The confusion of ideas on the origin of contagious and epidemic diseases was about to be suddenly enlightened; Pasteur had now taken up the study of the disease known as charbon or splenic fever. This disease was ruining agriculture; the French provinces of Beauce, Brie, Burgundy, Nivernais, Berry, Champagne, DauphinÉ and Auvergne, paid a formidable yearly tribute to this mysterious scourge. In the Beauce, for instance, twenty sheep out of every hundred died in one flock; in some parts of Auvergne the proportion was ten or fifteen per cent., sometimes even twenty-five, thirty-five, or fifty per cent. At Provins, at Meaux, at Fontainebleau, some farms were called charbon farms; elsewhere, certain fields or hills were looked upon as accursed and an evil spell seemed to be thrown over flocks bold enough to enter those fields or ascend those hills. Animals stricken with this disease almost always died in a few hours; sheep were seen to lag behind the flock, with drooping head, shaking limbs and gasping breath; after a rigor and some sanguinolent evacuations, occurring also through the mouth and nostrils, death supervened, often before the shepherd had had time to notice the attack. The carcase rapidly became distended, and the least rent in the skin gave issue to a flow of black, thick and viscid blood, hence the name of anthrax given to the disease. It was also called splenic fever, because necropsy showed that the spleen had assumed enormous dimensions; if that were opened, it presented a black and liquid pulp. In some places the disease assumed a character of extreme virulence; in the one district of Novgorod, in Russia, 56,000 head of cattle died of splenic infection between 1867 and 1870. Horses, oxen, cows, sheep, everything succumbed, as did also 528 persons, attacked by the contagion under divers forms; a pin prick or a scratch is sufficient to inoculate shepherds, butchers, knackers or farmers with the malignant pustule.

Though a professor at the Alfort Veterinary School, M. Delafond, did point out to his pupils as far back as 1838 that charbon blood contained “little rods,” as he called them; it was only looked upon by himself and them as a curiosity with no scientific importance. Davaine, when he—and Rayer as well—recognized in 1850 those little filiform bodies in the blood of animals dying of splenic fever, he too merely mentioned the fact, which seemed to him of so little moment that he did not even report it in the first notice of his works edited by himself.

It was only eleven years later that Davaine—struck, as he himself gladly acknowledged, by reading Pasteur’s paper on the butyric ferment, the little cylindrical rods of which offer all the characteristics of vibriones or bacteria—asked himself whether the filiform corpuscles seen in the blood of the charbon victims might not act after the manner of ferments and be the cause of the disease. In 1863, a medical man at Dourdan, whose neighbour, a farmer, had lost twelve sheep of charbon in a week, sent blood from one of these sheep to Davaine, who hastened to inoculate some rabbits with this blood. He recognized the presence of those little transparent and motionless rods which he called bacteridia (a diminutive of bacterium, or rod-shaped vibriones). It might be thought that the cause of the evil was found, in other words that the relation between those bacteridia and the disease which had caused death could not be doubted. But two professors of the Val de GrÂce, Jaillard and Leplat; refuted these experiments.

They had procured, in the middle of the summer, from a knacker’s yard near Chartres, a little blood from a cow which had died of anthrax, and they inoculated some rabbits with it. The rabbits died, but without presenting any bacteridia. Jaillard and Leplat therefore affirmed that splenic fever was not an affection caused by parasites, that the bacteridium was an epiphenomenon of the disease and could not be looked upon as the cause of it.

Davaine, on repeating Jaillard and Leplat’s experiments, found a new interpretation; he alleged that the disease they had inoculated was not anthrax. Then Jaillard and Leplat obtained a little diseased sheep’s blood from M. Boutet, a veterinary surgeon at Chartres, and tried that instead of cow’s blood. The result was identical: death ensued, but no bacteridia. Were there then two diseases?

Others made observations in their turn. It occurred to a young German physician, Dr. Koch, who in 1876 was beginning his career in a small village in Germany, to seek a culture medium for the bacteridium. A few drops of aqueous humour, collected in the eyes of oxen or of rabbits, seemed to him favourable. After a few hours of this nutrition the rods seen under the microscope were ten or twenty times larger than at first; they lengthened immoderately, so as to cover the whole slide of the microscope, and might have been compared to a ball of tangled thread. Dr. Koch examined those lengths, and after a certain time noticed little spots here and there looking like a punctuation of spores. Tyndall, who knew how to secure continuous attention by a variety of comparisons, said at a scientific conference in Glasgow a few months later that those little ovoid bodies were contained within the envelope of the filament like peas in their pods. It is interesting to note that Pasteur, when he studied, in connection with silkworm diseases, the mode of reproduction of the vibriones of flachery, had seen them divide into spores similar to shining corpuscles; he had demonstrated that those spores, like seeds of plants, could revive after a lapse of years and continue their disastrous work. The bacterium of charbon, or bacillus anthracis as it now began to be called, reproduced itself in the same way, and, when inoculated by Dr. Koch into guinea-pigs, rabbits and mice, provoked splenic fever as easily and inevitably as blood from the veins of an animal that had died of the disease. Bacilli and spores therefore yielded the secret of the contagion, and it seemed that the fact was established, when Paul Bert, in January, 1877, announced to the SociÉtÉ de Biologie that it was “possible to destroy the bacillus anthracis in a drop of blood by compressed oxygen, to inoculate what remained, and to reproduce the disease and death without any trace of the bacteridium ... Bacteridia,” he added, “are therefore neither the cause nor the necessary effect of splenic fever, which must be due to a virus.”

Pasteur tackled the subject. A little drop of the blood of an animal which had died of anthrax—a microscopic drop—was laid, sown, after the usual precautions to ensure purity, in a sterilized balloon which contained neutral or slightly alkaline urine. The culture medium might equally be common household broth, or beer-yeast water, either of them neutralized by potash. After a few hours, a sort of flake was floating in the liquid; the bacteridia could be seen, not under the shape of short broken rods, but with the appearance of filaments, tangled like a skein; the culture medium being highly favourable, they were rapidly growing longer. A drop of that liquid, abstracted from the first vessel, was sown into a second vessel, of which one drop was again placed into a third, and so on, until the fortieth flask; the seed of each successive culture came from a tiny drop of the preceding one. If a drop from one of those flasks was introduced under the skin of a rabbit or guinea-pig, splenic fever and death immediately ensued, with the same symptoms and characteristics as if the original drop of blood had been inoculated. In the presence of the results from those successive cultures, what became of the hypothesis of an inanimate substance contained in the first drop of blood? It was now diluted in a proportion impossible to imagine. It would therefore be absurd, thought Pasteur, to imagine that the last virulence owed its power to a virulent agent existing in the original drop of blood; it was to the bacteridium, multiplied in each culture, and to the bacteridium alone, that this power was due; the life of the bacteridium had made the virulence. “Anthrax is therefore” Pasteur declared, “the disease of the bacteridium, as trichinosis is the disease of the trichina, as itch is the disease of its special acarus, with this circumstance, however, that, in anthrax, the parasite can only be seen through a microscope, and very much enlarged.” After the bacteridium had presented those long filaments, within a few hours, two days at the most, another spectacle followed; amidst those filaments, appeared the oval shapes, the germs, spores or seeds, pointed out by Dr. Koch. Those spores, sown in broth, reproduced in their turn the little packets of tangled filaments, the bacteridia. Pasteur reported that “one single germ of bacteridium in the drop which is sown multiplies during the following hours and ends by filling the whole liquid with such a thickness of bacteridia that, to the naked eye, it seems that carded cotton has been mixed with the broth.”

