When John Edmonson, a 24-year-old Californian, came home from college for Christmas in 1978 his spirits were buoyed with the thoughts of gastronomical treats he was accustomed to enjoying, especially fresh-from-the-ocean seafood such as abalone, which he pried from the costal rocks himself while snorkeling. "I could tell lots of different species by their taste, and often could identify the waters they came from," Edmonson says with pride.

But the holiday euphoria was shattered in one terrifying instant when a drunken driver smashed broadside into Edmonson's car at high speed, completely wrecking the vehicle and inflicting multiple injuries on the young man, including near-fatal blows to his head that damaged vital nerves.

"Of course I was lucky to have lived," Edmonson says, "but the terrible shock was that I could neither taste nor smell anything."

Edmonson's loss of taste and smell is a development fairly common among those who sustain serious head injuries. But such accidents account for only a portion of the 2 million or so Americans who suffer from disorders of taste and smell. Those senses are influenced in their effectiveness by almost every bodily function, and hence they frequently got out of kilter.

But few physicians have devoted much attention to treatment of crippled senses of taste and smell. It's generally agreed that the nation's preeminent specialist in the field is Washington's Dr. Robert I. Henkin, director of the Center for Molecular Nutrition and Sensory Disorders at the Georgetown University Medical Center. Prior to his 1975 appointment as head of what is familiarly known as the "Taste and Smell Clinic," Henkin directed a National Institutes of Health agency that delt with taste and smell disorders among other things.

Henkin has treated more than 3,000 patients for the ailment Edmonson was suffering from. With his medical colleagues he handles 500 patients annually, the clinic's full capacity.

"He's the authority in this field," says one ear, nose and throat specialist. Another doctor, a general practitioner who refers patients to him, also cites Henkin as tops.

Henkin knew almost immediately what he was going to do for Edmonson. First came a battery of head-to-toe tests, including tests to determine smell and taste acuity. He promptly prescribed a zinc compound to make up for the deficiency in this trace metal often found among those suffering taste and smell dysfunctions.

The mechanics of smelling and tasting are reasonably well known, although some aspects are still being studied. Over-simplified, the temporal lobe of the brain is the part of the sensory system that handles taste and smell, that is, sorts out evidence of the two senses and sends the results on through the cranial system. But first, whatever is being tasted or smelled must come in contact with a sensor, such as a taste bud -- there are at least 1,000 of these, mainly on the tongue, but including other mouth and throat areas. In the case of smell, the "signal" is picked up, mainly in the nose, and then transmitted by the olfactory nerves to the temporal lobe's smell and taste center.

That center sorts out the signals and sends them on through the nerve system to a "slot" that, in effect, says, sweet, sour, pleasant or putrid.

The close relationship between taste and smell has been proved by examination of the two functions: both types of sensors are continually bathed in a protein-rich fluid. An important element in this fluid is zinc; if the fluid dries up, the patient experiences a zinc deficiency that throws the taste and smell functions out of order.

Henkin, who is an unusual combination of musician, physician and philosopher, insists that a smooth-working olfactory system, far from being a triviality, is an important factor in human experience.

"What I'm talking about is the quality of life," he says. "I think that the quality of life is not just keeping one alive. That is, preserving life, but how much better a person may feel if he has the use of his taste and smell senses even though they might not be quite as sharp as they were before."

Curing taste and smell trouble is relatively unknown to the public, for although the number of people afflicted is large, no one has died from such disorders. (There have been suggestions of suicides, however.) Henkin deplores the public's indifference. "I got into this field of taste and smell almost by accident," says. "But I've become a taste and smell buff.

"In medicine, preserving life is important. Most doctors do that. But there are many things they can do that are not lifesaving. The quality of life one can live is important, such as being able to enjoy living although one's sight or hearing are deficient. Why should one miss the joys those senses impart? There's no great difference in not being able to see or hear perfectly and not being able to taste or smell."

The physician is particularly aware of the increasing interest in the taste acuity of older people. "Food becomes increasingly interesting to them, often the main topic of conversation," he says.

Henkin agrees, indeed echoes some of the more trenchant observations of the great gastronome, Jean Anthelm Brillat -- Savarin in his Physiology of Taste. Brillat-Savarin wrote of the importance of the quality of life, with good food properly prepared ranking high on the list of factors that contribute to it.

"Gastronomical knowledge is necessary to every man," he wrote, "because it tends to add to the sum of his predestined pleasure." Brillat-Savarin goes on to say that a number of opinions have been broached about the way in which the sensation of taste functions, and then said his own personal one is that "this is a chemical operation which is accomplished . . . by moisture. That is to say, the sapid molecules [of the food] must be dissolved in no matter what kind of fluid so they may then be absorbed by the sensitive projections, buds or suckers which line the apparatus for tasting." He continues with the opinion that "The greatest service rendered by chemistry to alimentary science is the exact comprehension of osmazone," which he defines as "that preeminently sapid part of meat . . . that aqueous extract of meat containing those constituents that determine its taste and smell. Osmazone is responsible for the essence of good soups, the heart of the richest consommes, the savory tinge in sauces, the crisp coating on roasted meat, and it is the property that sends the gastronome to the second joint as the most tasty part of the fowl."

