by Andrew Brown
This connection is very unlikely to have occurred to anyone else, but prompted Sage to think more deeply about the fundamental properties of gels, and how there might be similarities between hydrated cement and the structure of living cells, for example. In September he was back at the Royal Institution, giving the general introduction to a three-day international meeting on ‘Swelling and shrinking’ held by the Faraday Society. Modestly describing himself as a newcomer to the field of colloid science, he pointed out that the definition of a gel was still a very loose one: ‘It has been taken to cover any fluid-containing system showing mechanical rigidity, with a structure which cannot be elucidated by the optical microscope. It is extremely difficult to draw a line between a weak gel and an anomalous fluid showing viscous elasticity, or between a gel and a paste of microscopically visible particles.’31 He referred to his work with Fankuchen with the gels of TMV that ‘demonstrated conclusively regular hexagonal two-dimensional associations of elongated particles with distances apart ranging from contact up to at least 500 Å’.32 He went on to tease out the question that he thought should be explored in many colloids.
The regularity of the structures showed that we are here dealing with energy systems possessing minima at these distances, or to put it another way, with attractive and repulsive forces in equilibrium, this equilibrium itself being determined by the ionic constitutions of the medium. Other work has shown that also in soaps, clays and inside the crystals of proteins, long-range forces, leading to equilibria are involved. One of the most interesting features of this conference should be the discussion of the physical nature of these long-range forces.
I am myself somewhat uncertain whether we are dealing here with a single or a complex phenomenon. It may well be that the forces working over a distance of the order of 10–30 Å, such as occur in clays, soaps and proteins, may be of a different kind from the longer range forces observed in the virus and hydroxide tactoids; and that the first may in fact be fairly normal association through water or solvent molecules held in fixed positions. But whether this is so or not, the longer range forces need a different type of explanation.33
Bernal’s introduction set the stage for a stimulating meeting of the Faraday Society, one which he had conceived as a result of the earlier meeting for the building industries, and it demonstrated his subtlety and fluency of thought. One can trace in his remarks strands of previous research including the thermodynamics of water and liquid structure that he initiated with Fowler, the virus work with Fan, Perutz’s observations about haemoglobin crystals acting as a sponge, and his own ideas on protein folding due to hydrophobic forces.
Many of the topics he mentioned were under investigation at Birkbeck. He continued to work on crystalline plant viruses with Carlisle, and the Cement Section were beginning to examine the structure of tricalcium silicate and related compounds, using powder and single crystal X-ray crystallography. Helen Megaw left in 1946 to become Director of Scientific Studies at Girton College, Cambridge. After a short hiatus, her role as assistant director for the Cement Section was taken over by Dr Jim Jeffery, who knew Sage slightly from the political scene in Cambridge before the war. Confronted with the task of studying crystals of tricalcium silicate, Jeffery found them to be impossible to orientate correctly for X-ray photographs. Sage informed him, somewhat impatiently, that similar problems confronted the crystallographers at the RI in the old days and ‘had been solved as a routine matter’.34 He gave Jeffery some clues, which enabled him to get the crystals properly set and soon led to his first research paper.
In his progress report for the opening of the Biomolecular Research Laboratory, Jeffery remarked that work in his section was being held back by a lack of available research workers. He would soon acquire a research student, Alan Mackay, who came with the perfect credentials for Birkbeck: a Cambridge physics degree and socialist convictions. Even before arriving, Mackay had come under Sage’s influence, at a distance. He had chosen The Social Function of Science for a prize won at Trinity College; his introduction to crystallography had been provided both by a course of lectures given by Peter Wooster and at a summer school set up by Helen Megaw in Cambridge. After graduating, he took a job with Philips, the electrical company. At the Philips Laboratory he became involved in research on calcium phosphate, one of the materials used in fluorescent tubes. He decided to study its structure by X-ray crystallography and to do this as a part-time PhD student at Birkbeck. Sage was his nominal supervisor, but immediately handed him on to Jim Jeffery. Mackay soon discovered that ‘supervision was rather slight. But the atmosphere was very cooperative and people just got on with things.’35
With his Birkbeck teams making the best of their limited resources to address fundamental questions, their professor continued to play an innovative role in government service. The post-war need for the efficient and rapid expansion in housing seemed to Bernal to provide an ideal opportunity for science to transform a rather backward industry. In a 1946 radio broadcast, Sage informed his audience that the really astonishing thing was how little building had changed over the preceding four or five thousand years: ‘the bricks, the mortar, the scaffolding, the trowels, the hods and most of the building appliances including the plans of the architect and the estimates of the contractor are all known from the times of ancient Egypt and Babylon.’36 Amongst major industries, building was the least mechanized, which was absurd when one considered that building a traditional house involved transporting about one hundred tons of materials and then lifting them against gravity. Building was a slow process because of the conditions faced by the workers – cold, damp, dust, poor food – which despite the labour-intensive nature of the industry had been largely ignored. Equally overlooked were the requirements of the eventual users of a home. As Sage pointed out in an earlier broadcast: ‘It is probable we know far more about the domestic habits in the Trobriand Islands than in the London suburbs.’37
The solution to many architects, engineers and politicians seemed to lie with the use of novel materials and the provision of prefabricated homes. Indeed so many new prototypes were being suggested that the Minister of Health (who had ultimate responsibility for housing) suggested that Bernal should study ‘every kind of the 1,300 varieties of prefabricated house which have been put forward, deciding which seem the best, and pulling all the ideas together’: a terrible task, thought Sage, which was ‘certain to get me down’.38 As usual, he found some solace in science.
