Homage to Gaia (23 page)

During the early 1950s Archer Martin and his colleague of those days, Tony James were busy establishing the science of
chromatography
. Their work was truly important and made possible so many of the great advances in reductionist science that took place in the 1950s. The MRC's greatest triumph was the worldwide expansion of biotechnology which grew from the support it gave to pioneers of molecular biology and to these instrument scientists. I first heard news of the new and exciting method of chemical analysis called gas chromatography from Keith Dumbell early in 1951, when he returned to Salisbury after a visit to the Mill Hill Institute. I knew all about chromatography. It was a method of separating substances by passing a solution through a tube filled with some inert absorbent powder like starch or silica. A distinguished Russian botanist, Mikhail S Tswett, had invented chromatography in 1906 and he used it to separate and identify the pigments of flowers. He dissolved the
pigments
that colour flowers in alcohol and then placed a few drops of the alcohol solution on the top of a tube filled with powdered chalk. When he washed the chalk column with a hydrocarbon solvent, the pigments moved down the chalk and separated as coloured bands; each one a different substance. It was the separation and recognition of the pigments by their colours that gave the technique the name chromatography. In fact, it was merely the separation of different substances, and since most substances are not coloured, the word chromatography is a little odd. All chemists knew about
chromatography
and I had often used it to separate otherwise inseparable substances. But what was gas chromatography? In my mind, I
pictured
a tube full of tiny bubbles, a froth of gas. Somehow, liquid solutions percolated through these bubbles and in the process
components
of the solution separated. This image was quite wrong but typical of me at that age. In fact, the gas chromatograph column is filled with fine powder, usually coated with an involatile liquid. An inert gas like nitrogen passes through the column just as liquid passed through Tswett's original column. Vapours carried by the moving gas separate by absorbing differently on the material of the column. Scientists worldwide were soon using this powerful technique to
separate and identify the numerous substances that go to make up a flavour or a perfume, the fatty acids of the blood, or the hydrocarbons of petroleum. The name chromatography stuck, even though the separation of coloured vapours was a rare event indeed.

His friends knew Dr AJP Martin as Archer, the inventor of many important developments of Tswett's original method. Most deservedly, he was awarded a Nobel Prize for this work, along with his collaborator Dick Synge. Archer was the kind of scientist with whom I could empathize. He was oblivious of dress and would come to the lab on hot summer days dressed in shorts, an open-necked shirt, and wearing sandals. The National Institute of Medical Research was a government laboratory and in the early 1950s it was bad form to appear so dressed. We were free to dress casually and were not, like most civil servants, required to wear suits, but it would have been out of place for one of us to dress as Archer did—almost as inappropriate as a hospital nurse wearing heavy makeup and a
miniskirt
at her duty on the wards. It says something about the
management
of the Mill Hill laboratory that they tolerated such behaviour from distinguished eccentrics like Archer. We are freer now to dress as we like but somehow in discarding the constraints we have lost a sense of anticipation—the joy that comes from earning the rewards of seniority. As a young scientist I knew that I could not dress like Archer but I knew that fame, if it came, would let me throw away my stifling shirt and tie. That feeling of anticipation and the security of a place in society are missing from the untidy egalitarianism of today. Archer Martin was no father figure for me but in the many encounters we had in the next few years he gave me confidence in my own odd way of doing science, which was not so different from his. I was especially grateful for his insistence that the first experiment in a new subject should be a rough one and intended only to get the feel of it. Exact science should come second, not first.

I started collaborating with Martin and James to make new
detectors
for their gas chromatograph even before leaving Parkes's
department
; this work was successful beyond all my expectations, and soon we had a range of new detectors that enhanced the power of the gas chromatograph. Among these was the argon detector that made gas chromatography accessible to scientists in many different fields, and the electron capture detector, ECD, which was to prove so important in the environmental revolution soon to come. Chapter 7, later in this book, is entirely about the ECD. I continued working with red cells
and, with Tony James, fed them
¹⁴
C-labelled acetate to see if the blood cells synthesized fatty acids. They did, although by the time I left Mill Hill it was not clear whether the red cells were active in this way or whether it was only the white cells that synthesized fatty acids. We were surprised to find that the cells of human blood synthesized the so-called essential fatty acids, linoleic and arachidonic acids. Detector development took up so much of my time that the red cell experiments took second place and the pressure of work made me feel the need for somewhere to escape to for weekends in the quiet of the countryside.

