Louis Pasteur (1822-1895) in 1886.

In 1896, Emile Duclaux would comment:

“To everybody’s surprise, even Pasteur’s, almost all of these chickens (vaccinated) would resist, while the new chickens coming from the market would succumb […]  What spirit of divination prodded Pasteur to knock at this door which was asking only to be opened?”

Pasteur in fact again finds the effects of the ageing of the illness already noted in the corpuscules of the silkworm, and he again sees as well the story of Jenner:  in 1796, Edward Jenner had innoculated Man with a cow illness, vaccine, thereby preserving him from smallpox.  But between Jenner and Pasteur, there had been the discovery of microbes.  Further, with the chickens of Summer 1879, an unexpected and very important phenomenon was appearing in the course of the manipulation:  resistance to virulence.  This new fact initiates for Pasteur and his pupils a study programme, that of the virus-vaccines.

The second act takes place at Maison-Alfort.  During the researches on chicken cholera, those on anthrax continue.  If the guinea pig is a living reservoir transporting chicken cholera, the scholar determines that it is the earthworms which, in the countryside, play this role for anthrax.  By bringing soil to the surface, they bring the germs of animals who have died from anthrax and have been buried in the pastures by the peasants.  The healthy animals then graze on grass mixed with germs and in turn perish.  It is again Doctor Toussaint who sets off the researches of Pasteur and his pupils.  Toussaint announces that he has succeeded in vaccinating sheep thanks to a culture of anthrax submitted to heat.  Pasteur asks the Minister of Agriculture for the authorisation to make some tests on Toussaint’s vaccinating liquid at the Ecole veterinaire in Maison-Alfort:  it is a failure, the innoculated sheep all die.  The attenuation obtained by Toussaint is very real, but not definitive, the anthrax microbe, momentarily weakened, had become virulent again.  However, it is the right direction, and the team begins laboratory trials.  It finds the temperature and the limit of the length for attenuating the virulence of the bacteria, without removing from them a certain possibility for multiplying.  At the Academie, on Monday 28 February 1881, Chamberland, Roux and Pasteur co-sign a communication on the anthrax vaccine and the whole table of virulences.

The third act then takes place in the country, at Pouilly-le-Fort, near Melun.  This time, Pasteur is directing the play.  Hippolyte Rossignol, Veterinary Surgeon, suggests a farm as the place of action.  The actors will be sheep.  Rossignol has taken care of everything:  contacts have been made with the local aediles, with the Societe d’Agriculture in Melun.  This Society is presided by the Baron de La Rochette, a friend of the Sciences, and it has been placed at the disposition of the scholar and his team along with its flock of sixty sheep.  Senators, conseillers generaux, Farmers, Veterinary Surgeons, Medical Doctors are all there.  The Press too has been invited.  Pasteur writes the programme of the day, a great number of copies of which are distributed.  Certain sheep are to be vaccinated, others not, and it will be predicted to the audience right to the last sheep how many will die when they are later put in contact with the anthrax microbe!  The preliminary experiments in the laboratory and in Alfort have been rehearsals, but certain colleagues have not been convinced.  The Scientist wants to strike hard, take risks, and cover in ridicule his adversaries, like Colin.  Further, there is suspense:  the injections are made on 5 May 1881, the results will only be known on 2 June.  They return to Paris.  On 2 June 1881, before leaving for Pouilly-le-Fort, the Master writes to his disciples:

“Last Tuesday, we innoculated all the sheep, the vaccinated and the unvaccinated, with very virulent anthrax.  And the telegramme (from Rossignol) announces that, when we arrive today at two o’clock, all of the unvaccinated ones will be dead.  As for the vaccinated ones, they are all standing.  The telegramme ends with the words:  stunning success.  There is joy in the laboratory and at home.  Rejoice my dear children.”

But a vaccinated ewe dies on 4 June.  Is this a defeat?  No, the autopsy shows that the death was provoked by that of the foetus that the ewe was carrying.

The curtain falls, Pasteur can bow to the public.  The experiments of Pouilly-le-Fort will resound prodigiously.  Henry Bouley, from La Revue Scientifique, will write:

“Pouilly-le-Fort, as famous today as all the great battlefields, where Monsieur Pasteur, a new Apollo, did not fear to launch oracles, more certain of success that the God of Poetry could ever be.”


Among his childhood memories, Pasteur counted a terrible one.  The event went back to the month of October 1831.  Terror was spreading throughout the Jura because of a rabid wolf which was biting animals and people along its route.  The people bitten on their hands and heads were succumbing to rabies, with atrocious suffering.  In the Communes of Villers-Farlay, Ecleux and Mouchard alone, there had been eight victims.  The young Louis had seen cauterized with a red-hot iron, in the forge situated a few metres from his father’s house, the wounds of an inhabitant of Arbois named Nicole, who had been attacked by the wolf.  Nicole had not survived.

For years, the fear of this rabid wolf survived throughout the whole region.  This ill was reputed incurable, and, on top of that, the patient bitten by an animal was often finished off by members of his or her own family.  In 1810, a Philosopher had asked the Government to adopt the following Law:

“It is forbidden, on pain of death, to strangle, suffocate, bleed from all four members, or in any other way cause the death of an individual suffering from rabies…”

In 1816, only fifteen years before Pasteur had seen the blacksmith’s red-hot poker burn Nicole’s flesh, the newspapers were recounting the death of an unfortunate rabies sufferer suffocated between two mattresses.  On the subject of this mercy killing, they were saying in the Press of the epoch:

“So it is the duty of the Doctor to repeat that this illness cannot be transmitted from human to human, and that there is no danger in caring for those suffering from it.”

Some people who had been bitten by rabid dogs were submitted to the bite of a viper to try to neutralize the virus.  A cruel and useless ordeal.

To be continued.