FOR SEVERAL days, in temperatures well over 90 degrees in dusty pink-walled Marrakesh and hilly Fez, I had been surprised - no, amazed - by an herbal-sweet fragrance exuded by the native Moroccans I'd met in the casbahs and medinas, the museums and mederas, the hotels and restaurants and bars. I and other sweating tourist were hard put to stay "fresh" in the unprecedented heat.

Was it the Moroccans' calm, their seeming refusal to be plagued by those everyday anxieties that bother most American? No. For the Moroccans are a volatile and voluble people, despite their outwardly serene appearance. But I had been intrigued by the scent, light but detectable, that so many Moroccans - men and women alike - I had passed closely or spoken to seemed to carry with them . . .

Some people collect postcards of every city they visit while they are traveling and I am no exception. But recently I have begun to collect something else: a sample or two, here and there, of the local colognes or essences - none of them Paris-imported or costly - of the countries I am in. Most of the scents that I buy I don't "wear" (I wouldn't dare, in many instance - except sometimes for a tiny drop on the back of the hand to carry with me to work and appreciate through the day). But then that is, for me, not their purpose; their purpose is only to be, yes, "sniffed" for a moment when I want to remember.

On my return to New York, the unstoppering of a plain and simply labeled bottle can immediately return me to the Auvergne in Southern France, to Parma in Italy, to Yugoslavia's Dubrovnik or Korcula or Hvar, in a way that no postcard or color slide or other souvenir can. Now I was on the scent of something which, to me, meant Morocco.

I had smelled the "something" again, on the bus ride from Fez to Meknes early that afternoon, and was determined to discover at last what it was. It was not overly flowery. It wasn't fully herbal. It wasn't musky. And, it wasn't strong. Earlier on, I had half believed it might be the herbs that are sold in shops in the medinas of all Moroccan cities and towns - or even the myrtle or thyme or rosemary, themselves, as they grew in certain parks and around mosques and other holy places. The elerly guide at Marakesh's 16th-century Saadiah Tombs had plucked a sprig (was it rosemary?) from a shrub near the Chamber of the Twelve Columns and pressed it into my hand, indicating I should breathe its fragrance . . .

By now, in Meknes, I had visited the mosque and mausoleum of Moulay Ismail - the only Moroccan mosque inside which a non-Moslem may venture - and my three-hour tour of the "Berber City" was ending. I asked my young guide, Hassan, in French: "Can you tell me what is the most common native cologne or perfume in Morocco something - perhaps relatively inexpensive - that both men and women use? Probably it's something made from a flower or herb grown here in Morocco."

Hassan an atypically quiet guide and about 15 years old, thought before he answered. "It may be za . . . I'm not certain."

"Za . . ." I repeated. Then I remembered a sort of aspiration as he had said the word. More like "Z-ha."

He explained that z-ha could be bought in large economy-sized nottles in any marketplace: from these it was sprinkled about Moroccan homes.

"But they must wear it, too. I'm almost positive," I reminded him.

"Probably they wear a concentrate," he suggested.

The huge El-Mansour Gate with its ogival horseshoe-shaped archway, rose near where we were standing, the main entrance to the medina. Hassan led me back to a hole-in-the-wall-sized perfumer's shop. I saw some tall, heavy glass bottles of the crystal-clear liquid of whose concentrate I wanted a sample, and knew at once that I couldn't carry a container of this larger, more diluted version with me. My luggage already contained geodes and other semiprecious rocks purchased from Berbers in the Atlas range east of Marrakesh; two engraved metal wall plates of hopefully good quality brass purchased in Fez, no eighth an inch on them left unetched; and the typical-of-Meknes black iron vase with Arabic decor and script baked on its sides in silver, which I'd bought a half-hour before.

Having no concentrate of z-ha, the white-haired perfumer suggested some Jasmin Arouss, which I purchased.

Late that afternoon, I returned to Fez along with a busload of both Western and djellabah-clad Moslems who - if I wasn't smelling some plant that lined the road or covered the gentle hills betweeen the two neighbor cities - were once more faintly giving off the no-longer-mysterious z-ha scent. Two hour later a parfumiere in the "New City" of Fez, where my hotel was located, assured me that she could locate some z-ha concentrate but not until late the next morning. I would have left for Tangier by then, I told her sadly.