I was now receiving a good salary as a tenured member of the scientific staff, enough indeed to contemplate a mortgage on a small cottage in the village. We did not have enough spare cash for the required deposit but could afford the monthly payments and with the help of a colleague, Thomas Nash, a bachelor, who put up half the price of the cottage, we bought it. Pixie's Cottage was on the Wood Yates Road at the top of Bowerchalke village. It was a tiny thatched cottage with a small well-tended front garden. Strangely, thatched cob walls surrounded the house and garden and enhanced its privacy. On the ground floor were a living room with oak beams and a tiny kitchen. Upstairs were two small bedrooms and an even smaller
bathroom
. Neither Helen nor I cared for London, still less for the
suburban
living in Finchley. Our cottage at Bowerchalke was a refuge and we went there whenever possible.

We grew to know and love the village, the villagers, and the
glorious
, still unspoiled countryside around. We were not churchgoers and so we met villagers in the shop or the post office or in the pub, The Bell. Chris and Arthur Gulliver ran the village pub and their families had been in the village since time beyond imagining. The pub was a place for social encounters rather than for heavy drinking. Indeed, the landlady made it clear she disapproved strongly of drunkenness and would not hesitate to turn drunkards away. We found little difficulty in getting to know most of the villagers, and the notion that country folk are hard to make friends with, or that it is necessary to live for generations in a village before one is accepted, is rarely true. More often, those who complain are expressing their own inability to change and become amenable.

The Bowerchalke community was alive and had been so for
hundreds
of years. It was complete with a fine village school which Mrs Adams, its capable Welsh schoolteacher, ran with an assistant. There
was a village cricket team good enough to win against the county team of Somerset. There was a bus service into Salisbury several times a day. The bus was another meeting place where villagers gossiped and shared the news. One of the bus drivers was rumoured to have a lover in a village, Bishopstone, half way to Salisbury. Here the bus would stop for brief encounters while the driver slaked his passion, and then resumed, as before, the journey to Salisbury. This idyllic existence in Bowerchalke, as in other villages across the south of England, was doomed, but we did not know it then in the 1950s. Agribusiness and the car culture were preparing their deadly assault that was to overwhelm and destroy the villages and the countryside of southern England. Like many a successful campaign of conquest, it did not begin with outright war. The long years of privation softened our resolve.

Back at Mill Hill, in order to concentrate on detector development, I took on a post-doctoral scientist, Charles Rowe from Birmingham, who then took over my blood experiments. They gave me a spacious lab on the third floor at the north end of the Institute with an office in a separate room from the lab. To work on this floor was quite an honour; a sizeable proportion of the labs were the workplaces of Nobel Laureates or those who would later receive the prize. Archer Martin, who had now moved to the other end of the floor, had previously occupied my lab. These were near ideal working conditions and I was lucky to have the infant technique of gas chromatography to exercise my inventive talents. I made too many inventions, for I had during that period no chance to fully develop or understand any single one of them. I was like a keen gardener presented with all the plants at the Chelsea Flower Show—delighted and at the same time frustrated by the lack of ground in which to plant them. One
invention
I made but never reduced to practice was super-critical fluid chromatography. This analytical method makes use of that strange state of matter that exists between gas and liquid. If water is heated to above 374° C or carbon dioxide to above 31° C, no amount of
pressure
will keep them in the liquid state. What is interesting for
chromatography
is that these dense gases will dissolve solids as well or better than the liquids from which they came. Super critical steam will even dissolve rocks. I went as far as notarizing an invention record when I visited Yale in 1958, but there was no time when I was back at Mill Hill to develop the invention. It has subsequently become one of the main branches of chromatographic science.

