A ""curious"" (to use one of Sargent's favorite words) portrait of the man James McNeill Whistler called ""a sepulchre of dullness and propriety."" The remark may have been prompted as much by Whistler's need to maintain his reputation for waspishness as by jealousy of an immensely successful rival. Whatever the cause, from the evidence contained in Olson's biography (the first in 30 years) there was more than a dollop of troth in the characterization. Reserved, fastidious, work-obsessed, wary of romantic involvements, truly comfortable only in the company of his sister Emily, Sargent, at least as presented here, is a decidedly lackluster subject for biography. Though he associated with some of the most colorful artistic and literary personalities of the late 19th and early 20th centuries--Henry James, Isabella Gardner Stewart, Robert Louis Stevenson, the Sitwells, Stanford White, Claude Monet--he remained more Brahmin than bohemian, more George Apley than Guillaume Apollinaire. To complicate the matter further, his biographer either refuses or is unable to penetrate the armor of respectability with which Sargent protected his inner life. Nor will he speculate about the possible sources of his subject's almost pathological aloofness. It is as if Olson is afraid of what he may discover behind Sargent's ever-""proper"" facade. As a result, this portrait lacks the thrust and tension of good biography, the challenge of speculative reporting. Happily, Olson's writing is erudite, dotted with felicitous phrases. Charlotte Cushman, for example, is described as ""an actress of uncompromising ugliness."" And of the writer Vernon Lee (Violet Paget), Olson says, ""If anyone ever wore blue stockings, Violet Paget put on two pairs. . . She had a talent for emptying rooms."" Occasionally, Olson allows his personal dislike of anything smacking of ""flamboyance"" to take over and he strikes out with unnecessary maliciousness, as when he describes Whistler as ""distorted and odious."" Of Isabella Gardner Stewart, a generous supporter of Sargent, he says "". . .her greatest achievement was that she bought."" Such mean-spirited attacks make the reader more than a little skeptical about Olson's objectivity when dealing with Sargent himself. A successful biography of the enigmatic painter may yet be written--when and if all the facts become known. If Olson has them, he isn't telling.