Kolthoff

As the first scientist in the series of geeks you should know, I give you Izaak Maurits Kolthoff. My first introduction to him was at a conference where a student from Minnesota was wearing a t-shirt that read �I.M. Kolthoff � and you�re not.� He was revered, feared, and marveled at during his own tenure, publishing 809 articles until his retirement, after which he published 136 more as an emeritus. Let me repeat that: 945 articles, and 136 peer-reviewed articles as an emeritus! He taught 67 graduate students, and his scientific progeny number in the thousands, now. If for no other reason that that level of publication and educational output, he should be widely known. Instead, he�s Chemistry�s equivalent of Appert.

He didn�t win any of the big prizes. His genius was not in the new mathematical theory, it was in his synthesis of many disciplines into a whole that would thoroughly penetrate and illuminate an object of study. Because of that, he languishes in obscurity, while lesser minds, who saw less of science, but attached their names to a single topic, rose to prominence because their students and adherents beat a one-topic drum until prizes appeared. In the words of one biographer:

Divisions between disciplines in science were not always as permeable as they are today. For example, chemistry students find that a foundation of mathematical principles, physics, quantum mechanics and kinetics is compulsory, but this was not always the case. It usually takes a person of global vision to understand how crossovers in the sciences are feasible and mutually beneficial. In the field of analytical chemistry, the person to either thank or blame (depending on how well you liked those classes�) is Izaak Maurits Kolthoff, the “father of modern analytical chemistry”.

Kolthoff was born in Holland, but his primary home for most of his life was Minnesota. It is not surprising that America became home to the man and the discipline of Analytical Chemistry. The discipline is the read-headed stepchild of Chemistry. Not much science actually goes on day-to-day in an Analytical lab � it is more concerned with what and how much than why, but without the what and how much, theory would be so much baseless, useless cogitation. Analytical Chemistry suits the practical American mind.

For the basic biographical stuff, I�m going to crib generously from this biographical sketch by Kolthoff�s student, the South African solvent chemist Johannes Coetzee, which is the best and most scientifically detailed of the many pieces on Kolthoff available on the net. Readers with Chemistry degrees probably already know who Kolthoff is, but if you are chemically skilled and don�t know his work, Coetzee�s is really the only Net sketch that elaborates in any sort of detail about the science of all of Kolthoff�s work rather than glomming onto one particular aspect or just devolving into a laundry list. If any of you have access to ACS publications at work, there are several good pieces over the years in Analytical Chemistry (the 1989 piece was where I first started digging when I became aware of the man). By the way, there are probably no more than two or three degrees of separation between any scientist. I never met Kolthoff, but I have attended seminars by (and spoken to) Coetzee, and although he would not know me from Adam if he met me again, he knew my thesis advisor. Coetzee, like his mentor, skated back and forth across the interface between Analytical and Physical Chemistry, spending as much time in the latter as the former. A powerful combination.

Kolthoff was born to Jewish parents in Utrecht in 1894. In 1911 he entered the school of Pharmacy in Utrecht – lacking an education in Latin or Greek, he could not matriculate as a chemist.* At the pharmacy school, analytical rigor was emphasized, since the main difference between a medicine and a poison is the dose. This turned the young Kolthoff on to Analytical Chemistry, then considered by [Nobel Prize Winner] Ostwald to be the maidservant of Physical Chemistry. By 1918 the old orders of Europe were slipping away and Utrecht abandoned the Latin and Greek requirements, allowing Kolthoff to matriculate into the Ph.D. program. His first paper concerned the basis for a lot of Analytical Chemsitry: pH.

Despite his refusal to learn Latin and Greek, Kolhoff was no slouch at foreign languages:

The majority of his early publications were in Dutch, German, or French and, after 1924, increasingly in English.

His talent for hard work was already apparent, and Utrecht kept him on after he earned his Ph.D.;

He remained at the University of Utrecht, first as “conservator” and then, from 1923 until 1927, as “privaat docent” (lecturer) in electrochemistry. The significance of the pH concept was not generally recognized at that time, and Kolthoff gave many lectures on it to academic and industrial chemists, biochemists (especially bacteriologists), and pharmacists. At the same time his research productivity was astronomical. During the ten-year period from 1917 until 1927 he published 270 papers and 3 books, but it was the originality, insight, and timeliness rather than the mere bulk of these publications that created an enviable international reputation for Kolthoff at an early age.

