Louis Pasteur: His Life and Labours

by René Vallery-Radot

But to return to the animals of the laboratory: From the little white mice, which hide themselves in a packet of wadding, to the dogs which bark furiously in their iron cages, all are devoted to death. But it is not only the inmates of the laboratory which daily succeed each other upon the operating and dissecting tables. From divers parts of France, hampers full of fowls which have died of cholera, or of some other disease, are sent to Pasteur. Here is an enormous basket packed with straw containing the dead body of a pig which had died of measles. This fragment of lung, packed in a tin box, belonged to a cow which died of peripneumonia. Other packets are still more precious. Since Pasteur went to Pauillac two years ago, to watch for the return of a ship which was to bring back some passengers attacked with yellow fever, he sometimes receives from a distant country a bottled dose of vomito negro.

Everywhere, on the work tables, are to be seen tubes filled with blood, microscope slides carrying little drops. In the stoves are ranged the cultivating flasks, which resemble little flasks of liqueur. The point of a needle dipped into one of these flasks is sufficient to cause death. Enclosed in their glass prison, millions upon millions of microbes live and multiply.

It is really a curious spectacle this workshop of research and discovery. How numerous and varied are the subjects which are being studied, and with what energy and patience does Pasteur attack them! It is not only to the most dreaded diseases that he has applied the germ theory. He has extended it to certain common disorders. Everything to him is a subject for experiment. In May 1879, a person who was working in the laboratory was troubled with boils, which reappeared, as usually happens, at short intervals, sometimes on one part of the body, sometimes on another. Pasteur, whose mind was constantly dwelling on the part played by microscopic organisms, asked himself if the pus of the boils did not contain a parasite, the presence and development of which, and its accidental transport here and there in the body, might be the cause of the local inflammation and of the formation of the pus. The constant reappearance of the evil would be thus accounted for.

The pus of the first boil, which was situated on the nape of the neck, was collected in great purity; some days afterwards, the pus of a second boil, then of a third boil, was collected. The pus, or the blood-stained lymph of the red swelling which preceded the formation of the pus, were sown in a sterilised infusion, and each time a microbe, formed of little spherical points connected in pairs, frequently united in small clusters, was seen to develop itself. The cultivating liquid was sometimes infusion of fowl, sometimes of yeast. In the infusion of yeast the little grains are suspended in pairs throughout the liquid, which is uniformly thickened with them. In the fowl infusion, the grains are united into little clusters, which cover the sides of the vessels, the liquid remaining clear as long as it is not shaken.

New observations were made upon a series of boils, in the case of a man sent to Pasteur by Dr. Maurice Raynaud. The same parasite was again found—a unique parasite, distinct from all others. At the Hospital Lariboisière, a woman whose back was covered with boils, offered another opportunity for experiment, and with the same result. It appears certain, then, that every boil contains a microscopic aerobic microbe, and that to it are due the local inflammation and the consequent formation of pus.

When guinea-pigs or rabbits are inoculated with the cultivating liquids, little abscesses are formed, which, however, quickly disappear. As long as the cure of these little abscesses is not quite completed, one can extract from them the microscopic organism which has formed them. When the little parasite is sought for in the general blood of those attacked with boils it is not found. The cause of this, no doubt, is that an aerobic parasite has always some difficulty in developing itself in the blood. The blood corpuscles appropriate, and do not willingly give up to a foreign organism, the oxygen which they require. There is a struggle for life, and in the struggle against the boils the victory is not doubtful. It might be thought, then, that the little organism of boils does not exist in the blood, but there is no doubt that if, instead of a small drop of blood, one could put several grammes or more into cultivation fruitful results would follow. The little parasite is no doubt conveyed by the blood at one time or other. It is transported from a boil, in the process of development, to another point of the body, where it may be fortuitously arrested, there to cultivate itself and form a new boil.

'It is to be wished,' said Pasteur, 'that a patient would submit to a number of punctures on different parts of the body, distant from boils already formed or in process of formation, and that with the blood thus taken from the general circulation a multitude of cultivations might be carried on. I am persuaded,' he added, 'that, among these cultivations, we should find some fruitful in the little organism of the boils.'

But whilst Dr. Maurice Raynaud gave Pasteur the means of studying boils, Dr. Lannelongue enabled him to investigate that serious disease of the bones and marrow called 'osteomyelitis.' In February 1880 that skilful surgeon, who has published a highly esteemed work on osteomyelitis, and on the possibility of its cure by trepanning the bone, followed by washings and antiseptic dressings, conducted Pasteur to the Hospice Trousseau. A little girl twelve years of age, attacked with this cruel malady, was about to be operated upon. The right knee was much swollen, as was also all the leg to below the calf, and a part of the thigh above the knee. After having chloroformed the child, Dr. Lannelongue made a long incision below the knee, from which pus flowed abundantly. The bone of the tibia was laid bare for a considerable length. Three trepanning perforations were then made in the bone, from each of which the pus issued in great quantities. Pasteur carefully collected, with all the conditions necessary to the preservation of their purity, the pus of the exterior and the pus of the interior of the bone, and, returning to his laboratory, he examined them attentively. The direct observation, by a microscope, of the two specimens of pus was extremely interesting. It was obvious that they contained, in large quantities, an organism like that of boils, in pairs of two or four, and also in parcels, some with a clearly defined outline, others scarcely visible, and with very faint outlines. The external pus showed an abundance of pus globules, but that of the interior did not show any. It was like a paste entirely composed of microbes, so numerous and fertile that, in less than six hours after sowing them in the cultivating liquid, the development of the little microbe had commenced, and was rendered visible to the naked eye by a slight but general turbidity of the liquid.

Its close resemblance to the organism of the boil might lead to the assertion that they are identical, if it were not known how great are the physiological differences that may exist between microscopic parasites of the same appearance and the same dimensions.