Absolute Zero and the Conquest of Cold (18 page)

In his maturity, James Dewar claimed that his most formative early experience was the long illness brought on by his falling through the ice of a pond in 1852, when he was ten. During the two years it took for this youngest son of a vintner and innkeeper in Kincardine-on-Forth, Scotland, to recover from the rheumatic fever that followed the fall and his rescue—an illness that crippled his limbs, reducing him to moving about on crutches—the village carpenter taught him how to construct violins, as an exercise to strengthen his fingers and arms. Dewar later referred to his violin-making as the source of his manipulative skills in the laboratory. The connection he did not articulate, but which seems equally true, was that his fall through the ice birthed a fascination with cold that informed and directed his most productive years. Between the moment at the close of December 1877 when Dewar learned about Cailletet's liquefaction of oxygen, and the moment in 1911 when Kamerlingh Onnes discovered superconductivity, Dewar was increasingly consumed with reaching absolute zero and discovering the properties of matter in the ultracold environment, so completely consumed that his research became an obsession.

In 1859, then seventeen, Dewar had matriculated at Edinburgh University, residing there with his elder brother, a medical student; to earn a post as a laboratory assistant, as evidence of his dexterity he displayed one of the fiddles he had made. At Edinburgh he won various high prizes in mathematics and natural philosophy, and during his university years he studied with or assisted in the laboratories of several of the most respected physicists and chemists of the day. He designed a brass-and-wood model of what Friedrich Kekulé, the father of structural chemistry, had postulated as the structure of benzene. Dewar's model showed that the actual benzene ring could be any of six different forms; a leading British chemist sent the model to Kekulé, who asked Dewar to spend a summer with him in Ghent, a signal honor. Appointed in 1875 as Jacksonian Professor at Cambridge, Dewar taught there for the next forty years, but he never fulfilled one of the requirements of that post—to discover a cure for gout—and although he rubbed shoulders there with accomplished physicists and chemists, and collaborated on some fine spectroscopic research with colleague George Downing Liveing, he was not at ease at Cambridge. "The crudity of youth was still upon him," a chemist friend, Henry Armstrong, later reminisced, "and the free manners of a Scottish university were not those of conventional Cambridge—his sometimes imprecatory style was not thought quite
comme ilfaut
by the good. No attempt was made to tame him or provide means for the development of his special gift of manipulative skill."

In addition to Dewar being "a terrible pessimist," Armstrong recalled, he was "not great as a teacher," perhaps because his mind was "too original and impatient" and because "he never suffered fools gladly"; moreover, when Dewar had not meticulously prepared himself, his lectures could be "incoherent." Yet when he did carefully prepare lectures, they were "logical" and "fascinating"—characterizations applied to the March 31,1876, Friday evening discourse that Dewar delivered at the Royal Institution, the success of which sealed his 1877 appointment there as Fullerian Professor of Chemistry. With his wife, Helen, the thirty-five-year-old Dewar moved his furnishings into a small apartment at the Royal Institution. The Dewars were childless, as every resident couple had been since the inception of the Royal Institution in 1799. Augmenting the apartment were the facility's well-stocked library, a separate Conversation Room in which tea and coffee were served and where members could peruse journals or newspapers from the Newspaper Room, and other amenities. Dewar went to work in the basement laboratories, which John Tyndall, the current director, had had redone in 1872, demolishing—at great emotional cost to himself, Tyndall let it be known—the place where Faraday had made his many discoveries. This basement "studio," Armstrong later recalled, was much to Dewar's liking, full of heroic scientific ghosts and available to be visited at all hours of the day and night. The only thorn in Dewar's side was Tyndall, who continued as director for a time. Tyndall was an insomniac, Dewar suffered from chronic indigestion; sometimes, late at night, both resident geniuses walked the halls; Dewar could occasionally be heard by the staff, speaking to the ghost of Faraday.

Impressed by the important work done by Davy and Faraday on electricity, magnetism, and several other areas in which chemistry and physics overlapped, Dewar resolved to maintain their level of experiment and insight. When in December 1877 Cailletet showed the way to reopen the series of gas-liquefaction experiments that Faraday had abandoned in 1845, Dewar seems to have decided that the gods of scientific inquiry were indicating the direction his future work must take.