I�m sure the old orders had not completely passed away � life could not have been all beer and skittles for a Jewish researcher in Holland in the 1920s. And so, presaging our predatory brain-drain practices of the 1930s, 40s, and 50s, America poached Kolthoff in 1924, to the unlikely location of Minnesota:

In 1924 Kolthoff was invited on a lecture tour in Canada and the United States, and in 1927 he was offered a one-year appointment as professor and chief of the Analytical Division of the School of Chemistry of the University of Minnesota (annual salary $4,500). In his letter of acceptance he promised, “I may assure you that [on] my side I will try to do my duty as well as possible and I hope that your expectations will not be disappointed.” His one-year appointment became permanent and he remained at Minnesota until his nominal retirement in 1962 despite attempts by other institutions (including his alma mater, the University of Utrecht) to attract him.

Of passing interest is the international and egalitarian nature of American science in the early-to-mid 20th century. Looking at Kolthoff�s list of graduate students here, one sees that his first two students were Ruth Elmquist, who seems to have gone on to work for the USDA and Tohru Kameda in 1930. At a time when minorities, foreign nationals, and women were excluded from or discouraged from participating in much of public life, that stands out. But we scientists should not pat ourselves too much on the back, either � as the new guy in the department, Kolhoff probably got the students no one else wanted to take on.

Kolthoff was an interesting character if you like to poke fun at Kuhn, like I do. There are very few paradigm shifts in science. Most science is rote stuff building incrementally on previous publications, more engineering (including molecular engineering) than science. A few, a very few, publications change the way we think about the world in a fundamental scientific way. But there is a path in-between those two, and it�s the path that Kolhoff took. If a superior intellect,** through either lack of opportunity or lack of that final spark of genius (the spark that makes someone write a paper like Einstein�s Nobel winner on Brownian Motion), applies itself systematically to a new discovery, that intellect can often go further than the original creator / discoverer. Sometimes this is because the discoverer may have discovered the phenomenon or technique at hand on his or her way to solving a completely different problem, and so allows a significant issue to drop through lack of attention. Sometimes it�s because the original discoverer is too focused on one particular aspect of the problem, and sometimes it�s because they are out giving talks and resting on their laurels, and sometimes it�s through basic lack of industriousness, especially when a third-rate scientist discovers something neat purely by accident. Whatever the reasons (and there are more than the ones I elucidated above), what keeps practicing scientists sharp is the fear that someone like Kolhoff is going to swoop in and beat them at their own game. As Derek Lowe put it:

Today’s law is: You are in real trouble if someone knows more about your project than you do. That’s a realization that hits people at some point in their graduate school career – preferably not much past the midpoint. It marks the transition from being a student to being a working scientist. After all, when you’re still a student, other people are expected to know more about what you’re doing than you do yourself; you’re supposed to be learning from them.

But that has to change at some point. It’s not that you suddenly get as smart or as experienced as the better grad students or post-docs in the group, let alone your PhD advisor. More talented people might be better at your project than you if they devoted all their time to it, but they’re not doing that: you are. No, you get to where you know the ins and outs of your own project, your corner of the research world, better than anyone else. With that comes the realization that no one else is going to get your project done for you, and no one else is going to get you out of grad school. If you don’t reach that level of involvement and expertise, something has gone wrong, and things will continue to go wrong for you.

The average researcher wants to keep ahead of everyone else, because if he or she doesn�t, well, it�s embarrassing at best, funding death at the worst. But Kolthoff was that more talented person who �might be better at your project than you�, and the scary thing about him was how much energy and time he would bring to bear on a project that interested him, and how little time he actually spent going up the learning curve. Here�s an example of this dynamic from Kolhoff�s career:

Kolthoff became interested in voltammetry in 1933 when J. Heyrovsky, the inventor of polarography (voltammetry at the dropping mercury electrode) and future Nobel laureate, visited Minneapolis. Two of Kolthoff’s top students, J. J. Lingane (Ph.D., 1938) and H. A. Laitinen (Ph.D., 1940) began working on voltammetry, Lingane on the fundamentals of the dropping mercury electrode, Laitinen on solid microelectrodes. In 1939 Kolthoff and Lingane published a 94-page paper in Chemical Reviews. This was followed in 1941 by an influential monograph with Lingane as coauthor, Polarography (Interscience, New York), expanded in 1952 into two volumes.

