"What is it--strychnine?" I asked.
"No," he replied, regarding it thoughtfully with some satisfaction. "That is lead carbonate. There can be no doubt that the turbidity of the water was due to this powder in suspension. A little dissolves in the water, while the scales and incrustations in fine particles are carried along in the current. As a matter of fact the amount necessary to make the water poisonous need not be large."
He applied a little instrument to the cut ends of the pipe. As I bent over, I could see the needle on its dial deflected just a bit.
"My voltmeter," he said, reading it, "shows that there is a current of about 1.8 volts passing through this pipe all the time."
"Electrolysis of water pipes!" I exclaimed, thinking of statements I had heard by engineers. "That's what they mean by stray or vagabond currents, isn't it?"
He had seized the lantern and was eagerly following up and down the line of the water pipe. At last he stopped, with a low exclamation, at a point where an electric light wire supplying the Minturn cottage crossed overhead. Fastened inconspicuously to the trunk of a tree which served as a support for the wire was another wire which led down from it and was buried in the ground.
Craig turned up the soft earth as fast as he could, until he reached the pipe at this point. There was the buried wire wound several times around it.
As quickly and as neatly as he could he inserted a connection between the severed ends of the pipe to restore the flow of water to the houses, turned on the water and covered up the holes he had dug. Then he unwrapped the package which we had tugged about all day, and in a narrow path between the bushes which led to the point where the wire had tapped the electric light feed he placed in a shallow hole in the ground a peculiar apparatus.
As nearly as I could make it out, it consisted of two flat platforms between which, covered over and projected, was a slip of paper which moved forward, actuated by clockwork, and pressed on by a sort of stylus. Then he covered it over lightly with dirt so that, unless anyone had been looking for it, it would never be noticed.
It was late when we reached the city again, but Kennedy had one more piece of work and that devolved on me. All the way down on the train he had been writing and rewriting something.
"Walter," he said, as the train pulled into the station, "I want that published in to-morrow's papers."
I looked over what he had written. It was one of the most sensational stories I have ever fathered, beginning, "Latest of the victims of the unknown poisoner of whole families in Stratfield, Connecticut, is Miss Isabel Pearcy, whose father, Randall Pearcy, died last week."
I knew that it was a "plant" of some kind, for so far he had discovered no evidence that Miss Pearcy had been affected. What his purpose was, I could not guess, but I got the story printed.
The next morning early Kennedy was quietly at work in the laboratory.
"What is this treatment of lead poisoning by electrolysis?" I asked, now that there had come a lull when I might get an intelligible answer. "How does it work?"
"Brand new, Walter," replied Kennedy. "It has been discovered that ions will flow directly through the membranes."
"Ions?" I repeated. "What are ions?"
"Travelers," he answered, smiling, "so named by Faraday from the Greek verb, io, to go. They are little positive and negative charges of electricity of which molecules are composed. You know some believe now that matter is really composed of electrical energy. I think I can explain it best by a simile I use with my classes. It is as though you had a ballroom in which the dancers in couples represent the neutral molecules. There are a certain number of isolated ladies and gentlemen--dissociated ions--" "Who don't know these new dances?" I interrupted.
"They all know this dance," he laughed. "But, to be serious in the simile, suppose at one end of the room there is a large mirror and at the other a buffet with cigars and champagne. What happens to the dissociated ions?"
"Well, I suppose you want me to say that the ladies gather about the mirror and the men about the buffet."
"Exactly. And some of the dancing partners separate and follow the crowd. Well, that room presents a picture of what happens in an electrolytic solution at the moment when the electric current is passing through it."
"Thanks," I laughed. "That was quite adequate to my immature understanding."
Kennedy continued at work, checking up and arranging his data until the middle of the afternoon, when he went up to Stratfield.
Having nothing better to do, I wandered out about town in the hope of running across some one with whom to while away the hours until Kennedy returned. I found out that, since yesterday, Broadway had woven an entirely new background for the mystery. Now it was rumored that the lawyer Minturn himself had been on very intimate terms with Mrs. Pearcy. I did not pay much attention to the rumor, for I knew that Broadway is constitutionally unable to believe that anybody is straight.
Kennedy had commissioned me to keep in touch with Josephson and I finally managed to get around to the Baths, to find them still closed.
As I was talking with him, a very muddy and dusty car pulled up at the door and a young man whose face was marred by the red congested blood vessels that are in some a mark of dissipation burst in on us.
"What--closed up yet--Joe?" he asked. "Haven't they taken Minturn's body away?"
"Yes, it was sent up to Stratfield to-day," replied the masseur, "but the coroner seems to want to worry me all he can."
"Too bad. I was up almost all last night, and to-day I have been out in my car--tired to death. Thought I might get some rest here. Where are you sending the boys--to the Longacre?"
"Yes. They'll take good care of you till I open up again. Hope to see you back again, then, Mr. Pearcy," he added, as the young man turned and hurried out to his car again. "That was that young Pearcy, you know. Nice boy--but living the life too fast. What's Kennedy doing--anything?"
I did not like the jaunty bravado of the masseur which now seemed to be returning, since nothing definite had taken shape. I determined that he should not pump me, as he evidently was trying to do. I had at least fulfilled Kennedy's commission and felt that the sooner I left Josephson the better for both of us.
I was surprised at dinner to receive a wire from Craig saying that he was bringing down Dr. Gunther, Mrs. Pearcy and Isabel to New York and asking me to have Warner Pearcy and Josephson at the laboratory at nine o'clock.
By strategy I managed to persuade Pearcy to come, and as for Josephson, he could not very well escape, though I saw that as long as nothing more had happened, he was more interested in "fixing" the police so that he could resume business than anything else.
As we entered the laboratory that night, Kennedy, who had left his party at a downtown hotel to freshen up, met us each at the door. Instead of conducting us in front of his laboratory table, which was the natural way, he led us singly around through the narrow space back of it.
I recall that as I followed him, I half imagined that the floor gave way just a bit, and there flashed over me, by a queer association of ideas, the recollection of having visited an amusement park not long before where merely stepping on an innocent-looking section of the flooring had resulted in a tremendous knocking and banging beneath, much to the delight of the lovers of slap-stick humor. This was serious business, however, and I quickly banished the frivolous thought from my mind.
"The discovery of poison, and its identification," began Craig at last when we had all arrived and were seated about him, "often involves not only the use of chemistry but also a knowledge of the chemical effect of the poison on the body, and the gross as well as microscopic changes which it produces in various tissues and organs--changes, some due to mere contact, others to the actual chemicophysiological reaction between the poison and the body."
His hand was resting on the