Prior to his installation in the Royal Institution, Dewar had been a thoughtful and deft experimentalist; at Albemarle Street he developed into the greatest showman of science, "a combination of the magician with the actor," Henry Armstrong recalled, with "force and individuality comparable with that displayed by the most individual actor of his time, his friend Sir Henry Irving." An equal influence on the theatrics of Dewar's performance was his stage, the amphithea
ter at the Royal Institution. Behind the twelve-column, thirteen-window exterior, a grand stairway led to the second floor and the relatively compact and steeply angled open semicircle of an amphitheater, with its dark wooden pews and banquettes seating about 750. Good sightlines from every vantage point and fabulous acoustics won it acclaim as among the world's best theaters for the spoken word. Also adding to Dewar's brilliance was an almost perfect audience, the distinguished, educated, moneyed crowd of the Friday night lectures, an audience that possessed enough elementary understanding of science to appreciate his demonstrations. Many guests would come dressed as for the opera.

In his first lecture as a resident, Dewar demonstrated the production of droplets of liquefied oxygen from a Cailletet machine, along with other fascinating low-temperature tricks. Under his hand, solid dry ice boiled in liquid ether, continuously giving off gas bubbles. Forty years earlier, Faraday had done the same thing in the same venue, using dry ice in ether, the Thilorier mixture. After crediting Faraday with having "a mind full of subtle powers of divination into nature's secrets," Dewar went his predecessor one better, demonstrating that the solid's temperature was so far below ordinary freezing that when he dropped it in water, it did not emerge from the water coated with ice.

As text to accompany such presentations, he scoured the literature of his forebears—contained in the institution's library, which he liked to frequent—to find facts and portents about liquefaction. His most trenchant prediction was a long-forgotten, 1802 gem from John Dalton: "There can scarcely be a doubt entertained respecting the reducibility of all elastic fluids of whatever kinds into liquids; and we ought not to despair of effecting it in low temperatures, and by strong pressure exerted upon the unmixed gases." Dewar promised the Friday Nighters that he would continue the Royal Institution's tradition of work in liquefaction and the exploration of low temperatures.

Dewar seemed to have found in the bag of tricks that low-tem perature research made possible, and that were less available in other areas of chemistry and physics, a reason for being that science alone could not provide him. To a far greater degree than many equally competent experimenters, he enjoyed performing and being appreciated by lay audiences. Several hundred years earlier, Robert Boyle had acidly described the difference between his own work and that of men such as Cornelis Drebbel, writing that "mountebanks desire to have their discoveries rather admired than understood, [but] I had much rather deserve the thanks of the ingenious, than enjoy the applause of the ignorant." James Dewar sought appreciation from many audiences, and he perhaps pursued low-temperature research rather than other areas because it could provide him with applause from lay audiences as well as from fellow scientists.

For the next several years after his initial Friday night demonstration of the Cailletet process, however, Dewar made little progress, hampered by the same difficulties Cailletet and Pictet encountered in producing more than a droplet at a time of liquefied oxygen and nitrogen. In the meantime, two men at the Jagiellonian University in Krakow, Syzgmunt Florenty von Wróblewski and Karol Stanislaw Olszewski, seized the lead in the liquefaction race.

The year of greatest importance to Polish youth in the mid-nineteenth century had been 1863. Syzgmunt von Wróblewski was eighteen that year; Karol Olszewski, seventeen. Von Wróblewski was the son of a lawyer from the Lithuanian area, and a student at the university at Kiev, then a city under Russian control. Since 1795 Poland had been partitioned, its area split mainly between the Austrian and Russian monarchies; the cause of a free Poland had been in contention afterward, occasioning such outbursts as the proclamation by Karl Marx and Friedrich Engels in 1849 that the liberation of Poland was the most important task facing the workers' movement in Europe. A January 1863 Russian plan to press-gang Polish students into the tsar's army sparked student revolts throughout the land. Von Wróblewski joined that revolt and for his participation was arrested, convicted, and sentenced to hard labor in Siberia.