Near the Grand Socco, or "big marketplace," in Old Tangier the next afternoon, after visiting the Mendoubia Garden, I bought a bar of soap. "Is it Moroccan-made?" I asked, and the storekeeper nodded.

I inquired if there were a perfumer's nearby. In the medina, Rue Sebou, not far from the Petit Socco - and near my hotel. The Mamora, within the medina's walls - I would find one, he told me.

Following his directions, through the narrow and colourful streets of the Tangier median (better paved but far less exotic and native than the winding up-and-down ones of Fez or the dusty thatched-shaded ones of Marrakesh). I was directed by a rugmaker: "Just ahead, on the right."

It was a tiny shop, fully open on the alley way that bore the name "rue," and not more than six feet from floor to ceiling. Two stools sat before a perhaps five-foot-long counter, crowded with bottles of perfumes, colognes, essences. Two shelves filled the three side and back walls and held large, square, glass-stoppered container of the heavier - and headier - concentrates.

Greeting me graciously, the storekeeper and a friend of his who occupied one of the stools were in no hurry to make me buy. We talked of Morocco and American and Tangier before the perfumer finally began to daub the palms and backs of my hands - and eventuallly, for lack of space, my wrists - with nearly every exotic fragrance he sold: tuberose, sandalwood, lemon, jasmine . . . As my nose grew inured to distinction, I opted for what I'd originally come for: z-ha. He had it in abundance, in both heavy and light concentrates. (The word, which I had not properly understood at Meknes, was spelled "azahar" on the bottles' label.) He explained, to my surprise, that it was an orange-blossom scent.

With purchases that cost me less than $2, I returned to my hotel.

As I walked, I could not help recalling:

First, Le Puy, in the southwestern Auvergne, with its bastionlike romanesque cathedral, its red statue of Notre Dame de France atop the Rocher Corneille, and its impossibly perched Saint-Michel Church on the immense "stalagmite" that is called Mont Aiguilhe. In a shop on the Boulevard Sain-Louis, in 1976, I purchased, for nine francs, a bottle of Verveine, or verbena. A mere dab on the back of my hand still brings back southern France.

Second, Parma in Italy and its Duomo - in the so-called Centro Episcopale with the famous Baptistry and San Giovanni's Church. In an antechamber to the cathedral, in 1972, I'd bought several needlelike bootles of green-tinted Parma Violet for myself and friends.That charming city of Napoleon's Marie-Louise, whose famous portrait hangs among the museum's vast collection of Correggios, returns in the instant when I un-stopper one of those (remaining) bottles.

Third, Hvar (on an island of the same name) and Korcula (likewise) and Dubrovnik, along Yugoslavia's Venice-haunted Adriatic coastline, with gaunt and bare-topped limestone mountains towering above the most vividly blue-green waters I had yet encountered. On that excursion in 1974, I'd seen the plant growing first, lavender on the lower hillside and in the valleys. Black-dressed matrons in their middle or final years sold an essence of it in little rubber-topped vials at street corners; they doubtless made it themselves. I bought some in each of the three cities, and still can conjure up Dalamatia with it.

And I can't neglect essence-memories of Paris and Madrid. When I think of the Spanish capital I recall the Myrurgia bought for a girfriend. When I think of Paris it is of the scents of Chanel, Joy, and or myself, Monsieur de Givenchy and Paco Rabanne. But these are not the simple smells that "mean" a country. (Perhaps because Paris and Madrid are, indeed not as "simple" as the enchanting nations they rule?)

My boat left Tangier the following, sunny-cool morning for Algecircas. From the ship's stern, I looked back sadly at the city's gleaming,, chalk-white medina climbing the hill to its Casbah - outpost of the continent I was leaving. But I had many photographs, postcaard, and souvenirs of that first African nation to recognize the new United States of America, some 180-odd years before. What's more, I had something else.

Thinking of it at that instant, I pulled out of my coat pocket one of the minuscule bottle of azahar, and inhaled. Suddenly the thought passed through my mind that, now, I knew at last what Shakespeare meant by "all the perfumes of Arabia . . ."