?" asked Kennedy.
"Perhaps not--I can't say," he urged. "But she is gradually getting worse instead of better."
Kennedy thought a moment. "Has anything else happened?" he asked slowly.
"N-no. That's enough, isn't it?"
"Indeed it is," replied Craig, trying to be reassuring. Then, recollecting Betty, he added, "Reginald, go back and tell your sister for me that she must positively make the greatest effort of her life to control herself. Tell her that her mother needs her-- needs her well and brave. I shall be up at the house immediately. Do the best you can. I depend on you."
Kennedy's words seemed to have a bracing effect on Reginald and a few moments later he left,