Hedged Bets

In Copenhagen and Paris they planned cyclotrons along with the more familiar high-tension apparatus. In both cases the decisions were influenced, if not inspired, by the policies of the Rockefeller Foundation, which, as we know, in 1932 adopted Weaver's program excluding support for basic physics. Weaver did not wait for supplicants. In May 1933 he discussed opportunities with Niels Bohr, then shopping at the Rockefeller Foundation's headquarters in New York; Bohr's Institute for Theoretical Physics, which had been extended in the 1920s with some $45,000 of Rockefeller money, seemed poised for a push toward biology. Bohr himself had been lecturing in a vague philosophical way on the connection between his interpretation of quantum physics and the limits of biological research. More encouraging, no doubt, to Weaver was the possible collaboration of Georg von Hevesy, who was considering resigning from his institute for physical chemistry at the University of Freiburg (which, to complete the circle, had been built with the help of $25,000 from the Rockefeller Foundation). In the summer of 1933 Hevesy decided to leave Nazi Germany; in January 1934 the Rockefeller Foundation granted $6,000 to establish him in Bohr's institute for three years.

Hevesy was the world's expert in the use of naturally radioactive substances as tracers in chemical research. If he and Bohr could be teamed with August Krogh, professor of physiology at the University of Copenhagen, whose institute, yes, the Foundation had helped to build, the sort of group that Weaver wished to create would come into being and the Foundation would have the satisfaction of integrating and capitalizing its earlier investments. By the spring of 1934 Bohr had become actively interested in biology, "aided undoubtedly," according to W.E. Tisdale, the Rockefeller man who spoke with him, "by the ramifications involved in the purification of the German race." Bohr's plans, then still "rather vague and philosophical," firmed during the next six months, under the impact of the neutron activation work of Fermi's group: he would collaborate with Hevesy and Krogh, beginning with heavy-water physiology and continuing with artificial radioactive substances to be produced by a high-tension set.^[32] In the spring of 1935, the three put forward a proposal, which the Rockefeller Foundation immediately funded, for $54,000 over five years, of which $15,000 was payable on request for apparatus and the balance provided an annual grant for research expenses. With a pledge from the Danish Carlsberg Foundation to pick up Hevesy's salary when his Rockefeller stipend expired, the project had the guarantee of a good long life.^[33]

The $15,000 was to go for "the installation of an apparatus for the production of radio-active materials, patterned after the equipment of Lawrence at Berkeley." The rationale for the installation, according to Tisdale, advised by Hevesy, was to make possible preparation of radioisotopes not obtainable from high-tension apparatus operating at 1 MV. "Von Hevesy assures me that this project, involving as it does so much physics, is completely orien-

ted toward bio-physical problems and is in no wise an attempt on Bohr's part to obtain equipment to permit him in any wise to compete with the Rutherfords, the Lawrences, and others who are working in the field of pure [!] physics." Nonetheless, as Tisdale could not help but realize, a particle accelerator "would not be limited in its usefulness to the single purpose of preparing radioactive materials for the cooperative problem, but would also permit of studies in nuclear physics from the physics point of view." It was an awkward matter, this possible application to physical science of a machine built for biological research, but the eminence of Bohr, as Weaver had earlier remarked, would "probably protect us from anything that would reach real embarrassment" in so blatant a compromise of the Foundation's policy against supporting pure physics.^[34]

Although the cyclotron had been reviewed favorably in Denmark in 1934 as the machine of choice above a million volts, it was not the preference of the Copenhagen group. In November 1934 they considered the merits of Cockcroft-Walton, Van de Graaff, and Lawrence machines, and decided on a high-tension set designed for 2 MV. Having obtained 150,000 kroner for his primary objective from the Carlsberg Foundation, Bohr asked the Rockefeller Foundation for a cyclotron as a secondary piece of apparatus.^[35]

Hevesy did not wait for either machine. He procured a source for his experiments by raising enough Danish money to buy 600 grams of radium for Bohr's fiftieth birthday in October 1935. The cost of the gift, $21,000, exceeded the estimate for the cyclotron; but it could be used immediately, mixed with beryllium, to yield the neutrons to convert sulphur into radiophosphorus for Hevesy to feed to rats. The foundations of the hall to house the high-tension apparatus were going down as the radium came to hand.^[36]