Zinc and also copper compounds are usually prescribed by Henkin for taste and smell disorders, but they are not sure-fire cures. He also sometimes prescribes a drug called cyclic-AMP, which he describes as one that amplifies the sense of smell.

He also has used placebos -- sugar pills with no active drug in them -- and some patients with smell and taste disorders go better on them. The number of recoveries in patients treated with placebos was sufficiently numerous to show that in some cases right thinking alone was enough to work cures.

But zinc remains the main weapon in Henkin's armamentarium. Zinc's efficacy was shown by Henkin and his colleagues in a double-blind test, a research exercise in which the research director was the only person who knew whether the pills given a patient were zinc, some other active substance or placebos. Since the person delivering the pills did not know what they contained, there was no possibility his manner could suggest to the patients whether they were receiving an effective remedy or not.

Though knowledge of Henkin's work is still relatively limited among general practitioners, his findings have turned up frequently in medical journals (more than 150 studies since 1956). His reputation caught the attention of general readers most notably in an article about his work written by Berton Rouche that appeared in the Sept. 12, 1977, New Yorker. Such publicity has resulted in many referrals of patients. Other patients, such as Edmonson, simply telephoned Henkin directly for an appointment after reading about him and his work.

Henkin had an unusual preparation for the specialty that now distinguishes him. A product of the University of California, he graduated with honors in music and was elected to Phi Beta Kappa. He went on to take his master's and doctorate in music at the same institution, and then became a professor of music at his alma mater.

Buriously, his parents were not musically inclined; in fact it was almost against their will that he followed his musical inclination. He pursued a successful career in music, composing songs for radio, screen and stage. Since he plays several instruments, he developed the custom of composing material on the same instrument that would be featured in the finished music. But Henkin had always been interested in science. When eventually he concluded that the Holloywood producers who were buying his music were mangling it when they used it, he abandoned his first career and entered medical school. Intership and residency followed.

As a physician, Henkin presents an engaging, informal bedside manner. Rather than a white gown, he frequently goes about his work with shirt sleeves rolled up. The affable physician, a young-looking 50, is beloved by his patients. I have interviewed many of them, and even among those who have experienced minimal cure results, praise for the doctor is lavish.

Taste and smell always fascinated him ("I became a taste-and-smell-buff"). The olfactory tests he has devised are said to be models of scientific research. And they are tremendously important to people who place taste and smell high on the list of things that make life worth living.

Some people lay little value on a well-developed sense of smell or a sharp sense of taste.I know those with dull noses especially who seem little bothered by their handicap. Not so John Edmonson. After four months of treatment with the zinc Dr. Henkin prescribed, he reported that he had improved slightly, and he looked toward continuing improvement. But the young Californian was still deeply troubled by what happened to him at the hands of the drunken driver. "I'm suing the driver of the car, but also the bartender who served him all those drinks, although he was not in the car with the drunk. But you know, I never would have brought the law suit if it hadn't been for my loss of taste and smell."

Edmonson's point of view may be extreme. However he says that he feels strongly that the loss of a limb, or eyesight, would be less of a handicap than loss of taste and smell.

"That loss is like someone closing a door on you. The psychological damage can't be measured in money. That's the reason I'm going on with the legal action."

Edmonson continued confident at that point that he had a chance to regain some of his taste and smell perception.Of course he did, although Henkin is careful never to guarantee anyone anything. And disappointments do occur with some patients. Take Jean Valjean (not his name), a highly skilled chef in an East Coast city who learned his trade in the Old Country, as one used to say. He came to the United States some 20 years ago and worked his way to the top of his profession. Then in a bad fall he fractured his skull in four places; the fractures were accompanied by nerve damage. As he began to mend, he found he had entirely lost his sense of smell though his tastebuds remained as acute as ever.

The chef returned to work. Nothing was said by his culinary colleagues in town about his smell dysfunction, although nearly everyone in the business knew about it.

"Inability to smell is a handicap," he admits. "I don't know if something on the stove is burning. However, that makes me more attentive and also even more careful than is usual about quantities in a recipe and time on the stove. And of course I taste even more frequently as I am going along than I did before the fall." (He doesn't mention the fact that smelling ingredients is one of the first things a chef does.) He has turned his handicap into a spur to excellence at the range through even more than usual attention to basics such as quantities and temperatures.

After a few months of progress, Valjean's condition deteriorated. Both he and Henkin continue hopeful that he will improve, and the doctor is now taking another tack with the treatment, Valjean confesses ruefully, he sees scant evidence that his sense of smell is returning.

