THE ORIGINAL ARTICLE IN GERMAN
There are about 75 million cells in a tablespoon of blood. My grandfather, Rudolf Höber, an early cellular physiologist, spent his whole life studying these microscopic entities, trying to figure out how they work. He and others knew that electric current is conducted within and between these cells. How much electric current? How does it work? How do you measure it? My grandfather figured it out. He published the method of measuring conductivity in cells in a German scientific journal, Pflüger’s Archiv für die gesamte Physiologie der Menschen und der Tiere [“Journal of General Physiology of Humans and Animals.”] In the original, it looked like this:
A couple of years ago, I was surprised to learn that my grandfather’s work on the measurement of electrical current in cells was still considered relevant, sufficiently so that it warranted publication of its own commemorative article. Ron Pethig, Professor of Bioelectronics and Dr. Ilke Schmueser, Researcher, both at the University of Edinburgh, published “Marking 100 Years Since Rudolf Höber’s Discovery of the Insulating Envelope Surrounding Cells and of the Beta-Dispersion Exhibited by Tissue” (Journal of Electrical Bioimpedence, vol. 3, pp. 74-49, 2012).
THE ARTICLE AS NEWLY TRANSLATED INTO ENGLISH BY JAMES C. M. HWANG AND DIETER G. AST, 2020
Recently, I was unexpectedly contacted by James C. M. Hwang, a senior research professor in materials science at Cornell University. He had just completed an article on “Label-free Noninvasive Cell Characterization by Broadband Impedance Spectroscopy“, to be published next year by the Institute of Electrical and Electronic Engineers in its IEEE Microwave Magazine . His article reviews work done by various scientists in the past, including that of my grandfather, and finds that the principles they explored may be adapted to promise advances in science and engineering using today’s technologies. He found the work of my grandfather sufficiently interesting and relevant today that he enlisted a German-native-speaker colleague, Prof. Dieter G. Ast, to collaborate with him on producing an English translation. And now I am very pleased to be able to present “A Method to Measure the Electrical Conductivity Inside Cells,” available for the first time in English, thanks to Profs. Hwang and Ast. In the continuing documentation of our family’s history, we are grateful to them for this work. The complete translation appears at the end of this post.
HAVING TROUBLE UNDERSTANDING THESE ARTICLES?
I have been told that my Opa Rudi, the great physiologist, had hopes that I might follow him into a career in the sciences. Alas, my life took me in different directions. As a result, I must admit that my understanding of my grandfather’s groundbreaking article is limited, even in English. Nevertheless, it is a great satisfaction that scientists who do have the necessary knowledge find his work of a century ago to be relevant for further research, discovery and invention in the twenty-first century.
NOTE: The copyright on my grandfather’s original article is arguably still owned by the successor to the original publisher. Hence the following notice: Translated by permission of Springer Nature, Rudolf Höber, Pflüger’s Archiv für die gesamte Physiologie der Menschen und der Tiere, “Eine Methode, die Leitfähigkeit im Innern von Zellen zu messen,” copyright 1910.
Rudolf and Josephine Höber, my grandparents, fled Nazi Germany for Philadelphia already in 1933, but their son Johannes and his wife Elfriede were holding on in Düsseldorf in the belief that the Nazis couldn’t last. By 1937, my grandparents were desperate to have their children join them in America, so Rudolf and Josephine invited the young couple to come and visit them in America. It turned into a grand trip.
Elfriede kept a travel diary capturing her impressions of the country that would later become home to her and Johannes and their little girl, Susanne.
Elfriede complained on every page about the “unbearable,” “insane” heat (Washington and Philadelphia before air conditioning) but otherwise she and Johannes found much to like in America. They were impressed by Washington, where many of the iconic government buildings along the Mall had recently been finished, and they liked the democratic feel of the place.
In Philadelphia, the family attended the graduation of Johannes’s sister, Ursula, from the University of Pennsylvania medical school. They were impressed by the 1,500 graduates and the audience of 8,000 in Philadelphia’s Convention Hall, with Roosevelt’s Secretary of State Cordell Hull as commencement speaker.
