Biography of Léon Fredericq

Léon Fredericq was born in Ghent in 1851. His father, Dr. César Fredericq, was a renowned physician and author of a treatise on Botany. His mother, Mathilde Huet, was the sister of French philosopher François Huet. His elder brother, Paul Fredericq, was Professor of History at the University of Liège, and Dr Simon Fredericq, the younger, was also a distinguished physician. Léon Fredericq was also related to Julius MacLéod, botanist, biologist, professor at the University of Ghent and director of the Ghent Botanical Garden, and to sisters Rosalie and Virginie Loveling, women of letters. Léon Fredericq grew up in this richly talented and well-educated family environment.

Attracted to the observation of nature from an early age, he naturally turned to the study of natural sciences, which he studied at the University of Ghent from 1868 until he obtained his doctorate in 1871. That same year, Richard Boddaert, Doctor of Natural Sciences and Medicine at the University of Ghent, hired Léon Fredericq to prepare courses in human physiology and comparative anatomy. He also began studying medicine, which he completed in 1875. 

In 1876, he was awarded a travel grant that enabled him to receive a thorough education in physiological methods from foreign masters. It was in the laboratories of the Sation Biologique Roscoff - located in northern France - that he discovered the many possibilities for study offered by marine fauna. On his return, he worked on blood coagulation, making a major contribution to the study of this phenomenon. He was noticed by Théodore Schwann, who appointed him to succeed him in his chair.

In 1879, at the age of 28, he took over the chair of Physiology. In 1881, he met and married Bertha Spring, sister of Walthère Spring, a great chemist and professor at the University of Liège. In 1887, he founded the Institute of Physiology in Liège.

Considered a pioneer in the then rapidly developing discipline of physiology, he was responsible for numerous discoveries, including those concerning respiration, blood pressure and circulation, and the invention of the oxygenograph. In marine physiology, he discovered, among other things, hemocyanin and autotomy.

Indeed, the studies he carried out in his youth - in disciplines as varied as physiology, biology and medicine, as well as physics and chemistry - provided him with a wealth of knowledge that he incorporated into his work. This knowledge, combined with his ingenuity, enabled him to develop a large number of new processes and to conduct research in various fields, including medicine and human physiology, as well as the comparative physiology of lower animals and, more specifically, marine animals. Léon Fredericq was a prolific researcher.

A committed and encouraging teacher, his clear and objective teaching inspired many students. He usually carried out his research in the shared laboratory in the presence of his students, who were thus able to follow the entire research process and the methods employed.

In 1904, together with Paul Héger, founder of the Brussels Institute of Physiology, he created the Archives internationales de Physiologie , which published the work of the master and his students and was one of the first channels for the dissemination of French-speaking experimental medicine.

During the First World War, Léon Fredericq used his lectures to mock the enemy: "Under enemy occupation, these lectures were an opportunity for him to exercise his mocking verve at the expense of the invaders. More than once, the representatives of the Tudish authority who listened to him wondered what could possibly be the meaning of certain allusions which put the audience into a state of gaiety and whose meaning they were unable to penetrate." (1)

By the end of the war, he was already approaching retirement age. His professorship ended in 1921, and his son Henri Fredericq succeeded him in the professorship and as director of the Institute of Physiology. Zénon Bacq continued his work in the field of physiology and Marcel Florkin succeeded him in the field of biochemistry.

Léon Fredericq was also a lover of the Haute Fagnes region. In 1924, he obtained funds from the University of Liège to set up a scientific station - known today as the Station de Recherches Scientifiques des Hautes Fagnes - at Baraque Michel. He was thus at the origin of the first research station on Mont-Rigi. In his spare time, he was also a renowned watercolorist.

Forced to take to his bed in June, he died at home in September 1935.

Léon Fredericq's research was diverse and varied: Anatomy, human physiology, comparative physiology, zoology, marine biology, medicine, chemistry, etc.

He also studied a phenomenon he called "autotomy". This is the self-mutilation reflex of certain animals, particularly reptiles and invertebrates, in the face of danger.

Other studies focused on the molecular concentration of marine animal tissues, and the influence of the external environment on them.

Vitalist theories and the awakening of scientific curiosity

Physiology is born of the experimental method.

In 1838, the rector of the University of Louvain, Pierre-François-Xavier de Ram, hired a new anatomist, Théodore Schwann, who introduced the experimental method perfected by François Magendie, and a mechanistic approach to living phenomena, considering the plant or animal as the sum of the properties of its chemical molecules.

The experimental method is a scientific approach that involves repeating an experiment in order to test the validity of a hypothesis by obtaining new qualitative or quantitative data, which may or may not be consistent with the initial hypothesis. Among the pioneers of the experimental method were Johann Müller and François Magendie.

Physiology also asserted itself as a deterministic discipline, and the industrial revolution provided its explanatory model, the steam engine.

