Dr. Lawrence A. Norton, 78; specialized in dermatology

"He said, 'I want to know more about one thing than anybody in the world, rather than referring people to other doctors,' " said his wife, Mary.

That one thing was nails, and along with his practice in Wellesley Hills, Dr. Norton shared his expertise nationally and internationally through newspapers and magazines, debunking myths and offering precise advice to those who wanted strong, long fingernails.

Dr. Norton, who had been putting the finishing touches on a history he wrote of the Dedham Country and Polo Club, died May 13 in Newton-Wellesley Hospital after suffering cardiac arrest while golfing. He was 78 and had lived in Dedham for 38 years.

For those impatient with how slowly nails grow, Dr. Norton noted that active fingers hasten the process.

"Any movement that lightly jars the fingertips, such as playing the piano or typing, stimulates the nail matrix to generate new cells," he told McCall's magazine in the mid-1990s.

Weather is a factor, too, he said, and don't be surprised to glance at your hand and see manicured nails growing in an uneven pattern.

"There are differences from finger to finger," he told The New York Times in 1988. "The middle and fourth finger tend to grow a little faster than the fifth and the thumb. That's a Trivial Pursuit question, believe it or not."

Also, he told the Times, "nails grow faster in the summer, some research indicates, while winter and a cold environment tend to slow nail growth."

Along with running his practice in Wellesley Hills for 27 years, Dr. Norton was a clinical professor of dermatology at Boston University School of Medicine. He had served as vice president for the American Academy of Dermatology and the American Dermatological Association, and was permanent secretary of the Atlantic Dermatological Conference.

In 1998, the year he retired, the Dermatology Foundation, a nonprofit based in Evanston, Ill., presented Dr. Norton with its Clark W. Finnerud Award, which is given to a dermatologist who "skillfully blends clinical practice with writing and teaching dermatology and thereby serves as a mentor and role model."

Of course, some teaching was as simple as using scientific fact to ease the minds of those who cling to the eerie tales of fingernails continuing to grow after death.

"That is an optical illusion," he told the Times in 1988. "Tissues around the nail tend to shrink away from the hard nail after death, giving the impression of something still growing."

Dr. Norton grew up in West Orange, N.J., and in 1948 graduated from the Hotchkiss School, a private boarding school in Lakeville, Conn. After graduating from Yale University in 1952, he went to New York Medical College in Valhalla, N.Y., where he received a medical degree in 1956.

While in medical school, he was ready to play tennis with friends one day, but they needed a fourth for doubles. An acquaintance invited Mary Holland, who also grew up in West Orange. "Somebody up in heaven told me this was the right thing," she said.

The Nortons married in 1954; and then he served for two years as a captain in the Air Force, stationed at Hanscom Air Force Base.

For several years in the early 1960s, Dr. Norton had a general practice in Mendham, N.J., before resuming studies at Boston University School of Medicine to specialize in dermatology. In 1971, the family moved to Dedham, and he opened a dermatology practice in Wellesley Hills.

Now and then, he would shake his head at his profession and those who elevated the scientific aspects above all else.

"One of the things he said to me several times in my adult life, was that medicine was not a science, it was an art," said his son Sam of Miami. "The old school of medicine was that you needed to know your patient better than you knew the medical science."

Even as a specialist, Dr. Norton brought the sensibility of his early years as a physician to the care of patients.

"He started his career as a general practitioner in a small town in New Jersey," Sam said. "Part of his whole approach at that time was to get to know the whole family - from grandfather to father to son - because that gave him a much clearer picture of how to treat the patient."

That interest in more than just surface information extended beyond the office.

"He never wanted to be the center of attention," said his son Larry of Fairfield, Conn. "He always was interested in other people and was great at getting to know people and having them tell others about themselves. He asked a lot of great questions and made other people feel like they were the most important person in the room."

He added that his father "always had a great touch with people, whether it was in his profession or in the church or with his family. He was a doctor and had that bedside manner that people loved, and that was his whole being, that was how he treated people in general."

Dr. Norton, a member of the vestry at St. Paul's Episcopal Church in Dedham, began family meals on holidays or for important gatherings by saying grace.

"The grace that he inevitably said was very simple, 'Give us grateful hearts, oh Lord, for all our blessings, and help us to be mindful of the needs of others,' " Sam said. "And that's how he lived his life, being mindful of the needs of others and thankful for his blessings."

In addition to his wife and two sons, Dr. Norton leaves a daughter, Anne Norton Groves of Denver, and six grandchildren.

A memorial service will be held at 11 a.m. Friday in St. Paul's Episcopal Church in Dedham. Burial will be private.

Correction: Because of a reporting error, the maiden name of Mary Hammond Norton was incorrect yesterday in an obituary on her husband, Dr. Lawrence A. Norton of Dedham, a dermatologist who died May 13.