In the first photo, Jamie's expressive eyes dance, a wide grin reveals a toddler's glee.

The second picture is the same boy, about 11 and grown handsome. His eyes, ringed by darkened circles, seem empty.

Miller remembers when her son changed. He was still a toddler, just beginning to talk. He was happy and healthy.

"Then he began waking up at night screaming," she said.

He would thrash and bang. On car rides, Jamie would howl like a wounded animal.

And when he was calm, he was too calm. Jamie became impassive and detached. He no longer talked and, when he did, he could no longer make the simple sentences he had begun to string together.

Miller went to doctors.

"They were saying he was manipulating me," she said. "We knew he was in intense pain."

The cure, once it came, seemed simple enough. Her son was diagnosed as gluten and dairy intolerant, so the fam- ily removed breads, yeast and milk from its diet. Jamie's banging and screaming stopped.

But his empty stare and his hopelessly arrested development stayed.

And Miller again started looking for answers.

"There was no map for us to go by," she said. It took five years for doctors to finally diagnose autism but, once the diagnosis came, the pieces fell in place.

According to some studies, one in 150 children has some form of autism, a syndrome characterized by impaired social, communication and sensory skills. Affected children are prone to repetitive movements and display an unnatural need for sameness.

The number of children diagnosed with autism nationally has risen steadily over the decades, from one in 10,000 when the disorder was first tracked, to one in 500 just about a decade ago.

Miller, along with a growing movement of doctors, scientists and hopeful parents, thinks she knows why.

Two years ago, the U.S. Food and Drug Administration told pharmaceutical companies to stop using thimerosal as an ingredient in some early-childhood vaccinations.

Thimerosal, a concentration containing a 50 percent mercury compound, is used as a preservative in the vaccines and in countless over-the-counter children's medications. Over the years, it has been yanked from ingredient lists for everything from infant stuffy-nose drops to children's eardrops and eyedrops.

Mercury is a known cause of birth defects and brain damage.

Miller's son's symptoms appeared within weeks, even days, after his first round of childhood inoculations.

She is part of a growing multiparty suit being planned against pharmaceutical companies that produced thimerosal-containing vaccines. The suit is waiting for lawyers in a number of states to organize their strategy and for science to catch up with their theory. A number of other class actions have been filed.

The FDA has never said thimerosal is a danger, though it sets safe exposures to mercury at 0.1 micrograms per kilogram of a person's weight, far less than what infants receive through thimerosal-containing vaccinations.

The FDA and drug companies are cooperating to phase out use of thimerosal but, by some estimates, hundreds of thousands of doses of thimerosal-containing vaccines remain stockpiled.

Despite guidelines, many children younger than a year old are vaccinated with old vaccines. Following the FDA's recommended schedule of vaccines, a child receiving the old vaccines receives 62.5 micrograms of mercury during a single doctor's visit. By age 2, children may receive as much as 237.5 micrograms of mercury through these stockpiled vaccinations.

New vaccines without thimerosal, by comparison, expose children to just 37.5 micrograms over the same period.

An FDA spokesman declined comment and referred calls to the administration's Web site.

The site references a number of studies that showed no conclusive link between mercury and autism. It says studies continue because "while the available scientific data do not establish that these neurodevelopmental disorders are caused by Thimerosal, at the same time, they do not establish that these neurodevelopmental disorders are not caused by Thimerosal."

The official stance of the American Association of Pediatrics is that there is no connection between thimerosal and autism.

A fact sheet on the association's Web site takes a firm stance: "There are no studies that show a link between Thimerosal in vaccines and autistic spectrum disorder."

Drug companies, too, have affirmed their stance that thimerosal is safe. They cite independent scientific studies, more than 60 years of use and the more than 350 million doses distributed as evidence of safety.

Eileen Dolich, a spokeswoman with Merck & Co. Inc., which manufactures vaccines that previously contained thimerosal, said she could not comment on the issue because of pending litigation related to the preservative.

Miller is not convinced.

She and other mothers point to a bill being pushed in Congress that would absolve drug companies of any future liability for injuries resulting from thimerosal.

"That's as good as an admission of guilt," Miller said.

And to officials who are not swayed by new research and arguments supporting the theory, she invites them to live a day in the shoes of a mother whose toddler goes from normal to seemingly borderline psychotic.

"You cannot imagine living with these children when they are so . . . so toxic," she said.

The lack of a recall infuriates parents convinced of a link between thimerosal and their children's disabilities.

