by ship, to Egypt. At a market in Cairo, Langerhans bought a selection of fish for Haeckel’s collection. They continued their journey by sea to Jaffa (Tel Aviv did not exist at that time) and onwards over land to Jerusalem.
From Kiepert’s report and sketchbook we learn in more details about this trip – they rode to Jericho, the Dead Sea, Amman, and Tiberias. Kiepert fell ill with typhoid in Jerusalem where Langerhans collected skeletal bones and became interested in leprosy. He wrote about his experiences to Virchow, who had the letter about leprosy printed in his archive [4]. The research about the different ethnic groups in Palestine was published in 1873 [5].
In June Kiepert and Langerhans continued their journey via Cyprus and Rhodes to Smyrna and then on to Constantinople. To his great regret, Langerhans’ clothes, revolver, and most of the skulls, which had been collected for Haeckel, together with other biological objects, were stolen there. But even worse was news which reached them whilst returning to Germany by ship on the Danube. As a result of the Ems Dispatch, a statement issued by Bismarck, France declared war on Prussia. The journey to Berlin now became hurried. Langerhans was called up to serve in the army of Prussia and for 3 months he worked in a military hospital in Berlin. In July, Langerhans was called to the front in France as a military physician. We know from the letters of his friend Hoffmann, how terrible the experiences of a military doctor in this war were. Although there was already the possibility of anesthesia, asepsis was not clinical practice and the infections which followed surgical procedures were catastrophic.
In May 1871, Langerhans returned to Berlin but failed to find employment. Coincidentally, at this time, an opportunity arose to accompany Prof. Karl von Kupffer, the first describer of Kupffer’s cells in the liver, on a research trip to Norway. Paul accompanied him and the two fished, for a whole month, at Arendal, located near to Oslo, to find Ascidians.
After this expedition came to an end, Paul made his way to the “Mecca” of physiology, to Prof. Carl Ludwig at the University of Leipzig. As a side-note, some years later, a young Scot named John James Rickard Macleod also trained there in physiological research. Macleod later received the Nobel Prize for the application of the hormone that is formed in the islands named after Langerhans.
Langerhans stayed in Leipzig for only a few weeks. In Freiburg, a position in pathology became available. However, this position required a habilitation. Langerhans hurriedly completed this but it contained a mere 16 pages. Virchow stepped in and wrote some letters to support the nomination. Langerhans reciprocally sent a letter of thanks to Rudolf Virchow:
Dear Uncle
You have become a prosector in Freiburg. That is, in fact I am, but it is as clear as day that I am as innocent of it as an encephalitic newborn, because without your letter Ludwig would never have written to Ecker and I would never have got this position. So allow me to assure you explicitly that I am perfectly clear about how great the disproportion between your goodness and my own merit is again here.
Your grateful pupil,
Paul Langerhans
Freiburg im Breisgau 23.10.1871
In Freiburg, Langerhans lectured on osteology and led the microscopic course. He was no longer interested in research on the pancreas – but his friend Albin Hofmann was still working on this topic in the laboratory of Prof. Frerichs (the teacher of Bernhard Naunyn) in Berlin. When Hofmann was appointed to a chair at Dorpat (Tartu in Estonian), his successor was a young Baron, born in Cologne, named Josef von Mering. Von Mering, together with Oskar Minkowski, later discovered pancreatic diabetes while at the University of Strasbourg.
At the end of 1873, Paul tried to become a professor. The dean of the faculty, Prof. Kussmaul (well-known because of his description of “Kussmaul breathing” in diabetic ketoacidosis) was in support of this appointment, but the ministry of the Kingdom of Baden refused due to him not having lectured for a sufficient time.
During his time in Freiburg, Langerhans also travelled regularly to Sweden and Norway and, in the summer of 1873, together with Albin Hoffmann, to Italy. Finally, a few days after his 27th birthday, Paul Langerhans was appointed Professor Extraordinarius in Freiburg. To celebrate this, he and his friend Albin Hoffmann, who had travelled from Dorpat, journeyed together to Switzerland – the two did not know that this would be their last happy trip together. On September 11, 1874, Prof. Nothnagel diagnosed Paul Langerhans with pulmonary tuberculosis. Nothnagel was a good friend of Langerhans in Freiburg. Later, when Nothnagel held the chair in Jena, Langerhans travelled to Jena to continue to consult him.
After having received the news about Paul’s diagnosis Hoffmann wrote to him from Estonia, dated September 20, 1872:
My dear friend,
You can imagine how I was touched by your letter. You must absolutely not stay north of the Alps until late October. It would be a pleasure for me to visit you in Cairo. We may give up hopes and plans, but we are young enough to start new ones, and the friendships will continue. I am convinced that everywhere in the world you can find interesting work, you should not consider two years of life in Germany as valid as 20 years in Egypt.
In the case of tuberculosis, the most important medical advice at the time was to escape the cold winter in the north. Langerhans took his friend’s suggestions seriously. He went to Naples, allegedly to work for one semester at the Zoological Institute there. However, he struggled to work and spent the winter in Capri with fever attacks. He had to extend his vacation several times and finally decided to move on to Madeira.
Madeira, the island of eternal spring, was considered, in the 19th century, to have an ideal climate for people with tuberculosis. Many wealthy German and English tuberculosis patients were sent there. It was once again his rich grandmother who financed Langerhans’ travel to and stay in Madeira. There have never been any controlled investigations as to whether Madeira really had a positive influence on the course of the disease. But at least the sick member of the family was far away and did not cough blood any more at home! Later the “Zauberberg hospitals” in the Alps came into fashion as an exile of people with tuberculosis. In October 1875, Langerhans arrived in Funchal, Madeira. He did not know anyone there and lived, bedridden, in a hotel where he continued to suffer from fever attacks. After a few months though he felt better and rented an apartment. He even began zoological research again. Through Rudolf Virchow he managed to receive a scholarship of 2,000 Reichsmarks from the Berlin Academy.
In 1878 Langerhans travelled to Berlin. For Prof. Ehlers he brought along a collection of annelids (also known as ringed worms) and prepared publications about them. He also visited Prof. Nothnagel in Jena to ask for his medical advice. Langerhans finally quit his employment in Freiburg and travelled from Berlin to Tenerife, but returned to Madeira in July 1879. He continued his research on annelids – some of them today are still named after Langerhans [6].
Fig. 6. Handbook on Madeira by Paul Langerhans, 1885 [7, 9].
In the meantime, his grandmother passed away and he had to earn his own living. As a result, Langerhans opened a private practice, specifically for German tuberculosis patients. One of his patients was the wealthy Alfred Ebarth, who hoped to improve his tuberculosis with his wife, Margarethe, and his daughter on Madeira.
The Ebarth family arrived in Funchal in October 1879. Langerhans treated the tuberculosis-stricken Alfred for many years. He also treated the Ebarth’s young son, who died of diphtheria on Madeira at the age of 1.5 years. Alfred Ebarth died in April 1883.
Paul must have been in love with the wife of his patient for some time, even prior to Alfred’s death. Margarethe promised