M. Chamberland, a pupil who became intimately associated with this work on anthrax, has defined as follows what Pasteur had now achieved: “By his admirable process of culture outside organism, Pasteur shows that the rods which exist in the blood, and for which he has preserved the name of bacteridia given them by Davaine, are living beings capable of being indefinitely reproduced in appropriate liquids, after the manner of a plant multiplied by successive cuttings. The bacterium does not reproduce itself only under the filamentous form, but also through spores or germs, after the manner of many plants which present two modes of reproduction, by cuttings and by seeds.” The first point was therefore settled. The ground suspected and indicated by Davaine was now part of the domain of science, and preserved from any new attacks.

Yet Jaillard and Leplat’s experiments remained to be explained: how had they provoked death through the blood of a splenic fever victim and found no bacteridia afterwards? It was then that Pasteur, guided, as Tyndall expressed it, by “his extraordinary faculty of combining facts with the reasons of those facts,” placed himself, to begin with, in the conditions of Jaillard and Leplat, who had received, during the height of the summer, some blood from a cow and a sheep which had died of anthrax, that blood having evidently been abstracted more than twenty-four hours before the experiment. Pasteur, who had arranged to go to the very spot, the knacker’s yard near Chartres, and himself collect diseased blood, wrote to ask that the carcases of animals which had died of splenic fever should be kept for him for two or three days.

He arrived on June 13, 1877, accompanied by the veterinary surgeon, M. Boutet. Three carcases were awaiting him: that of a sheep which had been dead sixteen hours, that of a horse whose death dated from the preceding day, and that of a cow which must have been dead for two or three days, for it had been brought from a distant village. The blood of the recently diseased sheep contained bacteridia of anthrax only. In the blood of the horse, putrefaction vibriones were to be found, besides the bacteridia, and those vibriones existed in a still greater proportion in the blood of the cow. The sheep’s blood, inoculated into guinea-pigs, provoked anthrax with pure bacteridia; that of the cow and of the horse brought a rapid death with no bacteridia.

Henceforth what had happened in Jaillard and Leplat’s experiments, and in the incomplete and uncertain experiments of Davaine, became simple and perfectly clear to Pasteur, as well as the confusion caused by another experimentalist who had said his say ten years after the discussions of Jaillard, Leplat and Davaine.

This was a Paris veterinary surgeon, M. Signol. He had written to the Academy of Sciences that it was enough that a healthy animal should be felled, or rather asphyxiated, for its blood, taken from the deeper veins, to become violently virulent within sixteen hours. M. Signol thought he had seen motionless bacteridia similar to the bacillus anthracis; but those bacteridia, he said, were incapable of multiplying in the inoculated animals. Yet the blood was so very virulent that animals rapidly succumbed in a manner analogous to death by splenic fever. A Commission was nominated to ascertain the facts; Pasteur was made a member of it, as was also his colleague Bouillaud—still so quick and alert, in spite of his eighty years, that he looked less like an old man than like a wrinkled young man—and another colleague, twenty years younger, Bouley, the first veterinary surgeon in France who had a seat at the Institute. The latter was a tall, handsome man, with a somewhat military appearance, and an expression of energetic good humour which his disposition fully justified. He was eager to help in the propagation of new ideas and discoveries, and soon, with eager enthusiasm, placed his marked talents as a writer and orator at Pasteur’s disposal.

On the day when the Commission met, M. Signol showed the carcase of a horse, which he had sacrificed for this experiment, having asphyxiated it when in excellent health. Pasteur uncovered the deep veins of the horse and showed to Bouley, and also to Messrs. Joubert and Chamberland, a long vibrio, so translucid as to be almost invisible, creeping, flexible, and which, according to Pasteur’s comparison, slipped between the globules of the blood as a serpent slips between high grasses; it was the septic vibrio. From the peritoneum, where it swarms, that vibrio passes into the blood a few hours after death; it represents the vanguard of the vibriones of putrefaction. When Jaillard and Leplat had asked for blood infected with anthrax, they had received blood which was at the same time septic. It was septicÆmia (so prompt in its action that inoculated rabbits or sheep perish in twenty-four or thirty-six hours) that had killed Jaillard and Leplat’s rabbits. It was also septicÆmia, provoked by this vibrio (or its germs, for it too has germs), that M. Signol had unknowingly inoculated into the animals upon which he experimented. Successive cultures of that septic vibrio enabled Pasteur to show, as he had done for the bacillus anthracis, that one drop of those cultures caused septicÆmia in an animal. But, while the bacillus anthracis is aËrobic, the septic vibrio, being anaËrobic, must be cultivated in a vacuum, or in carbonic acid gas. And, cultivating those bacteridia and those vibriones with at least as much care as a Dutchman might give to rare tulips, Pasteur succeeded in parting the bacillus anthracis and the septic vibrio when they were temporarily associated. In a culture in contact with air, only bacteridia developed, in a culture preserved from air, only the septic vibrio.

What Pasteur called “the Paul Bert fact” now alone remained to be explained; this also was simple. The blood Paul Bert had received from Chartres was of the same quality as that which Jaillard and Leplat had had; that is to say already septic. If filaments of bacillus anthracis and of septic vibriones perish under compressed oxygen, such is not the case with the germs, which are extremely tenacious; they can be kept for several hours at a temperature of 70° C., and even of 95° C. Nothing injures them, neither lack of air, carbonic acid gas nor compressed oxygen. Paul Bert, therefore, killed filamentous bacteridia under the influence of high pressure; but, as the germs were none the worse, those germs revived the splenic fever. Paul Bert came to Pasteur’s laboratory, ascertained facts and watched experiments. On June 23, 1877, he hastened to the SociÉtÉ de Biologie and proclaimed his mistake, acting in this as a loyal Frenchman, Pasteur said.

In spite of this testimony, and notwithstanding the admiration conceived for Pasteur by certain medical men—notably H. Gueneau de Mussy, who published in that very year (1877) a paper on the theory of the contagium germ and the application of that theory to the etiology of typhoid fever—the struggle was being continued between Pasteur and the current medical doctrines. In the long discussion which began at that time in the AcadÉmie de MÉdecine on typhoid fever, some masters of medical oratory violently attacked the germ theory, proclaiming the spontaneity of living organism. Typhoid fever, they said, is engendered by ourselves within ourselves. Whilst Pasteur was convinced that the day would come—and that was indeed the supreme goal of his life work—when contagious and virulent diseases would be effaced from the preoccupations, mournings and anxieties of humanity, and when the infinitesimally small, known, isolated and studied, would at last be vanquished, his ideas were called Utopian dreams.

