In the worst years, four of every 10 prisoners were nailed into simple, wooden coffins and carried away on a horse-drawn cart for communal burial.

They had died miserably of malnutrition, illness or the brutal regimen of a labor camp in southwest China. Tens of thousands of political undesirables and innocent intellectuals, victims of the witch hunts of Mao's China, languished for years at the camp, according to a former schoolteacher who spent 21 years there before her release in 1979.

"We used to think the dead ones were lucky," recalled the former prisoner, now 70, who has provided one of the most detailed personal accounts of life in China's version of the Gulag archipelago.

The survivors paid dearly with up to 20 hours a day of hard labor hauling coal or collecting manure, she said. They were constantly hungry, forced to subsist on rice and cabbage soup. They slept 100 to a room, stretched out on the bare ground with no more than leaves as a cushion. The rebellious were beaten, locked up and subjected to mob-style criticism.

"It was bitter all the way through," she said. "I labored from my forties through my sixties and there wasn't a moment of hope, not for all those years . . . . We were called 'stinking intellectuals' not fit to live."

No Solzhenitsyn has emerged to chronicle the depths of China's vast network of "reform through labor" camps, built by Mao to punish his enemies and discipline a generation of westernized intellectuals--writers, scholars, artists and scientists--whom he suspected of dangerous nonconformism and bourgeois thinking.

It was only after Mao died in 1976 and China passed to the rule of moderate men that the last survivors were finally released in 1979 to tell their stories.

The handful willing to discuss their past with foreign reporters say they were framed, filed away and all but forgotten without so much as a hearing. They give general descriptions of the camps as black holes of despair where food was meager, labor hard and punishment cruel.

The onetime schoolteacher, in an interview with The Washington Post, offered a window into the daily routine, living conditions and inmates of one of Mao's prisons.

Like other prison camp refugees, she demanded anonymity to protect her from possible reprisals. She asked to be identified only as "Wang," and The Post also agreed to delay publication of her story for several weeks to help ensure her anonymity.

Although Mao's successors have freed most of China's historical scapegoats and decried past persecutions of intellectuals, Peking continues to operate the labor camp colossus to "reform" common criminals and a few political activists arrested during the so-called democracy movement from 1978 to 1980.

One dissident named Liu Qing dramatized his plight last fall by smuggling a memoir out of a prison camp in Central China. While he gave a chilling account of injustices, his conspicuous failure to mention food deprivations and hard labor suggests that there has been vast improvement in prison conditions since Wang's tenure in the southwestern penal farm.

China's government refuses almost as a matter of policy to discuss the subject of labor camps, which are run by the highly secretive Public Security Bureau. Requests for interviews with security officials or for visits to labor camps routinely go unanswered.

Wang was put away in 1957 not for what she did, but for who she was. As the daughter of a wealthy family who had studied abroad and taught literature in the southern province of Yunnan, her very background was enough to arouse suspicion during Mao's antirightist campaign.

No official figures have ever been released to document the number of intellectuals victimized by that heresy hunt. A well-informed Chinese editor, however, recently told an American historian that as many as 700,000 were arrested, imprisoned or sent to the countryside to work during the 1957-58 campaign.

The persecutions turned out to be a mild prelude to Mao's Cultural Revolution 10 years later when millions of intellectuals as well as Communist Party veterans were brutalized.

Wang was one of the earliest victims of the 1957 campaign. She was rounded up, charged with being a counterrevolutionary and driven in a large truck to a labor camp in the rugged, coal-mining region outside Kunming, a provincial capital about 150 miles from the Sino-Vietnamese border.

"I never did anything wrong," she recalled almost 25 years later. "They ordered me to write a confession, but I didn't know what to say. So I wrote down what they told me. They said I was a counterrevolutionary. I asked them to check out my case. But I didn't dare to argue."

Upon arrival, she found barrack-style buildings lined up on a dusty, barren plateau surrounded by hilly wilderness. There was no electricity, no plumbing and no heat in the 400-square-foot dormitory where 100 inmates pressed together on the earthen floor until bunk beds were installed in later years.

The prison compound and its satellite outposts scattered throughout Kunming contained tens of thousands of prisoners, mostly intellectuals sprinkled with former Nationalist Chinese officials and a few Red Army veterans, she recalled.