Elfriede loved Connecticut: “This is the way I always imagined New England to be, with hills and forests scattered with enchanting villages with white wooden houses and white churches on trim green lawns under high trees. The houses are mostly laid back from the street and not separated by fences. As a result the country seems so open and gains a wonderfully elegant and fresh appearance.” In Woodbury, Connecticut, they asked directions of a police officer. “This guy was like a sheriff in the movies, going around in short sleeves with a big tin badge, unshaven, and stormed off in the middle of our conversation and threw himself into his car to chase another car that had exceeded the Woodbury speed limit.” The family drove from Philadelphia to Cape Cod in two cars, a Ford and a DeSoto, where Elfriede declared the beaches to be the loveliest she had ever seen.
Johannes and Elfriede traveled from Cape Cod (Fall River MA) back to New York by night boat! Elfriede: “Excellent cabin on the Commonwealth, a very old fashioned but very comfortable ship. Wonderful evening ride to Long Island Sound. Fantastic passage through the ocean of lights of the harbor of Newport. Night’s sleep interrupted by foghorns. Awoke at 6:15 in the East River. Reunion with the Empire State Building. Passage under the East River bridges that cross the river in great arches, all with two levels with eight lanes each. Generous good breakfast on board to prepare us for a day in New York.”
Johannes and Elfriede spent their last America day in New York, where Johannes indulged himself three times in “America’s national drink” — an ice cream soda. Elfriede: “Lunch in an enormous restaurant. The ladies room has 60 toilets, 30 for free and 30 for 5 cents. The noise of the streets is mind shattering. The noise of the El is deafening, the subway hellish. The people in this city seem to have lost all sense of hearing.”
And a highlight of the whole trip, an hour before they boarded the ship to return to Europe, was to go by New York’s City Hall and catch sight of Fiorello LaGuardia, whose reputation as a dynamic, progressive mayor had reached even into the corners of Hitler’s Germany. “We were able to watch as LaGuardia stood next to his car for a few minutes talking with advisers. Because we were speaking German, a man appeared next to us out of nowhere, unmistakably a cop, and didn’t let us out of his sight until the mayor left.”
Elfriede and Johannes returned to Düsseldorf in late June 1937, but the visit to his parents bore fruit. Six months later, Johannes and Elfriede began making their own plans to leave Germany and move to the United States. It would be nearly two more years, however, before the whole family could be reunited in Philadelphia.
The story of how Johannes and Elfriede eventually got out of Germany and into the United States is told in Against Time: Letters from Nazi Germany, 1938-1939. You can read more about that book here. Also available on Amazon.com.
By all accounts, my grandfather, Rudolf Höber, was a man with a sweet disposition. He had lived through tragedy in his own life, including the suicide of his father and the death of his brother in a mountaineering accident. Rudolf’s best friend, Albrecht Bethe, believed these experiences endowed him with a deep sympathy for the troubles of others. Although he was a brilliant scientist who explored the biochemistry of cells, he retained a sensitive appreciation for the beauty of the natural world as a whole. At a time when German professors held enormous social status and were known for their imperiousness, Rudolf was valued by his students and colleagues for his accessibility and camaraderie.
Among other things, Rudolf was a committed feminist. In an era when educational opportunities for women in science and the professions were limited, Rudolf mentored his new wife, Josephine, through medical school and into her practice as a physician. In addition, during his eleven years as an instructor [Privatdozent] at the University of Zürich (1898-1909) he supervised the dissertations of 24 medical students, two-thirds of whom were women.
Rudolf was named Associate Professor of physiology in the medical school at the University of Kiel in 1909 Then, exactly 100 years ago, Rudolf was appointed to the position of full professor and Director of the Physiological Institute. The title of Professor was then so exalted in Germany that it could only be bestowed by the Emperor himself. And so it was that Kaiser Wilhelm signed Rudolf’s appointment certificate on February 11, 1915.
