First Lady Rosalynn Carter returned yesterday to D.C. General Hospital as part of her continuing effort to beautify and improve physical conditions at the troubled public hospital that serves many of the city's poor.

As she did once before, Carter rode the metro subway to the hospital, purchasing and using a farecard as event was photographed by members of the press. Secret Service agents in her pary were waved through the fare gates without paying.

"I'm really excited about the hospital," Carter told her seatmate, a volunteer in her project to beautify D.C. General.

"I'm going to see what's been done. I haven't been out there since you all painted," she said, referring to her second visit to the hospital - a visit when she rolled up her sleeves and helped volunteers paint a hospital corridor.

The First Lady's companion asked if the hospital, which lost its accreditation in 1975, has finally regained it. "The hospital is accredited now, isn't it?" Carter asked her press secretary, who informed her, correctly, that it is.

One of the things volunteers have done to beautify the hospital is plant shrubs outside it.On the return trip from the hospital, one member of the Downtown Jaycees was telling another of a hasty, late night trip to the hospital to replace bushes that had died since being planted four months ago.

"Some of the (root) balls were still tight," said one man to another. "Those things looked like they'd never been watered."

A reporter speaking with Carter mentioned that the late Eleanor Roosevelt is said to have visited the hospital when she was First Lady and returned from the visit bemoaning conditions at the institution and calling for improvements. Do such visits make any difference, Carter was asked.

"I think you can tell the difference in the morale of the hospital already," she said, "because people are taking an interest in it. If the morle improves, it helps the patients."

Carter was at the hospital yesterday to thank those involved in her volunteer effort and launch a nursing education program being sponsored for nurses at the hospital by the American Nurses' Association.

As Carter was telling a group of nurses and hospital officials that "the people in the community have worked to make D.C. General a modern hospital," about 80 members of the community sat outside the emergency room waiting to see a physician.

Maytan Childs had been at the hospital since "about 8:30 (a.m.) I guess. I have an infected kidney, I think. I was over here about three weeks ago. They said I had an infection. . . They gave me some pills to take."

Childs, who says he earns between $125 and $150 a week, does not have private health insurance and earns too much money to qualify for Medicaid.So he goes to D.C. General, where "it doesn't cost me anything."

"I wouldn't say I'm pleased with the service," and I wouldn't say I'm not. There's just a whole lot of other people in here like me," he said.

"I've been waiting since 10:30 this morning," said Irene Washington, who was sitting in the emergency room waiting area at about 2:15, while the First Lady wa speaking in the auditorium. "You get the runaround here," said Washington, who had brought an elderly relative to the hospital for treatment.

As Carter prepared to leave the hospital, Natalie Spingarn, a member of the D.C. General governing board, praised Carter's involvement with the hospital:

"When Mrs. Carter first came to visit I likened her interest to a magic wand. I think you'll agree with me that she's waved that wand most constructively."