Two grass-roots Washington institutions are hurting this morning. It's not just a question of cash, although they would welcome some. It's also a question of something far tougher to come by: community support.

Case One: The Washington Free Clinic.

WFC was born 11 years ago to treat young antiwar demonstrators who had partaken of too many chemical refreshments. It has moved over the years into general diagnostic medicine, with an emphasis on treating and preventing sexually-related ailments. WFC now handles about 80 patients a week, two-thirds of whom are between 20 and 29 and earn less than $5,000 a year.

But the clinic is about to be evicted from its rent-free church-basement headquarters in Georgetown. The church can no longer afford a non-paying tenant. So the WFC board is looking for a couple of thousand square feet somewhere else.

The clinic would stay in Georgetown if it had to. But as Sarah Jewel, an instructor for female volunteers, put it: "Politically, to have an alternative organization like this in the heart of Georgetown is ridiculous."

Most of the WFC board would like to move to Capitol Hill, a community as diverse racially and economically as WFC's clientele. But the WFC board is willing to relocate in any community in the city whose residents will volunteer staff time and good will.

The immediate trouble is that WFC can't afford what most large places cost ( $800 a month and up).

"We probably could come up with that much for a couple of months. Maybe. But we plan to be around for years," said board chairman Sarah Spengler.

So it's a hunt for a place big enough and a neighborhood committed to alternative methods of health care.

So far: nothing. And the deadline is Labor Day weekend.

Case Two: the Eastern High School band.

Eastern's 100-piece ensemble started falling on hard times ten years ago when burglars stole half the instruments from a locked storeroom.

The hard times never stopped. And rock bottom was reached the last two years.

The band didn't perform at all, for a variety of reasons: not enoughtools to repair instruments, no consistently available place to practice, no money for new instruments and uniforms.

It may just be a coincidence that the Eastern football and basketball teams had subpar seasons over the last two years. But it's no coincidence that, without a band to add to the fun and the atmosphere, attendance at Eastern athletic events has slipped badly.

This summer, however, a new band director was hired. And a longtime behind-the-scenes sparkplug at Eastern has moved front and center as the paid "program developer" for the band.

She is Anita (Ma) Nance.

An Eastern biology teacher, Ma Nance has coached the Eastern cheerleaders in her spare time for years. But she is best known for her rabid rooting at Eastern sports events.

What other biology teacher do you know who wears an oversized white felt cowboy hat to basketball games and leads the E-A-S-T-E-R-N locomotive at the top of her lungs?

"What Ma wants, Ma gets," she declared the other day, with her usual brassy confidence. "But, hey, honey. I'm laying my cards on the table, sugar. I need all the help I can get."

Specifically, Eastern's band needs:

Eight sousaphones.

Two 8-by-28 drums.

A repair kit with tools to fix any and all major instruments.

"To get just that much, even if it's just loaned for a little while, would do more for morale around this place than anything I can think of," says Ma.

More precisely, it would mean Eastern would be able to field a band for the football opener, which happens in less than a month.

There are more visible causes in Washington than these two, but none more important to a couple of hundred young people on opposite sides of town.

I don't own a church hall or a sousaphone. But someone out there does.

Three belated cheers for Bruce Boyer, a 19-year old college student who was driving past the Washington Cathedral two Sunday nights ago when he saw a man snatch a woman's purse.

When the mugger started to escape by sprinting onto the grounds of the Cathedral, Boyer left his car in the middle of Wisconsin Avenue and gave chase on foot.

The grounds were very dark, but Boyer had a special edge: he had gone to St. Albans School, right next door, so he knew the pathways of the cathedral by heart.

Besides, Boyer plays lacrosse, hardly a game for those who can't sprint. So he was within easyeyeshot when the mugger jumpted into a waiting getaway car driven by another man.

Boyer wrote down the license number. Three days later, two Southeast men were arrested for robbery.

And the happiest ending of all: Boyer's car was still there when he got back to it. Without a ticket.