Karol Olszewski, born only months after his father died in the previous, unsuccessful revolt against the Russians, was naturally also caught up in the ferment of 1863. But before he could make his way to the frontline and commit the sort of offense for which von Wróblewski was sent to Siberia, the Austrian authorities detained him. They released him, unharmed, only after the revolt had been crushed. In 1866 Olszewski entered the venerable Jagiellonian University at Krakow—alma mater of Copernicus—and pursued his interest in chemistry and tinkering, becoming what a later colleague, Tadeusz Estreicher, described as a man of "great practical sense and ability in the construction of machinery." Held back by a lack of funds with which to complete his education and to buy machines and materials for his studies, Olszewski managed after three years to become the assistant to the chemistry professor. After repairing an old Natterer compression machine, he used it to solidify carbon dioxide; though the accomplishment was neither new nor particularly difficult, it established Olszewski as a good laboratory hand. He went to Heidelberg in 1872 to study chemistry under Robert Bunsen, inventor of the Bunsen burner, and returned, doctorate in hand, to become chemistry professor at Krakow in 1876.

Von Wróblewski's path to the Jagiellonian was more circuitous and loftier. In Siberia, interspersed with his bouts of hard labor, he read widely, especially in physics, and constructed for himself what he believed to be an entirely new theory of electricity. Released in a general amnesty in 1869, he was in very poor general health and on the verge of going blind. After two operations and six months in a dark room at a Berlin hospital, he emerged and began to study physics under Helmholtz, though he had been warned not to read or write lest he lose the remainder of his vision. During part of his recuperation, in the Swiss Alps he met Clausius, who encouraged him to continue his studies and to concentrate on things related to thermodynamics. Working variously at Berlin, Munich, and Heidelberg, von Wróblewski received a doctorate for his studies of electricity and did other research on the ways in which gases were absorbed by various substances. Offered a professorship in Japan in 1878, he turned it down in favor of the opportunity of returning to a Polish venue, even though Krakow remained under Austrian control; in exchange for his willingness to come to the Jagiellonian, he received a fellowship to spend the next few years studying in Paris, with forays to Oxford, Cambridge, and London. He wrote to his sponsors that he learned more in five months in England than he had in his previous five years of studies. In Paris he worked with a Cailletet liquefaction apparatus, and he brought one such machine with him when he took up his duties at Krakow in 1882.

It was a moment when the Jagiellonian University, which had been less active in science during the period of the partition of Poland, was again moving toward the forefront of research in a half-dozen varied scientific fields. Very quickly after von Wróblewski arrived in Krakow, the nearly blind theoretical physicist and the mechanically inclined practical chemist, Olszewski, decided to team up to attack the liquefaction of oxygen. The few drops produced by Cailletet were not enough for anyone to experiment with; what was needed was to make and keep a quantity of liquid oxygen at its boiling point, and that was what the Poles set out to accomplish. Though the two men were the same age, von Wróblewski was a full professor but Olszewski was not, von Wróblewski's presence at the Jagiellonian was more highly valued (and remunerated), and his research was well funded, whereas Olszewski had limped along with equipment a quarter century out of date. Today it is not clear which man came up with the idea for an improved way of producing liquefied oxygen; they both later claimed sole credit.

Regardless of whose idea it was, their innovation owed much to the theoretical explanation of the continuity of the gaseous and liquid states provided by van der Waals. Moreover, the basic principle they used—evaporation—dated back to ancient Egypt: the desert denizens regularly cooled foods at night in the open air by putting them under a pan of water and letting the water evaporate, which lowered the temperature of the pan and the food. Van der
Waals had made clear a principle that underlay all evaporation, that even in a liquid-gas mixture, the molecules in gaseous form are less dense than those in liquid form. This principle was the basis of the intuitive leap made by the Poles: their technique drew off the lighter molecules, lowering the temperature of the remaining ones, and resulting in liquefaction. In March-April 1883, utilizing a combination of the methods of Cailletet and Pictet, the new Cailletet pressure apparatus that von Wrôblewski had brought back from Paris, and Olszewski's adept handling of machinery, the pair liquefied air, then carbon monoxide and nitrogen, and, finally, oxygen. On April 9, 1883, they triumphantly reported to the Académie des Sciences that a measurable quantity of slightly bluish-color liquid oxygen was "boiling quietly in a test tube" in their laboratory, at a temperature of—180°C.