By 1930, Rudolf had become internationally known for his scientific work and for the work of the Physiological Institute he led. In recognition, the University faculty elected him to the position of Rektor, or Chancellor, of the University. Still, he retained his charm and good nature. In May, Professor Hugo Prinz sent Rudolf a memo requesting that the Rektor issue an order directing that students were not permitted to congregate on the steps of the classroom buildings during the interval between classes. Rudolf responded the next day:
Your request that a notice be posted directing students that they are forbidden to stand on the steps during the interval between classes has been placed before me today. I should like to recommend to you kindly that you not insist upon this. It is surely not practical to ensure compliance with the prohibition. Furthermore, the steps are so particularly alluring as a place to linger in the sunshine that your proposal strikes me as rather cruel. I hope that your discomfort will not be too great, and that you will understand that I cannot put the requested directive into effect.
With best wishes,
In 1933, Rudolf emigrated to Philadelphia, where he received an appointment at the University of Pennsylvania. He continued to be popular among his students and continued to mentor women students in particular until his retirement in 1947.
My mother, Elfriede Höber, and my father, Johannes Höber, were counting on Johannes’ father Rudolf to support Elfriede and my sister, Susanne, then nine. Rudolf had fled Germany five years earlier, in 1933, and was a visiting professor at the University of Pennsylvania School of Medicine. His stipend from Penn was small, however, and by 1939 he was already supporting six relatives who were unemployed refugees. Johannes had arrived in Philadelphia a couple of months earlier, so it was Elfriede who had to file the visa application with the U.S. Consul in Stuttgart. After weeks of delay, the Consul rejected her application because Rudolf’s income was insufficient to support her on top of the people he was already carrying.
Johannes was crushed when he received Elfriede’s letter with the bad news. In the few weeks he had been in America, however, he had made a friend at the office where he worked. This friend, Walter Phillips, sensed right away that something serious had happened. He asked Johannes what was wrong. When Johannes explained, Walter too was distressed that his new friend’s wife and daughter were trapped and might be unable to escape from Germany.
The next day, Walter did something totally unexpected. Although he was a young recent law school graduate with a limited income, both he and his wife Mary had inherited some money from their respective families. Without my father even asking, Walter and Mary volunteered to be guarantors for the support of my mother and sister, whom they had never met. Within days, Walter got an affidavit from his bank confirming his and Mary’s deposits and secured endorsements from leading lawyers in Philadelphia. He wrote his own extraordinary letter of support to the American Consul in Stuttgart:
I am informed that Mrs. Elfriede Höber, a Ph.D. of Heidelberg University, and Susanne Höber, Düsseldorf (Germany), Pempelforterstr. 11, have applied at your consulate for permanent residence. Mrs. Elfriede Höber and her daughter wish to come to Philadelphia to join their husband and father and his family who were admitted to the United States for permanent residence some time ago. Dr. Johannes Höber, the husband, also a Ph.D. of Heidelberg, has been working for me for about three months as a research assistant. He has proved himself to be an extraordinarily bright, intellectually honest, public spirited and able person. I am so much interested in keeping him in Philadelphia that I am willing to give my personal guarantee that his wife, after being admitted to the United States, will never become a public charge.
For my own identification you may be interested in the following facts: My family on all branches have lived in the United States since before the Revolutionary War. I am a graduate of Princeton University and also the Harvard Law School. … At present I am volunteering my time to the Philadelphia City Charter Committee in the interest of good local government. … As shown by a separate affidavit the financial responsibility of my wife and me together – we are giving a joint affidavit – should be sufficient to give the necessary guarantee required by law.
May I say again that Dr. Johannes Höber has in my opinion the makings of a fine American citizen and that to have his wife here would help him to be even more of an asset. She too, I have every reason to believe, would contribute much to America. …
Very sincerely yours,
Walter M. Phillips
The impressive stack of documents did the trick. Although it took several more weeks, the Consul in Stuttgart accepted Walter and Mary’s assurances and granted the Elfriede and Susanne visas on July 12, 1939. Without Walter and Mary’s selfless generosity, my mother and sister would never have gotten out of Germany and I would probably not be alive today. When I was born three years later my parents gave me “Walter” as a middle name. It is a name I carry with great pride and gratitude.
