The Cone sisters of Baltimore, Claribel and Etta, might have seemed eccentric to some of their contemporaries, not only because they continued to dress like staid and proper Victorians well into the 20th century but also because they collected avant-garde art.

Anyone who has seen the Matisse-rich Cone collection at the Baltimore Museum of Art will realize that the sisters - who otherwise lived the most conventional of spinster lives - were more aesthetically adventurous than 99 percent of Americans who witnessed the birth of the modern world.

Like Albert C. Barnes, a contemporary of younger sister Etta, they enthusiastically patronized the two most prominent European modernists, Picasso and Matisse, along with other progressive artists such as Cezanne and Gauguin.

Mainly, though, they concentrated on Matisse. Of the approximately 3,000 objects in the Cone collection in Baltimore, about 500 are by him, the largest group of Matisse works anywhere.

Even since I first visited the collection years ago, I've wondered how and why two Victorian spinsters from a wealthy but nonartistic mercantile family made such an astonishing conceptual leap. The question of what ignites such a passion for collecting art never fails to fascinate.

When a new biography,

The Cone Sisters of Baltimore:

Collecting at Full Tilt

(Northwestern University Press)

,

came into my hands, I thought the mystery might at last be resolved. The authors, the late Ellen B. Hirschland and her daughter, Nancy Hirschland Ramage, both art historians, are collateral Cone descendants.

They have produced a lively and graceful narrative that fleshes out the contrasting personalities of the sisters. Claribel, born in 1864 and elder by six years, became a physician and medical educator in pathology. She was devoted to German culture - the first Cones (originally Kahn) came to America from Germany in the 1840s. Claribel spoke the language fluently and spent the years of World War I in Munich.

She was also slightly more daring as a collector. Both Matisse's startling

Blue Nude

and its companion,

Pink Nude,

were her purchases.

Etta (1870-1949) was more social, more domestic, and more attuned to French culture. It was Francophone Etta, not Claribel, who first met Matisse and began acquiring his work. And it was she who nurtured the collection after her sister died in 1929. She determined, after much courting by other museums, including the Philadelphia Museum of Art, that it would stay in Baltimore.

The book set me straight on two long-held misconceptions. I had believed that Claribel was the dominant collector - that Etta was a supporting player. Not so. As the authors report, Etta began collecting first and did so actively for nearly 50 years.

I also had assumed that the sisters collected jointly. Wrong again. Each had her own collection until Claribel died, when Etta inherited her holdings and worked assiduously to fill gaps with an eye to leaving the collection to a museum.

The Cone Sisters of Baltimore: Collecting at Full Tilt

is a fascinating narrative that brings the sisters to life as individuals. Yet their motivation, beyond an obvious love of art (and where did that come from, one wonders), remains elusive.

Perhaps this is the natural order with many collectors. Perhaps they don't intellectualize their passion in a way that translates readily to speech or writing.

The maddening circumstance with the Cones is that, when she was a girl, Ellen Hirschland knew her great-aunt Etta well and traveled with her in France. Ellen recalls that they often talked about art - but the book does not report what Etta might have said.

As coauthor Nancy Ramage explained when I asked her about this, her mother was still a teenager during those trips, and just becoming interested in art. Etta might not have addressed the point. Furthermore, Ramage added, "I suspect she [Etta] didn't herself know the answer."

Such a "black hole" at the heart of major-league collecting also appears in another new book on the subject,

Old Masters, New World

(Viking), by Cynthia Saltzman. Ten years ago, Saltzman produced a fascinating account of how a famous portrait by Vincent van Gogh passed through the hands of various owners.

Portrait of Dr. Gachet

laid bare the convoluted twists and turns of the international art market, which in the case of Gachet involved confiscation of the painting by the Nazis.

Gachet

was particularly fascinating because after the painting's last owner died, it disappeared from the public arena.

Saltzman has achieved something similar with

Old Masters,

which relates how wealthy Americans developed a taste for prime old-master European pictures between 1890 and World War I.

The collectors here are all titans of the breed, beginning with J. Pierpont Morgan and including Henry Clay Frick, Benjamin Altman, Peter Widener of Philadelphia, Isabella Stewart Gardner, and Henry G. Marquand. To their "portraits" Saltzman adds several influential dealers such as Joseph Duveen and Otto Gutekunst.

All the players in this rousing history of rich people competing for the most valuable and historically significant old-master pictures are familiar, certainly to anyone who has visited the Frick Collection, the Morgan Library, the Isabella Stewart Gardner Museum, or the Metropolitan Museum of Art, all of which benefited hugely from their largesse.

Yet Saltzman revivifies the story by showing her readers how these alpha collectors schemed and maneuvered to outsmart the dealers and each other in their feverish quest for the best Rembrandt or the rarest Raphael.

With the possible exception of Gardner, and even that exception must be qualified, they seem to have been motivated primarily by the chase and the intense competition to grab as many fabulous paintings as they could.

Rarely in Saltzman's narrative does the reader sense a love of art for its own sake. No one explains why he or she pursued certain artists beyond the prestige that owning the works conferred. This isn't the author's fault; that's the way the new Midases played the old-master game.

Gardner and the Cone sisters remind us that much of the most prescient collecting a century ago was achieved by women. They include Bertha Palmer, whose impressionists now grace the Art Institute of Chicago; Louisine Havemeyer, who favored both old masters and impressionists; and Gertrude Stein, who got the Cones started.

A century ago, art collecting was one area in which women could compete on an equal footing with men. Often, like the Cones, they were more adventurous and confident of their own judgment. And, I suspect, they were more intimately connected to the art they acquired.

Contact contributing art critic Edward J. Sozanski at 215-854-5595 or esozanski@phillynews.com. Read his recent work at http://go.philly.com/

edwardsozanski.