SARANAC: America's Magic Mountain. By Robert Taylor. Houghton Mifflin. 296 pp. $17.95.

ROBERT TAYLOR has written a superb book, filled with the strong characters and vivid events that we expect in a novel, yet his subject is an actual slice of Americana.

The story spans two centuries at Saranac Lake, a village in the Adirondack mountains of upstate New York. The earliest visitors to this country of tall firs and brimming lakes are tourists, armed with rods and guns. They set up a rustic camp, fish from slowly drifting boats and savor the cool, pure air.

In that party are Emerson, Lowell and Agassiz, the first of a long troupe of celebrated figures who visit Saranac. Most seek refuge from the lower world's heat and pestilence -- for they are tubercular, victims of the White Plague that will destroy millions of adults and children until antibiotics appear in 1944.

Before that deliverance, many consumptives go to Saranac for treatment at the Adirondack Cottage Sanatorium, a sprawling complex of bungalows founded by Dr. Edward Trudeau. He prescribes a simple and often successful therapy: fresh air, a nourishing diet, absolute bed rest. Patients lie in bed 16 hours a day, breathing the cold, pine-scented air. They sleep, dreaming of warmth, and awaken to long nights of brooding silence.

The history of a tuberculosis colony might seem a morbid subject, but there is a rich variety in the lives of Trudeau's patients. Brought to Saranac by chance, each is "a culturally expressive figure" who reflects an era and its values. Many are writers, from Robert Louis Stevenson to Walker Percy and Sylvia Plath; others come from stadium (Christy Mathewson) and speakeasy (Legs Diamond) to the quiet alpine village.

Like the magic mountain in Thomas Mann's novel, Saranac transforms many of its pilgrims. They ascend, withdraw from normal routines, and often mark a turning point in life. Adelaide Crapsey gives up tedious scholarship to write poetry, mocking the graves below her window: "I'll not be patient. I will not lie still." Exiled from his native Hungary, B,ela Bart,ok composes the Concerto for Orchestra, a bold pastiche of folk and symphony tunes.

Taylor says that his book depicts "American culture seen through the prism of tuberculosis," an image that explains both his method and meaning. A prism refracts light into the spectrum of color; in this account, disease sparks the flame of human vitality. The parade of patients goes by, not pale wasted wraiths of romantic myth, but stubborn survivors who grasp at life. They drink and frolic, pass the hours of bed rest in cozy pairs: "There was a village term for it -- 'cousining'."

A COMPARABLE ENERGY characterizes the prose here. A man with a triple career (novelist; book and art critic for The Boston Globe; professor of English at Wheaton College), Taylor can spin many threads into a strong narrative line. His story winds from poetry to baseball, then on to microbiology and genre painting. We slip into a hunter's canoe to pursue a stately buck, then tour the luxurious rustic estate of Marjorie Merriweather Post, whose taste runs to color-coordinated fly swatters and kindling piled in shapely spirals.

The text is acutely visual, drawn with a sharp eye and fresh imagery. Taylor surveys pictures and buildings, paints landscapes with startling words. In summer he follows streams where "turtles lay in terra-cotta lassitude"; in winter the shadows on snow make "trembling slivers of pine-screened light." These images create an album-like narrative, linked by refrains and flashbacks to suggest the density of remembered time.

Each chapter centers on a few characters, whose common destiny brings them to Saranac. The roster is a gallery of greats, some seen in passing (Mark Twain, Teddy Roosevelt) and others in brief profile, such as Albert Einstein and Somerset Maugham. (Pondering the unified field theory, Einstein alarms his neighbors by sailing without a life preserver.) The most complex portrait is of Norman Bethune, a Canadian surgeon who nearly kills his wife's lover, and later ends his days in Red China, a martyr to the revolutionary cause.

No novelist could safely invent such an improbable figure; Taylor is telling the truth but also shaping it with a vision. Like the other patients, Bethune changed during his convalescence: "Saranac had been the pivot of his life, and his career had a symmetry to it, the muddled time before his tuberculosis and his apotheosis afterward." As he and the others come and go, their mountain hospice abides -- as it will for any reader of this absorbing book.