The contrast of tiny bodies walking along the high corridors of our national art collection looking with some wonder at huge painted canvases, necks craned, hands stretched pointing, is enough to make the average gallery-goer turn away from the pictures and stare at the group itself. For Gilen Kinyon, one of the gallery lecturers, it is a daily occurrence. She has stopped her latest group of six-year-olds in the Dutch portrait room to settle them into the gallery. “We don’t,” she begins to tell them, “have studded animals or dinosaurs or wax works or even buttons to press.” She pauses. “We only have pictures.”

The National Gallery education programme began in 1976. The philosophy for primary children has always been to learn through play. Anthea Pippin, the gallery’s education officer, notes how the responses of primary children are surprisingly fresh and rewarding. Unburdened by the baggage of cultural knowledge and themselves more prolific artists than the average gallery-goer (what primary child does not paint?), the gallery is a more natural environment than might first be expected.

“At this age,” she say, “paintings are fun. It’s not about facts. Rather, they’re developing a visual literacy. They are learning that looking at pictures in this way is normal. And they are learning through play. Playing with ideas, using their imagination”.

In the programme, pupils are shown pictures from the nation’s collection. They are introduced to paintings not with the aggrandising adjectives of art critics or even the facts of art history, each image instead becomes a world of knowledge and a living picture. Like the scene in Mary Poppins where Mary and her wards leap into the pavement pictures of Burt the sweeper, the children, aided by the lecturer’s stream of questions, enter the painting through a leap of imagination - becoming absorbed by the scene and the characters involved.

In the Dutch genre room, Gilen Kinyon continues to give her lecture to Year 1 of Coleridge Primary School. “What sort of pictures do we have?” she asks.

“Old pictures,” responds a serious five-year-old after glancing around the room.

“And we mustn’t touch them.” says Gilen.“Why not?” “Because they might smudge,” comes the reply.

In the ensuing hour the children are taken to three pictures. Despite their instructions not to point, their response to the great canvases cannot be contained: arms shoot up, looks of surprise or horror - they have seen their first Tiepolo and Rubens.

They laugh at the huge dresses of the 18th-century women in Thomas Lawrence portraits and are shocked silent when they pass Veronese’s “Allegories of Love”; battle scenes, torture scenes, scenes of the great myths prompt different responses; some children name familiar characters in the Nativity scene. They are all immediately fascinated, but as Anthea Pippin says: “We give them no more than an hour - we want them to leave hungry.”

That these huge gilt-framed pictures on the walls belong to them has already been explained amid much delighted laughter. (“So who do they belong to?” Gilen Kinyon had asked. “They belong to Kareen. In fact, Kareen and Emma own the paintings at the National Gallery. And they share them with Jacob.”) It is an ownership disputed by those gallery-goers who write to complain that they cannot reach their favourite paintings because of the volume of children. These dissatisfied customers of art have even been known to stand in the middle of a group of primary children in order to get close to their favourite. That art is still sacred to many people is illustrated by letters of complaint from visitors to the gallery: what, they ask, can a child so young learn from the visit?

The children from Coleridge primary were learning about mini-beasts - insects and small animals. Taken through the gallery into the Sackler Room, they were stopped them in front of a rural scene: a field, a stream, in the stream a horse wagon - Constable’s “Haywain”. Never once mentioning the name of the artist, they are invited to join the characters in the scene and examine the detail, Gilen Kinyon encouraging them with “put your eyes in”. Ducks, birds, butterflies, dogs emerge, a discussion starts about the farming activity in the picture.

She asks what might happen next in the picture? Why are there no tractors? What lies beneath the stream we can’t see? Who are your favourite characters? If you were painting it, how would you colour the field? Will it rain? How will the wagon be rescued?

Again, in front of Cranach’s “Venus and Cupid”, the children are encouraged to observe detail and respond to many varied aspects of the picture - not least to laugh at the oddity of Venus dressed in only a hat and necklace. A discussion of anatomy follows. Who is Cupid? Can you see the bees which have stung Cupid? Someone tell me about a honeycomb. Where would you be in this scene if you could enter it?

Each visiting class has an individual picture itinerary. Merrow Church of England School, for example, whose termly topic was weather, were taken to see Rousseau’s “Tropical Storm with Tiger”. Imitating the noises depicted in the picture - the sound of thunder and rain, the roar of the Tiger - as well as discussing the tropical vegetation of the scene (and prompting anecdotes from the children about Tigers), is all part of the spontaneity and stimulation of a lecture.

Perhaps more than anything, such visits stretch a child’s imagination and invoke a sense of history. The contrast of familiar contemporary references with alien historical ones prompted basic yet fascinating questions: why didn’t Gainsborough use a camera to record his daughters? Would a modern Botticelli have painted Venus like Pamela Anderson? Why can’t Cranach’s Cupid steal his honey from the fridge or buy it from the supermarket?

Anthea Pippin is firm in the belief that being present in gallery itself is an experience. Coping with the public there, when often the children become more of a spectacle than the pictures, is a daunting experience. And if the children come away as interested in the guard-rails as they are in the paintings, it has been just as successful.

She also believes that it is as good for the children to be there as it is for the adult visitors to see them there: the nation’s art, after all, belongs to the nation’s children.

* The National Gallery’s education department offers talks on any aspect of the collection, for both primary and secondary groups.

Each talk is prepared according to the age and requirements of the individual group, and special needs groups are welcomed. Specific themes can be requested and there is no booking fee.

The minimum number for a booked group is 10, the maximum 60. Bookings should be made by the teacher in charge: telephone the education officer in the education department, 0171 747 2424