The account of Pouilly-le-Fort that Pasteur published in June 1881 is six pages long and says nothing about how the vaccine was made. The account he wrote for himself fills three pages of a notebook and says exactly how. This piece is about that notebook: what it is, where it went, who read it, and what they made of it. I could not read it myself; the Bibliothèque nationale’s finding aid lists it but shows no digital copy, and Gallica refused an automated reader. What follows rests on Gerald Geison’s book of 1995, which reproduces the pages in facsimile and translates them, and on the library’s catalogue.

The cupboard

Pasteur kept laboratory notebooks from his student days to the end of his life, and in 1878, at fifty-five and already a national figure, he told his family never to show them to anyone. For most of a century they obeyed. The notebooks stayed with the family after his death in 1895, through the lives of his son and of his grandson, Louis Pasteur Vallery-Radot, a physician and the last direct male descendant, who gave most of the family’s papers to the Bibliothèque nationale in 1964. The gift ran to 189 volumes, 152 of them notebooks, and access stayed restricted until his death in 1971. There was no printed catalogue until 1985. The library’s shelfmarks for the collection are NAF 17923 to 18112; the laboratory notebooks run in a numbered series from the first on crystals in the 1840s, through the fermentations, the wines, the silkworms and the beer, to the diseases.

The one that matters here is NAF 18016, which the catalogue describes as “XCIV, 10e cahier. Du 10 novembre 1880 au 10 avril 1882” and which Pasteur himself labelled the tenth notebook; Geison, who gave the notebooks his own running numbers, calls it Cahier 91 and gives its first date as 20 November. The catalogue indexes the names on its pages: Thuillier, Chamberland, Bouley, Roux, the veterinarian Bourrel who supplied the mad dogs for the rabies work, and at folio 166 “Rossignol, Hippolyte, vétérinaire.” Seventeen months of the laboratory are in it: the chicken cholera, the anthrax vaccines, the first rabies experiments, Pouilly-le-Fort.

The three pages

Geison’s reading, which he says agrees on the central point with Antonio Cadeddu’s independent one, runs as follows. Since mid-January 1881 the notebook had been accumulating evidence that anthrax cultures could be attenuated by air at 42 to 43 degrees; on 1 February Pasteur called one of them “very probably a vaccine” for sheep. But the first trials of those cultures on sheep are not recorded until early March, a week after the Académie had been told of great success on sheep, and well into April the results were, in Geison’s words, “decidedly inconclusive, if promising,” and spread across several strains. On 13 April 1881 the notebook records a comparison: two sheep vaccinated with an air-attenuated culture of Pasteur’s, two with a culture Chamberland had attenuated in broth containing potassium bichromate, all four then given virulent anthrax. One of Pasteur’s two died. Chamberland’s two lived. Pasteur wrote that Chamberland’s vaccine was the surer, sûr.

The second page is headed “Charbon. Vaccination à Melun” and dated 26 April. On it, in a footnote in what Geison calls Pasteur’s microscopic and hard-to-decipher hand, he recorded the agreement of 28 April with the society of Melun and his intended method: the twenty-five sheep would receive on 5 May a culture so weakened by potassium bichromate that it no longer harmed mice, then strengthened by three successive passages through mice. These are folios 106 to 107 in Pasteur’s own pagination, 108 to 109 in the library’s stamp.

The third is page 113, which records what was done. The culture used for the first vaccine on 5 May “was an anthrax culture attenuated by Ch[amberland] with bichromate and which, no longer being lethal at all, had been reinforced by three successive passages in three mice.” The second, of 17 May, had also been attenuated by bichromate, for only a few days, without the mice, and had killed two of four unvaccinated sheep in the laboratory. The same page notes the departures from the signed protocol on 28 and 29 May, when one vaccinated and one unvaccinated sheep were given the virulent culture two and three days early, and the “foretaste” their fate gave of 2 June. Geison’s diagram of the trial puts the public version and the notebook side by side at each date: public, “presumably Pasteur’s oxygen-attenuated vaccine (no details)”; notebook, “Chamberland’s potassium-bichromate culture.”

