Popular Science Monthly/Volume 87/July 1915/The Progress of Science
THE REPUBLIC OF LETTERS AND OF SCIENCE
The importance of maintaining good will between the scientific men and the men of letters of the different nations is so great that we are glad to have the opportunity of printing here the remarks made by Professor Heinrich Morf at the opening of his winter course at the University of Berlin. As translated for us by Miss Agatha Schurz, Professor Morf said:
"On the morning of the first day of August I closed these lectures on the history of French literature. All hope of preserving peace had not yet vanished at that hour, and I belonged to the optimists. My optimism, however, was put in the wrong by the course of events, and we are now living in a state of war.
"The terrible conflict of arms is also a, conflict of minds. Who could pride himself—if, indeed, it were a matter of pride—on having preserved his perfect composure! Even those who are not directly involved in the strife of arms, the neutrals, take sides spiritually and morally. The whole world is divided and torn into two great hostile camps. The greater part of the Latin world is our enemy. The intellectual bridges which connect nations seem to have been shattered, and across the yawning abyss ugly and agitated words are flying back and forth. The worst civil war is raging in the Republica litterarum, in the domains of science and art, which at other times unite all mankind and make of them world-citizens of a Civitas Dei.
"But of that civil war of the world let us not speak here. We have met for a labor of peace. The appeal which we teachers of German universities sent out into a world torn by war begins with the words 'We professors at Germany's universities serve science and devote ourselves to a labor of peace. As soon as your teacher has ascended this platform and has closed the door of this lecture-room to the outer world, we shall and must turn away our thoughts for an hour from that which day and night oppresses our hearts, and we must compel our minds to concentrate on scientific work. The passions of the day must not enter here: we will leave them behind us. Science demands of us this act of self-discipline and of self-control. Whoever does not feel capable of it will not be able to serve science or to enter into any close relation to her; he will remain unsatisfied even in this lecture-hall devoted to her service.
"I should like to speak to you here of the French culture of the past, just as I have always done since I first took upon myself, thirty-five years ago, this task in Bern, on the borderland of the French and German languages. At that time I referred to Goethe, as I do to-day; for he has taught us that, with sympathetic interest for the culture of the Latin peoples, may be combined a deep love for the Teutonic, for our own. For all these years I have spoken to German youth of these Latin subjects with a feeling born of respectful regard for what is foreign to us, and of love for what is our own. That they appreciate what I have done they have kindly proved to me, even in these dreadful days, when friendly notes from writers personally unknown to me have reached me from the western front, expressing grateful remembrance of the hours when they had here studied French culture with me.
"The purely scientific character of these lectures, therefore, will not be changed. I should like, as heretofore, to train your minds to a scientific mode of thought, and to lead you to a dispassionate historical conception and judgment of things of the past of foreign lands. Scientific work of this kind does not separate, it unites; it teaches to understand and to discern, not to despise. While I am saying this to you, the figure of my teacher, Gaston Paris, appears before me. Those years of study, those fellow-students, arise before my mind, with which are connected indelible memories of distant days of my youth and of recent happy intercourse. You have often heard from me the names of these collaborators and investigators. I have often here expressed to you what our science owes them, for what I myself am indebted to them.
"Beyond the bloody struggle of the present looms the dominating personality of Gaston Paris. Gratefully I salute his spirit from this place. I have often acknowledged the deep decisive influence he has exercised upon me; the best that I can give you has been aroused in me by him. Listen to the words with which he, the man of thirty, reopened his lectures at the Collège de France in December, 1870, in besieged Paris, 'surrounded by the iron ring, which the German armies have closed about us.' After a short reference to the work of the last term and to the students who had followed the call to arms, and some of whom might be in the hostile army of the besiegers, he spoke of the scientific problems which even in these anxious hours, 'when the Fatherland claimed all our thoughts,' still had a right to be considered.