The old professors, whose career had been built on a combination of theories which they were pleased to call medical truth, dazed by such startling novelties, endeavoured, as did Piorry, to attract attention to their former writings. “It is not the disease, an abstract being,” said Piorry, “which we have to treat, but the patient, whom we must study with the greatest care by all the physical, chemical and clinical means which Science offers.”

The contagion which Pasteur showed, appearing clearly in the disorders visible in the carcases of inoculated guinea-pigs, was counted as nothing. As to the assimilation of a laboratory experiment on rabbits and guinea-pigs to what occurred in human pathology, it may be guessed that it was quite out of the question for men who did not even admit the possibility of a comparison between veterinary medicine and the other. It would be interesting to reconstitute these hostile surroundings in order to appreciate the efforts of will required of Pasteur to enable him to triumph over all the obstacles raised before him in the medical and the veterinary world.

The Professor of Alfort School, Colin, who had, he said, made 500 experiments on anthrax within the last twelve years, stated, in a paper of seventeen pages, read at the Academy of Medicine on July 31, that the results of Pasteur’s experiments had not the importance which Pasteur attributed to them. Among many other objections, one was considered by Colin as a fatal one—the existence of a virulent agent situated in the blood, besides the bacteridia.

Bouley, who had just communicated to the Academy of Sciences some notes by M. Toussaint, professor at the Toulouse veterinary school, whose experiments agreed with those of Pasteur, was nevertheless a little moved by Colin’s reading. He wrote in that sense to Pasteur, who was then spending his holidays in the Jura. Pasteur addressed to him an answer as vigorous as any of his replies at the Academy.

“Arbois, August 18, 1877.—My dear colleague ... I hasten to answer your letter. I should like to accept literally the honour which you confer upon me by calling me ‘your master,’ and to give you a severe reprimand, you faithless man, who would seem to have been shaken by M. Colin’s reading at the AcadÉmie des Sciences, since you are still holding forth on the possibility of a virulent agent, and since your uncertainties seem to be appeased by a new notice, read by yourself, last Monday, at the AcadÉmie des Sciences.

“Let me tell you frankly that you have not sufficiently imbibed the teaching contained in the papers I have read, in my own name and in that of M. Joubert, at the AcadÉmie des Sciences and at the Academy of Medicine. Can you believe that I should have read those papers if they had wanted the confirmation you mention, or if M. Colin’s contradictions could have touched them? You know what my situation is, in these grave controversies; you know that, ignorant as I am of medical and veterinary knowledge, I should immediately be taxed with presumption if I had the boldness to speak without being armed for struggle and for victory! All of you, physicians and veterinary surgeons, would quite reasonably fall upon me if I brought into your debates a mere semblance of proof.

“How is it that you have not noticed that M. Colin has travestied—I should even say suppressed—because it hindered his theory, the important experiment of the successive cultures of the bacteridium in urine?

“If a drop of blood, infected with anthrax, is mixed with water, with pure blood or with humour from the eye, as was done by Davaine, Koch and M. Colin himself, and some of that mixture is inoculated and death ensues, doubt may remain in the mind as to the cause of virulence, especially since Davaine’s well-known experiments on septicÆmia. Our experiment is very different....”

And Pasteur showed how, from one artificial culture to another, he reached the fiftieth, the hundredth, and how a drop of this hundredth culture, identical with the first, could bring about death as certainly as a drop of infected blood.

Months passed, and—as Pasteur used to wish in his youth that it might be—few passed without showing one step forward. In a private letter to his old Arbois school-fellow, Jules Vercel, he wrote (February 11, 1878): “I am extremely busy; at no epoch of my scientific life have I worked so hard or been so much interested in the results of my researches, which will, I hope, throw a new and a great light on certain very important branches of medicine and of surgery.”

In the face of those successive discoveries, every one had a word to say. This accumulation of facts was looked down upon by that category of people who borrow assurance from a mixture of ignorance and prejudice. Others, on the other hand, amongst whom the greatest were to be found, proclaimed that Pasteur’s work was immortal and that the word “theory” used by him should be changed into that of “doctrine.” One of those who thus spoke, with the right given by full knowledge, was Dr. SÉdillot, whose open and critical mind had kept him from becoming like the old men described by Sainte Beuve as stopping their watch at a given time and refusing to recognize further progress. He was formerly Director of the Army Medical School at Strasburg, and had already retired in 1870, but had joined the army again as volunteer surgeon. It will be remembered that he had written from the Hagueneau ambulance to the AcadÉmie des Sciences—of which he was a corresponding member—to call the attention of his colleagues to the horrors of purulent infection, which defied his zeal and devotion.

No one followed Pasteur’s work with greater attention than this tall, sad-looking old man of seventy-four; he was one of those who had been torn away from his native Alsace, and he could not get over it. In March, 1878, he read a paper to the Academy, entitled “On the Influence of M. Pasteur’s Work on Medicine and Surgery.”

Those discoveries, he said, which had deeply modified the state of surgery, and particularly the treatment of wounds, could be traced back to one principle. This principle was applicable to various facts, and explained Lister’s success, and the fact that certain operations had become possible, and that certain cases, formerly considered hopeless, were now being recorded on all sides. Real progress lay there. SÉdillot’s concluding paragraph deserves to be handed down as a comment precious from a contemporary: “We shall have seen the conception and birth of a new surgery, a daughter of Science and of Art, which will be one of the greatest wonders of our century, and with which the names of Pasteur and Lister will remain gloriously connected.”

In that treatise, SÉdillot invented a new word to characterize all that body of organisms and infinitely small vibriones, bacteria, bacteridia, etc.; he proposed to designate them all under the generic term of microbe. This word had, in SÉdillot’s eyes, the advantage of being short and of having a general signification. He however felt some scruple before using it, and consulted LittrÉ, who replied on February 26, 1878: “Dear colleague and friend, microbe and microbia are very good words. To designate the animalculÆe I should give the preference to microbe, because, as you say, it is short, and because it leaves microbia, a feminine noun, for the designation of the state of a microbe.”

Certain philologists criticized the formation of the word in the name of the Greek language. Microbe, they said, means an animal with a short life, rather than an infinitesimally small animal. LittrÉ gave a second testimonial to the word microbe—

“It is true,” he wrote to SÉdillot, “that ??????? and a?????? probably mean in Greek short-lived and long-lived. But, as you justly remark, the question is not what is most purely Greek, but what is the use made in our language of the Greek roots. Now the Greek has ???, life, ????, to live, ????, living, the root of which may very well figure under the form of bi, bia with the sense living, in aËrobia, anaËrobia and microbe. I should advise you not to trouble to answer criticisms, but let the word stand for itself, which it will no doubt do.” Pasteur, by adopting it, made the whole world familiar with it.

