They are sitting around a lunch in the Member's Dining Room in the Capitol, squabbling a little as tired, foot-weary, sightseeing youngsters will do. They've been to the White House. They've tromped around the Capitol. And that night they'll be, well, on display at a conference on death. Of the four youngsters, three have cancer. The fourth lost her brother to the disease last summer.

A congressman stops by to visit and to hear about the special program for the children and the families that catastrophic illness strikes. Suddenly, unexpectedly, everyone at the table is holding hands, the young people, their mentor Jerry jampaolsky, the congressman, a mother, some visitors. The congressman says a prayer. "Dr. Jerry" says a prayer. And in this ost cynical of political places, the tears well up in a visitor's eyes. . . .

There is a special room at the Center for Attitudinal Healing in Tiburon, Calif. It's in an old building, "broken down," with rotten pilings, members of the group will tell you, off an alleyway cluttered with debris and garbage cans. There is a bright new room in a new building nearby, but, ask anyone, it isn't the same.

Said Andrea Dezendorf, 10, (leukemia), a member of the group, "It's really so special . . . It almost feels . . . how can I explain it? I don't know . . . it's like someone has to ground you and pull you down. . ."

"Just going in that room," says Jerry Jampolsky, "you feel this tremendous flow of love and energy."

It is the room the children meet in at the center, the children who are dying. But they don't see it that way. The children, they prefer to say, are learning to live.

"We hold hands," said Joe Orr, 14 (leukemia). "We get in a circle and hold hands and we send love and energy to everybody . . . Like, if somebody's feeling sick, we hold hands and send energy round and after a while you'll see that person will get to smiling, cherry, like that, like it helps them. It helps us to hold hands and share love and energy with each other . . ."

The center, free and (they know only too well) non-profit, was founded by Gerald G. Jampolsky, M.D. ("Listen," he said, "nobody calls me Dr. Jampolsky. Call me Jerry.")

It was, he recalls, "just something that came into my head" on a trip back to the West Coast from a speaking engagement in the East.

Of course it is never quite as simple as that, as he admits readily.

It started around 1975 because his life was falling apart. "I was just coming out of a 20-year marriage and a very painful divorce. I developed an alcohol problem and an incapacitiating back pain and my internal world was in great chaos. The outside world saw me as a very successful, nationally-prominent physician . . ."

Jampolsky is a psychiatrist. He was internationally known as a specialist in learning disabilities. In the depths of his crisis he came upon a program called "A Course of Mircales" in Tiburon, and although he says, "I wasn't interested in God or any kind of spiritual pathway . . . to my surprise as I began to read, there was this inner voice that sad, 'physician, heal thyself.'"

The rest is history. Recent history to be sure, but the kernel of an idea that popped into Jampolsky's mind 20,000 feet over the Rockies, 5 years ago, has blossomed in to a child-to-child support network that crosses the continent, that has been heralded on network TV shows ("Donahue," "60 Minites," "Today") and now promises an impact even on businss empires -- and who knows what else, later.

The childrens center and Jampolsky's personal philosophy have had a tendency to blend, growing as they do from the same basic ideas, so when he lectures on the philosophy, he's learned to bring the children along.

"Children have a way of making things very simple. The first thing is to forgive, and that's a powerful message. One little mustard seed of a child can do more . . ."

Very briefly, very simply, Jampolsky's message is this:

There are two basic emotions: love, which is our natural inheritance, and fear, which our mind invents.

There are three thinigs we can accomplish in life, one is to have a single goal of having peace of mind, second is to see forgiveness as our single function and third is to listen to our inner voice for guidance and direction.

Jampolsky has a sometimes disconcertng way of speaking in aphorisms, such as "forgiveness is the key to happiness" or "healing" is letting go of fear," or "helping another person allows you to feel peace."

These are, though,his statements of principle, the underpinnings of the center, and of the almost born-again experience of this 54-year-old former skeptic ("I thought people who chose a spiritual pathway were . . not using their intellect properly").

How he arrived at his own spiritual pathway is recounted in his book, "Love is Letting Go of Fear." A Place to Cope

Jampolsky and an entourage from the center were in Washington recently to participate in the St. Francis Center's Conference on Death.

At their lunch on Capitol Hill, (courtesy of Rep. Charles Rose [D-N.C.] who was, however, out of the country,) the group conducted a kind of impromptu rehearsal of their later apperance at the center for the benefit of Rep. Berkley Bedell (D-Iowa) and Milton Friedman, a Rose aide.

