EVERYTHING TO LOSE: A Diary, 1945-1960. By Frances Partridge. Little, Brown. 383 pp. $22.50.

WHEN IT COMES to those whom Virginia Woolf labeled "Bloomsberries," one must approach a memoir with a scorecard or a program. Relationships become that complicated. Frances Marshall, now 86, is a case in point. She had worked in David Garnett's Gerrard Steet bookshop in the 1920s, and in the 1930s married Ralph Partridge. He was first married to Dora Carrington, whom he shared with his friend Lytton Strachey, with whom he also shared a house, Ham Spray, in Hampshire. Strachey's death, and Carrington's suicide in the aftermath, released both the house and the husband for Frances, who is still living at Ham Spray as the war in Europe ends, and this segment of her diary opens. (Two previous volumes of reminiscences chronicled Frances Partridge's life to 1945.)

The operative word in Bloomsbury relationships was always "civilized." Sexual arrangements were untroubled by gender. What occurred in the shifting population that inhabited Gordon Square and Bloomsbury Square and related outposts in the country was what Frances labeled "re-shuffles." In post-war England, however, civilization is breaking down: divorces and even more violent manifestations of barbarism intrude upon Ham Spray, even American warplanes surely carrying, Frances thought, nuclear bombs.

Bloomsburyites were notable pacifists, particularly in the 1914-18 war. Now, Frances is distressed by the vindictiveness of the French nation in 1945 in hustling the doddering puppet of Nazified Vichy, Henri P,etain, to trial. He was only "a gaga old man of ninety whose crime is that he made peace." As the Cold War intensifies she and Ralph are "gloomily struck" by the distance some of their friends have come from those Oxford undergraduates of the 1930s "who voted against fighting for king and country." Ralph, a major in the Great War but Bloomsbury pacifist thereafter, insists that there is no such thing as self-defense -- "that killing your enemy in war is assassination," and that "one should prefer being assassinated to assassinating." Both conclude that since the ultimate weapon has taken shape, "the Bomb will go off, and whether it was by accident or design will make no difference."

Although the outside world has become "a lunatic asylum of raving maniacs," Bloomsburyites who survive Lytton Strachey and Maynard Keynes and Virginia Woolf live, however they can, within the group, and decades of Frances Partridge's diaries record their most trivial doings. By Bloomsbury standards, she once contended, "personal relationships" were all that was worth living for. It was a matter of "fact," she told the skeptical Gerald Brenan, that neither Lytton Strachey "nor any other Old Bloomsbury writer" (and Brenan was one of them) had written "for money or fame." Yet Frances and her husband would toil at books and journalism for sheer survival, even taking pittances for translation work.

Nothing of Frances Partridge's other writing evidences the verve for vivid description of her diaries. From the opening pages her knack for capsulizing sensory impressions is remarkable. "V.E. Day" celebrations in London on Germany's surrender leave her feeling "like a sheet of old newspaper." Big Ben can now toll again, the "deep boom" of its voice "the nearest I can imagine to God." On the other hand, novelist Elizabeth Bowen's "attractive stammer" causes her to begin "r" words "with a whirring sound like a clock about to strike."

Faces are fixed in a few words. Alix Strachey in old age has a head like "an Easter Island image." Bertrand Russell's new wife is "a Lamia-like woman with an expression of widely distributed hostility." Cecil Beaton's smooth pink face "is rather like that of a sly moose or gnu, slit by a narrow little grin," while Philip Toynbee displays "a large empty stretch of unreplaced teeth in the centre of his face." Edward and Constance Garnett peer "through the thickest spectacles imaginable, with the questioning, but unseeing gaze of fish in an aquarium." At the Memoir Club, the preserve of Old Bloomsburyites who exchange scraps of personal history with each other, and blackball newcomers, Vanessa Bell reads from letters to her by Maynard Keynes -- "the dry husks of something that had once been dynamically alive" -- and they stir "the emotions concealed behind those old masks."

Feeling is evoked with similar sensitivity. Christmas shopping at Hamleys, the toyshop, requires an antidote, and Frances goes to look at young Frances Bacon's "completely original and absolutely terrifying" paintings. Unsentimental about the monarchy, she accepts the death of George VI with the assumption that he was "probably a good, hard-working man (and) there are plenty other such." On a "hot and heavy day . . . something of a Chekhov atmosphere" broods over our garden "with ambulant couples stooping to study a flower." On a "womblike" channel boat at night she and Ralph "creep into our tiny cabin and lie like biscuits in a tin."

ALTHOUGH the narrative line is weak, largely one of visitors and visits, and the declining health of Frances' husband, whose death closes the diary in 1960, not 1962, as the title declares, it is her gift for chronicling the felicitous image that sustains the book. Mrs. Partridge voices a concern early about "being imprisoned in my own vocabulary." One never senses this, perhaps because of her ability to capture the most quotable words in a conversation. Complaining of the "arid" music and paranoid plotting of homosexual composers like Benjamin Britten, Henry Lamb suggests, "I suppose these buggers have to get their pariah-feelings off their chests." Deprecating the philosophizing of C.E.M. Joad, Desmond McCarthy expostulates, "He's a fungus sprouting in the tub of Bertrand Russell." Gerald Brenan observes Dylan Thomas exiting drunk, "his large baby's head wobbling on its stalk." Accused French collaborationist Alfred Cortot is invited to perform in London, and Dorothy Bussy, Lytton Strachey's sister, declares, "I would much rather have had a German."

When, at the Memoir Club, Duncan Grant murmurs about difficulties in reading letters which seem to be written in "vanishing ink," Vanessa Bell responds ("sepulchrally"), "A pity all letters aren't written in that in my opinion." V.S. Pritchett, measuring moans from friends that gloomy weather is inducing deep depression, comments, "Oh, yes, I have my revolver always at my elbow." A London cabbie, overhearing a conversation, advises, "Madam, it seems to me the boy's making a big mistake and is liable to blot his escutcheon." And, finally -- but it hardly exhausts the possibilities -- an obviously green Air India pilot squeals jubilantly on the intercom as he touches down on the tarmac, "Oh boy! On boy! How is that for smooth? What you say?"

Just as frankly, Leonard Woolf, after Frances' query as to whether she is likely to live long enough to read the gossipy gold mine of Virginia's diaries, predicts to her in 1953, "I think you might just about manage to." She has managed as well to publish her own. While not in the Virginia Woolf class, its images of the later Bloomsbury will keep it fresh.