Heyerovsky is the Man when it came to discovering Voltammetry, but as for understanding completely what�s going on there, Kolhoff is and was the go-to guy. (Kolthoff is pretty much the go-to guy for all of the fundamentals of Electrochemistry.***) Ninety four pages is one hell of a non-book monograph, especially in the 1930s; although the modern pressure to publish early and often was not present at that time, which allowed Kolthoff to dally on such things, and in my opinion, wipe the floor with Heyerovsky. If it were not for Kolthoff and his promotion of Voltammetry, one might argue that Heyerovsky might not have received that Nobel. Don�t get me wrong, Heyerovsky deserved the Nobel for being their first, but I think Kolhoff played a part in popularizing the work that led to that prize. Some of this was due to Heyerovsky being in the wrong place at the wrong time (Europe of 1939-1945), but most of it was due to the fact that Kolthoff saw a juicy bone and pounced on it, and I think that Heyerovsky did not have the broad view of science that Kolthoff did.

Kolthoff�s success in science was due to the fact that he could put a lot of things together from a variety of sources into something new. If you bring a broad scope of knowledge to bear on something, rather than focusing on your specialty, you can often see something others don�t. But such an intellect is not likely to come up with a new mathematical theory****. It is likely to create something practical, as did Kolthoff (most of the time). Kolthoff understood mathematical science very well, but did little to advance it. He was too busy using it. It�s the difference between someone who builds a better TIG welder and someone who uses that apparatus to weld together a better car. Both understand a lot about welding, but the emphasis is very different.

That�s not to say that Kolhoff did not carry out any studies of fundamental science. It�s probably his work on precipitation (when an insoluble product drops out of solution because of a chemical reaction) and co-precipitation (when other junk that you don�t want comes out with your product) that had the most impact on fundamental Physical Chemistry, although the importance of precipitates in classical wet Analytical Chemistry can not be overlooked, which is what turned Kolthoff�s attention there in the first place. But those studies were largely experimental and observational in nature, and did not advance the fundamental math of Physical Chemistry in any significant way.

During the period 1932-48 he published 37 papers on aging of precipitates and coprecipitation. He continued with these studies, but on a smaller scale, until 1960. These investigations were fundamental, rather than applied, and attracted much attention (e.g., by Otto Hahn).

Because he took what he knew and applied it everywhere, with great intensity, he founded a couple of fields that only came to full flower very late in his career. One that springs to mind is the application of electrochemistry to biology:

Beginning in 1950 and continuing until 1980 Kolthoff carried out extensive studies of the reactivity of these [sulfur-containing] groups in native and denatured albumin. These papers may be among the first in bioelectrochemistry, an active field at the present time.

I worked in a pretty esoteric area of science, and I am amazed at how many of the topics I studied were also touched by Kolthoff. Although I was not a student of any of his progeny, my own scientific career is intertwined with Kolthoff�s in several ways. First of all, I was a TA. Kolthoff was one of the first to systematically study and describe mathematically the complex acid / base titrations involved with buffers. Any TA who�s ever made a buffer solution for their lab section is using Kolthoff�s very earliest work:

Proton transfer reactions in analytical chemistry: the pH concept, titrations, indicators, and buffers. Kolthoff’s first paper dealt with the titration of phosphoric acid as a mono- and diprotic acid and appeared in 1915. This was followed by a number of papers dealing with both fundamental and applied aspects of proton transfer reactions, subjects taken for granted today but very incompletely understood at the time.

Emphasis mine. First paper. If you have ever done an experiment with buffers, in high school or college, odds are either carbonate or phosphate was involved. Every time you laymen hear the term �pH�, most likely Kolhoff�s opus was involved in some way. That alone would be quite a legacy, but as I said, Kolthoff had almost limitless energy.

He touched quite a few of the topics I studied in grad school as well. For a while, I worked with colloids, and early in his career, Kolthoff interacted with Kruyt, and apparently published quite a few colloid papers, although I have never read them.