Though during that month of March, 1878, Pasteur had had the pleasure of hearing SÉdillot’s prophetic words at the AcadÉmie des Sciences, he had heard very different language at the AcadÉmie de MÉdecine. Colin of Alfort, from the isolated corner where he indulged in this misanthropy, had renewed his criticisms of Pasteur. As he spoke unceasingly of a state of virulent anthrax devoid of bacteridia, Pasteur, losing patience, begged of the AcadÉmie to nominate a Commission of Arbitration.

“I desire expressly that M. Colin should be urged to demonstrate what he states to be the fact, for his assertion implies another, which is that an organic matter, containing neither bacteridia nor germs of bacteridia, produces within the body of a living animal the bacteridia of anthrax. This would be the spontaneous generation of the bacillus anthracis!”

Colin’s antagonism to Pasteur was such that he contradicted him in every point and on every subject. Pasteur having stated that birds, and notably hens, did not take the charbon disease, Colin had hastened to say that nothing was easier than to give anthrax to hens; this was in July, 1877. Pasteur, who was at that moment sending Colin some samples of bacteridia culture which he had promised him, begged that he would kindly bring him in exchange a hen suffering from that disease, since it could contract it so easily.

Pasteur told the story of this episode in March, 1878; it was an amusing interlude in the midst of those technical discussions. “At the end of the week, I saw M. Colin coming into my laboratory, and, even before I shook hands with him, I said to him: ‘Why, you have not brought me that diseased hen?’—‘Trust me,’ answered M. Colin, ‘you shall have it next week.’—I left for the vacation; on my return, and at the first meeting of the Academy which I attended, I went to M. Colin and said, ‘Well, where is my dying hen?’ ‘I have only just begun experimenting again,’ said M. Colin; ‘in a few days I will bring you a hen suffering from charbon.’—Days and weeks went by, with fresh insistence on my part and new promises from M. Colin. One day, about two months ago, M. Colin owned to me that he had been mistaken, and that it was impossible to give anthrax to a hen. ‘Well, my dear colleague,’ I said to him, ‘I will show you that it is possible to give anthrax to hens; in fact, I will one day myself bring you at Alfort a hen which shall die of charbon.’

“I have told the Academy this story of the hen M. Colin had promised in order to show that our colleague’s contradiction of our observations on charbon had never been very serious.”

Colin, after speaking about several other things, ended by saying: “I regret that I have not until now been able to hand to M. Pasteur a hen dying or dead of anthrax. The two that I had bought for that purpose were inoculated several times with very active blood, but neither of them has fallen ill. Perhaps the experiment might have succeeded afterwards, but, one fine day, a greedy dog prevented that by eating up the two birds, whose cage had probably been badly closed.” On the Tuesday which followed this incident, the passers-by were somewhat surprised to see Pasteur emerging from the Ecole Normale, carrying a cage, within which were three hens, one of them dead. Thus laden, he took a fiacre, and drove to the AcadÉmie de MÉdecine, where, on arriving, he deposited this unexpected object on the desk. He explained that the dead hen had been inoculated with charbon two days before, at twelve o’clock on the Sunday, with five drops of yeast water employed as a nutritive liquid for pure bacteridium germs, and that it had died on the Monday at five o’clock, twenty-nine hours after the inoculation. He also explained, in his own name, and in the names of Messrs. Joubert and Chamberland, how in the presence of the curious fact that hens were refractory to charbon, it had occurred to them to see whether that singular and hitherto mysterious preservation did not have its cause in the temperature of a hen’s body, “higher by several degrees than the temperature of the body of all the animal species which can be decimated by charbon.”

This preconceived idea was followed by an ingenious experiment. In order to lower the temperature of an inoculated hen’s body, it was kept for some time in a bath, the water covering one-third of its body. When treated in that way, said Pasteur, the hen dies the next day. “All its blood, spleen, lungs, and liver are filled with bacilli anthracis susceptible of ulterior cultures either in inert liquids or in the bodies of animals. We have not met with a single exception.”

As a proof of the success of the experiment, the white hen lay on the floor of the cage. As people might be forthcoming, even at the Academy, who would accuse the prolonged bath of having caused death, one of the two living hens, a gray one, who was extremely lively, had been placed in the same bath, at the same temperature and during the same time. The third one, a black hen, also in perfect health, had been inoculated at the same time as the white hen, with the same liquid, but with ten drops instead of five, to make the comparative result more convincing; it had not been subjected to the bath treatment. “You can see how healthy it is,” said Pasteur; “it is therefore impossible to doubt that the white hen died of charbon; besides, the fact is proved by the bacteridia which fill its body.”

A fourth experiment remained to be tried on a fourth hen, but the Academy of Medicine did not care to hold an all-night sitting. Time lacking, it was only done later, in the laboratory. Could a hen, inoculated of charbon and placed in a bath, recover and be cured merely by being taken out of its bath? A hen was taken, inoculated and held down a prisoner in a bath, its feet fastened to the bottom of the tub, until it was obvious that the disease was in full progress. The hen was then taken out of the water, dried, and wrapped up in cotton wool and placed in a temperature of 35° C. The bacteridia were reabsorbed by the blood, and the hen recovered completely.

This was, indeed, a most suggestive experiment, proving that the mere fall of temperature from 42° C. (the temperature of hens) to 38° C. was sufficient to cause a receptive condition; the hen, brought down by immersion to the temperature of rabbits or guinea-pigs, became a victim like them.

Between SÉdillot’s enthusiasm and Colin’s perpetual contradiction, many attentive surgeons and physicians were taking a middle course, watching for Pasteur’s results and ultimately accepting them with admiration. Such was the state of mind of M. Lereboullet, an editor of the Weekly Gazette of Medicine and Surgery, who wrote in an account of the AcadÉmie de MÉdecine meeting that “those facts throw a new light on the theory of the genesis and development of the bacillus anthracis. They will be ascertained and verified by other experimentalists, and it seems very probable that M. Pasteur, who never brings any premature or conjectural assertion to the academic tribune, will deduce from them conclusions of the greatest interest concerning the etiology of virulent diseases.”

But even to those who admired Pasteur as much as did M. Lereboullet, it did not seem that such an important part should immediately be attributed to microbes. Towards the end of his report (dated March 22, 1878) he reminded his readers that a discussion was open at the AcadÉmie de MÉdecine, and that the surgeon, LÉon Le Fort, did not admit the germ theory in its entirety. M. Le Fort recognized “all the services rendered to surgery by laboratory studies, chiefly by calling attention to certain accidents of wounds and sores, and by provoking new researches with a view to improving methods of dressing and bandaging.” “Like all his colleagues at the Academy, and like our eminent master, M. SÉdillot,” added M. Lereboullet, “M. Le Fort renders homage to the work of M. Pasteur; but he remains within his rights as a practitioner and reserves his opinion as to its general application to surgery.”

