An N. C. Wyeth cowpoke and mount, punctiliously arrayed in period gear, pause on a winter's morning; the sun hangs above the frigid mesa like a snowball. The man extends a white envelope toward a rustic mailbox labeled Cream of Wheat. "Where the Mail Goes, Cream of Wheat Goes," is the legend. The reader blinks.

Elsewhere, a perfect dimestore Indian lashes a crate of Kellogg's Toasted Corn Flakes to the back of a mule before a flawless pueblo -- the scene underscored by the slogan, "Known Everywhere -- Sold Everywhere -- Used Everywhere."

Both illustrations are hypnotic. Both are geared to children, or the child within: that primitive realm of the psyche where everyone reaches for a cookie or flicks his tongue mindlessly like a lizard.

The use of art in advertising, which came to prominence after the invention of color lithography in 1827, quickly supplanted the printed word and began to invade the area of the unconscious most dear to the consumer: his dream life. This encroachment was a trick that commercial advertising learned from medicine shows, in which entertainment was bracketed by sales spiels, and the slackjawed vulnerability of suspended disbelief was harpooned before the moment could pass. The gains of such hucksterism can be measured today in the success of its progeny -- radio and television advertising. But this "colonization" of our unconscious, as futurist Sam Love dubs it, began nationally in magazines such as The Ladies Home Journal, Woman's Home Companion, Good Housekeeping and The Youth's Companion.

There the roots of contemporary advertising were struck deep. There the art of promulgating restlessness and dissatisfaction in consumerism was stropped razor-keen.

The women's magazines filled a void, easing loneliness and boredom; their stories spun a globe of fantastic voyage, impossible romance. No subscriber could aspire to such adventure -- tickets to Paris or the Barbary Coast were dear. But in the narrative of pictorial advertising, there was possibility: Buy the product, become the character. A charwoman in Staten Island could use Palmolive shampoo and become the Egyptian princess in the McMein illustration. A housewife in Duluth could purchase Fleischmann's yeast and produce children as ruddy as those in the Rockwell ad. A ranch woman in Winnemucca could use Mavis cosmetics and expect orgasms to flow like the rainbow swirls in Packer's Art Nouveau. If the subscriber refused, uneasiness set in -- the restlessness and dissatisfaction of corporate intention. The choice modern advertising offered was this: Buy the product or don't fantasize.

The higher the quality of art, the sharper were advertising's barbs. And these illustrations often were high art. Great sums were paid to artists such as Norman Rockwell, N. C. Wyeth and Maxfield Parrish, who produced full-page color ads that today are collector's items. Lesser known artists such as Coles Phillips also fared admirably, creating in effect a new art form in mass media. The Europeans -- Henri de Toulouse-Lautrec, Pierre Bonnard and friends -- had brought high art to poster advertising, but the American touch was something special. Coles Phillips rendered the Willys Overland a chariot of the empyrean, and the woman who drove it his "fadeaway girl." Phillips' use of beautiful models, Art Deco furnishings and sophisticated dream sets created a magic in his illustrations of unqualified swank.

Earnestine G. Miller, a Washington communications specialist, owns hundreds of full-page color advertisments like these, some of which were reproduced in her recent book The Art of Advertising (St. Martin's Press).

"They are paradigms of successful advertising," Miller explains. "Classics of the art." What Miller finds paradigmatic in the advertisments is their picture magic. To achieve this, illustrations created an "instantaneous impression from purely visual apperance" to communicate "desirability and identification to the consumer." What Miller neglects to pinpoint in her exgesis of technique is the insidiousness with which advertisers introduced art to hucksterism. This lamentable ploy created cheerfully crafted artifacts, but established in America's dream life a beachhead for commerce, whcih was hardly worth the price.

Few of the early illustrators are remembered. Their ads are unsigned; their influence lies in their effect upon graphic design and upon consumerism in America. Some are masterpieces of pure design, stylish as anything in Pop Art -- such as the 1921 as for Wesson Oil showing a thin stream of vegetable oil pouring toward a frying pan, with two testicular-looking eggs in the foreground. Sexuality for the subliminal hook is now expected by consumers, but in 1921 was not. A Wolfhead underwear ad in a 1919 Ladies' Home Journal, with flesh showing between slip and stocking, was outrageous for its day. And effective. What a short distance from Wolfhead to Maidenform Bra, with barley a skip to Calvin Klein.

The heritage of early illustrators is in the picture magic of contemporary ads such as those for Schlitz beer, Marlboro cigarettes and the Weyerhaeuser Company. These ads, with their explosive, imaginative clout, continue to invade that area of the brain that art lays open like an oyster shell. Their narrative quality and ingenuousness has translated easily to network television, the advertising medium of today, and will no doubt flourish on cable and video disc. But despite the early artist's reluctance to sell his audience down the river, an innocence has been tapped, a confidence betrayed.

"There's an element in this period of advertising which has been lost," Miller says. "Ads today are less literate, and created for immediate effect. People had time to dream then; one's monthly periodical was a special event. It was lingered over. There's nostalgia for these ads for the period they evoke. And for their campiness. The Fairy soap ads with their slogan, 'Have You a Little Fairy in Your Home?" are quite popular with male homosexuals. A Coles Phillips illustration recently sold in New York for $4,500. The quality of work like Phillips' and others has no equivalent today. There are very few illustrations in contemporary advertising, though I'm happy to see more of late used in fashion ads. Practically everything's photography."

One would like to think illustrators abandoned advertising, not vice versa, and that some moral stand was taken. This seems unlikely. Photography and video tape simply overwhelmed the industry. If tasteful illustrations linger, such as the advertising posters of Lou Stovall and Lloyd McNeil, they are innocuous beside their elder bretheren. The baton has been passed. Contemporary advertising is in the hands of technicians, no less deceptive for lessons they learned at the knee of high art.