Possessing a sharp sense of smell and taste is not only a matter of maintaining the quality of life; there are some quite practical aspects to be considered as well. One Henkin patient, a house painter who lost his sense of smell, had been accustomed to mixing solvents with his colors and judging the amount of each by the way it smelled. The painter was no different from a chemist who habitualy sniffs what he is concocting. When his sense of smell disappeared, he obviously was in trouble.

Happily for the painter he recovered.But at best the process of healing still is often long an tedious. The executive of a small bakery on Long Island who suffered a loss of smell lamented: "For two years I have been unable to enjoy the fruits of living." When the baker and I met, he had just gone through a battery of Henkin tests. Now he is reported to have improved materially.

Patients come to Henkin's clinic following a variety of calamities. A 6-year-old boy fell down the stairs and apparently damaged his head. In any event, the first indication he could no longer smell turned up no long afterward when his mother took him to a bakery and asked how he like the aroma. He said he couldn't smell anything.

A middle-aged woman experienced diminishment of her ability to taste and smell in the aftermath of major throat surgery that also crippled her ability to speak. Another middle-aged woman's olfactory problems were associated with epileptic seizures, and her problems increased following the death of a favorite grandson. Both of those patients have improved under Henkin's care.

Another case with what appears to have a happy ending is that of a young business executive who had a severe blow in his head in an auto accident. He lost all accuracy to his sense of smell and taste and began to find intolerable the aromas of ordinary foods being cooked by his wife. Not surprisingly this became the source of great family strain. The couple found it necessary, moreover, to decline all their dinner invitations. Now, after treatment, the executive is improving.

The case of Adolph Coniglio has had perhaps the most significant impact on the treatment of taste ad smell disorders. Coniglio owned and ran a pizzeria in a small New Jersey town. He was seemingly in good health when, about a decade ago, he came down with the flu. Influenza-like ailments frequently are the prelude to taste and smell disorders. A local doctor treated Coniglio, and when he was well he returned to his establishment. He was shocked to find that the standard ingredients of his pizza tasted dreadful. Equally bad, he said, was the fact that just about everything smelled like garbage. The stench was not confined to things around his restaurant; the same was true at home. He found his only surcease was to repair to a wooded section near his home where the odors were more neutral by comparison. But that didn't help when he injeted something foreign into the sylvan scene, such as cigarette smoke. That produced a stench he couldn't stand. The only things he could stand to eat were ice cream, fruit, plain potatoes and milk.

Coniglio's trouble continued. A series of doctors diagnosed the ailment variously and inaccurately as a tumor that required immediate surgery, which he declined, and purely mental.

Psychiatrists did nothing for him. Transquilizers were ineffective. So was other medication. Examination by doctors in Rome and Naples where his mother was vacationing were futile. Back home, Coniglio was beginning to believe the one doctor who thought he had some mental illness, but luckily another physician ruled out insanity.

Finally a doctor who could find nothing wrong with Coniglio said he knew of someone who probably could help: Dr. Robert I. Henkin. After Henkin gave Coniglio a brief taste test in New York, he told him that if Coniglio would come down to the National Institutes of Health and enter as a patient, the physician would try to find out what was wrong. At this point, Henkin believed he was dealing with a case of idiopathic hypogeusia, that is, a taste disorder of unknown origin, along with attendant disorders such as distorted sense of smell.

Coniglio was one of the first patients that Henkin studied in great detail at NIH, although he had earlier experiences that pointed to origins and possible cures for taste and smell disorders.

Such afflictions are fairly common. A head cold can be the cause for losing taste and smell to some extent. Fortunately such dysfunctions when the cold subsides. The same can be true with flu.Hepatitis and pregnancy also are common causes of taste and smell troubles, as are tumors, hypothyroidism and surgery.But most docotrs know so little about these malfunctions that they think the trouble is mental. More often it's metal. The human body as traces of many metals, among them zinc, that bear on taste and smell.

Coniglio's condition continued to improve for several months, then declined. The patient called Dr. Henkin, who immediately put him back on zinc -- unknown to him, he had been on placebos for months. But Dr. Henkin was dissatisfied with this blind test, and immediately instituted a double blind test in which neither the patient nor the doctor administering the portion would know what the patient was getting. This proved conclusively that zinc was the answer. Coniglio recovered. "My taste and smell was now 100 percent," he reported recently.

Edmonson sounded nearly as euphoric in a telephone conversation. I had with him not long ago in this California home. "I can now taste and smell 95 to 98 percent as well as I could before the accident," he said. "I'm coming to see Dr. Henkin again soon, a visit I had to delay because I broke a leg skiing." The driver of the car that struck Edmonson had no insurance or money, and a change in California law appeared to have relieved the bartender of liability. The bartender, however, agreed to settle the suit with Edmonson out of court.

"I've just put the unfortunate accident out of my mind," Edmonson said.