The Fiery Cross - Diana Gabaldon [595]
I waved one of the slides gently in the air, drying it.
“My blood type is A. Now, I happen to know that my father’s blood was type O. In order to show up with type O blood, that means that both his genes must have been for O. So whichever of those genes he gave me, it has to have been for O. The A gene therefore came from my mother.”
Seeing a familiar glaze come over his features, I sighed and set the slide down. Bree had been drawing pictures of penicillin spores for me, and had left her pad and graphite pencil by the microscope. I took it and flipped to a fresh page.
“Look,” I said, and drew a quick chart.
“Do you see?” I pointed with the stick of graphite. “I don’t know my mother’s type for sure, but it doesn’t matter; for me to have type A blood, she must have given me her gene for it, because my father hadn’t one.”
The next slide was nearly dry; I laid down the pencil, put the slide in place, and bent to look through the eyepiece.
“Can you see blood types—these antibodies—through a microscope?” Roger was quite close behind me.
“No,” I said, not looking up. “The resolution’s nowhere near good enough. But you can see other things—I hope.” I moved the knob a fraction of an inch, and the cells sprang into focus. I let out the breath I had been holding, and a small thrill went through me. There they were; the disc-shaped pinkish blobs of the red blood cells—and here and there, inside a few of the cells, a darkish blob, some rounded, some looking like miniature nine-pins. My heart thumped with excitement, and I made a small exclamation of delight.
“Come look,” I said, and stood aside. Roger bent, looking quizzical.
“What am I looking at?” he asked, squinting.
“Plasmodium vivax,” I said proudly. “Malaria. The small dark blobs inside the cells.” The rounded blobs were the protozoans, the single-celled creatures transferred to the blood in a mosquito’s bite. The few that looked like bowling pins—those were protozoa in the act of budding, getting ready to reproduce themselves.
“When they bud,” I explained, bending for another look myself, “they multiply until they burst the blood cell, and then they move into new blood cells, multiply, and burst those, too—that’s when the patient suffers a malarial attack, with the fever and chills. When the Plasmodium are dormant—not multiplying—the patient is all right.”
“And what makes them multiply?” Roger was fascinated.
“No one knows, exactly.” I drew a deep breath, and corked up my bottles of stain again. “But you can check, to see what’s happening, if they are multiplying. No one can live on quinine, or even take it for a long period—Jesuit bark is too expensive, and I don’t know what the long-term effects on the body might be. And you can’t touch most protozoans with penicillin, unfortunately.
“But I’ll check Lizzie’s blood every few days; if I see the Plasmodium increasing sharply, then I’ll start giving her the quinine at once. With luck, that might prevent an outbreak. Worth a try, certainly.”
He nodded, looking at the microscope and the pink-and-blue-splotched slide.
“Well worth it,” he said quietly.
He watched me move about, tidying up the small debris of my operations. As I bent to retrieve the bloody cloth in which he’d wrapped his hand, he asked, “And you know Bree’s blood type, of course?”
“Type B,” I said, eyes on the box of bandages. “Quite rare, particularly for a white person. You see it mostly in small, rather isolated populations—some Indian tribes in the American Southwest, certain black populations; probably they came from a specific area of Africa, but of course by the time blood groups were discovered, that connection had been long lost.”
“Small, isolated populations. Scottish Highlanders, perhaps?”
I lifted my eyes.
“Perhaps.”
He nodded silently, clearly thinking to himself. Then he picked up the pencil, and slowly drew a small chart of his own on the pad.
“That’s right,” I said, nodding as he looked up at me in question. “Exactly