"If a baby walker turns over and hurts three or four children in the nation, it's immediately recalled," said the Rev. Lisa Sykes, whose son Wesley, 6, is autistic. "I am so frustrated with our government that there has been no recall."

It's an interesting but wholly unfounded theory, said Dr. Paul Strehler, a Richmond-area pediatrician whose nephew is autistic.

Most Richmond-area pediatricians contacted by The Times-Dispatch for this article declined to comment, citing the controversy surrounding thimerosal. But Strehler has little patience for what he called unfounded conjecture.

Strehler acknowledged that mercury is bad but stressed that in the levels administered with vaccines, it is insignificant. "I've been a pediatrician for over 13 years," he said. "I have not observed a relationship between vaccinations and autism."

It's like saying thunder causes rain, he said. "I think the [autism and vaccinations] happen at about the same time in life, but one doesn't cause the other. You could blame baby formula, too. Baby formula is given during the first year of life, and some babies who get it also get autism."

Sykes and others insist the evidence is far stronger than many in the medical field are willing to admit. She points to what she calls an alarming double standard when it comes to declaring drugs safe for adults as opposed to children.

"We tell women not to drink alcohol," Sykes said. "But we put mercury in [pregnant mothers'] flu shots. You're playing roulette, and you don't even know it."

Roulette? The odds are not even that good, says Dr. Boyd Haley, an outspoken scientist who has spent the past 12 years studying mercury toxicity. He is a professor and chairman of the department of chemistry at the University of Kentucky in Lexington.

"I can absolutely guarantee that a pregnant woman shouldn't be exposed to mercury," Haley said, calling a child in utero "a magnet" for any mercury that enters the mother's system. "Some people will say certain levels are OK. They have no data for that."

Haley said studies have been done on adult animals and on adult humans to determine safety levels, but he called these studies irrelevant when applied to children.

"Ask them where is your data where you tested this on infant monkeys or on infant rats or infant anything," he said. "They just don't have it."

According to the theory Haley and some other scientists are formulating, the children who have thimerosal-containing shots and then become autistic have a genetic or physical weakness that makes them susceptible.

Additionally, he points to a phenomenon widely accepted in scientific circles called synergistic toxicity. When exposure to a toxic element is combined with exposure to another toxic element, "it increases the toxicity of both a hundredfold," he said.

But theories need verification, and Haley's has yet to have entered the mainstream among those who study the toxic effects of mercury and other substances.

Carl Wolf is the toxicology lab supervisor at Virginia Commonwealth University Health Systems. He said he is not familiar with any research supporting mercury poisoning as a potential cause of autism.

"But I suppose it could be a possibility," Wolf said. "Mercury has detrimental effects on the nervous system, more related to the peripheral nervous system rather than the central nervous system."

Wolf expressed some doubt that a healthy body, regardless of age, would not be able to process and purge levels of mercury common in thimerosal-containing vaccines.

"We have a metabolism to handle [mercury] pretty much from birth. Our body generally does very well at excreting anything that we would consider a poison," he said. "Most of it should be clear [of the body] by the time they go for their next doctor visit."

But what if it does not clear the body, asked Haley, stressing his theory that some children lack a system developed enough to process the element.

"The bottom line is thimerosal has a history of being very toxic," he said, calling irresponsible the current decision by federal agencies to rely on existing mercury-safety standards set for adults: "A lack of proof isn't a proof of a lack of something."

Lisa Sykes and her fellow parents say they have all the proof that is necessary living under their roofs.

"This is not a psychiatric disorder," Sykes insists. "These kids are catastrophically sick, and we're just not saying that the pharmaceutical companies are liable."

Today, Jamie Miller is a beaming, happy boy.

He is tall, with sandy hair cut in a typical child's mop. He enthusiastically runs to greet visitors to the Millers' home in the city's affluent West End.

The smile frozen in the photo of Jamie as a toddler once again flashes easily and often accompanies a hearty laugh. His parents even describe him as an extrovert.

In some ways, he is unusual among children with autism.

But he still will not maintain eye contact. His balance is somewhat off-kilter. His attention darts around the room. He occasionally rocks in place as if considering and reconsidering his next thought.

These are all common symptoms among autistic children.

If Mary Miller could go back to a time before Jamie changed, she truly believes he would be a different boy today.

"Be educated, be able to make an informed decision," Miller said, affirming that she still would have gotten Jamie vaccinated - as long as it was with vaccines not containing thimerosal. "I would tell parents to read the literature provided by the drug manufacturers themselves."