With Andrea Dezendorf and Joe Orr were Sharon Winter, 20 (lymphoma) and Maria Stein 13 and her mother, Marge. Maria's brother, Will Stein, died last August, but the Steins remained in the group, actually formed one in their own home during the California gas crisis and will form yet another later this year when the family moves to Houston.

Maria is a member of the siblings group at the center. "Tell us, " Jampolsky prompts.

Maris takes a deep breath. "Well, we get together and talk about what it's like to have a brother or sister who is sick with cancer and all the problems it causes, like, when your plans are ruined sometimes you think 'Oh I wish he (or she) was dead,' and then you feel really guilty. But if you go to meetings and you say that, you find that a lot more people have the exact same feeling and you understand that it's not just you . . ."

"We came to the center," recalled Marge Stein, "because we didn't think there was much hope for William to live much longer, according to the doctor's reports, and I wanted to help William die. What I discovered was that William learned to live from this center because of his feeling of self worth, that he was able to help other people . . ." Choosing to Fight Off Fear

"What makes the center so successful" specualted Jampolsky, "is that it is such a horizontal thing. We let the children do it. Nobody's there for an authority trip."

"Children can demonstrate you have a choice of seeing the world through love rather than fear . . . experiencing peace, rather than fear.

"For example, take a child, 11 years old. She is a new student at her school and she's playing volleyball and her wig's knocked off. No one knows that she's bald. She runs into the classroom, hides under the desk and then runs home. She hasn't been back to school for two weeks and the school nurse refers her family to us.

"She comes to her first meeting and one of the first things I do is asks all the children to raise their hands who've lost their hair. [Hair loss is an almost inevitable side effect of chemotherapy. It usually grows back.] almost all the children do and the 11-year-old who is so scared begins to smile for the first time in so long . . .

"Then she begins to ask questions about the problems she's facing and here the kids who've already gone through it begin to tell her in a way I wouldn't be able to tell her, the other professionals wouldn't be able to tell her . . . the whole purpose is to experience joining.

"Then the next week another new girl comes in and last week's new girl begins to help. We immediately put the children in telephone contact with other kids who are calling so that the whole focus is all the energy going to help others and you're not thinking of yourself as sick or in agony or in pain. . ." Long-Distance Courage

Some 75 children and young adults with catastrophic illnesses are coming to the center now, says Jampolsky, with some 800 or so more who keep in phone contact. Now there is a coast-to-coast toll-free number for a dial-a-dial program which plugs the caller into a recording of a child talking about how he or she dealt with one of the common problems. (800-227-20309)

The program at the center, Jampoilsky emphasizes, is in addition to -- not instead of -- the traditional medical model. The program is spiritual, but religion per se is left to the individual.

But of course the one "model," as the professionals call it, becomes part and parcel of the other. The center members rally close any time there is a crisis. Recently, said Jampolsky, "we had a kid who had a bone marrow transplant at UCLA hospital. I and the others went to see him. He had very great trouble for a while, but he made it and the psychiatric team there has now asked us to go back because they found this famly so different.

"They said, 'families in this situation are always in terrible anguish and this family wasn't. They seemed to have it together' and the upshot is we're going to do a symposium for them at UCLA. . ."

If there is any symbol, it is the rainbow. ("There are rainbows just everywhere," announces Andrea.) And Andrea, Joe Orr and several others prepared a book called "There is a Rainbow Behind Every Dark Cloud," designed to impart their own experiences to others of their age with their own problems.

Notes from "Rainbow":

"It's okay to cry. It's okay not to like hospitals and shots, to be homesick, to be upset about being lonely, and to be mad that this is happening to you . . . It's okay to feel sorry for yourself and to be mad at the world . . . and to talk about death and your fears about it.

"When other kids tease you, you can pay no attention to them; you can fight them; or you can choose to see that they are scared.(We found that sometimes a kid teases you because they are the ones who are scared.)

"Forgiveness is forgiving the doctor if he puts a needle in and you find out he put it in the wrong place and has to put it in a second time . . .

"One of us thought, "When you die, your body leaves you and you soul goes to heaven. There it joins other souls and becomes one soul. And sometimes the soul comes back to earth and acts as a guardian angel to someone.' We all seemed to like that way of looking at death." CAPTION: Picture, Dr. Gerald Jampolsky, By Harry Naltchayan -- The Washington Post.; Illustration 1, no caption, By Andrew Dezendorf; Illustration 2, no caption, By Joseph Orr, from "There Is a Rainbow Behind Every Dark Cloud," a book written by the children; Copyright 1978, The Center for Attitudinal Healing.