As prices for 19th- and early 20th-century American art keep zooming into the stratosphere at the New York auctions, the American painting boom is having reverberations in Washington. Newly surfaced here this week are big-bucks sales, dozens of black lights (for spotting recent repairs), syndicates, leasing deals -- and now, the sudden appearance of more new galleries to handle the 19th-century art trade.

One of the most promising new ventures is "The Art Fund Gallery," opening today at 1338 Wisconsin Ave. NW. with several high-quality works that come as a surprise in a field recently inundated with second- and third-rate material. Works rangae in price from $1,200 for a pleasant 1882 drawing by Theodore Robinson to $100,000 for "Pueblo Family," an early 20th-century Taos school painting by Joseph Henry Sharp. If you've never heard of Sharp, you are not alone. But the painting was sold before the show opened.

These paintings were acquired over several years by collector Bill Lewis, a businessman who bought art with a separate checking account he called "the art fund" -- thus the gallery's name. Two years ago, Lewis began dealing privately, and recently accelerated his purchasing. The result: 43 paintings that may prove easier to sell than to replace with equally good stock.

To satisfy the run on western art, there are several good paintings, including a fine little landscape by John Mix Stanley, dated 1868, and a curious oil of Andrew Wyeth's mother as a cowgirl, painted by his father, N. C. Wyeth. Two partraits of children by George Caleb Bingham and Edmund Lind Morse, son of S. F. B. Morse, are other five-figure items of unusual interest.

Recently rediscovered women painters -- a growing force in this market -- are also well-represented here, notably Marguerite Pearson of Boston, a paraplegic, who captured the essence of early 20th-cebtury gentility in her beautifully painted scene of a woman reading by a window.

Concurrent with the new interest in 19th-century American work is a resurgence of interest in the similarly ignored and equally maligned work of 19th-century European painters. The Art Fund plans to show them as well, now represented by a portrait of Sarah Bernhardt dressed as Pierrot by a mid-19th-century Italiam painter named Giuseppe De Nittis.

The gallery also has an art-leasing plan for businesses and offices, whereby paintings may be leased over a period of years, the leasing fees deducted from income as a business expense, and the paintings ultimately purchased at the end of the lease for a fraction of the original cost.

The Angus Shyte Gallery, 406 7th St. NW, is hosting its second American art show of the season -- "19th and Early 20th Century Paintings" -- assembled with the help of five physician-collector-investors who've decided to sell off part of their holdings.

"We'd thought of starting a gallery of our own," says the sole Washingtonian in the group, Dr. John Harbert, who's decided instead to stick to his own specialty -- nuclear medicine. Harbert acquired the five lively and handsome impressionist painting by August Lundberg on view here -- along with 30 more he has at home -- through participation in a syndicate that acquired the Lundberg estate several years ago.

Nearly as interesting as the art-world machinations that brought it together are the paintings in this show, notably a tiny, sparkling seascape by William Trost Richards, an intriguing little landscape by John Henry Twachtman, and a view of Lake George by John Frederick Kensett. There are also lesser works by big names like Inness, Whittredge and Blakelock, and, as is often the case in these shows, superior works by lesser-knowns. Edward B. Butler's "Gray Day in the Berkshires" and Muriel Alvord's slightly awkward but compelling Connecticut landscape (at $725) represent the lower end of the price spectrum which climbs to $25,000 for the most expensive work remaining in the show -- William Burr's "Blacksmith Shop." The show continues through June 4.

Poshest of the new art establishments is Guarisco Gallery Ltd., which has opened without fanfare off the interior courtyard at 2828 Pennsylvania Ave. NW, next to the Four Seasons Hotel. Devoted chiefly to 19th-century European art, this gallery was established by a wealthy industrialist and shipper from Morgan City, La., for his two daughters. His own collection -- which is heavy on marine paintings by Montague Dawson and others (most of them better and cheaper than Dawson) -- forms the core. A cooperative venture with two London agents will keep Dutch, German, French and English painting coming, along with a few Americans.

Montague Dawson has his followers among sailors and ship fanciers, if not among lovers of art, but those who can ignore Dawson and the cornball English country views will find things worth looking at here. Eugene de Blaas, an Italian genre painter who died in 1932, has his sentimental charms in a giggly scene entitled "The New Suitor," and a portrait by A. Harlamoff, court painter to Czar Alexander II, is of historical interest. Also on the up side is a charming impressionist painting by one Sir Alfred Munnings. Best of all -- and possibly least expensive of all -- are several endearing marine painting by Englishman Thomas Buttersworth, who died in 1830.

The paintings have all been recently scrubbed clean, and some look almost too "new." It turns out that some are new, including the floral still lifes by Cecil Kennedy who apes the past. It is said that the queen of England has favored Kennedy with her patronage. Royal art patronage obviously isn't what it used to be.