Only when talk got around to something called aflatoxin did Rosalynn Carter begin to get the drift. Until then, she said Romania's First Lady Elena Ciausescu clearly had the edge on scientific subjects.

Aflatoxin - a disease affecting peanuts - Mrs. Carter told luncheon guests yesterday, was something she knew quite a bit about, being the wife of a former peanut farmer who had scrutinized many a peanut for signs of it.

The lunch, at the Smithsonian's Museum of History and Techonology, honored Elena Ceausescu, a distinguished academician who is director of Romania's Institute of Chemical Research, a member of the National Council of Science, Academy of Science and on the Communist Party's central and executive committees.

Drawing heavily from the scientific community for her guest list, Mrs. Carter told the group that "public awareness of science and technology was heightened with the space age."

It was, in fact, a chemist - james Smithson - who had donated his legacy to the United States for what later became the Smithsonian Institution, the Smithsonian's Undersecretary-elect Michael Collins told Chemist Ceausescu.

In unscheduled remarks of her own. [TEXT OMITTED FROM SOURCE] following a luncheon of Senegalese soup, sole Veronique, asparagus and strawberries cardinale, Elena Ceausescu called for collaboration between American and Romanian scientists.

"I would suggest that all efforts be dedicated to man and not to destroying mankind," she said through an interpreter.

Guests later toured two exhibits, the Atom Smasher and Art and Science.