Another area where my path intersected Kolhoff�s involved an application of crown ethers:

Throughout his career he emphasized the role of chemical principles in analysis and was one of the earliest workers to understand the fundamental significance of crown ethers and their complexes. Jean Marie Lehn, who received the Nobel Prize in Chemistry (1987) for his work with crown ethers, held the inaugural I.M. Kolthoff Lecturership (1979).

Several of my publications concerned emulsion polymerization, which Kolthoff studied deeply enough to obtain several patents during his tenure in the Chemical Rubber Program started by the US government after our rubber supplies from the Far East were cut off by Japan.

In 1942 the Office of Rubber Reserve was set up to promote the production of synthetic rubber as a crucial part of the war effort. Kolthoff was one of several prominent professors, including physical chemist P. Debye, organic chemists M. Karasch and C. S. Marvel, and colloid chemists W. D. Harkins and J. W. McBain, invited to work with the major rubber companies. Kolthoff was asked to develop analytical methods so that the rates at which reactants were consumed could be determined. A key constituent turned out to be n-dodecyl mercaptan, referred to as “OEI,” for “one essential ingredient.” Kolthoff quickly developed an effective method for the determination of OEI based on amperometric titration at the rotated platinum microelectrode with silver nitrate. This method found worldwide use after the war, when it was published (1946). In typical fashion, immediately following this important applied research, Kolthoff launched a thorough fundamental investigation into factors influencing the rates of reaction of mercaptans, as well as the kinetics and mechanism of emulsion polymerization in general. These studies led to the development of novel initiating systems that worked at lower temperatures than usual and that produced so-called “cold rubber” with superior properties.*****

As a result of these endeavors, Kolhoff held three fundamental patents in the field of the emulsion polymerization of rubber. But I do note that these advances were made by applying Kolhoff�s favorite techniques (amperometry and voltammetry) to a system that had never benefited from such scrutiny before. This is what I mean about metastable states awaiting the pebble that starts the avalanche: all the pieces were in place to do this years, perhaps decades, before WWII, but no one had looked at it, because natural rubber was cheap � who needed expensive studies on how to improve the efficiency of a cheap process?

Kolthoff�s Achilles Heel was that he was a bigger peckerwood than your average bear, even among that universe of bears who happen to be Chemistry professors. I�m going to be egotistical here and crib myself, not out of an inordinate pride in my mediocre writing, but because I�m too lazy to re-write these thoughts:

I am more than a little familiar with the history of chemistry, and I lay the blame for this tendency to juvenile and aggressive behavior in Electrochemistry at the feet of a man who unfortunately is also one of my scientific heroes, I.M. Kolthoff. Almost every Ph.D. Electrochemist, most Analytical Chemists, and many Physical Chemists can trace their scientific pedigrees back to a student or Post-Doc of Kolthoff�s. Every major American Electrochemist I know of is a scientific child, grandchild, or great-grand-child of Kolthoff�s, with the minor exception of the Czech polarography inventor’s (Heyrovsky) progeny. I�m going to start a series on �Scientists You Should Know�, and Kolthoff is going to be the first one. So I really respect the man and his scientific legacy. But as a human being? Huh. Let�s let one of his most famous students (and a legendary solution chemist himself) J.F. Coetzee, tell it like it was:

Kolthoff could be harsh with his coworkers. I believe he did not fully realize just how intimidating he could be. Quite often after research conferences some of his graduate students and postdoctoral associates appeared to be in a state of shock. Kolthoff, in turn, would grumble afterwards about “a tale of woe” and “babe in the woods.” Nevertheless, the great majority of his coworkers became his devoted friends after they left. Kolthoff, in turn, expended great effort in promoting their careers, at least for those people who had satisfied him that they were serious professionals.

I can�t think of a better prescription for turning out passive-aggressive a$$wipes than this. Can you? “Didn�t realize how intimidating he could be”. Horse crap. A famous prof knows how famous he is, and just how much influence he has. This passage was written by one of his most devoted students and life-long friends. I wonder what one of those students he didn�t judge to be a �serious professional� would have to say? And how arbitrary were those judgments? I don�t know.

Before you think I�m piling on the man, let�s get one thing straight: in the grand scheme of things, only one personality trait matters in a scientist � everything else is window dressing. Which is why we get so many scientists with poor window dressing. But the one trait that is essential is a willingness to get one�s mental model readjusted by the world as revealed by experiments:

Kolthoff similarly emphasized fundamental principles, but he had an open mind about current hypotheses. He would often speculate about the probable outcome of experiments, but when unexpected results were obtained he would be entirely magnanimous in abandoning the assumptions on which his predictions had been based.

