The trim, nattily dressed, silver-haired man climbed the four flights of stairs at a lively pace without once stopping to catch his breath.

And according to his daily custom, when he arrived at his office he sat down and monitored his heartbeat with his watch.

"Same as always. Bating at a rate of 100 and back to 60 in a couple of minutes," 97-year-old Joel Hildebrand declared. "That indicates a clean aorta. They'll have to figure other means of getting rid of me."

He walks up and down the stairs every weekday to and from his office. "It helps keep me alive," he said.

"I would walk the four miles from my home but I can't spare the time, so I drive."

Hildebrand is the University of California's amazing, ageless scholar. He is the dean of American chemistry and the eldest active professor-scientist in America today.

His most recent book, "Viscosity and Diffusivity: A Predictive Treatment," was published last year. He is now writing another book, one in a lighter vein, entitled "The Pleasures of a Nonagenarian."

"No one has ever written a book on that topic so far as I know," the professor said with a mischievous wink.

"It's too bad there are so many unhappy senior citizens. I hope the book will be an inspiration to many of them. It's important for other people not to have tensions, not to worry about things they cannot help.

I'm at peace with the world. I'm healthy, busy and happy. I never fret nor worry.

"And I have no intentions of slowing my pace. I plan to continue working until I'm 100 and then some. No reason why I shouldn't. I have always treated my body with respect, never abuse it with drugs, tar, gluttony or stasis."

He has never worn glasses and spends hours every day reading. This winter he cut a cord of wood from an oak tree that toppled in his yard.

"I have all my own teeth except for three caps," he laughed. "I have never had a headache in my life. My hearing is acute. I hear the highest notes in an orchestra."

Hildebrand is a University of California fixture. He arrived on campus in 1913 and has been there ever since. He earned his Ph.D. in chemistry in 195 at the university of Pennysylvania, where he taught for seven years before coming to the West Coast.

His freshment chemistry text, first published in 1918 and revised in several editions since, continues to be standard work in the field.

A few months ago Hildebrand published his 275th scientific paer. He says he has several more in the works.

"Every time you explain one area, there's something else beyond. One paper suggests another," he said.

He is the winner of practically every major chemistry award and is past president of American Chemical Society.

"Oh, I have had and am still having a wonderfully exciting time of it," he said enthusiastically. "I have been able to do so many things."

He got up and walked toa window in his office in Latimer Hall and looked across the quad at one of the largest buildings on campus, Hildebrand Hall.

"They had a rule here never to name a building after a living person," he chuckled. "But they got tired of waiting for me to die. So in 1966 when it was completed, the university named the new chemistry building after me.

It's what you start that's most exciting, rather than what you finish," he insisted. "I'm still very much alive, still starting things. . . "