In L'enseignement de la physiologie en Allemagne, Léon Fredericq explains:
"If physiology has become a chapter of general mechanics, if we have been able to define it as 'the study of the physical and chemical phenomena of which the organism is the seat', it is to the Berlin school that we owe our greatest debt. Today, the hypothesis of the vital force has had its day, joining the horror of the void, Johannes Kepler's sidereal rector spirit and the other metaphysical principles, as superfluous as they were harmful, that cluttered science in its early days. Descartes' old formula, positing that there are no two mechanics, one for gross bodies and the other for living bodies, and that the laws of nature are identical everywhere, has been taken up victoriously by the modern school of physiology. We now know that our organism, like all bodies in the universe, is subject to the two great laws of the conservation of matter and the conservation of energy: if the substance of the vital vortex comes from outside, its movement is also borrowed from the outside world. Movement, like matter, can be transformed, but it cannot be created from nothing. Schwann's cell theory (1839) and Helmotz's theory of conservation of energy (1847) were instrumental in bringing physiology into line with this new approach. Just as the human organism can neither create nor destroy matter, it is equally powerless to annihilate motion or generate it from nothing. Its activity is limited to transforming matter or motion borrowed from the outside world. The living machine is subject to the laws of mechanics and ordinary physical chemistry, like a common fire engine. Both, in terms of their material activity, can be reduced to the same schema: a steam engine consumes fuel, transforms the positional energy accumulated in the coal or firewood into calorific energy on the one hand, and into work or motion energy on the other. In the final analysis, its movement comes from the sun, since it is the energy of the sun's rays which, in the green part of plants, decomposes carbonic acid and sets oxygen free, while carbon serves to build up the plant's wood tissues [...] Our body is therefore a chemical machine, drawing, like the steam engine, in the final analysis the sum of its energy from the sun's rays: the ox eats the grass and we eat the ox [...] Wherever the subject allowed, physiology became applied chemistry, physics, mechanics, mathematics. It demanded the exact means of investigation available to these sciences, and a facility in keeping with these new needs. »

Fredericq's representations are in line with those of his colleague Paul Héger and Ernest Solvay, patron of the Instituts de Physiologie at the Université Libre de Bruxelles.

While the refinement of biological questions went hand in hand with that of tools and techniques, scientific facilities at Belgian universities were less well funded and in poorer condition than at German universities in the ^19th century. And yet, good scientific equipment was crucial to the development of physiology. It was a necessity for laboratories to be sufficiently equipped for light microscopy techniques, or for the preparation, filtration and fixation of biological samples. In addition to extending the studies of naturalists, these techniques also more often involved chemistry and physics, and led to the blossoming of specific disciplines such as cytology, histology and physiology.

Milestones in Belgian physiology

"To understand the properties of the organism, it is necessary to know those of the cell (Claude Bernard).

• Theodore Schwann studied phenomena such as putrefaction and alcoholic fermentation, and discovered the existence of pepsin. Cell theory provided the frame of reference for the global study of living organisms. Animal experimentation provided a tool for investigation.

• Léon Fredericq conducted numerous studies into breathing, pressure and blood circulation.

• Léon Fredericq and Paul Héger both carried out numerous studies on the heart and arteries.

• Marcel Florkin, a disciple of Léon Fredericq, continued his analysis of major physiological functions such as respiration, osmotic regulation in marine and terrestrial invertebrates and vertebrates, and the electrical properties of nerves and muscles.

• Zénon Bacq will also be joining Fredericq in Liège, where he will be in charge of courses in animal physiology and general pathophysiology. He will also contribute to the development of molecular pharmacology.

Founder of the Mouvement National pour la Sauvegarde de la Nature and founding member of the Cercle des Entomologistes Liégeois, Léon Fredericq was above all a lover of the Hautes-Fagnes, whose distinctive flora and fauna he soon discovered, due to the specific climate reminiscent of northern or sub-alpine regions. His many hikes enabled him to write several publications on the flora and fauna, but his greatest contribution to the preservation of this ecosystem was to encourage its classification as a nature reserve (the largest in Belgium) and then, in 1924, to found the first scientific station on Mont Rigi, a research station belonging to the University of Liège and located in the heart of the Fagnes.

From 1885 to 1888, Léon Fredericq collaborated with architect Lambert Noppius on the construction of the Physiology Institute on Place Delcour in Outremeuse. The building now houses the Centre d'histoire des sciences et des techniques , which boasts a large collection of laboratory instruments and tools bequeathed by Léon Fredericq.

• Member of the Royal Academy's Science Class in 1879

• Member of the Académie de Médecine in 1882

• Montyon Prize for experimental physiology in 1888 (with Augustus D. Waller)

• Member of the Société des Sciences médicales de Luxembourg (1884);

• Member of the Société de Biologie de Paris (1885);

• Member of the Geneva National Institute (1886);

• Member of the Royal Academy of Medicine in Rome (1887);

• Member of the Académie Léopold. Carol. des curieux de la nature de Halle (1888);

• Membre de l'Academia medico-phisica de Florence (1891);

• Member of the Barcelona Academy of Medicine;

• Member of the British Association for the advancement of Science (1895) ;

• Member of the Physiological Society; National Academy of Sciences Antonio Alzato de Mexico (1896);

• Member of the Imperial Military Medical Academy, St Petersburg (1899);

• Membre de la Kaiserliche königliche Gesellschalt der Aerzte de Vienne (1909);

• Member of the Paris Academy of Medicine (1914);

• Member of the Institut de France; of the Academia Linceorum in Rome.

• Honorary doctorate from numerous universities: Brussels, Groningen, Lausanne, Lyon, Sant-Andrews, Hamburg

• President of the International Congress of Physiology held in Liège in 1892

• Permanent member of the Physiology Congress Steering Committee

• Entitled to the title of Baron by HM King Albert in 1931

• Invited, with Pavlov, as guest of honor at the XIIIth International Congress of Physiologists in Boston in 1929

Royal Academy of Overseas Sciences

National biography. Royal Academy of Sciences, Letters and Fine Arts of Belgium

Cercle des Entomologistes Liégeois

Art collections of the University of Liège (Belgium): Galerie Wittert

Fund Léon Fredericq

Hautes-Fagnes Scientific Station

ST2S: Human Biology and Pathophysiology: the history of physiology