Institute

With his diverse and varied life’s work, Max von Pettenkofer is one of the most exciting minds in 19th century science. From a poor farmer’s son and short-lived dropout, he made it to the scientific elite and, as president of the Academy of Sciences, even to the highest-ranking representative of the research disciplines in the Kingdom of Bavaria. He achieved extraordinary things in many fields. However, Pettenkofer discovered his true mission with scientific hygiene, for which he conclusively built an entire edifice of thought. As a thought leader in health care, he created trends in public health. Pettenkofer turned his teaching and research institute into the world’s first center of excellence for hygiene, which attracted students from all over the world and became the international flagship of the University of Munich. Pettenkofer’s hygiene think tank became the hub of a global network.

 

Starting points: Chemistry and cholera

Although Max von Pettenkofer studied pharmacy and medicine in Munich from 1837, he never practiced medicine. He much preferred researching the processes in the human organism as a chemist even in his young life. With this choice, Pettenkofer demonstrated the right instinct for highly topical research and at the same time helped to make chemistry the key subject in contemporary medicine. The chemical branch of knowledge was trusted to finally shed light on the darkness that for centuries had hidden the inner life of the sick person from medical view and understanding. Already in the laboratory of Justus von Liebig in Giessen, where Pettenkofer trained, he displayed a high degree of independence in chemical thinking and discovered numerous detection methods for substances occurring in the human body and its juices. His appointment as professor of medicinal chemistry at the University of Munich in 1847 marked the first step on Pettenkofer’s career ladder, and in 1853 he was promoted to full professor of organic chemistry in the medical faculty. Throughout his life, Pettenkofer saw himself primarily as a medicinal chemist. This also applies to his work in the field of hygiene.

With his research on the origin and spread of cholera, Pettenkofer made a name for himself internationally as an epidemiologist in addition to his excellent reputation as a chemist. The epidemic, which originated in India, brought chaos and death to Europe in the 19th century. Even though Pettenkofer’s interpretation of cholera, the epidemic-relevant developmental step of which he placed in the soil, led him down a monstrously wrong path, the recommendations derived from it for warding off cholera proved to be extremely beneficial. The hydrological infrastructure recommended by Pettenkofer to purify the soil in cities – an efficient water supply with sufficient pressure in combination with a sufficient alluvial sewer system – were not only major technical projects, but also formed a new infrastructure for health. Max von Pettenkofer contributed significantly to people’s health happiness. In his cholera research, Max von Pettenkofer recognized, on the one hand, the elementary importance of prevention and, on the other, the fact that diseases and epidemics obviously have a lot to do with filth and unhygienic environmental and living conditions. This insight led him to take a closer look at the subject of hygiene. And as with the fight against cholera, he soon set new standards in this area as well.

 

Project Hygiene

Hygiene refers to the totality of all measures taken to protect and promote the health conditions of individuals and human society. When Pettenkofer began his efforts in this regard, the hygienic conditions were alarming. Especially in underprivileged residential areas, conditions were dire. Many people lived in one apartment, and sanitary facilities were rudimentary. Even if people were not yet afraid of bacteria – they had not yet been discovered – other pests were all the more numerous.

The fact that environmental factors and personal hygiene play a role in dealing with health risks had been thought of since ancient times. Pettenkofer drew on this ancient tradition of knowledge on the one hand and the contemporary sanitary reform ideas in France and England on the other, and placed himself at the forefront of this movement. As a genuine scientist, he was disturbed by the fact that – on closer examination – medical experts in the field of health care knew in principle little more than any lay person equipped with common sense. Pettenkofer drew a sharp line between himself and this rather intuitive “gut knowledge” and declared it his goal to capture hygiene with the language of modern science. He wanted to be able to say with certainty exactly what “fresh air” and “clean water” were in scientific precision and terminology, what constituted “good food” and what constituted “good clothing,” and when a home was truly “healthy.”

