One of the nation's finest private art collections -- that of the late Henry P. McIlhenny of Philadelphia -- has been left in its entirety to the Philadelphia Museum of Art.

The bequest includes seven works by Degas (among them the superb "Interior: The Violin" of 1868-69 and "Mary Cassatt at the Louvre" of 1880), Ingres' 1812 portrait of the Countess of Tournon, David's "Pope Pius VII and Cardinal Caprara" (1805), four pictures by Delacroix (including a small version of "The Death of Sardanapalus," dated 1844), van Gogh's "Rain" (1889), three Toulouse-Lautrecs (among them his self-portrait of 1896 and his "Dance at the Moulin Rouge" of 1890), three Renoirs, two Matisses and Ce'zanne's portrait of his wife (1883-87).

McIlhenny, an art historian who studied at Harvard with noted connoisseur and collector Paul Sachs, actually willed to the museum three separate collections: one of more than 50 choice French pictures of the 19th and 20th centuries, a second of 19th-century British art (installed for many years in his Irish castle in County Donegal), and a third of decorative arts.

"It wasn't the size of his collection that was so impressive," Director J. Carter Brown of the National Gallery of Art said yesterday. "It was its quality. He had an extraordinary eye. He began collecting impressionist and postimpressionist pictures while still an undergraduate. I spent part of my honeymoon at his house in Ireland and was astonished by his Victorian collection. He formed that one early, too. He installed his pictures carefully. Every object sang."

The market value of McIlhenny's legacy is impossible to estimate. But if sold today at auction, it would almost certainly bring in more than $100 million.

McIlhenny died at 75 on May 11 following heart bypass surgery. His family, whose money came from the manufacture of gas meters, long had supported the Philadelphia Museum with a loyalty comparable to that displayed by the Mellons for the National Gallery of Art. His mother -- in whose memory he bequeathed his art -- had been a museum trustee. His sister Bernice McIlhenny Wintersteen, who predeceased him by 18 days, had been the museum's president from 1964 to 1968. Her last gift to the museum, announced Monday, included two Picassos and Matisse's "Lady in Blue" (1937).

Her previous gifts had included Bronzino's "Portait of Cosimo I de Medici," Degas' pastel of "The Mante Family" and "In the Street" by Toulouse-Lautrec.

Henry McIlhenny had served the museum for more than half a century, and not only as a benefactor. He worked there as the curator of decorative arts from 1935 to 1964, and had served as chairman of the board for the seven years prior to his death.