It was a sad chapter from bygone days.

Betty Talmadge, a reluctant witness, came before the Senate Select Committee on Ethics looking into five charges of financial misconduct against her former husband, Sen. Herman Talmadge.

Theirs had been a bitter divorce (1977) and property batt,e and it was their first fact-to-fact confrontation in months. The senator moved over to shake the hand of the woman he had been married to for 35 years. She responded, "Hello, Herman." After six weeks of somewhat yawning testimony, photographers and cameramen were waiting to catch every second. What they got was a courtly gavotte.

And the reluctant witness seemed matched by reluctant questioners; the whole session was touched with kidglove gentility. The senators, the committee counsel and Talmadge's lawyers slid over her answers. Afterward, and aide to Talmadge said, "This was not a time for vitriol." Through it all, Talmadge looked intently, often impassively at his former wife, behind a smokescreen billowing from his countless stogies. Talmadge occasionally allowed himself a brief smile.

In the world of politics, there were many reasons to keep yesterday's testimony as amiable as possible. The couple has, as one lawyer said, "so many mutual friends." The senator has an eye toward his 1980 re-election and being courtly to an ex-wife still sets well back home. Mrs. Talmadge, defeated last year in her first bid for congress, remains in the meat brokerage business inn Georgia and is not anxious to make waves against the still-powerful Democratic senator.

Mrs. Talmadge, 55, asked the committee to excuse her from testifying on the grounds of "marital privilege." Her request was denied. She read an opening statement. She was there, "only because I have been ordered to do so by the United States Senate. Unfortunately it is being said back in Georgia that I am the cause of Senator Talmadge's current problems before this committee. This is simply not true."

Her voice firm, Mrs. Talmadge said she came before the committee with "deep regret and disappointment" but no "bitterness." However, Mrs. Talmadge went out of her way to mention twice that it was her husband who had sought the divorce. His face was a mask as Mrs. Talmadge repeated a fact that comes quickly from a woman-scorned memory bank. It is one fact that she repeats often, "He filed the lawsuit for a divorce while I was away from home on a brief vacation on the Georgia coast. And, unbelievable as it seems, I learned of it on television after I returned to our home."

The senator and Mrs. Talmadge were both in their Lovejoy home at the time of the newscast. "I was shocked," she said yesterday, "that he would take his action without even discussing it with me in advance."

She then broke down, her voice quavering when she talked about the legal fight for Lovejoy. "We both wanted the homeplace where our late son, Bobby, is buried." (He drowned in 1975 at age 29.)

Mrs. Talmadge got the home in 1978. It was for her grandchildren, said Mrs. Talmadge, that she did not want to testify. The smoke billowed from Talmadge's cigar even more as she said, "Senator Talmadge and I had 35 years together. I bore his children, helped run our business, waited at home, campaigned, helped whenever I could with constituents and all those dozens of tasks that become the lot of the political wife. And, yes, sometimes I fussed with him."

There was, throughout those years, a "way of life." For those used to a more conventional "way of life" when it comes to currency, this was the part of Mrs. Talmadge's testimony that caused a quick intake of breath throughout the room:

For years, the money was there, nestled inside an overcoat pocket - at one time up to $45,000 in $100 bills - a private drawing accout as it were. And for years, said Mrs. Talmadge, she took $100 bills from that secret mother lode. One day in 1974, she removed from $12,000 to $15,000 from that overcoat pocket - about "one-third" of the amount in the pocket. Gasps were audible as senators, reporters and the audience added it all up - from $36,000 to $45,000 in an overcoat pocket.

It was routine - "custom" - to keep the money there. She dipped into it for "household expenses." When asked if her husband took from it, she paused, then reluctantly answered yes, she has seen him remove money at least several times a year. In earlier years it was nickels and dimes - fives and tens and twenties. Later, it was $100 bills.

Mrs. Talmadge was asked how she knew how much money was there when she grabbed that wad of $12,000 to $15,000 in 1974 after a dispute with Talmadge and a staff aide.