This was a mild way of putting it; M. Le Fort’s words were, “That theory, in its applications to clinical surgery, is absolutely inacceptable.” For him, the original purulent infection, though coming from the wound, was born under the influence of general and local phenomena within the patient, and not outside him. He believed that the economy had the power, under various influences, to produce purulent infection. A septic poison was created, born spontaneously, which was afterwards carried to other patients by such medicines as the tools and bandages and the hands of the surgeon. But, originally, before the propagation of the contagium germ, a purulent infection was spontaneously produced and developed. And, in order to put his teaching into forcible words, M. Le Fort declared to the AcadÉmie de MÉdecine: “I believe in the interiority of the principle of purulent infection in certain patients; that is why I oppose the extension to surgery of the germ theory which proclaims the constant exteriority of that principle.”

Pasteur rose, and with his firm, powerful voice, exclaimed: “Before the Academy accepts the conclusion of the paper we have just heard, before the application of the germ theory to pathology is condemned, I beg that I may be allowed to make a statement of the researches I am engaged in with the collaboration of Messrs. Joubert and Chamberland.”

His impatience was so great that he formulated then and there some headings for the lecture he was preparing, propositions on septicÆmia or putrid infection, on the septic vibrio itself, on the germs of that vibrio carried by wind in the shape of dust, or suspended in water, on the vitality of those germs, etc. He called attention to the mistakes which might be made if, in that new acquaintance with microbes, their morphologic aspect alone was taken account of. “The septic vibrio, for instance, varies so much in its shape, length and thickness, according to the media wherein it is cultivated, that one would think one was dealing with beings specifically distinct from each other.”

It was on April 30, 1878, that Pasteur read that celebrated lecture on the germ theory, in his own name and in that of Messrs. Joubert and Chamberland. It began by a proud exordium: “All Sciences gain by mutual support. When, subsequently to my early communications on fermentations, in 1857—1858, it was admitted that ferments, properly so called, are living beings; that germs of microscopical organisms abound on the surface of all objects in the atmosphere and in water; that the hypothesis of spontaneous generation is a chimera; that wines, beer, vinegar, blood, urine and all the liquids of the economy are preserved from their common changes when in contact with pure air—Medicine and Surgery cast their eyes towards these new lights. A French physician, M. Davaine, made a first successful application of those principles to medicine in 1863.”

Pasteur himself, elected to the AcadÉmie des Sciences as a mineralogist, proved by the concatenation of his studies within the last thirty years that Science was indeed one and all embracing. Having thus called his audience’s attention to the bonds which connect one scientific subject with another, Pasteur proceeded to show the connection between his yesterday’s researches on the etiology of Charbon to those he now pursued on septicÆmia. He hastily glanced back on his successful cultures of the bacillus anthracis, and on the certain, indisputable proof that the last culture acted equally with the first in producing charbon within the body of animals. He then owned to the failure, at first, of a similar method of cultivating the septic vibrio: “All our first experiments failed in spite of the variety of culture media that we used; beer-yeast water, meat broth, etc., etc....”

He then expounded, in the most masterly manner: (1) the idea which had occurred to him that this vibrio might be an exclusively anaËrobic organism, and that the sterility of the liquids might proceed from the fact that the vibrio was killed by the oxygen held in a state of solution by those liquids; (2) the similarity offered by analogous facts in connection with the vibrio of butyric fermentation, which not only lives without air, but is killed by air; (3) the attempts made to cultivate the septic vibrio in a vacuum or in the presence of carbonic acid gas, and the success of both those attempts; and, finally, as the result of the foregoing, the proof obtained that the action of the air kills the septic vibriones, which are then seen to perish, under the shape of moving threads, and ultimately to disappear, as if burnt away by oxygen.

“If it is terrifying,” said Pasteur, “to think that life may be at the mercy of the multiplication of those infinitesimally small creatures, it is also consoling to hope that Science will not always remain powerless before such enemies, since it is already now able to inform us that the simple contact of air is sometimes sufficient to destroy them. But,” he continued, meeting his hearers’ possible arguments, “if oxygen destroys vibriones, how can septicÆmia exist, as it does, in the constant presence of atmospheric air? How can those facts be reconciled with the germ theory? How can blood exposed to air become septic through the dusts contained in air? All is dark, obscure and open to dispute when the cause of the phenomena is not known; all is light when it is grasped.”

In a septic liquid exposed to the contact of air, vibriones die and disappear; but, below the surface, in the depths of the liquid (one centimetre of septic liquid may in this case be called depths), “the vibriones are protected against the action of oxygen by their brothers, who are dying above them, and they continue for a time to multiply by division; they afterwards produce germs or spores, the filiform vibriones themselves being gradually reabsorbed. Instead of a quantity of moving threads, the length of which often extends beyond the field of the microscope, nothing is seen but a dust of isolated, shiny specks, sometimes surrounded by a sort of amorphous gangue hardly visible. Here then is the septic dust, living the latent life of germs, no longer fearing the destructive action of oxygen, and we are now prepared to understand what seemed at first so obscure: the sowing of septic dust into putrescible liquids by the surrounding atmosphere, and the permanence of putrid diseases on the surface of the earth.”

Pasteur continued from this to open a parenthesis on diseases “transmissible, contagious, infectious, of which the cause resides essentially and solely in the presence of microscopic organisms. It is the proof that, for a certain number of diseases, we must for ever abandon the ideas of spontaneous virulence, of contagious and infectious elements suddenly produced within the bodies of men or of animals and originating diseases afterwards propagated under identical shapes; all those opinions fatal to medical progress and which are engendered by the gratuitous hypotheses of the spontaneous generation of albuminoid-ferment materia, of hemiorganism, of archebiosis, and many other conceptions not founded on observation.”

Pasteur recommended the following experiment to surgeons. After cutting a fissure into a leg of mutton, by means of a bistoury, he introduced a drop of septic vibrio culture; the vibrio immediately did its work. “The meat under those conditions becomes quite gangrened, green on its surface, swollen with gases, and is easily crushed into a disgusting, sanious pulp.” And addressing the surgeons present at the meeting: “The water, the sponge, the charpie with which you wash or dress a wound, lay on its surface germs which, as you see, have an extreme facility of propagating within the tissues, and which would infallibly bring about the death of the patients within a very short time if life in their limbs did not oppose the multiplication of germs. But how often, alas, is that vital resistance powerless! how often do the patient’s constitution, his weakness, his moral condition, the unhealthy dressings, oppose but an insufficient barrier to the invasion of the Infinitesimally Small with which you have covered the injured part! If I had the honour of being a surgeon, convinced as I am of the dangers caused by the germs of microbes scattered on the surface of every object, particularly in the hospitals, not only would I use absolutely clean instruments, but, after cleansing my hands with the greatest care and putting them quickly through a frame (an easy thing to do with a little practice), I would only make use of charpie, bandages, and sponges which had previously been raised to a heat of 130° C. to 150° C.; I would only employ water which had been heated to a temperature of 110° C. to 120° C. All that is easy in practice, and, in that way, I should still have to fear the germs suspended in the atmosphere surrounding the bed of the patient; but observation shows us every day that the number of those germs is almost insignificant compared to that of those which lie scattered on the surface of objects, or in the clearest ordinary water.”

