Gordimer's warning to South Africa; July's People, by Nadine Gordimer. New York: The Viking Press. $10.95.

Nadine Gordimer writes with such foreboding now that she has become the Jeremiah of South African novelists. Unlike her brilliant 1979 novel, "Burger's Daughter," set on the eve of a revolution in South Africa, her latest work, "July's People," takes us beyond revolution.

Saying in only 160 pages what many books would take 350 pages to say, it begins with the old white order in the last stages of eclipse by black revolutionaries, as the Smales, a white Johannesburg family, adjust to uncertain sanctuary.

While Gordimer may offer little hope of redemption for a country she feels undeserving of a quick, easy solution, her writings are not alarmist. Nor does she harangue the reader.

Like drops from a faucet falling rhythmically on a hard surface until they erode it, her observations penetrate unobtrusively. Her most disarming technique is the devastating revelation tucked casually in a throwaway line.

A telling aphorism, for example, that speaks volumes about the master-servant relationship, which underpins the South African way of life and this book, is her disclosure that "to be seen is not necessarily to be acknowledged."

July, servant for 15 years to the Smales, and their provider and custodian when he smuggles them out of South Africa to his home in Botswana, was similarly placed.For all the well-meant charity they bestowed on him, the Smales didn't learn until reaching Botswana what July's African name was, who his family were, or how they lived so many miles from Johannesburg in government-enforced separation.

The story is about July, and Bam and Maureen Smales, and, to a degree, their respective families. The master has become not actually the servant but at the very least subservient to one whose life and duty has been to serve. The Smales are enmeshed in a relationship of their own making. When debating whether to entrust to July the keys to the vehicle in which they made their escape, Maureen is humiliated by the injured but almost menacing innocence of his truculent reply: "Me, I'm your boy, always I'm have the keys of your house. Every night I take that keys with me in my room, when you go away on holiday, I'm lock up everything . . . it's me I've got the key for all your things, isn't it?"

For a while the Smales survive in their sanctuary, leading lives of quiet desperation. Then the war follows them to their protected turf. In the end not even the demands of family can hold them; we are told on the final page that Maureen is running "like a solitary animal at the season when animals neither seek a mate nor take care of young, existing only for their lone survival, the enemy of all that would make claims of responsibility."

Few writers can match Nadine Gordimer's poetic insight, her political resilience, and extraordinary intellectual vision in mirroring the travail of contemporary South Africa.