Growing up, my father had no reason to think of himself as Jewish. He was baptized and confirmed in a Protestant church, his father was baptized and confirmed in a Protestant church and his father’s parents were married in a Protestant church in 1865. My father’s mother had been born into a Jewish family but converted to Protestant when she was a teenager. By the time my father was grown, his family lived an entirely secular life. They rarely if ever attended church, though they celebrated the holidays of the Christian calendar.
Several years ago, I found a newspaper clipping pertaining to the antisemitic Nuremberg laws among the papers of my grandfather, Rudolf Höber. Rudolf came to Philadelphia from Nazi Germany in 1933 as a professor at the University of Pennsylvania. Two years later, my father, Johannes, sent Rudolf this clipping from Germany. The article, captioned “Who is a Citizen?” was clipped from the Kölnische Zeitung (Cologne Daily) of November 15, 1935. The article is the first publication of the implementing regulations for the Nuremberg laws, which stripped German Jews of their citizenship. When Rudolf and his wife Josephine had left Germany, Johannes had stayed behind in Düsseldorf with my mother and sister. In the letter my father asked his father, Rudolf, for information about Rudolf’s father, Anselm. Was there any possibility that Grandfather Anselm, who died before Johannes was born, had Jewish origins that could have an impact on Johannes?
My father’s status as a Christian or as a nonbeliever was irrelevant to Adolf Hitler and the National Socialists. The Nazis considered Jewishness a “race,” an inheritable genetic trait separate and apart from the religion. Their laws defined a person as “Jewish” if he or she had three grandparents who came from Jewish families. Under that definition, hundreds of thousands of Germans who regarded themselves as Christians or nonbelievers were brutally persecuted by the Nazis as “Jews.” Individuals of mixed Jewish and non-Jewish ancestry were sometimes subject to less harsh treatment, but the administration of this purported legal structure was capricious– a bureaucrat’s guess at interpreting the code could mean the difference between life and death. Many scholars of the Nazi period today put the term “Jewish” in quotation marks when writing about individuals subject to these codes in order to distinguish between those defined as Jewish by the Nazis and those who used other criteria to identify themselves.
I became aware of all this only years after my father died. My parents were refugees from Hitler’s Germany and I understood them to have left because it was impossible for them, as Social Democrats, to live under Hitler’s inhuman regime. This letter and newspaper clipping show, however, that my father had also faced danger from the Nazis because of his grandfather’s Jewish ancestry. In my father’s letter to his father, he asked for information about Anselm. Under the crazy calculus of the Nuremberg laws, the birth certificate of the grandfather my father never knew might have been of crucial significance for his own future.
My grandfather’s response to my father was not among the papers that my family was able to preserve. My father probably left it behind in Germany when he came to the United States three years later. Suffice it to say that my father continued to live the secular life he always had and managed to avoid any situation in which the question of his grandfather’s Jewish birth might arise. He was thus able to evade the brutal consequences of being deemed a Jew in Nazi Germany. Readers of the posts on this website may recognize that I have subsequently discovered a great deal about my family’s Jewish origins. Much of that would have come as a complete surprise to my father.
When the Nazis took over Germany in 1933, one of their first acts was to fire thousands of the nation’s most brilliant scientists and academics from their university positions, either because they were Jewish or because they were deemed “politically unreliable.” Those expelled included Albert Einstein, Martin Buber, Paul Tillich, Edward Teller and countless others. My grandfather, Rudolf Höber, a professor of physiology at the University of Kiel, was also one of them. I previously wrote about his last months at Kiel here. All of these fired individuals faced the difficult problem of finding a new place to teach and continue their research.