He came down to the smallest details, seeing in each one an application of the rigorous principles which were to transform Surgery, Medicine and Hygiene. How many human lives have since then been saved by the dual development of that one method! The defence against microbes afforded by the substances which kill them or arrest their development, such as carbolic acid, sublimate, iodoform, salol, etc., etc., constitutes antisepsis; then the other progress, born of the first, the obstacle opposed to the arrival of the microbes and germs by complete disinfection, absolute cleanliness of the instruments and hands, of all which is to come into contact with the patient; in one word, asepsis.

It might have been prophesied at that date that Pasteur’s surprised delight at seeing his name gratefully inscribed on the great Italian establishment of sericiculture would one day be surpassed by his happiness in living to see realized some of the progress and benefits due to him, his name invoked in all operating theatres, engraved over the doors of medical and surgical wards, and a new era inaugurated.

A presentiment of the future deliverance of Humanity from those redoubtable microscopic foes gave Pasteur a fever for work, a thirst for new research, and an immense hope. But once again he constrained himself, refrained from throwing himself into varied studies, and, continuing what he had begun, reverted to his studies on splenic fever.

The neighbourhood of Chartres being most afflicted, the Minister of Agriculture, anticipating the wish of the Conseil GÉnÉral of the department of Eure et Loir, had entrusted Pasteur with the mission of studying the causes of so-called spontaneous charbon, that which bursts out unexpectedly in a flock, and of seeking for curative and preventive means of opposing the evil. Thirty-six years earlier, the learned veterinary surgeon, Delafond, had been sent to seek, particularly in the Beauce country, the causes of the charbon disease. Bouley, a great reader, said that there was no contrast more instructive than that which could be seen between the reasoning method followed by Delafond and the experimental method practised by Pasteur. It was in 1842 that Delafond received from M. Cunin Gridaine, then Minister of Agriculture, the mission of “going to study that malady on the spot, to seek for its causes, and to examine particularly whether those causes did not reside in the mode of culture in use in that part of the country.” Delafond arrived in the Beauce, and, having seen that the disease struck the strongest sheep, it occurred to him that it came from “an excess of blood circulating in the vessels.” He concluded from that that there might be a correlation between the rich blood of the Beauce sheep and the rich nitrogenous pasture of their food.

He therefore advised the cultivators to diminish the daily ration; and he was encouraged in his views by noting that the frequency of the disease diminished in poor, damp, or sandy soils.

Bouley, in order to show up Delafond’s efforts to make facts accord with his reasoning, added that to explain “a disease, of which the essence is general plethora, becoming contagious and expressing itself by charbon symptoms in man,” Delafond had imagined that the atmosphere of the pens, into which the animals were crowded, was laden with evil gases and putrefying emanations which produced an alteration of the blood “due at the same time to a slow asphyxia and to the introduction through the lungs of septic elements into the blood.”

It would have been but justice to recall other researches connected with Delafond’s name. In 1863, Delafond had collected some blood infected with charbon, and, at a time when such experiments had hardly been thought of, he had attempted some experiments on the development of the bacteridium, under a watch glass, at the normal blood temperature. He had seen the little rods grow into filaments, and compared them to a “very remarkable mycelium.” “I have vainly tried to see the mechanism of fructification,” added Delafond, “but I hope I still may.” Death struck down Delafond before he could continue his work.

In 1869 a scientific congress was held at Chartres; one of the questions examined being this: “What has been done to oppose splenic fever in sheep?” A veterinary surgeon enumerated the causes which contributed, according to him, to produce and augment mortality by splenic fever: bad hygienic conditions; tainted food, musty or cryptogamized; heated and vitiated air in the crowded pens, full of putrid manure; paludic miasma or effluvia; damp soil flooded by storms, etc., etc. A well-known veterinary surgeon, M. Boutet, saw no other means to preserve what remained of a stricken flock but to take it to another soil, which, in contradiction with his colleague, he thought should be chosen cool and damp. No conclusion could be drawn. The disastrous loss caused by splenic fever in the Beauce alone was terrible; it was said to have reached 20,000,000 francs in some particularly bad years. The migration of the tainted flock seemed the only remedy, but it was difficult in practice and offered danger to other flocks, as carcases of dead sheep were wont to mark the road that had been followed.

Pasteur, starting from the fact that the charbon disease is produced by the bacteridium, proposed to prove that, in a department like that of Eure et Loir, the disease maintained itself by itself. When an animal dies of splenic fever in a field, it is frequently buried in the very spot where it fell; thus a focus of contagion is created, due to the anthrax spores mixed with the earth where other flocks are brought to graze. Those germs, thought Pasteur, are probably like the germs of the flachery vibrio, which survive from one year to another and transmit the disease. He proposed to study the disease on the spot.

It almost always happened that, when he was most anxious to give himself up entirely to the study of a problem, some new discussion was started to hinder him. He had certainly thought that the experimental power of giving anthrax to hens had been fully demonstrated, and that that question was dead, as dead as the inoculated and immersed hen.

Colin, however, returned to the subject, and at an Academy meeting of July 9 said somewhat insolently, “I wish we could have seen the bacteridia of that dead hen which M. Pasteur showed us without taking it out of its cage, and which he took away intact instead of making us witness the necropsy and microscopical examination.” “I will take no notice,” said Pasteur at the following meeting, “of the malevolent insinuations contained in that sentence, and only consider M. Colin’s desire to hold in his hands the body of a hen dead of anthrax, full of bacteridia. I will, therefore, ask M. Colin if he will accept such a hen under the following condition: the necropsy and microscopic examination shall be made by himself, in my presence, and in that of one of our colleagues of this Academy, designated by himself or by this Academy, and an official report shall be drawn up and signed by the persons present. So shall it be well and duly stated that M. Colin’s conclusions, in his paper of May 14, are null and void. The Academy will understand my insistence in rejecting M. Colin’s superficial contradictions.

“I say it here with no sham modesty: I have always considered that my only right to a seat in this place is that given me by your great kindness, for I have no medical or veterinary knowledge. I therefore consider that I must be more scrupulously exact than any one else in the presentations which I have the honour to make to you; I should promptly lose all credit if I brought you erroneous or merely doubtful facts. If ever I am mistaken, a thing which may happen to the most scrupulous, it is because my good faith has been greatly surprised.

“On the other hand, I have come amongst you with a programme to follow which demands accuracy at every step. I can tell you my programme in two words: I have sought for twenty years, and I am still seeking, spontaneous generation properly so called.

“If God permit, I shall seek for twenty years and more the spontaneous generation of transmissible diseases.

“In these difficult researches, whilst sternly deprecating frivolous contradiction, I only feel esteem and gratitude towards those who may warn me if I should be in error.”

