The National Geographic Society helped millions get through an eternity in the waiting rooms of doctors and dentists. Those smartly honed magazine articles and never-before-seen pictures deftly transported us deep into the cultures of far-away places.

Today, in the rapidly proliferating world of home videos, National Geographic still does it, bringing us its best efforts to watch at our convenience, in our homes. No dentist's treatments, just treats. Three new titles are being released this week to bring to 19 the number of National Geographic Videos available.

As sometimes happened with the magazine articles, you may feel initially that you're not very interested in the video's topic. But once you begin to watch, you become engrossed, informed and impressed. By the end of the reel, you find yourself trying to control an urge to engage someone in conversation on the subject of which you now consider yourself an authority.

The three releases due out Wednesday are "Egypt: Quest for Eternity," "Man-Eaters of India" and "Tropical Kingdom of Belize." All National Geographic Videos, promoted as undeniably collectable and attractively priced at $29.98 each, are available at many video shops and can be ordered directly from The Society by phone. (Washington-area residents: 921-1200. Others: 1-800-638-4077.) They are also on sale at Explorer's Hall in the National Geographic Building, 1145 17th St. NW, at a discounted price of $26.95.

Every three months three additional cassettes are released. Less than eight months ago "Secrets of the Titanic" was released as a special single and has become National Geographic's top-seller: 120,000 sold in less than seven months. When it aired on WTBS in March, "Titanic" shattered the all-time basic cable record with an 11.4 rating and 17 share. The three releases coming up in November are "Realm of the Alligator," "Among the Wild Chimpanzees" and "Jerusalem: Within These Walls." Many of these releases are by-products of the National Geographic "Explorer" cable series, which airs on WTBS where it is the highest-rated originally-produced non-sports program on basic cable.

Although most releases are about one hour long, "Egypt: Quest for Eternity" runs for 80 minutes as Eyptologists unravel and interpret the riddles of one of history's greatest civilizations. The viewer is treated to a fascinating look at the great temples of Luxor and Karnak, a trip on the Nile to see modern and ancient civilizations co-exist, and on to the Land of the Dead and into the colossal tombs of kings.

"Man-Eaters of India" is a docudrama produced by BBC and presented last November by National Geographic under the title "Man-Eaters of Kumaon." That was the title of Jim Corbett's book and the famous hunter's conversion to conservationist 60 years ago, long before the idea of preserving tigers or any species was in vogue. His switch from rifle to primitive movie camera is captivating. He once took 4 1/2 months to carve out and bait a "studio" in the jungle so he could be the first to capture the tiger on film. "Taking a picture is far more pleasure than acquiring a trophy," he wrote. Corbett is credited with saving the tiger population of India, and his work led to India's first tiger reserve, named in his honor.

"Tropical Kingdom of Belize" is simply a delightful hour's pause. In this small Caribbean nation no bigger than Massachusetts, water touches everything. Not a single person is visible in any of the scenic footage. The lone touch of humanity is the graceful narration of E.G. Marshall. To follow the water from the mountain tops, down cascading falls to lush rain forests (where as much as 30 inches of rain can fall in three days) and lagoons and on to the world's second longest reef (175 miles) is another of those stunning treats that only National Geographic can deliver.

Here is a complete list of National Geographic's video library of adventure:

The Sharks

Land of the Tiger

Iceland River Challenge

Gorilla

Incredible Human Machine

Yukon Passage

African Wildlife

Save the Panda

Atocha: Quest for Treasure

Born of Fire

Rain Forest

The Great Whales

Miniature Miracle: The Computer Chip

Creatures of the Namib Desert

Polar Bear Alert

Secrets of the Titanic

Egypt: Quest for Eternity

Man-Eaters of India

Tropical Kingdom of Belize