People talk a lot about the importance of mentors, and scientific trainees are regularly encouraged to find strong mentors to help them find their way as they work to become grown-up scientists. Sometimes, though, mentoring doesn't happen in explicit coaching sessions but in casual conversations. And sometimes, when you're not looking for them, mentors find you.

Back in the spring and autumn of 1992, I was a chemistry graduate student starting to believe that I might actually get enough of my experiments to work to get my Ph.D. As such, I did what senior graduate students in my department were supposed to do: I began preparing myself to interview with employers who came to my campus (an assortment of industry companies and national labs), and I made regular visits to my department's large job announcement binder (familiarly referred to as "The Book of Job").

What optimism successes in the lab giveth, the daunting terrain laid out in "The Book of Job" taketh away.

It wasn't just the announcements of postdoctoral positions (positions, I had been told, which provided the standard path by which to develop research experience in an area distinct from the one that was the focus of the doctoral research) that listed as prerequisites three or more years of research experience in that very area. The very exercise of trying to imagine myself meeting the needs of an academic department looking for a certain kind of researcher was ... really hard. It sounded like they were all looking for researchers significantly more powerful than I felt myself to be at that point, and I wasn't sure if it was realistic to expect that I could develop those powers.

I was having a crisis of faith, but I was trying to keep it under wraps because I was pretty sure that having that crisis was a sign that my skills and potential as a chemist were lacking.

It was during my regularly scheduled freak-out over the binder in the department lobby that I really got to know Dr. Lu Valle. While I was in the department, his official position was as a "visiting scholar", but since he had been the director of undergraduate labs in the department for years before he retired, he wasn't really visiting, he was at home. And Dr. Lu Valle took it upon himself to make me feel at home, too -- not just in the department, but in chemistry.

It started with light conversation. Dr. Lu Valle would ask what new listings had turned up in the binder since the last time he had seen me. Then he'd ask about what kind of listings I was hoping would turn up there. Soon, we were talking about what kind of things I hoped for in a chemical career, and about what scared me in my imagination of a chemical career.

That he bothered to draw me out and let me talk about my fears made those fears a lot more manageable.

But Dr. Lu Valle went even further than just getting me to voice my fears. He reassured me that it was normal for good chemists to have these fears, and that everyone had to get across the chasm between knowing you could be a good student and believing you could be a successful grown-up scientist. And he took it as an absolute given that I could get across this chasm.

Now, I should note for the record that my advisor did much to encourage me (along with pressing me to think harder, to make sure my data was as good as it could be, to anticipate flaws in my interpretations, and so forth). But the advisor-advisee relationship can be fraught. When you've been busting your hump in the lab, showing weakness of any sort in your interactions with your PI can feel, viscerally, like a bad idea. I think that for a good stretch of time in my graduate lab, I put a spin on many of my interactions with my PI that was significantly more optimistic than I felt inside. (Then, I worked like mad so that my optimistic projections of what I would be able to accomplish had a reasonable chance of coming true.)

Being able to voice some of my worries to a senior chemist who didn't need me to make headway on one of his research projects -- and for whom reassuring me wasn't part of the official job description -- really helped. Dr. Lu Valle didn't need to mentor me. He didn't need to interact with me at all. But he did.

Somewhere in the course of our discussions, as we were talking about the frustrations of getting experiments to work, Dr. Lu Valle mentioned that his advisor had made him completely disassemble, then completely reassemble, complex apparatus -- not just to get an experiment under control, but to persuade him that taking the whole thing apart and putting it all back together (even repeatedly) was within his powers.

That was the conversation in which that I learned that Dr. Lu Valle's advisor had been Linus Pauling.

Now, maybe it amped up the pep-talks a little that a senior scientist who seemed to have complete faith that I was going to do fine had been trained by a guy who won two Nobel Prizes. But mostly, I think it reassured me that Dr. Lu Valle remembered what it was like to be a graduate student and to have to get over the chasm of not knowing if you can do it to believing that you can.

After the season of job interviews passed, I drifted away from "The Book of Job" and back to my lab to get some more experiments done and to get writing. Then, in January of 1993, while he was on vacation in New Zealand, Dr. Lu Valle died.

It was at his memorial service (which happened to be on my twenty-fifth birthday) that I learned the remarkable details of Dr. Lu Valle's life that didn't come up in our conversations in the department lobby. A press release from the Stanford University News Office describes some of the high points:

James E. Lu Valle, a visiting scholar at Stanford and retired director of undergraduate laboratories in the Chemistry Department, died Jan. 30 in Te Anau, New Zealand, while on vacation. He was 80.

