In June 2026, the Pasteur Museum purchased a handwritten letter by Louis Pasteur, dated March 11, 1886, from the Belgian auction house Arenberg Auctions. The letter describes the first days of the public appeal that was launched to fund the creation of the Institut Pasteur. Nearly 140 years after it was written, it contains echoes of the upcoming Pasteurdon campaign.

Image

Transcript of the letter:  

A letter written in haste

On March 1, 1886, Louis Pasteur presented the results obtained on 350 patients to the French Academy of Sciences and called for the creation of a permanent vaccine center.^[1] During the session, Louis Pasteur said these words: "Based on the most rigorous statistics, we can see just how many people have already been saved from certain death. Post-exposure rabies prophylaxis is scientifically proven. A rabies vaccine center should be founded." On March 8, a committee unanimously adopted the plan for an "Institut Pasteur" and the principle of a public appeal. The letter acquired by the museum was written three days later, at the precise moment when donations were beginning to be collected.

Image

We read: "You may send me your donations to the "Institut Pasteur." I will pay them into the Crédit Foncier or the Banque de France, and you will receive a receipt within a few days." These few lines illustrate just how makeshift the administrative side of the appeal was at this early stage – it was Louis Pasteur himself who received and banked the first donations. The mention of Crédit Foncier and Banque de France is also revealing: their respective governors, Albert Christophle (1830-1904) and Pierre-Joseph Magnin (1824-1910), sat on the Patronage Committee set up by the Academy of Sciences, and the two institutions made sizeable contributions to the appeal:[2] 40,000 francs from Crédit Foncier and 12,000 francs from Banque de France.[3]

The letter also gives us an idea of Pasteur's state of mind regarding his detractors. He wrote: "You would not believe how delighted I was to read the last paragraph of your letter, even though I pay no heed to this vile detractor." This sentence echoes the violent attacks that had been leveled at him by some physicians and journalists, accusing him of quackery or financial motivation – claims that, paradoxically, did nothing to stop the popularity of the appeal with the public.

On March 12, 1886, the first meeting of the Institut Pasteur Board of Governors and General Meeting board was held. The question of how the appeal should be organized was a key topic of discussion. On page 3, we read: "Mr. Magnin says that the money already deposited or waiting to be deposited could be centralized at Crédit Foncier, which would issue receipts and would also ensure that the institute receives the small amounts of interest the bank pays on deposits." Pasteur's letter and the minutes of this first meeting therefore corroborate each other and give us an insight into the first steps of the collection process.


 

Image

A collective effort

The subsequent appeal exceeded all expectations and took on an unprecedented momentum. More than 100,000 people contributed, with a list of donors published every day in the French Official Journal. They included foreign monarchs – Emperor Alexander III of Russia (1845-1894), who gave 40,000 rubles, the Emperor of Brazil, Pedro II (1825-1891), and the Sultan of Turkey, Abdul Hamid II (1842-1918) –, major donors like Madame Boucicaut (1816-1913), owner of Au Bon Marché, who gave 250,000 francs, the Rothschild family (56,000 francs), the French Parliament (200,000 francs), and ordinary people like police officers, postmen, school students – even the young Joseph Meister himself scraped together a few coins. People from every social class joined in.[4]

The cause was also taken up in cultural and artistic circles – on May 11, 1886, a grand charity gala was held at the Trocadero Palace, with the participation of Alexandre Dumas, Charles Gounod and Camille Saint-Saëns.

A total of nearly 2.58 million gold francs was collected – the equivalent of a billion euros today! These funds paid for an 11,000m² plot on rue Dutot in March 1887. Building work began in June that year and the Institut Pasteur was officially inaugurated on November 14, 1888 by French President Sadi Carnot (1837-1894). The new institute brought together a rabies treatment center, a research institute on infectious diseases and a teaching center under one roof.
 

An acquisition that contributes to the Institut Pasteur's memory

This letter enhances the collections of the Pasteur Museum, which are growing every year thanks to active monitoring of auction house catalogs and donations from individuals. 

As well as its historical value, the letter reminds us that the Institut Pasteur was created through an unprecedented wave of public generosity, with donations of all sizes. The Pasteurdon campaign, launched this week, continues this legacy, encouraging people from all horizons to support today's biomedical research.

If you are interested in the latest museum news, have any questions or are in possession of any technical or scientific objects that can provide clues to the past activities of the Institut Pasteur's laboratories, feel free to contact the museum team at musee@pasteur.fr  and follow us on social media (LinkedIn, Instagram).

[1] Op. Cit.
[2] Gabriel Galvez-Behar, Le financement des débuts de l’Institut Pasteur : analyse des souscriptions (188-1891), consulté en ligne
[3] Jean-Luc Chappey, « VII. L’Institut Pasteur, scandales et finances », in Pasteur et les antivax (p. 125-173). Agone, consulté en ligne
[4] Gabriel Galvez-Behar, Le financement des débuts de l’Institut Pasteur : analyse des souscriptions (188-1891), consulté en ligne