The apparatus itself consumed much more than its budget—it swallowed the Carlsberg Foundation's 150,000 kroner and the Rockefeller Foundation's $15,000—and gave back much less. Unable to get beyond the region already well explored at Cambridge and elsewhere, it offered no incentive to applications to basic physics and so served its purpose, as an Italian physicist disdainfully reported, "of biological research." Early in 1937 Bohr returned to the Rockefeller Foundation for $12,500 to complete his cyclotron, for which he had also to raise additional support in Denmark. That came primarily from the Thrige Foundation of Odense, a charity run from the profits of a large electrical concern, which gave the magnet and generators.^[37]

In Paris Joliot did Bohr one or two better. The discovery of artificial radioactivity in 1934; the Nobel prize for chemistry in 1935; and, not least, the coming to power of the Popular Front, which appreciated science, in 1936, and which Irène Curie served for a time as undersecretary of state for scientific research; all this catapulted Joliot from chargé de recherches and consort of Marie Curie's daughter to a professorship at the Collège de France and the leadership of French nuclear physics.^[38] Early in 1935, before acquiring the prize or the professorship, Joliot had turned to the Rockefeller Foundation for help in converting his research to biophysics, since, according to Tisdale, "he had no hope of competing with the Rutherfords, the Lawrences, etc., who seem to have a great deal of capital behind them." As for himself, Joliot said, he had access to a small Van de Graaff at an engineering school outside Paris near Arcueil, where he wished to build two more accelerators, both high-tension machines, that is, transformers in series (to reach 2 MV) and an impulse generator (3 MV). All would be used to make isotopes for biological research; three were required so that at least one would always be working to meet the expected high demand. Not a word about cyclotrons.

Joliot had collected promises for the land and for operating expenses calculated at 120,000 francs; all he needed was the capital investment, some two million francs for erecting and equipping the laboratory, from the Rockefeller Foundation. "We know the great profit that science and humanity have drawn from the judicious help that the Rockefeller Foundation has given to similar undertakings."^[39]

The Foundation's initial response was not favorable. Weaver doubted that Joliot could compete successfully with the Cavendish, Berkeley, Caltech, and the Carnegie Institution, and he doubted that Joliot's conversion to biology was sincere. "I suppose that Joliot and his associates have been only human in their desire to give a biological slant to their proposal." But Joliot's professions convinced the men in the field. There was no alternative to making big complicated tools of physics to create biologically useful radioisotopes and no way to make up-to-date tools without research into their basis in physics. The magnitude of Joliot's proposal forced the Foundation to reconsider its policy of closing out support for physics per se. "The proposal as a whole is indicative of the limitations that are inherent in our saying that 'pure physics' has gone far enough—now let's give no more support to it but only to its applications. That attitude runs into a ditch every time."^[40] The Foundation eventually did decide to help Joliot, but not before he had helped himself.

By the end of 1935 Joliot had added the impulse generator at the laboratory of the Companie générale electrocéramique at Ivry to his arsenal. This device, rated at 3 MV, proved a very poor source of radioisotopes but a cornucopia of x rays, of which it gave the equivalent of the gamma radiation from more than a kilogram of radium. That impressed the Rockefeller Foundation. In 1937, after Rutherford had advised a major British center for cancer treatment to invest in 20 grams of radium for a single bomb, Tisdale informed the same center that Joliot could give in 19 seconds an irradiation of high-voltage x rays equivalent to six

hours' exposure to a gram of radium. Such apparent progress; lavish support from the French government, which put up well over two million francs to buy and furnish a "Laboratoire de synthèse atomique;"^[41] strong collaboration with French biologists; and "the ability and expertise which merited the award of the Nobel prize" brought Rockefeller support to Joliot's nuclear enterprises, some $20,684 for the study of life, disease, and death, in December 1937.^[42] Joliot stuck to his word: neither he nor his wife did any of their research in nuclear physics or chemistry during the 1930s with beams from Joliot's accelerators. Instead, they used their standard, old-fashioned source, polonium, which gave enough alpha particles to use either directly or, via beryllium, as a source of neutrons.

When the committee planning expansion of the Cavendish went to Paris during Easter 1937, it inventoried Joliot's equipment as follows: the impulse generator at Ivry; a small Van de Graaff at the Collège de France; two more Van de Graaffs brought from Arcueil for exhibit in Paris; and, again at the Collège, "in a room surrounded by paraffin and borax solutions," a cyclotron under construction. It was the stepchild of Joliot's family of accelerators. Arno Brasch visited the family in the spring of 1938. In his report, he made no mention of the cyclotron, which was not yet working, but lavished praise on the complex of high-tension generators, which had no equal anywhere in his experience.^[43]