Claude Monet, the Impressionist painter, lived half his long life in the village of Giverny, out from Paris, and painted his famous waterlilies there and argued with Clemenceau, the French statesman, about cataract operations, and smoked like a volcano and grew his favorite of all roses, the five-petaled yellow climber 'Mermaid.'

His great-grandson, Jean Marie Toulgouat, left his own house -- 200 meters distant from Monet's -- to visit the "New Painting" show at the National Gallery. He could be snared by any inquisitive person at the Jockey Club last week, eating a tournedos of beef and crying (improbably) "Vive AT&T," because, he said after another heavy stroke on the beef, that corporation paid for him and four other notable descendants of the Impressionists to see here "the thinking man's Impressionist show," as it is called by J. Carter Brown, gallery director.

Not just another nice Impressionist show at all, but an enormous selection (an eighth of all the pictures shown by these painters in their own salons between 1874 and 1886) of the very pictures that Monet, Degas and so on chose to represent themselves to an astonished and often hostile public.

Monet died in 1926 at 86, and not before transforming his house and garden to suit all his esthetic notions, from the two-toned yellow dining room to the intensely thought-out garden.

"You remember that superb photograph of him, a few weeks before his death, sitting in a chair at the edge of his lily pond gazing out at the waterlilies and the Japanese bridge he was so fond of.

"His sight had deteriorated a few years before," Toulgouat said, "and the truth is he couldn't see colors as they were. He did all right with reds and yellows, but the blues were dark and somber, and no green."

Clemenceau, an old friend, virtually browbeat him into having cataract operations, and after that he had several years of normal vision. He was still working on the great series of waterlily panels that Clemenceau had arranged to be bought by the French government, and Clemenceau was alarmed they would all be ruined as Monet kept fiddling with them with impaired vision. It all turned out well, of course.

"He had his own firm ideas. The garden had been an orchard, and he kept some of the fruit trees. He laid out all the beds and walks and rose arches and lily ponds.

"He had a lot of trouble with his waterlilies at first. The earliest varieties were tender and didn't like the cold water. Later he got hardier kinds and they did well. But even today," Toulgouat said, "we have trouble with the red ones that seem more tender than the yellows and pinks.

"I was born the year after he died, and of course the house and garden were the same, no changes were made. My uncle, years later, would point out what Monet had here in this bed or that, because, of course, change gradually crept in. He was devoted to irises and loved to get new varieties of them. In those days many of the finest new kinds were bred in France, as now they are all bred in America.

"Along the big walk he kept to lavender and blue ones, and the big arches here and there were covered with roses. He liked single ones -- five petals like the wild kind -- best."

His favorite, 'Mermaid,' came along just in time, an English rose introduced in 1918, so he had only a few years' joy of it.

"He also liked the loose semidouble wichuraiana hybrids and had them all over fences that you could see from the waterlily ponds. And he loved dahlias, but the single kinds, especially one called 'Etoile de Digouin,' which we had for years and years until one year I was too late digging it up for the winter and it froze. We'd certainly like to have it again, if it could be found.

"He liked his flower beds to have only one color. And he hated leaves that were not green -- hated variegated leaves and purple and gray ones.

"His garden was not like most French ones," Toulgouat said. "In many ways it looked English, in the new style of formal beds, but great luxuriance of planting so that things burst out and broke the formality.

"Ironically, the family gave the house and garden to the Beaux-Arts in 1966, the very academy that refused his paintings so that he and the other Impressionists had to hold their own shows separately. The place is now open to the public.

"When the Germans came in the war, the family were afraid damage would be done. My great-aunt Blanche heard there was a high German officer whose family had bought Impressionist pictures, so she wrote him, and a couple of days later two Germans arrived with signs, complete with eagle and swastika, saying entrance to the place was verboten.

"Then when the Allies came, some Englishmen showed up to take over the place. No pleas seemed to have any effect, so Blanche wrote the American command, and in a couple of days two Yanks showed up with signs saying the place was off-limits. So no damage was done by anybody.

"When I was a boy the whole family continued to meet for dinner in the old house. There were 300 of his paintings still there.

"He smoked three packs a day for 60 years. He got the kind in pink packets, because they were the strongest. He didn't smoke them all the way down, though, and my great-aunt used to save all the butts and give them to bums."

Toulgouat's wife, Claire Joyes, has become an authority on aspects of Monet. Her book, "Monet: Life at Giverny," has recently been reissued by Vendome Press.

Joining Toulgouat at luncheon was Minnie Cassatt Hickman, art collector, writer and great-grandniece of Mary Cassatt. Other descendants of famous Impressionist figures here for the show are Sophie Renoir, actress and great-granddaughter of Pierre Auguste Renoir; Franc,oise Cachin, curator of the new Muse'e d'Orsay and granddaughter of Paul Signac; and Madame Durand-Ruel, gallery owner, art patron and great-granddaughter of Paul Durand-Ruel, earliest patron of the Impressionist group.