I spent most of my time developing the argon detector, which was the first practical device that could analyse sensitively and
quantitatively
the compounds emerging from a gas chromatograph column. It took advantage of the property of rare gas atoms, such as those of argon, to form short-lived highly energetic metastable states. When a vapour molecule collided with a metastable argon atom it was ionized. In my argon detector the ions were collected and measured. It was exceedingly sensitive and much needed because the application of the Martin and James gas chromatograph in biochemistry was hindered by the lack of a general-purpose sensitive detector. I
discovered
the argon detector by one of those happy accidents that are part of a scientist's life. I had been trying unsuccessfully to apply a device called an ionization cross-section detector to the gas
chromatograph
, and although it worked it was miserably insensitive. The American scientists, JW Otvos and DP Stevenson had invented it at the Shell labs in California several years before and they recommended that hydrogen or helium be used for the carrier gases. Now, Institute rules required me to use nitrogen because hydrogen was too much a fire and explosion risk for apparatus left on overnight and unattended. Helium was in those days too expensive for use in Britain. Nitrogen worked well with Martin's gas density balance but was hopeless with the device I was trying.

In late 1956 I had one last set of experiments planned before I gave up trying to make an ionization detector work for gas
chromatography
. At that moment, my nitrogen supply ran out. My technician went to the stores to pick up another cylinder and returned saying that they were out of nitrogen and would argon do instead? She had sensibly brought up a small argon cylinder for me to try and I thought, well, why not? Theory suggested that the detector would be slightly less sensitive with argon than with nitrogen but this should not affect the experiments I intended to do, so I joined up the argon supply and started my last set of experiments. These were running the detector at a potential of between 500 and 2,000 volts. I added a three-microlitre sample of fatty-acid methyl esters to the top of the gas chromatograph column, reconnected the argon supply, and waited. Old-style gas chromatography with packed columns was a slow business requiring much patience, for substances could
sometimes
take hours to pass through the column. On this occasion, the air peak, representing the air that had leaked in with the sample appeared first. Then, to my amazement, the recorder pen went off scale. At first,
I thought there must be a short circuit, but on turning down the gain, I saw a series of large peaks emerging. Here was a detector
incomparably
more sensitive than anything I had expected, and I repeated the experiment several times and at different voltages until I was sure that argon gas had somehow amplified the signal hundreds if not
thousands
of times. Better still, the analysis of the fatty-acid esters was in more or less true proportion to the quantities expected.

We now had the detector Archer Martin and Tony James had sought, one that would allow them to exploit in full the potential of their wonderful invention. For the next two years, I was overwhelmed by the interest stirred by this discovery. I found myself describing it at laboratories in almost every state of the union and it took me to places like Peoria, Illinois and Bismarck, North Dakota. It was hardly an invention, for I had not planned to use argon; I did not want it named the Lovelock detector, so we called it the argon detector. Naming things is often difficult and to call it an argon detector was not a good idea, because argon was the only thing it did not detect. It is good to have recognition for a job well done, or a creative achievement, but in science I dislike the thought of rewards as the prime motivation for work. The joy of science lies, for me, in the sense of adventure and the retention of a child's sense of wonder, even to my dotage.

About two years later an even better invention—the flame
ionization
detector, FID—superseded the argon detector. It was more accurate and did not require a radioactive source of ions. This
invention
by IG McWilliam and RA Dewar was so successful that it is now the principal detector for analytical gas chromatographs. But the argon detector gave me two years of excitement and established gas chromatography as a key analytical method in biochemistry. On one occasion during my work on detectors, and when the ECD was proving to be a fascinating distraction with no apparent use, I asked the Institute Director if he disapproved of my working on ionization physics, for it then seemed most remote from medical research. Sir Charles replied, ‘All I care about is that you continue to do good science; I am not concerned that your work is in physics instead of medical research.' Looking back I see how right he was, for nothing I did at Mill Hill had as great an impact on medicine as did the ECD, but that is the story of Chapter 7.