A Capitol Hill bartender testified in Montgomery County Circuit Court yesterday that she served U.S. Rep. Louis Stokes (D-Ohio) one glass of white wine last March 25, and saw him leave sober just three-quarters of an hour before he was stopped by police on suspicion of drunk driving in Wheaton.

The bartender was one of eight witnesses called by attorneys for Stokes, the 58-year-old chairman of the House ethics committee who has been on trial since Wednesday, accused of driving while intoxicated, running a red light and driving on the wrong side of Randolph Road.

Circuit Judge William M. Cave said yesterday he will instruct jurors to find Stokes not guilty of driving on the wrong side of the road, because police charged him under a statute that does not apply to divided highways. Prosecutor Robert Greenberg agreed with Cave's decision.

Police have testified that Stokes failed three roadside sobriety tests. He was not given a chemical breathalyzer test, they said, because they released him when they thought he enjoyed congressional immunity.

Barbara Kachur, the bartender,, testified that Stokes looked "very drawn" and "very tired" but sober when he arrived at about 1 a.m. at the Hyatt Regency on Capitol Hill.

She said his eyes were red and watery, and that he complained that his allergy to pollen was bothering him. Kachur said she served Stokes one glass of wine, that he refused a second and appeared completely sober when he left at 1:30 a.m.

Other defense witnesses testified yesterday to the congressman's sobriety on the day he was arrested.

Rep. Lawrence J. Smith (D-Fla.) took the witness stand briefly, saying he heard Stokes make a brief speech the lunchtime before he was arrested, and talked with him afterward. Smith said he noticed "nothing abnormal" about Stokes and said his colleague "did not smell of alcohol" and had had nothing to drink.

Stokes' administrative aide, James Curtis Harper, said his boss was "definitely" sober when he met with him at 7 a.m. on March 24, and was still sober when he left him at 5:30 p.m.

Stokes' staff aide, Joyce A. Larkin, said Stokes was "totally exhausted" after a "very, very hectic day" when she left the office at 8:30 p.m., but that she did not see him drink anything during the day and "he was not intoxicated."

Stokes' wife, Jay, testified she spoke with her husband by phone at about 6 p.m. and again at about 11 p.m. and he "sounded fine." His daughter Lorene went to pick up her father at the Wheaton police station after he was released. She testified yesterday that she kissed him on the cheek, but could smell no alcohol. He was tired, she said, but not drunk.

Stokes' attorneys have acknowledged that the congressman had had two glasses of wine before he started driving home.

Police Sgt. Thomas Weidmann, who watched the arresting officer, Henry deSibour III, administer roadside sobriety tests on Stokes, testified yesterday that the congressman had bloodshot and watery eyes, stood slightly slouched, spoke slowly and had a "moderate odor" of alcohol on his breath.

Another officer who saw Stokes at the station, Cpl. William S. Isaacs Jr., agreed with the description, and said he believed the congressman "was under the influence of alcohol and possibly intoxicated."

A Capitol Hill police inspector who was consulted by Montgomery police on whether Stokes could be charged told jurors that deSibour told him Stokes "would have passed" a breathalyzer test if it had been administered. He said he assumed that meant Stokes was not intoxicated.

But deSibour told jurors earlier yesterday that, in police jargon, "passing" a breathalyzer test means being impaired or intoxicated.

The defense is expected to conclude its case late tomorrow and may put Stokes on the stand.