human
Have you learned anything yet?
gpt
Those brownish spots were blood, of course, was his reply as he stopped a moment in his work.
human
In the blood I discovered some other substance, though I can't seem to identify it yet. It will take time. I thought it might be a drug or poison, but it doesn't seem to be--at least nothing one might ordinarily expect.
gpt
How about the other spots, not the Chinese yellow?
human
Another problem I haven't solved. I dissolved enough of them so that I have plenty of material to study if I don't waste it. But so far I haven't been able to identify the substance with anything I know. There's a lot more work of elimination, Walter, before we're on the road to the solution of this case. Whatever stained the towel was very unusual. As near as I can make out the spots are of some protein composition. But it's not exactly a poison, although many proteins may be extremely poisonous and extremely difficult to identify because they are of organic nature.
gpt
There's one thing, he added.
human
Samples of the body fluids of the victim have been sent down by the coroner at Tarrytown and I have analyzed them. While I haven't decided what it was that killed Stella Lamar, I am at least convinced that it has something to do with these towel spots. They are not exactly the same--in fact, I should say they were complementary, or, perhaps better, antithetical.
gpt
The mark wasn't made by the needle which scratched her, then?
human
That's what I thought at first, that the point used had been wiped off on the towel. Then I decided that the spots had nothing to do with the case at all. Now I believe there is some connection, after all.
gpt
I--I don't understand it,
human
It's very baffling,
gpt
If the towel wasn't used to clean the fatal needle, I went on,
human
Exactly. As a matter of fact, if I had not been so confused yesterday by all the details of the case, by the many people involved, I would have noticed at a glance that the blood spots on the towel could not come from some one using it to wipe the needle. And any hypothesis that it had been used out in Tarrytown was ridiculous, because Miss Lamar was only scratched faintly and lost no blood. If I had been a little more clever I might have been altogether too clever. I might possibly have thrown the towel away, because there certainly was no logical reason for connecting it with the crime.
gpt
Just when do you suppose Stella was pricked?
human
That's a vital consideration. Just now I do not know the poison and so cannot tell how quickly it acted. He began to put aside his various paraphernalia.
gpt
Suppose we go at this thing by a process of deduction rather than from the end of scientific analysis. He sat on a corner of the bench.
human
What do we find?