The hints before the reading

Two people had said as much before anyone could check. Adrien Loir, Pasteur’s nephew, who worked in the laboratory as a young man, published a series of reminiscences in 1937 and 1938 under the title À l’ombre de Pasteur, in the shadow of Pasteur. In one of them he wrote that while Pasteur pursued attenuation by oxygen, Chamberland and Roux had tried antiseptics and obtained an obvious attenuation with potassium bichromate; that Pasteur had told them that so long as he lived they would not publish it before oxygen had been made to work; and that when, having signed the Melun protocol, he was asked by his assistants which vaccine he would use, he answered, in Geison’s translation, “The potassium bichromate one.” Loir gave no document, and the biographer of Roux, Émile Lagrange, hinted at the same thing in 1954. René Dubos, whose life of Pasteur of 1950 used Loir freely elsewhere, passed this over. Roux, who held the syringe at Pouilly-le-Fort and lived until 1933, wrote in 1896 that the vaccine there had been a spore-free culture attenuated by air, and never said otherwise. Cadeddu’s paper of 1987, whose abstract notes both Loir and Lagrange, was the first to set the notebook beside the published report; Geison’s chapter of 1995, “The Secret of Pouilly-le-Fort: Competition and Deception in the Race for the Anthrax Vaccine,” did it with facsimiles.

The quarrel

Geison’s charge was not that Pasteur kept quiet. It was that the published accounts “actively misrepresented” the vaccine, by tying the trial in their last paragraph to the method that had found the chicken cholera vaccine and by presenting it, at Versailles in June and London in August 1881, as part of a general campaign for oxygen-attenuated vaccines; and that the motive lay in the race with Toussaint, whose carbolic-acid vaccine the bichromate one too closely resembled. He conceded what Loir had argued: that the signed protocol said nothing about how the vaccine was to be made, that the oxygen vaccines were real and arrived within weeks of the trial, and that Pasteur may have thought of bichromate, an oxidising agent, as oxygen by other means, though there is no document for it.

Max Perutz, who had shared the Nobel prize for chemistry in 1962 for the structure of haemoglobin, reviewed the book for the New York Review of Books on 21 December 1995. His title was “The Pioneer Defended.” He wrote that Geison, “rather than Pasteur, seems to me guilty of unethical and unsavory conduct” when he burrowed through the notebooks for scraps of supposed wrongdoing; that bichromate and air “both” have “an oxidizing effect,” so that a charge of misrepresentation failed; that Chamberland’s treatment had kept the bacilli alive, as their passage through mice showed, where carbolic acid killed; and that Pasteur’s vaccines, being heritably attenuated, were the better ones. His verdict on Pasteur was “courageous, compassionate, and honest.” In February 1996 he published two corrections to the chemistry of his review. In April 1996 Geison replied that he had broached the oxidation reading himself, that an antiseptic kills or spares according to its concentration, and that the question was not whether the vaccine worked but whether the publications “gave a misleading account” of the research; Perutz answered that, if Geison knew bichromate was an oxidant, the charge was the more reprehensible. A further letter in 1997 called the review unfair. Geison died in 2001. The pages are where they were, in the rue de Richelieu, under a shelfmark, unread by the camera.

Sources

• Gerald L. Geison, The Private Science of Louis Pasteur (Princeton University Press, 1995), chapter 1 for the instruction of 1878, the gift of 1964, the restriction to 1971 and the catalogue of 1985; chapter 6 for the pages, the comparison of 13 April, Loir, Dubos, Roux’s essay of 1896, and the argument; appendixes A and B for the transcription and translation. In copyright; quoted in short phrases. press.princeton.edu
• Bibliothèque nationale de France, Département des manuscrits, Papiers Pasteur, NAF 17923–18112: the finding aid’s description of the collection (189 volumes, 152 notebooks, given by Professor and Madame Louis Pasteur Vallery-Radot) and of NAF 18016 with the names it indexes. No digital copy is shown for NAF 18016. archivesetmanuscrits.bnf.fr
• Antonio Cadeddu, “Pasteur et la vaccination contre le charbon: une analyse historique et critique,” History and Philosophy of the Life Sciences 9 (1987), 255–276. In copyright; its abstract read. philarchive.org
• M. F. Perutz, “The Pioneer Defended,” New York Review of Books, 21 December 1995; “Corrections,” 1 February 1996; Gerald L. Geison and M. F. Perutz, “Pasteur and the Culture Wars: An Exchange,” 4 April 1996; and “Pasteur’s Private Science,” 6 February 1997. In copyright; quoted in short phrases. nybooks.com, nybooks.com, nybooks.com, nybooks.com
• Louis Pasteur, “Compte rendu sommaire des expériences faites à Pouilly-le-Fort,” Comptes rendus 92 (13 June 1881), 1378–1383, read in the Œuvres de Pasteur, volume VI (Paris, 1933), pages 346–351, for what the public account does and does not say. archive.org