The Academy decided that the necropsy and microscopic examination of the dead hen which Pasteur was to bring to Colin should take place in the presence of a Commission composed of Pasteur, Colin, Davaine, Bouley, and Vulpian. This Commission met on the following Saturday, July 20, in the Council Chamber of the Academy of Medicine. M. Armand Moreau, a member of the Academy, joined the five members present, partly out of curiosity, and partly because he had special reasons for wishing to speak to Pasteur after the meeting.

Three hens were lying on the table, all of them dead. The first one had been inoculated under the thorax with five drops of yeast water slightly alkalized, which had been given as a nutritive medium to some bacteridia anthracis; the hen had been placed in a bath at 25° C., and had died within twenty-two hours. The second one, inoculated with ten drops of a culture liquid, had been placed in a warmer bath, 30° C., and had died in thirty-six hours. The third hen, also inoculated and immersed, had died in forty-six hours.

Besides those three dead hens, there was a living one which had been inoculated in the same way as the first hen. This one had remained for forty-three hours with one-third of its body immersed in a barrel of water. When it was seen in the laboratory that its temperature had gone down to 36° C., that it was incapable of eating and seemed very ill, it was taken out of the tub that very Saturday morning, and warmed in a stove at 42° C. It was now getting better, though still weak, and gave signs of an excellent appetite before leaving the Academy council chamber.

The third hen, which had been inoculated with ten drops, was dissected then and there. Bouley, after noting a serous infiltration at the inoculation focus, showed to the judges sitting in this room, thus suddenly turned into a testing laboratory, numerous bacteridia scattered throughout every part of the hen.

“After those ascertained results,” wrote Bouley, who drew up the report, “M. Colin declared that it was useless to proceed to the necropsy of the two other hens, that which had just been made leaving no doubt of the presence of bacilli anthracis in the blood of a hen inoculated with charbon and then placed under the conditions designated by M. Pasteur as making inoculation efficacious.

“The hen No. 2 has been given up to M. Colin to be used for any examination or experiment which he might like to try at Alfort.

“Signed: G. Colin, H. Bouley, C. Davaine, L. Pasteur, A. Vulpian.”

“This is a precious autograph, headed as it is by M. Colin’s signature!” gaily said Bouley. But Pasteur, pleased as he was with this conclusion, which put an end to all discussion on that particular point, was already turning his thoughts into another channel. The Academician who had joined the members of the Commission was showing him a number of the Revue Scientifique which had appeared that morning, and which contained an article of much interest to Pasteur.

In October, 1877, Claude Bernard, staying for the last time at St. Julien, near Villefranche, had begun some experiments on fermentations. He had continued them on his return to Paris, alone, in the study which was above his laboratory at the CollÈge de France.

When Paul Bert, his favourite pupil, M. d’Arsonval, his curator, M. Dastre, a former pupil, and M. Armand Moreau, his friend, came to see him, he said to them in short, enigmatical sentences, with no comment or experimental demonstration, that he had done some good work during the vacation. “Pasteur will have to look out.... Pasteur has only seen one side of the question.... I make alcohol without cells.... There is no life without air....”

Bernard’s and Pasteur’s seats at the Academy of Sciences were next to each other, and they usually enjoyed interchanging ideas. Claude Bernard had come to the November and December sittings, but, with a reticence to which he had not accustomed Pasteur, he had made no allusion to his October experiments. In January, 1878, he became seriously ill; in his conversations with M. d’Arsonval, who was affectionately nursing him, Claude Bernard talked of his next lecture at the Museum, and said that he would discuss his ideas with Pasteur before handling the subject of fermentations. At the end of January M. d’Arsonval alluded to these incomplete revelations. “It is all in my head,” said Claude Bernard, “but I am too tired to explain it to you.” He made the same weary answer two or three days before his death. When he succumbed, on February 10, 1878, Paul Bert, M. d’Arsonval and M. Dastre thought it their duty to ascertain whether their master had left any notes relative to the work which embodied his last thoughts. M. d’Arsonval, after a few days’ search, discovered some notes, carefully hidden in a cabinet in Claude Bernard’s bedroom; they were all dated from the 1st to the 20th of October, 1877; of November and December there was no record. Had he then not continued his experiments during that period? Paul Bert thought that these notes did not represent a work, not even a sketch, but a sort of programme. “It was all condensed into a series of masterly conclusions,” said Paul Bert, “which evidenced certitude, but there were no means of discussing through which channel that certitude had come to his prudent and powerful mind.” What should be done with those notes? Claude Bernard’s three followers decided to publish them. “We must,” said Paul Bert, “while telling the conditions under which the manuscript was found, give it its character of incomplete notes, of confidences made to itself by a great mind seeking its way, and marking its road indiscriminately with facts and with hypotheses in order to arrive at that feeling of certainty which, in the mind of a man of genius, often precedes proof.” M. Berthelot, to whom the manuscript was brought, presented these notes to the readers of the Revue Scientifique. He pointed to their character, too abbreviated to conclude with a rigorous demonstration, but he explained that several friends and pupils of Claude Bernard had “thought that there would be some interest for Science in preserving the trace of the last subjects of thought, however incomplete, of that great mind.”

Pasteur, after the experiment at the AcadÉmie de MÉdecine, hurried back to his laboratory and read with avidity those last notes of Claude Bernard. Were they a precious find, explaining the secrets Claude Bernard had hinted at? “Should I,” said Pasteur, “have to defend my work, this time against that colleague and friend for whom I professed deep admiration, or should I come across unexpected revelations, weakening and discrediting the results I thought I had definitely established?”

His reading reassured him on that point, but saddened him on the other hand. Since Claude Bernard had neither desired nor even authorized the publication of those notes, why, said Pasteur, were they not accompanied by an experimental commentary? Thus Claude Bernard would have been credited with what was good in his MSS., and he would not have been held responsible for what was incomplete or defective.

“As for me, personally,” wrote Pasteur in the first pages of his Critical Examination of a Posthumous Work of Claude Bernard on Fermentation, “I found myself cruelly puzzled; had I the right to consider Claude Bernard’s MS. as the expression of his thought, and was I free to criticize it thoroughly?” The table of contents and headings of chapters in Claude Bernard’s incomplete MS. condemned Pasteur’s work on alcoholic fermentation. The non-existence of life without air; the ferment not originated by exterior germs; alcohol formed by a soluble ferment outside life ... such were Claude Bernard’s conclusions. “If Claude Bernard was convinced,” thought Pasteur, “that he held the key to the masterly conclusions with which he ended his manuscript, what could have been his motive in withholding it from me? I looked back upon the many marks of kindly affection which he had given me since I entered on a scientific career, and I came to the conclusion that the notes left by Bernard were but a programme of studies, that he had tackled the subject, and that, following in this a method habitual to him, he had, the better to discover the truth, formed the intention of trying experiments which might contradict my opinions and results.”

