The Secret History - Donna Tartt [117]
“Henry, how do you know this?”
He was silent for a moment. Then he said: “Do you know those two horrible boxer dogs who belong to the couple who live upstairs?”
It was dreadful but I had to laugh, I couldn’t help it. “No,” I said. “You didn’t.”
“I’m afraid I did,” he said dryly, mashing out his cigarette. “One of them is fine, unfortunately. The other one won’t be dragging garbage up on my front porch anymore. It was dead in twenty hours, and only of a slightly larger dose—the difference perhaps of a gram. Knowing this, it seems to me that I should be able to prescribe how much poison each of us should get. What worries me is the variation in concentration of poison from one mushroom to the next. It’s not as if it’s measured out by a pharmacist. Perhaps I’m wrong—I’m sure you know more about it than I do—but a mushroom that weighs two grams might well have just as much as one that weighs three, no? Hence my dilemma.”
He reached into his breast pocket and took out a sheet of paper covered with numbers. “I hate to involve you in this, but no one else knows a thing about math and I’m far from reliable myself. Will you have a look?”
Vomiting, jaundice, convulsions. Mechanically, I took the sheet of paper from him. It was covered with algebraic equations, but at the moment algebra was frankly the last thing on my mind. I shook my head and was on the point of handing it back when I looked up at him and something stopped me. I was in the position, I realized, to put an end to this, now, right here. He really did need my help, or else he wouldn’t have come to me; emotional appeals, I knew, were useless but if I pretended that I knew what I was doing I might be able to talk him out of it.
I took the paper to my desk and sat down with a pencil and forced myself through the tangle of numbers step by step. Equations about chemical concentration were never my strong point in chemistry, and they are difficult enough when you are trying to figure a fixed concentration in a suspension of distilled water; but this, dealing as it did with varying concentrations in irregularly shaped objects, was virtually impossible. He had probably used all the elementary algebra he knew in figuring this, and as far as I could follow him he hadn’t done a bad job; but this wasn’t a problem that could be worked with algebra, if it could be worked at all. Someone with three or four years of college calculus might have been able to come up with something that at least looked more convincing; by tinkering, I was able to narrow his ratio slightly but I had forgotten most of the little calculus I knew and the answer I wound up with, though probably closer than his own, was far from correct.
I put down my pencil and looked up. The business had taken me about half an hour. Henry had got a copy of Dante’s Purgatorio from my bookshelf and was reading it, absorbed.
“Henry.”
He glanced up absently.
“Henry, I don’t think this is going to work.”
He closed the book on his finger. “I made a mistake in the second part,” he said. “Where the factoring begins.”
“It’s a good try, but just by looking at it I can tell that it’s insolvable without chemical tables and a good working knowledge of calculus and chemistry proper. There’s no way to figure it otherwise. I mean, chemical concentrations aren’t even measured in terms of grams and milligrams but in something called moles.”
“Can you work it for me?”
“I’m afraid not, though I’ve done as much as I can. Practically speaking, I can’t give you an answer. Even a math professor would have a tough time with this one.”
“Hmn,” said Henry, looking over my shoulder at the paper on the desk. “I’m heavier than Bun, you know. By twenty-five pounds. That should count for something, shouldn’t it?”
“Yes, but the difference of size isn’t large enough to bank on, not with a margin of error potentially this wide. Now, if you were fifty pounds heavier, maybe …”
“The poison doesn’t take effect for at least twelve hours,” he said. “So even if I overdose I’ll have a certain advantage, a