One after another Kennedy ran through them. All were vague and veiled, as though the writer wished by some circumlocution to convey an idea that would not be apparent to some third, inquisitive party.
What was back of it all? Had Jose been making love to another woman at the same time that he was engaged to Eulalie Sandoval? As far as the contents of the letters went there was nothing to show that he had done anything wrong. The mystery of the "other woman" only served to deepen the mystery of what little we already knew.
Craig dropped the letters into his pocket along with the shell, and walked around into the office of Sandoval. I followed him. Quickly he made a search, but it did not seem to net him anything.
Meanwhile I had been regarding a queer-looking instrument that stood on a flat table against one wall. It seemed to consist of a standard on each end of which was fastened a disk, besides several other arrangements the purpose of which I had not the slightest idea. Between the two ends rested a glass tube of some liquid. At one end was a lamp; the other was fitted with an eyepiece like a telescope. Beside the instrument on the table lay some more glass-capped tubes and strewn about were samples of raw sugar.
"It is a saccharimeter," explained Kennedy, also looking at it, "an instrument used to detect the amount of sugar held in solution, a form of the polariscope. We won't go into the science of it now. It's rather abstruse."
He was about to turn back into the outer office when an idea seemed to occur to him. He took the cartridge from his pocket and carefully scraped off what he could of the powder that still adhered to the outer rim. It was just a bit, but he dissolved it in some liquid from a bottle on the table, filled one of the clean glass tubes, capped the open end, and placed this tube in the saccharimeter where the first one I noticed had been.
Carefully he lighted the lamp, then squinted through the eyepiece at the tube of liquid containing what he had derived from the cartridge. He made some adjustments, and as he did so his face indicated that at last he began to see something dimly. The saccharimeter had opened the first rift in the haze that surrounded the case.
"I think I know what we have here," he said, briefly, rising and placing the tube and its contents in his pocket with the other things he had discovered. "Of course it is only a hint. This instrument won't tell me finally. But it is worth following up."
With a final glance about to make sure that we had overlooked nothing,
Kennedy closed and locked the outside door.
"I'm going directly up to the laboratory, Walter," decided Kennedy. "Meanwhile you can help me very much if you will look up this Teresa de Leon. I noticed that the New York letters were written on the stationery of the Pan-America Hotel. Get what you can. I leave it to you. And if you can find out anything about the others, so much the better. I'll see you as soon as you finish."