There was a small ripple of laughter in the room as Mrs. Talmadge answered, "By the SIZE."

The senator smiled thinly when Mrs. Talmadge said she once looked for money and the overcoat cache was gone. This was toward the end of their marriage when there was no communication between them. The money, she said, was moved to another hiding place. One committee member said, "and you couldn't find it?" Mrs. Talmadge added succinctly, "Nope."

One of the five charges against Talmadge is that he converted campaign contributions to his own use through a secret bank account. A former aide to Talmadge, Daniel Minchew, who has stated he was part of the scheme, earlier testified that he gave envelopes stuffed with $100 bills to Talmadge from a secret account. Talmadge has denied this and, in his testimony, called Minchew a "proven liar."

While Mrs. Talmadge's testimony contradicts Talmadge's often-repeated argument that most of his pocket money came from constituent gifts of $5 and $10 and $20 bills, she did not, on the other hand, corroborate Minchew's testimony with additional facts. Mrs. Talmadge said she did not know where the money came from. It often went "back and forth" between the Washington overcoat pocket and a dresser in their Lovejoy home, 35 miles outside of Atlanta.

Asked who transported it, Mrs. Talmadge, in a barely audible voice, said "the senator." A member of the committee asked her to repeat her response. "My former husband."

Her former husband seemed more than satisfied with Mrs. Talmadge's less-than-glowing remarks about Minchew, his chief accuser.

Asked "Do you have an objective opinion of Daniel Minchew in general?= Mrs. Talmadge shot back, "What do you mean by an objective opinion? . . . I did not like him, doesn't that answer your question?" She flatly denied Minchew's earlier allegations that he gave her money.

Asked if a dispute with Minchew did not precipitate a "rather violent argument" in the senator's office, Mrs. Talmadge said, "I slapped Mr. Minchew, if that's what you mean."

On the Hill, staff-spouse animosity is not unheard of, but in the latter days of her marriage, Mrs. Talmadge and Minchew carried it to extremes. She said he was interfering with her personal life and business affairs.

For years the Talmadges co-mingled their assets in a tangled web of complex financial holdings. It was brought out yesterday that Mrs. Talmadge's adjusted gross income in 1974 was $93,115. She had parlayed the Talmadge ham business into a $3-million venture before selling it in 1969.

Untangling all their property was part of the messy divorce battle. Mrs. Talmadge was the heavy loser when the Georgia Supreme Court ruled that she had to pay the senator three-quarters of a million dollars (less capital gains taxes). They upheld a rural jury's decision that Talmadge had not given her stock as a gift but for her to hold in trust for him.

Talmadge has acknowledged that he seldom generated any cash through his personal bank accounts and that his pocket money came from constituent gifts. Mrs. Talmadge's lawyer, Stell Huie, said yesterday that even at the time of the divorce proceedings Mrs. Talmadge did not know her husband was not writing checks to cash in order to finance those $100 bills that Mrs. Talmadge testified appeared in the overcoat pocket.

In the early days, the Talmadge marriage seemed happy enough. In 1948, as the 24-year-old wife of a well-known politician, "my heart was all aflutter," Mrs. Talmadge once recalled.

As a bride of 19, she said to the press, "I don't know a thing in the world about politics. Ask me about the home and children and maybe I can answer."

She grew into a shrewd business woman and shrewd political wife. She became friends with presidents and first ladies. Yesterday, she had just returned from Texas and a visit to Lady Bird Johnson, who has remained a close friend.

At the time of her divorce she charged her husband with "habitual intoxication." This spring, after a celebrated battle with the bottle at Long Beach Naval Regional Medical Center, Talmadge returned to the Senate.

When Mrs. Talmadge finished her testimony, there were no last looks at her husband, seated 12 feet away. She was ushered out of the mob scene of reporters by Capitol Hill police and two lawyers, looking stoically ahead, saying nothing to the many unanswered questions about his-and-her finances.

"All I want to do," she said, is to "put and end to this painful period of my life - and begin building a new one." CAPTION: Picture, Betty Talmadge; by James K.W. Atherton - The Washington Post