For Pettenkofer, deciphering the interactions between the human organism and its immediate environment formed the basic prerequisite for effective prevention of diseases and epidemics. Pettenkofer opened up the immediate space around the human organism, as it were, and gave people a new view of their world. This included topics such as soil, air and water quality, the influence of soil on the spread of diseases, the ventilation and heating of premises, the hygienic value of plants inside the home, personal hygiene, the function of clothing or cleanliness in the home and on the street.

Pettenkofer did not invent hygiene. But he ensured reliable knowledge production in the field of hygiene by consistently applying the experimental method. It was precisely for this achievement that Pettenkofer was awarded the golden Harben Medal in 1897 by the British Royal Institute for Public Health, at that time the world’s highest award in the field of hygiene. Pettenkofer endeavored to provide a secure scientific basis for measures that had previously been applied more intuitively or on an empirical basis. Thus, Max von Pettenkofer’s name is indeed associated with breakthroughs in modern hygiene and prevention as well as public health. In this sense, Pettenkofer is rightly considered the “father of modern hygienic science,” as the Reich Health Office once honorably dubbed him. To progress along his path, Pettenkofer combined medical expertise with the latest knowledge from physics, chemistry, technology, statistics and economics. All these different parameters together formed the basis of hygiene. With this “crossover thinking,” which is considered particularly progressive even from today’s perspective, he made hygiene the first interdisciplinary subject in medicine.

 

Hygiene as a subject and research field

Pettenkofer’s aim was to record the health-relevant relationships between the human organism and its environment without speculation and with scientific conciseness. He wanted to record all factors that contributed to a healthy life. With changing teams and collaborators, Pettenkofer set about researching these aspects and set standards worldwide.

The focus was on the three classical elements of air, water and earth. For Pettenkofer, keeping the air clean was an elementary task of health care and an urgent concern for residential hygiene. His studies on indoor climate also gave rise to the Pettenkofer number, which is still used today to assess indoor air quality. Pettenkofer’s measurements documented that the air in homes, schools, inns, and other locations was far from atmospheric air quality. In search of a simple measure for comparing the quality of indoor and outdoor air, Pettenkofer came up with carbonic acid, which was present in both indoor and outdoor air and could be easily measured using the method he developed. The carbon dioxide content served him as a measure of the volatile organic substances emitted by humans, which were actually responsible for a good or bad indoor climate. Pettenkofer determined that above a carbon dioxide concentration of one per mille, the air in an indoor space no longer met hygienic requirements. In connection with the quality of indoor air, ventilation and heating now became particularly important.

Since, in addition to air, water plays a central role in human life, Pettenkofer also turned his attention to water quality. Hygienically safe water remained a scarce commodity until the middle of the 19th century. Even though Pettenkofer underestimated the role of drinking water in the development of epidemics, he gave drinking water quality the highest priority and developed an exemplary quality control system for the precious water. Dirty water, like polluted air, poor food, unhealthy clothing, or individual excesses in life, could disrupt physiological processes in the human body, making individuals more susceptible to disease. With the testing program he developed, Pettenkofer made a major contribution to determining quality criteria for hygienically safe drinking water, which cities then used as a guide when setting up modern centralized water supplies. As early as the mid-1880s, microbiological tests were also part of the program to see whether water was contaminated with microorganisms.

For Pettenkofer, the development of a healthy environment also included the so-called assanitation of the soil. Since in Pettenkofer’s medical worldview the soil played a very special role in the spread of an epidemic such as the dreadful cholera, the assessment of the soil and its condition was a central point in addition to the above-mentioned cleaning of the soil. He developed a whole spectrum of factors that became relevant in urban planning and for the selection of building sites from an epidemiological point of view.

