Louis Pasteur (1822-1895) in 1886.

On 11 March 1878, an elderly gentleman, Charles-Emmanuel Sedillot, former Director of the Ecole du service de sante militaire in Strasbourg, is reading to the Academie des sciences a note entitled De l’influence des travaux de Monsieur Pasteur sur les progres de la chirurgie.  He says that they must stop the debates of no interest about the terms to be employed to designate the little organisms which are then forming a whole new world that can be seen under the microscope:  “microzoaires”, “microphytes”, “bacteria”, “bacteridies”, “vibrions”, “infusories”, “ferments”…  After exchanges with the Medical Doctor and Lexicographer Emile Littre, he proposes the word “microbe”, a term which will rapidly become generalized.  It is on the following 30 April, before this same Academie, that the famous communication La theorie des germes et son application dans la medecine erupts.  It is signed Pasteur, Joubert and Chamberland.  After expounding on numerous studies, including that of the anthrax bacterium, it asks the questions:

“How can septicaemia be spread through the air, since this long translucent thread which crawls in the patient’s blood, and is now baptised septic “microbe”, is killed by this air?  How can blood exposed to oxygen become septic by dusts contained in the air?”

Pasteur’s demonstration is brilliant, incisive, as always.  He shows that in a drop of blood filled with septic vibrions, only those in the superior layer of this drop are killed on contact with the air, protecting from the oxygen by their minuscule cadavers their brothers in the inferior layers which multiply by dividing, then gradually pass to the state of germs, change their form, metamorphose while waiting for the right time, now insensitive to the air.  In the eyepiece of the microscope, one then only sees a barely visible dust of brilliant spots.

“And there it is formed, living the latent life of germs, no longer fearing the action of oxygen, there, I say, is the septic dust.  […]  we can understand the seeding of putrescible liquids by the dusts of the atmosphere, we can understand the presence of the putrid illnesses on the surface of the Earth.”

A simple experiment should be meditated by the Surgeons:  after having practised, with a slash of the scalpel, a little opening in the thickness of the tissues of a leg of lamb, Pasteur makes a drop of the septic vibrion culture penetrate it.  The microbe goes to work, the flesh gangrenes.  He tells them:

“This water, this sponge with which you wash the wounds, deposit germs which, as you can see, have an extreme facility for propagation in the tissues and inevitably lead to the death of the people on whom you have operated in a very short time if the life, in these members, does not oppose the multiplication of these germs.  But, alas!  how many times is this vital resistance powerless, how many times do the wounded person’s constitution, his weakened state, his morale, the bad condition of his dressings oppose only an insufficient barrier to the infinitely small beings with which you have unwittingly covered him in the part of him that is damaged!  If I had the honour of being a Surgeon, […] I would use only dressings, bandages, sponges which had been previously exposed in an air brought to the temperature of 130 to 150 degrees Centigrade, I would use only water which has been submitted to a temperature of 110 to 120 degrees Centigrade.”

Pasteur even goes through the smallest details, none of them seems negligeable to him.

Louis Pasteur's friend, the Physiologist Claude Bernard.

The germ theory has taken off, nothing more will stop it despite the blind resistance of the doctors, but it will only be established at the price of many efforts.  Nevertheless, in 1882, four years after the birth of the word microbe, mortality falls from fifty to five per cent for surgical operations, this time surrounded by precautions of hygiene and antiseptic methods.  In the maternity hospitals where there were between one and two hundred deaths of mothers for one thousand births, the figures fall to less than three for one thousand.  Everywhere, hygiene grows, develops and finally takes its place in public preoccupations.  It is recounted that, a few years before, Pasteur had complained in front of Claude Bernard about the type of endless discussion that was opposing him at the Academie de medecine to the believers in spontaneous generation.  Claude Bernard is supposed to have replied:

“Something of you will remain.  This morning, my Surgeon Gosselin came to probe my bladder.  He was accompanied by a young intern, Guyon, who follows your doctrines.  Gosselin washed his hands after having probed me.  Guyon washed his before.”


It is in the Summer of 1879 that Pasteur has a new rush of genius.  The Chemist’s researches have then been moved from the town to the country where chicken cholera is ravaging farmyards.  Pasteur is going to study the chickens and their microbes in this 1879 Summer.  While observing these birds, Pasteur is going to commit a technical fault which, paradoxically, is going to open the way to an extraordinary discovery.

The first act of the play opens in the laboratory of the Ecole normale.  They are waiting for a parcel from a province, containing the head of a cock which has died from cholera, sent to Pasteur by a Toulouse Veterinary Surgeon, Doctor Toussaint.  The Doctor is unsuccessfully trying to multiply the illness in culture media.  He is asking advice.  Pasteur is interested.  He wants to obtain the proliferation of the microbe in test-tubes, to understand the epidemics which appear or disappear according to the seasons.  He also wants to understand how a microbe can be mute for a long time, while still remaining alive.  He multiplies the seedings and notes that a seeding every twenty-four hours conserves the microbe’s virulence.  He notices that an injection into a guinea-pig does not affect the little rodent, but causes a simple abcess, whose liquid is on the other hand fatal to the chickens.  The idea of a living reservoir develops.

The holidays are here, Summer 1879;  the team is resting;  the virulent cultures are abandoned in their test-tubes.  Back from holidays, they begin to innoculate with these aged cultures.  And, the chickens innoculated with this cholera are ill, but most of them don’t die.  General astonishment!  Since these chickens are there, might as well use them again.  This time, they are injected with new, virulent cultures…  and they resist!  The principle of the vaccine is in the process of being born.

To be continued.