Some American educators quickly recognized that Germany’s loss might well be America’s gain. The Institute of International Education, a foundation established in 1919 in the aftermath of World War I, quickly decided to establish a program to place exiled German academics in American universities. To head the new Emergency Committee in Aid of Displaced German Scholars, the IIE hired a recent graduate of Columbia University, a young man named Edward R. Murrow. A few years later, Murrow would become America’s most famous broadcast journalist, but in 1933 he led the effort to provide new careers for scientists and other scholars victimized by Hitler. His job was particularly difficult because the United States was in the depths of the Depression and money was tight everywhere. The Emergency Committee’s method was to match up a scientist with an appropriate university and have the university provide the scientist with a position. Then, using funds provided by the Rockefeller Foundation, the Emergency Committee would reimburse the university for all or part of the new faculty member’s salary. Once the word got around the scientific community that Rudolf Höber was interested in coming to the United States, a bit of competition arose to get him because of his prominence in cutting edge cellular biochemistry and biophysics. The Emergency Committee received offers from the University of Chicago, the University of California at Berkeley, the University of Tennessee and the University of Pennsylvania to create a visiting professorship for Rudolf. Ultimately the University of Pennsylvania won out in obtaining Rudolf for its medical faculty. The following is the offer extended to Rudolf by the University’s Vice president in charge of the School of Medicine:
Upon his arrival in the United States, Rudolf wrote to Murrow and expressed his appreciation for the work of the Emergency Committee in finding a place for him to continue his work in America. Murrow responded cordially.
Within a few months of receiving the offer from the University of Pennsylvania, Rudolf and his wife, Josephine, were on their way to America. They had escaped the Nazis and would live and work in Philadelphia for the rest of their lives.
Rudolf Höber and Josephine Marx were married in 1901. He already had his medical degree and a teaching and research position at the University of Zürich. In 1902, when he was 29, Rudolf published The Physical Chemistry of Cells and Tissues, a major theoretical work that would go through eight editions over the next 45 years. He also published as many as six technical articles annually documenting the results of his laboratory research.
With Rudolf’s encouragement, Josephine entered the medical school at Zürich and obtained her degree in 1909. She was a pioneering woman in the medical profession in Europe. Also in 1909, Rudolf and Josephine moved to Kiel, Germany, where Rudolf became professor of physiology and Director of the Physiological Institute at the University of Kiel. Although Josephine did not have an official position in the University, she was a partner and collaborator in Rudolf’s work, sharing his passion for the world of biochemistry, biophysics and the nature of cellular function. The couple travelled to the Stazione Zoologica in Naples and to the Woods Hole Marine Biological Laboratory to conduct research. In the 1920’s, Josephine became an active participant in the laboratory work, and collaborated on several of the research articles Rudolf published both in German and in English.
When the Nazis came to power in Germany in 1933, they expelled Rudolf from his position at the University of Kiel. Anxious to continue his life’s work, he accepted an invitation from the University of Pennsylvania to become a visiting professor at the medical school there, and he and Josephine moved to Philadelphia in 1934. The University, however, did not provide him with the kind of laboratory, apparatus and assistance that he had had at the University of Kiel. Although he received some financial support from American foundations, including the American Philosophical Society, Rudolf was frustrated by the limited facilities and staff available to him. Part of the solution was that Josephine joined him in the lab on a full time basis – without pay.
Rudolf and Josephine were equal partners in the lab for many years. The articles they wrote and published jointly continued to make findings in physiology that remain foundational in biotechnical work being done today.
Here is one of the articles Rudolf and Josephine co-authored, as published in the Journal of General Physiology:
To read the complete article, click here
Drawings of Hydra viridis and Podocoryne carnea by Rudolf Höber, age 17. [Click image to view full size.]
Rudolf Höber (1873-1953) was a prominent physiologist who conducted pioneering research into the electro-chemical properties of cell membranes. As an instructor at the University of Zurich, later a professor at the University of Kiel and head of the Physiological Institute there, and finally as a Professor at the University of Pennsylvania, he introduced many young doctors to the science of physiology.
Rudolf already became interested in biological science as a child, and started the serious study of microorganisms as a teenager. His notebook contains 83 meticulously detailed drawings of amoebae, paramecia, hydrae and the like. This notebook is a beautiful art object as well as a record of his studies. The image above is of one double page of that notebook, which Rudolf drew at the age of about seventeen.