During a long and varied career, Lu Valle's research covered electron diffraction, photochemistry, magnetic susceptibility, reaction kinetics and mechanisms, photographic theory, magnetic resonance, solid-state physics, neurochemistry and the chemistry of memory and learning.

Lu Valle was well known in track circles as the 400- meter bronze medal winner of the 1936 Olympics in Berlin. ...

Lu Valle ran in the Olympics the same year he graduated Phi Beta Kappa with a bachelor's degree in chemistry from the University of California-Los Angeles. He then returned for his master's degree in chemistry and physics, during which time he helped found the graduate student association and served as its first president. In 1983, UCLA named its new Graduate Student Union in his honor.

Lu Valle's career in chemistry started at age 8, when he found a chemistry set under the Christmas tree. He tried every experiment possible, and eventually filled the house with smoke. At his mother's insistence, the rest of his childhood experiments took place on the porch.

In 1940, Lu Valle earned a doctorate in chemistry and math under the tutelage of Linus Pauling at the California Institute of Technology. He then taught at Fisk University in Tennessee, after which he spent 10 years at Eastman Kodak working on color photography.

He was the first African American to be employed in the Eastman Kodak laboratories. While there, Lu Valle went on loan to the National Defense Research Committee to conduct research at the University of Chicago and the California Institute of Technology on devices for monitoring carbon dioxide in planes.

He later served as director of research at Fairchild Camera and Instrument and became director of physical and chemical research at Smith-Corona Merchant Labs in Palo Alto in 1969.

During that time, he made extensive use of the Chemistry Department library, in the process getting to know faculty members. When SCM closed its Palo Alto operations, the Chemistry Department asked him to head the freshman labs.

"He was eminently qualified, a first-class chemist," Professor Douglas Skoog recounted in 1984, "and we were glad to have him. In fact, he was overqualified for the job."

As head of the labs for seven years, his task was to assign teaching assistants and make sure that the right equipment was always ready.

In practice, he became a friend and counselor to the chemistry majors and pre-med students passing through the department. In an average year, 900 students would start freshman chemistry.

Lu Valle is survived by his wife of 47 years, Jean Lu Valle, of Palo Alto, and three children. Son John Vernon Lu Valle is an engineer with Allied Signal under contract to the Jet Propulsion Laboratory in Pasadena, and Michael James Lu Valle is associated with Bell Laboratories in New Jersey. Daughter Phyllis Ann Lu Valle- Burke is a molecular biologist at Harvard Medical School. A sister, Mayme McWhorter of Los Angeles, also survives.

Dr. LuValle never talked to me about what it was like to be an African American athlete competing in Hitler's Olympics. He didn't share with me his experience of being the first African American scientist working at Eastman Kodak labs. We didn't discuss the details of the research that he did across so many different scientific areas.

If I had known these facets of his past while he was alive, I would have liked to ask him about them.

But Dr. Lu Valle was, I think, more concerned with what I needed as someone trying to imagine myself taking on the role of a grown-up chemist. His success as the director of undergraduate labs had a lot to do with his ability and willingness to tune into what students needed, and then to provide it. With all of those accomplishments under his belt -- accomplishments which potentially might have made a student like me think, "Well of course an exceptional person with so much talent and drive succeeded at science, but I'm not that exceptional!" -- he wasn't afraid to dig back to his experience of what it was like to be a graduate student, to remember the uncertainty, frustration, and fear that are a part of that experience, and to say, "I got through it, and I have every reason to believe that you will, too."

I don't know whether personal experience is what developed Dr. Lu Valle's awareness of how important this kind of mentoring can be, but it wouldn't surprise me a bit. As an African American graduate student at Caltech in the 1930s, I'm sure he had lots of people expecting him to fail. Having people in his life who expected that of course he would succeed -- whether his parents, his advisor, or someone else with standing as a grown-up scientist -- may have helped him propel himself through the inescapable moments of self-doubt to the distinguished trajectory his professional life took.

It may not be accidental, though, that in a very white, very male chemistry department, Dr. Lu Valle was the one who put himself in my path when I was doubting myself most and reassured me that I would do just fine. Maybe he knew what it was like to have someone provide that kind of support when you need it.

I count myself as lucky that, in his retirement, Dr. Lu Valle still felt that the chemistry department was a home to him. Because of him, that department and the larger community of chemists felt like more of a home to me.