Guide Tour of Pasteur Museum, Paris, France

The Musée Pasteur is a museum dedicated to French scientist Louis Pasteur. It is located within the Institut Pasteur at 25 Rue du Docteur Roux, Paris, France, in the 15th arrondissement. The museum was established in 1935, in honor of Louis Pasteur, and preserves his memory in the apartment where he spent the last seven years of his life. The rooms, preserved as they are, testify to the daily life of the Pasteur couple, while in the room of scientific memories, the original scientific instruments retrace the many discoveries of the illustrious scientist. The visit ends with the superb Byzantine-inspired crypt where Louis Pasteur and his wife rest.

The Pasteur Museum, dedicated to the life of Louis Pasteur, is housed in the apartment occupied by him for the last seven years of his life. The visit ends with the Byzantine-inspired chapel. According to a plan by the architect Charles Girault, the crypt where Louis Pasteur and his wife rest, was decorated with mosaics, made by the Parisian mosaic workshop Guilbert-Martin. These were made on the basis of the drawings and cartoons of the painter Luc-Olivier Merson, evoking the various works and fields of activity of the scientist.

The building was classified as a historical monument in 1981. The museum finds its origin in a family donation in the 1930s. Professor Louis Pasteur Vallery-Radot, grandson of the scholar Louis Pasteur, anxious to perpetuate the spirit of the place by restoring the apartment to its original layout, donated all the furniture and objects that belonged to his grandparents to the Institut Pasteur. The apartments of Mr. and Mrs. Louis Pasteur are remarkably preserved and also offer perfect historical testimony to the Parisian bourgeois habitat at the end of the 19th century.

Louis Pasteur was a French scientist, chemist, physicist and microbiologist. A pioneer of microbiology, he enjoyed great reputation during his lifetime for his discoveries of the principles of vaccination, microbial fermentation, and pasteurization. His research in chemistry led to remarkable breakthroughs in the understanding of the causes and preventions of diseases, which laid down the foundations of hygiene, public health and much of modern medicine. His works are credited to saving millions of lives through the developments of vaccines for rabies and anthrax. He is regarded as one of the founders of modern bacteriology and has been honoured as the “father of bacteriology” and as the “father of microbiology”.

Pasteur was responsible for disproving the doctrine of spontaneous generation. Under the auspices of the French Academy of Sciences, his experiment demonstrated that in sterilized and sealed flasks, nothing ever developed; and, conversely, in sterilized but open flasks, microorganisms could grow. For this experiment, the academy awarded him the Alhumbert Prize carrying 2,500 francs in 1862.

Pasteur is also regarded as one of the fathers of germ theory of diseases, which was a minor medical concept at the time. His many experiments showed that diseases could be prevented by killing or stopping germs, thereby directly supporting the germ theory and its application in clinical medicine. He is best known to the general public for his invention of the technique of treating milk and wine to stop bacterial contamination, a process now called pasteurization. Pasteur also made significant discoveries in chemistry, most notably on the molecular basis for the asymmetry of certain crystals and racemization. Early in his career, his investigation of tartaric acid resulted in the first resolution of what is now called optical isomers. His work led the way to the current understanding of a fundamental principle in the structure of organic compounds.

Molecular asymmetry
In the work that Pasteur carried out at the beginning of his scientific career as a chemist, he solved in 1848 a problem which would later prove to be of capital importance in the development of contemporary chemistry: the separation of the two forms of tartaric acid.

Pasteur’s work in this field led, a few years later, to the birth of the field of stereochemistry with the publication of the book Chemistry in Space by van ‘t Hoff which, by introducing the notion of asymmetry of the carbon atom has greatly contributed to the development of modern organic chemistry.

Pasteur was motivated to investigate fermentation while working at Lille. Pasteur demonstrated that this theory that fermentation was caused by decomposition was incorrect, and that yeast was responsible for fermentation to produce alcohol from sugar. He also demonstrated that, when a different microorganism contaminated the wine, lactic acid was produced, making the wine sour. In 1861, Pasteur observed that less sugar fermented per part of yeast when the yeast was exposed to air. The lower rate of fermentation aerobically became known as the Pasteur effect.

Pasteur’s research also showed that the growth of micro-organisms was responsible for spoiling beverages, such as beer, wine and milk. With this established, he invented a process in which liquids such as milk were heated to a temperature between 60 and 100 °C. This killed most bacteria and moulds already present within them. Pasteur and Claude Bernard completed tests on blood and urine on 20 April 1862. Pasteur patented the process, to fight the “diseases” of wine, in 1865. The method became known as pasteurization, and was soon applied to beer and milk.

Beverage contamination led Pasteur to the idea that micro-organisms infecting animals and humans cause disease. He proposed preventing the entry of micro-organisms into the human body, leading Joseph Lister to develop antiseptic methods in surgery. In 1866, Pasteur published Etudes sur le Vin, about the diseases of wine, and he published Etudes sur la Bière in 1876, concerning the diseases of beer.

Silkworm disease
In 1865, Jean-Baptiste Dumas, chemist, senator and former Minister of Agriculture and Commerce, asked Pasteur to study a new disease that was decimating silkworm farms from the south of France and Europe, the pébrine, characterized on a macroscopic scale by black spots and on a microscopic scale by the “Cornalia corpuscles”. Pasteur accepted and made five long stays in Alès, between June 7, 1865 and 1869.

Pasteur first made the distinction between the two disease pébrine and flacherie. At a time where Pasteur had not yet understood the cause of the pébrine, he propagated an effective process to stop infections: a sample of chrysalises was chosen, they were crushed and the corpuscles were searched for in the crushed material; if the proportion of corpuscular pupae in the sample was very low, the chamber was considered good for reproduction. This method of sorting “seeds” (eggs) is close to a method that Osimo had proposed a few years earlier, but whose trials had not been conclusive. Pasteur also showed that the disease was hereditary. Pasteur developed a system to prevent pébrine. By this process, Pasteur curbs pébrine and saves many of the silk industry in the Cévennes.