Every day began at 5 a.m. with a quick breakfast--less than two ounces of rice dumped into small aluminum pots issued to prisoners when they entered the camp.

Inmates were then taken by foot to coal mining hills where work gangs ranging from several hundred to a few thousand hauled baskets filled with coal chunks to railway cars and unloaded them into bins. Each prisoner was expected to meet a harsh daily quota.

"The labor really was backbreaking," Wang recalled. "In the winter, it was very cold and the wind blew coal dust into our faces. The summer was steaming hot and sweat ran into our eyes. We really wanted to sit down for a while and rest, but we had no breaks."

No talking was permitted during work hours, which were supervised by armed police guards and prison camp trustees.

The hardest chore for Wang was pulling an oxcart laden with coal, she said. Slipping a thick rope around her shoulders, she would lug the cart with the help of two other inmates.

Once she injured herself while carrying a large bag of coal through a long, dark shaft, she recalled. She fell into a coal pit, badly bruising her arms and legs. She remained in the deep hole for some time until she mustered the strength to pull herself out.

Prisoners were forced to work seven days a week until sundown with only a brief intermission for lunch, which usually consisted of 14 ounces of rice and thin cabbage soup.

Dinner was the same, leaving the overworked prisoners with gnawing hunger most of the time, she said. Only during the Chinese New Year were they given meat, small morsels mixed into a soup with noodles and vegetables.

The meager food portions dwindled even further during times of economic crisis, such as the near-famine of 1959-61. During the chaotic Cultural Revolution, Wang and her campmates ate only rice and vegetable oil.

"Sometimes when we worked overtime, they gave us a little extra," she recalled. "For us, every bite was a treat."

After dinner, inmates often were sent back to work. Other nights, they held two-hour political study sessions at which they read official newspapers and studied the history of slavery from ancient to present times, Wang said.

During the province's busy agricultural seasons, she said, work schedules swelled to include predawn labor in nearby fields cutting high grass or collecting manure for fertilizer. Every prisoner was responsible for cutting about 900 pounds of grass daily.

"After eating supper," she recalled, "we were ready to fall flat on our backs. But very often we had political study until 10 o'clock. Then sometimes two or three hours after we had gone to bed, they got us up again to cut grass with sickles. There never was any rest."

Wang said she seldom was beaten because she was "well-behaved and very hard working," but others were pummeled and kicked for shirking work, refusing to confess alleged crimes or breaking camp regulations.

Despite reports from other camps that prisoners had been beaten to death by sadistic guards, Wang said she knew of no one dying from lashings at her penal farm.

The roughest punishment was reserved for striking inmates--she estimated that between 20 and 30 percent of the prisoners regularly rebelled by refusing work--and the relatively few who dared to escape.

Most escapees were recaptured by search teams with dogs, she said. They were dragged back to camp, locked up, beaten and brought before large groups of fellow prisoners who were ordered to curse and criticize them.

Strikers also were hauled into "struggle" sessions and forced to repent, she said.

Along with hunger, exhaustion and illness were the prisoners' almost constant companions. Doctors taken from the inmate population could authorize sick leaves, but Wang said they only excused prisoners who had bribed them. Everyone else had to work while ill.

Thousands died of maltreatment during her 21 years at the camp, said Wang. In years of food shortages and extreme weather conditions, as many as 40 percent of the camp population perished, she recalled.

"The situation became gradually better," she said. "But even then, there still were many people who died."

Despite the hardships, some form of family life went on for inmates who married during their years of captivity. Children were born and raised within the confines of the penal camp, according to Wang.

Mao's political heirs have moved to prevent the arbitrary arrests and confinements that filled labor camps with innocent people for most of the late chairman's era. In 1979, Peking adopted a new criminal code guaranteeing an open trial to anyone accused of a crime.

But a year later, the government ominously republished the 1957 "reeducation through labor" regulation allowing local police to sentence certain kinds of troublemakers to labor camps without court review or trial.

When the regulation was republished, the Guangming Daily newspaper praised the camps as humane institutions where criminals could be reshaped into patriotic and lawful citizens.

"Practice of more than two decades has proved that education through labor has indeed achieved notable results," said the national newspaper that is supposedly written for intellectuals.

At least one former camp resident disagrees.

"They kept me there for all those years when I hadn't done anything wrong," said Wang, opening her hands that look like dried wood from years of hard labor. "Now I'm 70 and my life is behind me."