You can be the biggest peckerwood in the world, but as long as you adhere to the scientific method, you are in the club.

If Kolthoff had a scientific weakness (outside his personality caveats), it was probably that he came of age in a time when you could do an awful lot of groundbreaking science with equipment that could be knocked up in someone�s garage. As Dirac lamented about the same time period in Physics: �It was very easy in those days for any second-rate physicist to do first-rate work. There has not been such a glorious time since then. It is very difficult now for a first rate physicist to do second-rate work�.

Kolthoff seemed to eschew instrumentation more complex than a polarograph, which I have knocked up in an undergraduate lab. Modern Analytical Chemistry can not be imagined without Spectroscopy, which is an instrumentation-heavy discipline, and I find it strange that I can scarcely find a paper devoted to spectroscopy (rather than mentioning a simple technique such as UV / Vis spectroscopy as a sidebar in the �Instrumental Methods� section) or chromatography in the oeuvre of a man whom some (including me) style as the father of Analytical Chemistry. Coetzee himself echoes the sentiment that fundamental science should be reachable through simple means of investigation:

While current analytical chemistry is strongly (arguably too strongly) instrumentation-oriented, Kolthoff’s work was chemistry-oriented. Much of his research was done before the great influx of increasingly sophisticated instrumentation after World War II. For him, instrumentation was a means to an end, not an end in itself.

I like that style, but those days were long past by 1950, so it is amazing that he was able to publish material with significant impact well into the 1980s. A good 10% of what I learned as a Chemistry major, both undergraduate and graduate, was either taken directly from his work or closely derived from it. Ten percent might not sound like a heck of a lot, but consider all the names that went into producing the stuff that went into my Chemistry education: Bacon, Lavoisier, Gay-Lussac, Le Chatelier, Henry, Hooke, Thompson (father and son), Davy, Newton, Huygens, Mendeleev, Markovnikov, Einstein, Schrodinger, Bohr, Hahn, Debye, Ostwald, Gibbs, Coblentz, Raman, Duhem, Langmuir, Flory, Marvel, Pauling, Woodward, Hoffman, Fick, Cottrell, Jensen, Tanabe, Sugano. To name a few off of the very, very top of my head. Ten percent in that company is tremendous. For some reason, his name is rarely placed among those I mentioned. I think it�s because of his working habits � never first, but always the most thorough, and in a lot of areas rather than sticking to one and beating his own drum until people marched to his tune. Basically, he was an Eratosthenes, second at everything, but that means he touched everything. That�s a heck of a legacy, and it�s what makes Kolthoff a Scientist You Should Know.

* This kind of crap is exactly why Britain lost her early scientific lead to the more egalitarian and less class-oriented Germans and Americans at the fin de siecle. Aside from some basic rules of nomenclature that can be learned in one painful afternoon, exactly what good were Greek and Latin to a scientist?

** Make no mistake, despite the shortcomings I point out later, Kolthoff was a superior intellect.

*** Electrochemistry in general (not just voltammetry) owes a lot to Kolthoff. I don�t think much of Electrochemistry today, because I think that Spectroscopy is a more powerful tool. But in the 1930s, the developments in instrumentation that allow one to perform quantitative spectroscopic experiments had not yet occurred (and the fundamental understanding of the interaction between light and matter was not yet well enough understood by enough people to make those leaps in instrumentation), so if you wanted to know not only what, but how much of something was in your sample, it was pretty much down to Electrochemistry or classical wet analysis, and Kolthoff did plenty of both as he applied everything he knew to each new problem.

**** There are a lot of math-smart people out there. For some reason there are not a lot of Kolthoffs. Perhaps it has something to do with comfort zones, perhaps not.

***** It�s pretty obvious that Prof. Coetzee was not a Polymer Chemist, because he missed the man who was arguably the greatest contributor to the CRP � P.J. Flory, whose work I studied in detail as a graduate student. Prof. Flory and Prof. Carl �Speed� Marvel will be subjects of upcoming installments in the �Polymers� section of Scientists You Should Know.