A healthy life included not only clean air and healthy living spaces, but also clean water and clean ground, proper clothing, personal hygiene and good food. Thus, Pettenkofer researched the physiological significance of our clothing and its interaction with the skin. He examined microscopically the substances used in clothing manufacture and analyzed the physical properties of textiles. At the top of his agenda was also personal hygiene. For Pettenkofer, bodily uncleanliness was the “most dangerous breeding ground for all diseases.” The new plentiful supply of running water improved bathing and showering facilities and facilitated regular washing with soap.

 

Hygiene as an academic discipline

The science of hygiene owes Pettenkofer not only a coherent body of thought, but also its academic anchoring in teaching. Pettenkofer ensured that thorough knowledge of hygiene and public health care became general medical knowledge. At his instigation, Bavaria was the first state to include hygiene in the compulsory curriculum in 1865 and established chairs for the subject, which were assigned to chemists entirely in accordance with Pettenkofer’s understanding. Pettenkofer himself received the newly established chair in Munich. Vienna and Leipzig followed in 1875 and 1878 as the next universities in the German-speaking world to establish chairs in hygiene. Amsterdam also established a professorship for hygiene as early as 1878. In 1882, all the states in the German Empire followed the path set by Bavaria and also made hygiene a compulsory subject.

After the subject of hygiene had been included in medical studies and even given a chair, a suitable teaching and research institution was still lacking. Initially, Pettenkofer had been given premises in the university building for a chemical laboratory. In 1855, he moved his “Laboratory for Physiological Chemistry” to the newly built Physiological Institute, where he remained until 1879. As the holder of a chair in hygiene, however, Pettenkofer converted his institution into a “Chemical Laboratory for Hygiene” as early as 1870. When Pettenkofer turned down an extremely tempting call to the University of Vienna in 1872, because it was associated with the promise of a new institute, the financial channels for a new institute building also opened in Bavaria. The ceremonial opening of the Hygiene Institute on April 19, 1879, impressively confirmed Max von Pettenkofer’s previous work. With two lecture halls and several laboratories as well as examination facilities, the new institute was excellently equipped for its tasks.

 

Think tank and competence center for hygiene

Pettenkofer subsequently developed the institute he had set up for systematic teaching and research in 1879 into a globally unique competence center for hygiene and environmental medicine. Pettenkofer’s think tank for hygiene became the ground station of his global hygiene mission. Soon the whole world was seeking advice and information from Pettenkofer on hygienic issues, and students made pilgrimages from far and wide to learn from Pettenkofer and from each other about “hygiene.” His teaching and research program met with great interest worldwide and allowed Munich to rise to become a global center of hygiene. Hygiene of the Pettenkofer brand became a Bavarian export to the whole world in the second half of the 19th century.

From Central, Southern, Eastern and Northern Europe, from England and Scotland, North and South America, from Russia and especially from faraway Japan, young doctors and researchers flocked to Max von Pettenkofer to learn hygiene from him. With his motivating personality, Pettenkofer captivated the young people. They took Pettenkofer’s knowledge back home with them and ensured a worldwide transfer of knowledge across national borders. A particular geographical focus in this respect was clearly Russia and Japan. In Moscow, Friedrich Huldreich Erismann (1842-1915), who came from Switzerland but was married to a Russian doctor and influenced by Pettenkofer, was appointed to the chair of hygiene at the University of Moscow in 1884, along with his own institute. As Erismann’s successor, Sergei Bubnov (1851-1909), another physician trained by Pettenkofer, took over the chair of hygiene in Moscow in 1896. Bubnow, who presided over the large International Hygiene Congress in Moscow in 1897, had worked with Pettenkofer in the early 1870s on sewerage issues and on housing, clothing and food hygiene. Among the young researchers who also made early pilgrimages to Pettenkofer from the Russian-speaking world were Aleksej Dobroslawin (1842-1889), Viktor Subbotin (1844-1898), Arkadij Jakobij (1837-1907) and Alexander Sudakow. Dobroslavin, who wrote a textbook on public health in 1882, subsequently received a chair of hygiene at the military academy in St. Petersburg, Subbotin became a full professor in Kiev, and Jakobij was responsible for teaching hygiene in Kharkov from the 1870s before moving to Kazan as a professor of hygiene in 1885. Sudakov taught hygiene in Tomsk from 1887, where he became a full professor in 1890.