I do not believe that, on the whole, patriotism has anything to do with science. The lecture-room is no political platform. Whoever uses the lecture-room to defend or to attack anything that lies outside of its purely intellectual province diverts it from its true purpose. I advocate unconditionally and without reservation the doctrine that science must adopt as her only aim the search of truth—truth for her own sake, without troubling herself whether this truth may, if put into practise, have good or evil, regrettable or gratifying consequences. Whoever indulges in the slightest concealment, the most trifling change in the presentation of those facts which are objects of his research, or in the deductions which he draws therefrom—though led by patriotic, religious or even moral considerations—is not worthy of a place in the great laboratory to which honesty is a much more indispensable title than skill or cleverness.
If the studies pursued in common are so conceive and are carried on in this spirit in all civilized countries, then they will constitute a great Fatherland, high above all barriers of hostile nationalities, undefiled by war, unmenaced by conquerors, in which minds can find the refuge and union which the Civitas Dei offered them in other days.
"Thus a young French scientist, who was at the same time an ardent patriot, spoke to his hearers on December 8, 1870. I do not know if patriotism in Paris has found similar expression today. Time will show. But I wish to remind you to-day of the words of this strong and noble man, who combined in wonderful harmony loyalty to the soil and citizenship of the world—love of his country and love of truth. May his words not have been spoken in vain!
"The German student of Romance subjects finds the fields of his labors to a great extent covered with ruins. The blossoms which had promised fruit have been blighted. The fruit which seemed already garnered is destroyed. New life will surely blossom from these ruins, for nature wills it so, for the salvation of mankind. Wherever the ground is strewn with wreckage we shall again draw furrows and scatter seed, and those who come after us will gather the harvest. And Teutons and Latins will enjoy it in common. Without this faith in the power and the perpetuity of the Civitas Dei of science, I should not stand before you to-day as your teacher of Romance philology, and your guide through French literature of the eighteenth century, which domain we expect to explore during this winter term quietly and with steadfast purpose.
PROFESSOR ONNES AND THE LEIDEN LABORATORY OF PHYSICS
The Franklin Institute has made the first awards of its Franklin medal, established last year by a gift from Mr. Samuel Insul, to Mr. Thomas Alva Edison and to Professor Heike Kamerlingh Onnes. Mr. Edison's great contributions to the applications of science are known to us all. It may be of interest to give some statement of the work of Professor Onnes and the Leiden Laboratory, taken from the report of the institute. At the present time it is well to remember the important contributions made to science by the smaller nations. It is certainly a remarkable fact that Holland should have more physicists of high distinction than the United States.
Heike Kamerlingh Onnes was born on September 21, 1853, at Groningen, Holland, where his father was engaged in manufacture. He was educated in the schools of his native town, and there also he began his university studies in 1870. Two years later he removed to Heidelberg, where he spent three semesters, working under the direction of Bunsen and Kirchoff. He then returned to Groningen, and a few years after he became assistant to Professor Bosscha at Delft, where he commenced work upon his thesis for the doctorate. In 1882 he and H. A. Lorentz were appointed professors of physics in the University of Leiden, then a little known and quite unpretentious seat of learning (so far as physical science was concerned), but which, as a result of the collaboration of these two highly-gifted young physicists, has become one of the world's great centers of physical research.
While Lorentz confined his energies mostly to the fields of theoretical and mathematical physics, Onnes directed his energies to the creation of a laboratory for experimental research. In spite of great obstacles, particularly of very inadequate appropriations for equipment and maintenance, the indefatigable director found ways and means of furnishing his laboratory with the special machinery and precision instruments required for the researches of the professors and their students. A very important—in fact, an essential—factor in this development was the establishment by Onnes of a training school for mechanicians, and it was in the shops of this school that many of the special instruments for the laboratory were constructed. At the same time the young men engaged there were trained to assist the director in carrying out the often difficult and intricate operations in his experimental work. On various occasions Professor Onnes was thus enabled to command a force of some thirty assistants, to each of whom a special duty was assigned.