Chicken cholera
Pasteur’s first work on vaccine development was on chicken cholera. He received the bacteria samples (later called Pasteurella multocida after him) from Henry Toussaint. He started the study in 1877, and by the next year, was able to maintain a stable culture using broths. After continuous culturing, he found that the bacteria were less pathogenic. Some of his culture samples could no longer induce the disease in healthy chickens.

In 1879, Pasteur, planning for holiday, instructed his assistant, Charles Chamberland to inoculate the chickens with fresh bacteria culture. Chamberland forgot and went on holiday himself. On his return, he injected the month-old cultures to healthy chickens. The chickens showed some symptoms of infection, but instead of the infections being fatal, as they usually were, the chickens recovered completely. Chamberland assumed an error had been made, and wanted to discard the apparently faulty culture, but Pasteur stopped him. Pasteur injected the freshly recovered chickens with fresh bacteria (that normally would kill other chickens), the chickens no longer showed any sign of infection. It was clear to him that the weakened bacteria had caused the chickens to become immune to the disease.

Pasteur attributed that the bacteria were weakened by contact with oxygen. He explained that bacteria kept in sealed containers never lost their virulence, and only those exposed to air in culture media could be used as vaccine.

In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in combating other diseases. Pasteur cultivated bacteria from the blood of animals infected with anthrax. When he inoculated animals with the bacteria, anthrax occurred, proving that the bacteria was the cause of the disease.

Many cattle were dying of anthrax in “cursed fields”. Pasteur was told that sheep that died from anthrax were buried in the field. Pasteur thought that earthworms might have brought the bacteria to the surface. He found anthrax bacteria in earthworms’ excrement, showing that he was correct. He told the farmers not to bury dead animals in the fields.

Pasteur had been trying to develop the anthrax vaccine since 1877, soon after Robert Koch’s discovery of the bacterium. Pasteur found that anthrax bacillus was not easily weakened by culturing in air as it formed spores – unlike chicken cholera bacillus. Pasteur did not directly disclose how he prepared the vaccines used at Pouilly-le-Fort. Although his report indicated it as a “live vaccine”, his laboratory notebooks show that he actually used potassium dichromate-killed vaccine, as developed by Chamberland, quite similar to Toussaint’s method.

Swine erysipelas
In 1882, Pasteur sent his assistant Louis Thuillier to southern France because of an epizootic of swine erysipelas. Thuillier identified the bacillus that caused the disease in March 1883. Pasteur and Thuillier increased the bacillus’s virulence after passing it through pigeons. Then they passed the bacillus through rabbits, weakening it and obtaining a vaccine.

Pasteur produced the first vaccine for rabies by growing the virus in rabbits, and then weakening it by drying the affected nerve tissue. The rabies vaccine was initially created by Emile Roux, a French doctor and a colleague of Pasteur, who had produced a killed vaccine using this method. The vaccine had been tested in 50 dogs before its first human trial.

This vaccine was used on 9-year-old Joseph Meister, on 6 July 1885, after the boy was badly mauled by a rabid dog. After consulting with physicians, he decided to go ahead with the treatment. Over 11 days, Meister received 13 inoculations, each inoculation using viruses that had been weakened for a shorter period of time. Three months later he examined Meister and found that he was in good health.

In 1886, he treated 350 people, of which only one developed rabies. The treatment’s success laid the foundations for the manufacture of many other vaccines. The first of the Pasteur Institutes was also built on the basis of this achievement.

The museum
After 30 years spent at the Normal School, Louis Pasteur moved in 1888 into the apartment reserved for him within the Institute. Now the Pasteur Museum, this place is rich in the collections it preserves and the personality it evokes.

Louis Pasteur will live in this apartment during the last seven years of his life from 1888 to 1895. Some time after the death of Madame Pasteur in 1910, with the exception of the constituent furniture and a few paintings, all of the scholar’s personal belongings were transported to Versailles in the Vallery-Radot mansion.

During the commemoration of the centenary of the birth of Louis Pasteur in 1922, the delegates of the Nations and the foreign Universities visit the apartment. In the living room, flasks, flasks, microscopes that belonged to Louis Pasteur are brought together in several display cases. These objects will constitute the preliminary collection of the room of scientific memories, created 15 years later.

The apartment been reconstructed, only the 1st and 2nd floors are refurbished. The original layout is restored as faithfully as possible, where certain objects, testimonies of admiration or recognition, evoke the work of Louis Pasteur. On May 20, 1936, the reconstruction was completed. The apartment then becomes the Pasteur Museum. The Pasteur Museum has since then been a souvenir museum. Both a scientific museum and an art museum, it also represents a very rare example of decorative art from the end of the 19th century.

The Pasteur Museum retains an important collection linked to the memory and life of Louis Pasteur. The collection of the Pasteur museum preserves a rich iconography dedicated to Louis Pasteur and the history of Pasteur. Photographs illustrate Louis Pasteur and other scientists, but also paintings, engravings, drawings, sculptures, medals, etc.

Pasteur Institute
After developing the rabies vaccine, Pasteur proposed an institute for the vaccine. In 1887, fundraising for the Pasteur Institute began, with donations from many countries. The official statute was registered in 1887, stating that the institute’s purposes were “the treatment of rabies according to the method developed by M. Pasteur” and “the study of virulent and contagious diseases”. The institute was inaugurated on 14 November 1888. He brought together scientists with various specialties. Since 1891 the Pasteur Institute had been extended to different countries, and currently there are 32 institutes in 29 countries in various parts of the world.