AS DOCTORS stand at the great door of advertising and knock. I assume it will open to them, but there is no reason to expect any decline of standards in the profession or any increase of quackery.

There is, unfortunately, a good bit of cynicism among jobbernowls, yarpslathers and all that ilk who are quick to think the worst of learned men.

Honest misunderstanding also accounts for much prejudice against the healing profession. As it happens, some of us have given much thought to these matters for many years and can therefore light flambeaux in dark corners, so to speak. So before getting on to Evelyn Zlotnick's hair dryer, which you will certainly wish to know about, it will be well to summarize the art of medicine, which can be done briefly:

Now many people smile at old remedies for plague, and a couple of doctors in my family never weary of saying that medicine now, for the first time, is truly scientific.

In the past, it was "just magic."

My great-great-grandfather, a doctor, cured many with violet leaves. Dr. Zion Zebulon Mitchell his name was and, as you can well imagine, there was no nonsense about him and few if any ever presumed to trifle with him.

And he cured them far and wide with violet leaves.

Well, they say now there is nothing in violet leaves to cure anybody of anything, but of course Zion Zebulon is not here to prescribe them, and that may make a difference.

Sometimes I have tried violet leaves myself, but with all deference to the past I have felt foolish rather than better. Nor do I think it did any good at all to hug an oak tree half an hour a day, as Chancellor Bishmarck did.

I have done that too - never mind the risks of ridicule - but unlike Bishmarck, derived no sudden radiance from the exercise.

Please understand, I am not suggesting a return to "natural" remedies, since nature and natural causes is what makes men sick in the first place. Rather I am sharing an important understanding of medicinal cures through the ages because an informed patient is a better patient, and more likely to pull through.

Sassafras no longer cures syphilis though it was the first cash crop of the Virginia colony and once cured thousands in London, where is was urgently shipped. In the early 1600s you could drop in for a cup of sassafras tea, like martinis nowadays, and everyone liked that.

But then it was discovered this cured syphilis and people stopped drinking it. They did not want anyone to think.

Then for a while tobacco was a fine cure, but now nobody smokes for his health's sake.

Mistletoe, so much in our thoughts during Christmas, used to cure people. For epilepsy, barrenness in women, rabies and toothache it was indicated.

But now they say mistletoe is poisonous. There you are.

How is it possible, the innocent wonder, that old cures no longer work? How does it happen that some swear by weed and berries, while others require nothing of a medicine except that it never leave its native test tube?

My experience shows that sometimes some things work and sometimes some things do not. This is an important concept, and without it no progress will be made in understanding medicine.

When you think of all the stuff men have swallowed over the centuries to cure them of what ails them, Lord!

To me it is a touching thing, and I do not much like to hear anyone sneer at mistletoe berries or penicillin and so on, because it shows a contempt for the human condition, and makes fun of the deep and pure desire for health.

Now think of this: We know that diseases vary in virulence. Flu, for instance, may be a nuisance or it may be a wholesale killer. This disease varies in its rage, for reasons we are not sure of.

Is it not reasonable to suppose, then, that magic bullets, in a manner of speaking, also vary in their target effectiveness?

Sassafras may not cure anybody now, but undoubtedly it once did.

And before anybody mocks ancient wonder drugs, let him reflect on some of the diseases that were once common, but now unknown.

Men used to fear the marthambles, the wambling trot, the strong fives, the moon-pall and the hockogrockle. Where are they now?

Cured by the miracle of medicine. Done in by violet leaves, as you might say.

(We are indebted to such good writers and researchers as Edith Sitwell and John Moore for the names of these former scourages, to give due credit.)

No man now says, "I have a touch of the hockogrockle," because long ago it was wiped out by a bit of vervain and mistletoe, and the appropriate treatment of their day.

As you know, mistletoe is properly gathered on the sixth day of the full moon, cut with a golden scythe. Tomorrow night is, by my reckoning, the right time.

Once I climbed trees to collect mistletoe to sell, and once I fell 40 feet from a tree into a bayou. I was not hurt at all. This good fortune (like the bad fortune of the fall to begin with) I attribute to the power of the mistletoe which made the entire trip with me.

Listen, mistletoe was really mistletoe in those days. Thick as your wrist.

A whole jeepload of it brought only $10, and jeeps then had no tops so it was a vast lot of it. But then those who purvey magical or sacred things often find the market is none too brisk.

But to get on:

What will happen to today's magical cures, the great gifts of our researches and pharmaceuticists, after our current diseases go the way of the marthambles and the strong fives? When our diseases are vanquished, what will become of the great medicines of today?

The useless cures of yesterday-violets through mistletoes-at least still have their charm.

But then no man can foresee tomorrow's world, or what people will think is splendid then. They may well kiss, in that future, beneath the mycins and the cortisones.

But what I thought you would want to know was the interesting use that Evelyn Zlotnick, the Washington hostess, has devised for her hair dryer.

In Peking she got fond of Peking duck, and learned to cook expertly. But you rub various damp things on the duck and have to wait for it to dry before getting on with the next step. One day, waiting for the ducks to dry right here on Mass. Ave., she tried the hair dryer. Perfect.

No kitchen, she now thinks, is complete without one.