 

In addition to the Russian Tsarist Empire, Japan sent a number of physicians to Pettenkofer. It was the time of the Meiji Reform, when Japan opened up to the West and adopted the best and most advanced from Europe. This included modern German medicine and, above all, hygiene. Numerous young doctors not only visited Pettenkofer, but also took courses with Robert Koch in Berlin. Among the well-known visiting physicians from Japan was the plague researcher Masanori Ogata (1854-1919), who returned to Tokyo in 1885 and was entrusted with the new teaching institution at the university along with the public health office. Pettenkofer’s ideas were spread in Japan mainly by the highest-ranking military physician Rintaro Mori (1862-1922), better known as Mori Ogai, or Jiro Tsuboi (1862-1903), who became the first dean of the medical school at Kyoto Imperial University in 1899; and finally Shimpei Gotoh (1857-1929), who, in addition to his merits in government service as a facilitator of modern hygiene, even made it to the position of Minister of the Interior and Foreign Affairs of the Japanese Empire and Mayor of Tokyo.

In other countries, too, and especially in German-speaking countries, Pettenkofer’s students made careers in the civil service or became university professors and held chairs in hygiene. In addition to the foreign representatives already mentioned, Gustav Wolffhügel (1845-1899), who became a full professor in Göttingen in 1877, and Karl Bernhard Lehmann (1858-1940), who initially went to Würzburg as an associate professor in 1887 and became a full professor in 1894 with the founding of the Institute of Hygiene, should be mentioned in this context without claiming to be complete. Josef Forster (1844-1910), as full professor, also took over the direction of the new Hygiene Institute in Amsterdam in 1878, before moving to the chair of the reform-oriented university in Strasbourg in 1896. Carl Flügge (1847-1923) became the first full professor of hygiene in Breslau in 1887 and director of the Institute of Hygiene in Berlin in 1909. Friedrich Renk (1850-1928), who played an important role in the Imperial Health Office, was appointed to the new chair of hygiene by the University of Halle in 1889, Josef von Fodor (1843-1901) became a full professor in Budapest, and Aladòr von Rozshegyi (Rospahegg) in Cluj-Napoca, which also belonged to the Austro-Hungarian Habsburg Empire at the time.

 

Role model and legacy

As it turns out, Pettenkofer’s Hygiene Institute served as a model at home and abroad. Pettenkofer was used as a model for the establishment of hygienic chairs, and Pettenkofer’s institution served as a model for numerous hygiene institutes. The Munich institute also provided the impetus for the founding (1917) of the now world-famous Johns Hopkins School of Hygiene and Public Health in Baltimore. With his modern methodical awareness of hygiene, Pettenkofer inspired many physicians to follow his example and to create the basis for sound hygiene and well-founded prophylaxis through their own epidemiological and etiological studies.

After Pettenkofer was relieved of his teaching duties at the university at the end of 1893, he also resigned as director of the Institute of Hygiene in 1894. His immediate successors on the chair and as directors of the Hygiene Institute were his two students Hans Buchner (1850-1902) and, after Buchner’s early death, the Viennese professor Max von Gruber (1853-1927). Even under them, the Munich institute retained its worldwide appeal. However, research and work with bacteria now became more and more important in Munich as well.

What must not be forgotten, despite all the science, is Max von Pettenkofer’s attitude, which was deeply rooted in humanism and love of humanity. He stood in the tradition of the Enlightenment, whose principles he consistently defended: reason and science, progress and humanism. These are the core values of his impressive life’s work and his legacy.

 

 

Text (deutsch): Prof. Dr. Wolfgang Locher, Institute for Ethics, History and Theory of Medicine at LMU Munich