The oldest museums in America have their storerooms full of paintings that were the rage in art more than a century ago but are now out of fashion. This gloomy repose is often the fate of the 19th century Barbizon painters of France. Their paintings were once prized by collectors all over the world, but the Barbizon painters had the misfortune to work just before the Impressionists came on the scene. These younger painters eclipsed them long ago.

A Barbizon show is thus a rare and pleasant chance to look closely at a group of wonderful landscape painters whose work paved the way for the now more famous Impressionist artists. Curator Simon Kelly of the Walters Art Museum in Baltimore has dipped into his stores and those of the Baltimore Museum of Art to help put on that kind of show. Of the 48 works in the show owned by the Walters, 34 have not been exhibited for decades. Called “The Road to Impressionism: Landscapes from Corot to Monet,” the exhibition runs until Jan. 17 at the Walters. There are no plans for the exhibition to travel.

Kelly has assembled 70 works from the most distinguished painters who lived or worked in Barbizon, a village on the edge of the forest of Fontainebleau 35 miles south of Paris. The two dozen artists in the exhibition include Jean-Baptiste-Camille Corot, Theodore Rousseau, Virgile Narcisse Diaz de la Pena and Jean-Francois Millet. Although they worked elsewhere as well, of course, all the artists spent a good deal of time in Barbizon to paint in the forest and exchange ideas about the art of the landscape. The village is still a favorite weekend refuge for Parisians, and the house and studio of Millet, who lived in Barbizon for 26 years, is now a museum.

The Barbizon painters were revolutionaries in their time. The art establishment looked down on landscape painting. The government-run Academy of Fine Arts decreed that the highest form of art was “history painting” -- large canvases that depicted the noble deeds of great figures from the Bible, mythology or history. The academicians put landscape painting on a lower rung. At best, it could serve as a backdrop for the great figures and their noble deeds.

The Barbizon painters, who began to trek through the forest of Fontainebleau in the 1820s, challenged the academic rules. They painted the dramatic beauty of nature for its own sake. They insisted that a landscape painter did not have to head off to Italy to find exotic natural beauty; the countryside of France was good enough. They usually painted right in the forest rather than back in the studio. They began to attract left-wing critics and new collectors who wanted to break from old fashions. As Kelly puts it, the Barbizon painters “were considered cutting edge.”

The village of Barbizon was chosen by the painters because it was so close to Paris and served as a gateway to a forest that has a dazzling variety of trees, flowers, hills, moors and outcrops of rock. By 1849, the railway reached the area, bringing in tourists and more painters. The village was a haven as well for artists who wanted to escape the politics and cholera epidemics of Paris. Sixty painters worked there between 1848 and 1865. By 1876, a French critic could write about the forest of Fontainebleau, “There is not a single artist among the most famous who has not passed through it.”

The Walters has a rich collection of Barbizon works because William Walters, a wealthy wholesaler of whisky in Baltimore, decided to pack up his family in 1861 and spend the Civil War years in Paris. Barbizon landscapes attracted his attention, and he and his son Henry continued buying these paintings as well as many others throughout the 19th and early 20th centuries. The son bequeathed the family gallery and all its art holdings to the city of Baltimore in 1931.

William Walters admired the Barbizon painters so much that he commissioned a painting in 1864 from Corot, one of the first to work in the forest of Fontainebleau. That painting, “The Evening Star,” which serves as the introduction to the exhibition, is serene, subdued, romantic and a little theatrical. A woman in robes leans against a tree and thrusts her arm toward the evening star while a shepherd coaxes his sheep down a trail. The painting was inspired by several lines of an 1830 poem by French playwright and poet Alfred de Musset.

Many Barbizon painters like Rousseau and Diaz de la Pena, friends who spent a good deal of time working in the forest, are far less theatrical than Corot. Their paintings are mostly pure landscape. In “Forest of Fontainebleau,” for example, painted in 1871, Diaz de la Pena, born in France of Spanish parents, depicted trees that seem to whirl in movement -- almost like a 20th century expressionist landscape. No figures break the pattern.

Rousseau generated a great deal of notice for the Barbizon painters when the Academy of Fine Arts rejected his paintings for its annual salon three years in a row during the 1830s. He became a martyr for the latest trend in contemporary art. Paul Perier, a banker and one of the new bourgeois collectors willing to buck the dictates of the academy, then sponsored Rousseau with commissions and grants. One of the show’s featured paintings, Rousseau’s “Frost Effect,” a realistic winter scene of frosted hills north of Paris, was purchased by Perier in 1845 and bought by William Walters almost 40 years later.

REALISTIC SCENES

The exhibition displays six works by Millet, the best-known Barbizon painter, including the eerie 1856 painting, “The Sheepfold, at Moonlight.” A shepherd in this painting tends his flock under a huge moon during what Millet called “the splendors and terrors of the night.” Millet, the son of a peasant family, was more interested in describing rural life than the beauty of nature, and his paintings are replete with dignified farm workers and their wives standing erect under the crush of labor. Critics discerned religious or socialist fervor in his paintings, but Millet continually denied that he was trying to do more than produce realistic scenes. Millet joined the Barbizon painters later than most, settling in the village in 1849 at age 35. Before the end of the century, he was acclaimed as much as Impressionists such as Claude Monet or Pierre-August Renoir are acclaimed today. Millet paintings now in the Louvre such as “Angelus” and “The Shepherdess and Her Flock” (a drawing by Millet of the former and a pastel by Millet of the latter are in the show) were constantly reproduced on postcards, calendars and magazine pages. In 1895, a critic, estimating the monetary value of art, listed “The Shepherdess and Her Flock” as the world’s most expensive painting.

By the 1870s, a younger group of painters known as the Impressionists began to make their mark in the art world. For them, the Barbizon landscapes seemed a little too staged and romantic. The Impressionists attempted what they regarded as more natural painting, trying to catch shifts of sunlight with lighter tones and sketchy brush strokes. They also depicted city life as often as the countryside.

But the Impressionists were not rebelling against the Barbizon painters. As the Walters exhibition tries to show, Impressionism was a logical next step. Charles-Francois Daubigny, who regarded himself as a Barbizon painter, converted a boat into a studio and chugged down the rivers of France, catching scenes right on canvas with hurried brush strokes. He was so intent on catching the light correctly that, forgetting his studio was floating, he once stepped so far back to examine his canvas that he fell overboard. The critic Theophile Gautier chided him in 1865 for being lazy and turning out works that were merely impressions. Gautier feared that “an evil demon hinders him now.”

Barbizon was a natural starting point for the new Impressionists. Monet and Renoir, two pillars of Impressionism, painted in the forest of Fontainebleau during the mid-1860s when they were young artists in their 20s. Millet and Rousseau were still living and working in Barbizon then. Monet’s 1871 landscape, “Windmills near Zaandam,” closes the Walters exhibition.

The Walters had originally intended to title its show “The Magic of Barbizon.” But, fearful that too few people know anything about Barbizon, museum officials came up with a title more familiar to museum-goers: “The Road to Impressionism.” It is always difficult for the magical Barbizon painters to escape the shadow of the Impressionists.