The work of this great laboratory at Leiden is recorded in the Leiden Communications, published since 1891, and includes a vast number of most important contributions to physical science. Among them are investigations on magneto-electric effects, as well as a series of most important papers upon magneto-optical phenomena, such as the classical one by Zeeman, describing the discovery of what is now known as the Zeeman-effect. But, while these early investigations were all carried out under Onnes's direction, they were in many cases inspired or suggested by his distinguished colleague, H. A. Lorentz. The really representative work of the laboratory has been in the field of molecular physics, and particularly in research at low temperature. The great bulk of the Leiden Communications is devoted to the records of those remarkable series of researches which were conceived by Onnes himself and carried out under his direction.
The history of these researches began with the creation of the cryogenic laboratory, and it may be divided into several distinct stages or periods. The first of these was occupied with the production of liquid oxygen on a large scale, and with the use of this material in a three-cycle process of obtaining 
August Weismann
The distinguished zoologist, late professor in the University of Freiburg, known especially for his contributions to the theory of heredity.
low temperatures, by which Onnes was enabled to maintain and control the temperature ranges from -23° to -90° (methyl chloride), from -105° to -165° (ethylene), and -183° to -217° (oxygen). This goal may be said to have been attained about 1894. The second stage was characterized by the introduction of liquid hydrogen and the production of temperatures below -217°. The abnormal behavior of hydrogen gas when it is allowed to expand under reduced pressures made it impossible to liquefy it at higher temperatures; and the condensation of this gas was first achieved by Dewar, of London, on May 10, 1898. This added a new range of available low temperatures from -253° to -250° in which Dewar made a number of highly remarkable observations, including the solidification of hydrogen. But Onnes very promptly appropriated this new range for his research work, and constructed novel and very efficient apparatus for the production and utilization of the new refrigerant.
The Netherlands government, realizing the importance of the work, now granted considerable appropriations for the extension and equipment of the laboratory, and with its completion a new era of constantly increasing low temperature research began. New methods and instruments for the exact measurement of temperatures below the boiling-point of liquid hydrogen were devised, and the behavior of mixtures of hydrogen and helium was systematically investigated. Finally, the apparently incoercible gas, helium, was reduced to the liquid state. This crowning triumph of low temperature research was achieved on July 10, 1908. This achievement aroused universal interest in the work of Onnes and doubtless prompted the award to him, in 1913, of the Nobel Prize in Physics.
During the past few years Onnes has made some most remarkable discoveries with reference to the electrical resistance of certain metals at temperatures only a few degrees above the absolute zero of temperature. The resistance of metals ordinarily varies approximately with the absolute temperature, but at temperatures only a few degrees above the absolute zero it suddenly becomes so small that it can hardly be measured. For mercury this "critical temperature" is 4.2° absolute; for lead it is 6.1°, and for tin 3.8°. Below these temperatures the resistance is practically nil, and Onnes terms this the "supraconductive" state. In this state the metals no longer obey Ohm's law—there is neither a potential drop nor a production of heat.
SCIENTIFIC ITEMS
We record with regret the deaths of Joseph Johnston Hardy, professor of mathematics and astronomy at Lafayette College; of Dr. Samuel Baldwin Ward, since 1884 dean of the Albany Medical College and professor of the theory and practise of medicine, and of James Blaine Miller, of the Coast and Geodetic Survey, a passenger on the Lusitania.
The Barnard gold medal awarded every fifth year by Columbia University, on the recommendation of the National Academy of Sciences, "to that person who, within the five years next preceding, made such discovery in physical or astronomical science, or such novel application of science to purposes beneficial to the human race, as may be deemed by the National Academy of Sciences most worthy of the honor," will be given this year to William H. Bragg, D.Sc, F.R.S., Cavendish professor of physics in the University of Leeds, and to his son, W. L. Bragg, of the University of Cambridge, for their researches in molecular physics and in the particular field of radio-activity. The previous awards of the Barnard medal have been made as follows: 1895—Lord Rayleigh and Professor William Ramsay; 1900—Professor Wilhelm Conrad von Röntgen; 1905—Professor Henri Becquerel; 1910—Professor Ernest Rutherford.