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.
When I went to my late sister Susanne’s Vermont home recently, I spotted this familiar old family vase. I placed it on a table on the sunny porch to photograph it. Then, with relatives watching, I turned the vase over and poured out — some ordinary sea sand.
How did I know there would be sand in the vase? The answer is a story I heard from my father a long time ago.
My great-grandfather, Jacob Marx, was a banker and investor in Berlin in the mid-nineteenth century. He made some smart investments in the industrial boom before and after the Franco-Prussian War in the early 1870s. Some of his new wealth he invested in art, including several antique Delft vases.
After Jacob died in 1883, the vases were owned by his widow, Marie, and when she died in 1913 they were inherited by my grandparents, Rudolf Höber and Josephine Marx Höber. At that time, Rudolf and Josephine lived on Hegewischstrasse in Kiel, a university city and naval harbor on the Baltic Sea.
Josephine displayed the vases atop a tall Schrank, an antique wardrobe cabinet in the family living room. Inconveniently, however, a streetcar line traversed the street in front of the residence, and every time a trolley went past the Delft vases shook and rattled. The noise annoyed Josephine, who also feared the old pieces would be shaken off the cabinet and break. To resolve the problem, she gave her ten-year-old son Johannes a metal pail and told him to go down to the shore of the Baltic, fill the bucket with sand and bring it home. Josephine then filled each Delft vase with sand. The extra weight kept them from rattling on top of the Schrank for the next 19 years.
In 1933, the Nazis forced Rudolf out of his position in Kiel and he and Josephine emigrated to Philadelphia. They took the vases with them — and the sand went along. Josephine died in 1941 and Rudolf in 1953 and then the vases — and the sand — were inherited by my parents, Johannes and Elfriede. They moved several times and at each move the vases were carefully packed and the sand with them.
Johannes died in Washington DC in 1977 and Elfriede in Oakland, California in 1999. When we divided up Elfriede’s possessions among her three children, my sister Sue expressed a desire to have the Delft vases. We wrapped them and transported them — and the sand — to the house in Barnard, Vermont, where she and her husband Lloyd worked and wrote in the summers for many years. And there they have remained until now. The next home for the Delft vases and the sand from the Baltic Sea remains to be seen.
More stories about the Hoeber family are to be found in Against Time: Letters from Nazi Germany, 1938-1939, published by the American Philosophical Society. Information is available here. Also available at Amazon.com
I love this picture. A balding man in a brown work coat lies on a wooden garden lounge chair incongruously brought into the paneled rooms of the Physiological Institute at the University of Kiel, Germany in 1927. The experimental subject is wired to an electrical apparatus on a table that is in turn wired to a morning-glory-shaped loudspeaker horn. We are standing with a group of medical students waiting intently for the sound of the subject’s heart muscles and nerves to emerge from the horn (and perhaps hoping that the 100-volt battery that powers the apparatus doesn’t do him any harm). The device emitted rhythmic notes of varying tones and intensity as the electrical impulses in the muscles and nerves varied with the heartbeat. Sometimes called the “electric stethoscope,” this instrument was adapted as a teaching tool to train doctors to diagnose the condition of the heart through sound.
One of the first persons to use the amplified sound of the heart to teach use of the stethoscope was my grandfather, Rudolf Höber (1873-1953). He was a pioneering physiologist at the Universities of Zürich, Kiel and Pennsylvania who has been remembered for discoveries in biochemistry and biophysics at the cellular level. A couple of years ago, The Journal of Electrical Bioimpedence noted the 100th anniversary of Rudolf’s discoveries related to the variability of electrical charges across cell membranes. Among other things, Rudolf was an inventor who devised instruments for measuring electrical characteristics at the cellular level; he even had a glass blower working for him to fabricate apparatus. Here is his diagram of a bioelectric device he created around 1910:
During World War I, the technology of vacuum tubes was developed that enabled the amplification of electrical waves for use in telephones. Rudolf adapted this technology to use in combination with his earlier bioelectric measurement devices — resulting in the mechanism at the top of this page.
This year the University of Kiel is marking its 350th anniversary with a series of events, including the medical school’s exhibition on prominent scientists who worked there. You can get information about the overall exhibition by clicking here and about Rudolf in particular here.
Since I started this website two years ago, I have published 41 stories here. To my astonishment, they have been read by hundreds of people in more than 50 countries. I have had just under 10,000 hits, far more than I anticipated when I started. I also did not anticipate that I would become friends with readers previously unknown to me who discovered the stories here: ocarina players in Indonesia who connected to the story of my grandfather Rudolf’s ocarina; a Swiss historian writing about the descendants of Moses Mendelssohn, one of whom was the wife of my great uncle Eduard; members of the medical faculty at the University of Erlangen in Bavaria, who were excited to find the portraits of Isidor Rosenthal and Anna Hoeber Rosenthal, who left their mark on that city; and my now-good-friend Phil White of Olathe, Kansas, who is writing a book about the Truman campaign my father worked on.
All of the stories on this website are made possible because of the Höber/Hoeber family’s mania over several generations for saving letters and other paper records. The earliest letter in the collection was written 174 years ago by Heinrich and August Oppenheim, my great-great grandmother’s brothers, who were congratulating their parents on their sister’s engagement to my great-great grandfather. The collection also includes love letters my great-grandparents exchanged daily in Berlin in the 1860s. The collection includes every income tax return my parents filed from 1939 to 1999. There are my grandparents’ photograph albums from the early 20th century in Zürich and professional papers my parents wrote from 1940 to 1980. The variety of material is dizzying. Together, this archive tells the story of a family that made a mark in business, science and progressive politics in Europe in the 19th and early 20th centuries, and then started all over again in the United States.
Organizing and preserving these family papers has taken years. I had to study German to be able to read some of the complex papers, and I have translated many documents into English so they are accessible to readers here. Physically arranging the papers so things could be found was a substantial task. They are now housed in archival manuscript boxes and filed in acid-free folders so they will be preserved for the future. The papers have been partially indexed, but I still have work to do in this area.
Eventually I will place the collection of these papers with a large historical manuscript archive here in Philadelphia. In the meantime, I will continue to write stories based on these letters for you, my kind readers.
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.