Dr. Nathan ("Call me Nate") Steinberg invents drugs for a living. "By his smell, you can tell, he's a chemist," he says and dissolves into giggles. "A good chemist will always have a nice explosion," he adds. "I'm full of jokes."

Steinberg, a research chemist for Merck Sharpe & Dohme in Rahway, is starring in the New Jersey program of the 1983 American Folklife Festival, this weekend and next on the Mall. The Smithsonian Institution has asked him down to share some occupational folklore from New Jersey's pharmaceutical workers.

William Craton (Tex) Guthrie is a retired airline pilot who started in 36-horsepower, single-engine biplanes. "As far as the general public was concerned in 1932," he recalls, "there was no future in airplanes. What good were they except to break your neck with?" Guthrie is part of the celebration's Folklife of Flight program.

Add the French/French-American program -- with familiar French themes such as cheesemaking and grapevine-grafting, and such American variations as Cajun cooking -- and you've got a good handle on the folklife festival: flying, New Jersey and France, oh my! Not to mention the chain-saw bears.

This extravaganza -- the Smithsonian's 17th celebration of folk life, art, craft and cuisine -- boasts doings night and day on the Mall and environs. It runs this Friday through Sunday, and from next Thursday, June 30th, till Monday, July 4th, with a savory selection of sights, sounds and smells.

Daytime events -- music, panel discussions and demonstrations, such as carving log sculptures of bears with chainsaws (a tradition among certain French-surnamed citizens of Maine) -- are scheduled from 11 to 5:30 outside the museums of American History and Natural History, at 14th Street and Madison Drive NW.

Starting at 7 on weekend nights, the festivities will move to the Sylvan Theater for performances of music from New Jersey and France: gospel, fiddle-playing and blues from Jersey -- as in the concert this Friday night -- and harmonica and guitar tunes under the felicitous influence of France. There'll be pre-concert dancing on one of the festival stages.

There'll also be plenty to eat: deep-sea clam strips, crabcake sandwiches, fresh Jersey tomato salad, chocolate croissants, chicken-and-shrimp creole, quiche, crawdads and more. And this weekend only, 16 of the craftsmen and musicians appearing on the Mall will be Smithsonian National Heritage Fellows, each the lucky winner of a $5,000 prize.

New Jersey highlights include a group of gospel-singing oyster-shuckers, silk-weavers and loom- fixers, crops from asparagus to zucchini on display in potted rows, and five ethnic celebrations from Italian to Japanese.

The French-inspired program features lacemakers and stonecutters, Cree and Chippewa Indians putting their French feet forward -- the Turtle Mountain Dancers will do the Red River Jig -- tall tales from lumberjacks and the making of pork-and-beef pie.

Highlights of Flight include a display of aviation memorabilia; pilots showing how they train on a cockpit mockup; and flight attendants, mechanics and other stalwarts swapping stories of the wild blue yonder. Restoration experts will meanwhile work on a 1912 Wiseman-Cooke biplane, with two hot-air balloons tethered nearby.

If this all sounds variously fun, tasty and edifying, some of you might still be wondering what Flight, New Jersey and France have to do with one another. The Smithsonian, it happens, says the three share quite a bit.

"It's the 200th anniversary of aviation, and it's also the 200th anniversary of the Treaty of Paris," says the Smithsonian's Peter Seitel. "The first manned flight was by two Frenchmen in the Montgolfier brothers' balloon in 1783. And the Treaty of Paris, which ended the Revolutionary War, was ratified in Princeton, New Jersey." icVoila!

In the meantime, here are two further matters you might consider: a Francophile's guide to Washington and revelations of cherished Garden State secrets, both by Anne Oman.