For instance, if instead of prefabricated houses we were dealing with insects, we should find that ordinary people, looking at insects, would say, ‘There are an awful lot of them, you cannot make sense out of them.’ In the course of time, however, scientists have found classificatory methods of dealing with something like 20,000,000 species of insects, so that a mere 1,300 prefabricated houses is a comparatively simple business.39
To attempt an answer, Bernal together with the BRS launched a bold experiment in the summer of 1945. A dozen developments, each comprising fifty houses, were to be put up using standard methods in various parts of the UK. The contractors’ work at each site would be carefully timed and costed. At the same time, twenty-one groups of fifty prefabs would also be constructed and compared to the conventional buildings. Adjunctive studies would be made at the BRS and at Birkbeck of individual trades such as plastering, plumbing etc. in an effort to analyse the individual skills required so that selection, training and safety could be improved.40 The exigencies of the times did not lend themselves to such methodical planning. The pre-war labour force of one million in the building industry had shrunk by about two-thirds; apart from the loss of housing stock due to bomb damage, families were being created at an unprecedented rate as men returned from military service, leading to extra demand.41
The Minister of Health, Aneurin Bevan, while holding firm views on the quality of public housing the country needed to produce, was necessarily more involved with planning the National Health Service. While Attlee would have been
better advised to move the housing problem to another ministry, there would still have been the inherent drawbacks for any central attempt to plan in detail and undertake such an important enterprise. These were sharply pointed up by Picture Post in September 1946.
Mr Dalton, the Chancellor of the Exchequer, is responsible for providing the capital required to pay out the housing subsidies. Mr Arthur Greenwood, the Lord Privy Seal, has certain, vague, overruling functions. No one quite knows what he does do. Mr Tomlinson, the Minister of Works, directs the building industry, licensing private builders, controlling building materials, and providing temporary and prefabricated permanent homes. Mr Isaacs, the Minister of Labour, has to provide the manpower. The Minister of Town and Country Planning can decide against house building on any site. The Minister of Agriculture must be consulted about rural housing. The Minister of Supply deals with materials, and especially with the provision of house components, of which there is a serious shortage. Mr Bevan’s writ does not run north of the border, where the Secretary of State for Scotland controls housing. The tenth cook is Sir Stafford Cripps, who, as President of the Board of Trade, is now calling upon all builders employing more than fifty men to reply to ninety questions. Everyone in this industry considers that the issue of these forms will add to the delays and costs of housebuilding.42
Against a backdrop of bureaucratic muddles, shortage of labour and materials, the freezing winter and sterling crisis of 1947, the Attlee government managed to oversee the construction of about 100,000 prefabs during its first two and a half years in office. Sage later regretted that the best examples of prefabs tested, ‘beautiful and suitable in every respect’, were never built because they were too expensive (the typical post-war unit cost about £1,000). He said ruefully: ‘To get anything that could actually be built by prefabrication and did not cost too much was beyond the wit of man, and so we went back to the bricklayer.’43 The post-war prefabs proved popular with their occupants because of their simple but liveable design; they often lasted decades longer than originally intended. In the opinion of one architect and town planner, looking back half a century, ‘Time has shown that their construction and space-for-living standards were soundly conceived and carried through, both within the “units” and in their gardens and neighbourliness; being put down often on inner-city sites after war damage, they made homes where they were wanted.’44
The third aspect of Sage’s post-war rebuilding effort, in addition to Birkbeck and public housing, was to help repair the edifice of science. The first public manifestation came at the United Nations Educational and Cultural Conference in London in November 1945. The Americans had wanted a UN agency devoted to educational and cultural reconstruction in those parts of Asia and Europe blighted by the Axis Powers, but British scientists, in the words of Julian Huxley, considered it ‘essential that the word “Science” or “Scientific” should occur in the title of the Organization… the Conference should put the S in UNESCO’.45 In his address to the Conference, Bernal endorsed this idea saying that an international scientific commission had long been needed and ‘never more than in the present period of rehabilitation and reconstruction’.46 Nor should it be confined to physical sciences because ‘one of the main lessons of the War was that mixed research teams, ranging from mathematicians and physicists to economists and psychologists, were needed to cope with regional problems in their entirety’. The war had seen a complete pooling of American and British Commonwealth resources in science and demonstrated that the effects of science transcended national boundaries. He referred to work carried out by Kendrew and others in Cairo who examined ‘all the related problems of the region – of agriculture, industry and health – from Morocco to Baluchistan’. He sensed an appetite for science in many undeveloped countries of the world, and the ‘history of the Soviet Republics of Central Asia shows how rapidly science can be built up and how eagerly it is seized on by a population starting from a medieval standard of culture’.47 In the aftermath of the atomic bomb, the Americans soon accepted the political necessity for having the S in UNESCO, and Huxley would become its first Director General.
