Imagine yourself, the chief curator of a futuristic museum of brains, taking a stroll through your collection.

On your left are row upon row of jars filled with the brains of the brilliant writers, artists, and composers who had bipolar disorder, a genetic illness characterized by alternating states of depression and mania. Sylvia Plath, Walt Whitman, Cole Porter, Anne Sexton, Vincent van Gogh, Gustav Mahler, Virginia Woolf, Hermann Hesse, Mark Rothko, Mark Twain, Charles Mingus, and Georgia O'Keeffe. In a smaller bottle are fragments of Ernest Hemingway's manic-depressive brain -- all that's left after he shot a bullet through his skull.

On your right are the brains of the obsessive-compulsives, including many of the world's great scientists. You reach for the one marked 'Isaac Newton,' open it, and drag your fingers over his gray-white frontal lobes. Might there be remnants of his genius preserved in his neuronal networks -- perhaps the time he formulated the law of gravitation or studied the nature of light? Could some fossil of his hatred toward his father and mother be buried within his brain's strata like an ancient ant trapped in amber?

The brain: about three pounds of soft matter that can freeze a split second of experience forever in its cellular connections. Ten billion nerve cells are the architecture of our experience. Recent studies have shown that even human talents are reflected in the brain's structure. As just one example, consider the dendrites -- tiny branches that convey signals to nerve cells. It turns out that machinists have more dendrites in certain areas of their brains than salespeople, at least the ones less clever with their hands.

Next to Newton's jar are the brains of other prominent British scientists: William Harvey, the discoverer of blood circulation, who built dark subterranean chambers in which to think; Sir Francis Galton, a distinguished late-19th-century eugenicist, known for his pioneering studies of human intelligence, who once resolved to taste everything in the hospital pharmacy in alphabetical order. He got as far as C and swallowed some castor oil before its laxative effects put an end to his gastronomical experiments.