In February 1946, the Association of Scientific Workers organized a conference on ‘Science and the Welfare of Mankind’. It provided an opportunity for leading British scientists to expound their views on the social and ethical responsibilities of science and to listen to opinions from a number of foreign delegates. During the conference a resolution was passed that a World Federation of Scientific Workers (WFSW) should be formed, and its inaugural meeting was held in London that July. The prime mover of the federation, Frédéric Joliot-Curie, was elected its first president with Bernal and Nikolai Semenov, a Soviet chemist, as vice-presidents. The meeting was attended by observers and delegates from eighteen associations in fourteen countries. Joseph Needham, now the director of the natural sciences division of UNESCO, sent a message of goodwill. Part of the reason for the strong turnout from overseas was the Newton Tercentenary celebrations organized by the Royal Society. The Federation’s lofty goals were reported in the Manchester Guardian by J.G. Crowther, who would soon find himself its Secretary-General. He was most impressed by Bernal’s speech: ‘it was a brief, condensed, deep but transparently clear description of the aims of the new organization.’48
Earlier in July, the crystallography world had reunited happily at the RI under the genial presidency of Lawrence Bragg. To Bernal’s delight, Fan was one of a number of Americans who came, and despite the travel restrictions, it was also possible for von Laue and two others to come from Germany. A Russian delegation arrived a few days late, and the meeting resulted not only in the creation of an international journal, Acta Crystallographica, but the founding of the International Union of Crystallography (IUCr). Sage of course played a prominent role in planning all of this and was as energetic outside the meetings, entertaining the visitors. He and Fan threw a party for the American contingent at his sister Gigi’s flat. This was a high-spirited event, momentarily interrupted by the discovery of ‘a dead rat under the davenport in front of the fireplace’, whose presence was explained away on the spurious grounds that Gigi’s husband was a taxidermist!49
The crammed summer schedule of meetings, coming just after he had completed his work for the Joint Technical Warfare Committee, and the demands of administering his fragmented physics department left Bernal himself little opportunity for travel. In November, he did manage to go to Paris for a meeting to honour the fiftieth anniversary of the death of Louis Pasteur. For his lecture, Sage chose to talk about Pasteur’s first great discovery of the chirality or handedness of molecules.50 This experiment took place in 1848, a year after Pasteur gained his doctorate, and established the concept of asymmetrical molecules which, through association with fermentation and other living processes, became the key to Pasteur’s later work with microbes. Sage traced the genesis of Pasteur’s breakthrough from previous knowledge of crystals and chemistry, and ascribed his singular success to an ability to combine physical and chemical methods of analysis. In a Marxist aside, he also pointed out that Pasteur’s discoveries and their enormous consequences depended on him choosing to work with tartar, (‘a by-product of the greatest chemical industry of antiquity and the Middle Ages – the fermentation of grapes’) which had been well-studied because of its economic importance.
Bernal’s lecture was not just an entertaining and humble genuflection to the great Pasteur. It had spontaneity and excitement not customarily heard at august, historic meetings. For once, his preparation had been diligent before coming to Paris, and he had reached his own conclusions about why Pasteur had successfully found a solution to a problem that ‘had occupied the best brains of European science for the best part of twenty years’. Then, the day before he was due to speak, Sage was given access to Pasteur’s original notebooks at the Sorbonne. No one but Pasteur had looked at them for nearly a century and they revealed ‘another story, no less an achievement but far more illuminating’, which caused Sage to
recast his lecture. He delivered it in French and showed the audience pages of Pasteur’s handwritten notebook. He marvelled at the detail and accuracy of Pasteur’s observations, his familiarity with precedent and his grasp of crystallography.
The puzzle confronting Pasteur was that a small proportion of tartaric acid seemed to consist of a chemically identical, but physically distinct substance he knew as paratartaric acid. It was established by Pasteur’s day that the predominant natural tartaric acid rotated polarized light to the right, whereas paratartaric acid was optically inactive. The two acids had different melting points and their salts differed in solubility. Pasteur prepared double salts of both acids and crystallized them out. He examined ‘a very great number’ of crystals of the tartrate double salt and found that they were all asymmetric in the same way, with small facets presenting to the left (hemihedral-to-the-left). When he came to the paratartrate crystals he expected them not to show any asymmetry, but in fact found that ‘all the crystals bore the facets of asymmetry’. At this point, an emotional Sage reported to the audience that Pasteur’s heart missed a beat (j’eus un instant un serrement de coeur). The paratartrate crystals were of two distinct types, twins or mirror images, with their asymmetries to the right or left. Pasteur then meticulously separated out the two types of crystal and dissolved them again into separate solutions. The solution from the crystals hemihedral-to-the-left rotated polarized light to the right, just like the common form of tartrate crystals. Those crystals that were hemihedral-to-the-right caused polarized light to rotate to the left. If he took an equal measure of both, the mixed solution was again optically inactive – the two forms cancelled each other out. As Bernal put it in Paris: ‘That is all – the page is complete – molecular asymmetry is established.’