Pasteur, much perplexed, resolved to put the case before his colleagues, and did so two days later. He spoke of Bernard’s silence, his abstention from any allusion at their weekly meetings. “It seems to me almost impossible,” he said, “and I wonder that those who are publishing these notes have not perceived that it is a very delicate thing to take upon oneself, with no authorization from the author, the making public of private notebooks! Which of us would care to think it might be done to him!... Bernard must have put before himself that leading idea, that I was in the wrong on every point, and taken that method of preparing the subject he intended to study.” Such was also the opinion of those who remembered that Claude Bernard’s advice invariably was that every theory should be doubted at first and only trusted when found capable of resisting objections and attacks.

“If then, in the intimacy of conversation with his friends and the yet more intimate secret of notes put down on paper and carefully put away, Claude Bernard develops a plan of research with a view to judging of a theory—if he imagines experiments—he is resolved not to speak about it until those experiments have been clearly checked; we should therefore not take from his notes the most expressly formulated propositions without reminding ourselves that all that was but a project, and that he meant to go once again through the experiments he had already made.”

Pasteur declared himself ready to answer any one who would defend those experiments which he looked upon as doubtful, erroneous, or wrongly interpreted. “In the opposite case,” he said, “out of respect for Claude Bernard’s memory, I will repeat his experiments before discussing them.”

Some Academicians discoursed on these notes as on simple suggestions and advised Pasteur to continue his studies without allowing himself to be delayed by mere control experiments. Others considered these notes as the expression of Claude Bernard’s thought. “That opinion,” said Pasteur—man of sentiment as he was—“that opinion, however, does not explain the enigma of his silence towards me. But why should I look for that explanation elsewhere than in my intimate knowledge of his fine character? Was not his silence a new proof of his kindness, and one of the effects of our mutual esteem? Since he thought that he held in his hands a proof that the interpretation I had given to my experiments was fallacious, did he not simply wish to wait to inform me of it until the time when he thought himself ready for a definite statement? I prefer to attribute high motives to my friend’s actions, and, in my opinion, the surprise caused in me by his reserve towards the one colleague whom his work most interested should give way in my heart to feelings of pious gratitude. However, Bernard would have been the first to remind me that scientific truth soars above the proprieties of friendship, and that my duty lies in discussing views and opinions in my turn with full liberty.”

Pasteur having made this communication to the Academy on July 22, hastily ordered three glass houses, which he intended to take with him into the Jura, “where I possess,” he told his colleagues, “a vineyard occupying some thirty or forty square yards.”

Two observations expounded in a chapter of his Studies on Beer tend to establish that yeast can only appear about the time when grapes ripen, and that it disappears in the winter only to show itself again at the end of the summer. Therefore “germs of yeast do not yet exist on green grapes.” “We are,” he added, “at an epoch in the year when, by reason of the lateness of vegetation due to a cold and rainy season, grapes are still in the green stage in the vineyards of Arbois. If I choose this moment to enclose some vines in almost hermetically closed glass houses, I shall have in October during the vintage some vines bearing ripe grapes without the exterior germs of wine yeast. Those grapes, crushed with precautions which will not allow of the introduction of yeast germs, will neither ferment nor produce wine. I shall give myself the pleasure of bringing some back to Paris, to present them to the Academy and to offer a few bunches to those of our colleagues who are still able to believe in the spontaneous generation of yeast.”

In the midst of the agitation caused by that posthumous work some said, or only insinuated, that if Pasteur was announcing new researches on the subject, it was because he felt that his work was threatened.

“I will not accept such an interpretation of my conduct,” he wrote to J. B. Dumas on August 4, 1878, at the very time when he was starting for the Jura; “I have clearly explained this in my notice of July 22, when I said I would make new experiments solely from respect to Bernard’s memory.”

As soon as Pasteur’s glass houses arrived, they were put up in the little vineyard he possessed, two kilometres from Arbois. While they were being put together, he examined whether the yeast germs were really absent from the bunches of green grapes; he had the satisfaction of seeing that it was so, and that the particular branches which were about to be placed under glass did not bear a trace of yeast germs. Still, fearing that the closing of the glass might be insufficient and that there might thus be a danger of germs, he took the precaution, “while leaving some bunches free, of wrapping a few on each plant with cotton wool previously heated to 150° C.”

He then returned to Paris and his studies on anthrax, whilst patiently waiting for the ripening of his grapes.

Besides M. Chamberland, Pasteur had enrolled M. Roux, the young man who was so desirous of taking part in the work at the laboratory. He and M. Chamberland were to settle down at Chartres in the middle of the summer. A recent student of the Alfort Veterinary School, M. Vinsot, joined them at his own request. M. Roux has told of those days in a paper on Pasteur’s Medical Work:

“Our guide was M. Boutet, who had unrivalled knowledge of the splenic fever country, and we sometimes met M. Toussaint, who was studying the same subject as we were. We have kept a pleasant memory of that campaign against charbon in the Chartres neighbourhood. Early in the morning, we would visit the sheepfolds scattered on that wide plateau of the Beauce, dazzling with the splendour of the August sunshine; then necropsies took place in M. Rabourdin’s knacker’s yard or in the farmyards. In the afternoon, we edited our experiment notebooks, wrote to Pasteur, and arranged for new experiments. The day was well filled, and how interesting and salutary was that bacteriology practised in the open air!

“On the days when Pasteur came to Chartres, we did not linger over our lunch at the HÔtel de France; we drove off to St. Germain, where M. Maunoury had kindly put his farm and flocks at our disposal. During the drive we talked of the week’s work and of what remained to be done.

“As soon as Pasteur left the carriage he hurried to the folds. Standing motionless by the gate, he would gaze at the lots which were being experimented upon, with a careful attention which nothing escaped; he would spend hours watching one sheep which seemed to him to be sickening. We had to remind him of the time and to point out to him that the towers of Chartres Cathedral were beginning to disappear in the falling darkness before we could prevail upon him to come away. He questioned farmers and their servants, giving much credit to the opinions of shepherds, who on account of their solitary life, give their whole attention to their flocks and often become sagacious observers.”

When again at Arbois, on September 17, Pasteur began to write to the Minister of Agriculture a note on the practical ideas suggested by this first campaign. A few sheep, bought near Chartres and gathered in a fold, had received, amongst the armfuls of forage offered them, a few anthrax spores. Nothing had been easier than to bring these from the laboratory, in a liquid culture of bacteria, and to scatter them on the field where the little flock grazed. The first meals did not give good scientific results, death was not easily provoked. But when the experimental menu was completed by prickly plants, likely to wound the sheep on their tongue or in their pharynx, such, for instance, as thistles or ears of barley, the mortality began. It was perhaps not as considerable as might have been wished for demonstration purposes, but nevertheless it was sufficient to explain how charbon could declare itself, for necropsy showed the characteristic lesions of the so-called spontaneous splenic fever. It was also to be concluded therefrom that the evil begins in the mouth, or at the back of the throat, supervening on meals of infected food, alone or mixed with prickly plants likely to cause abrasion.

It was therefore necessary, in a department like that of Eure et Loir, which must be full of anthrax germs,—particularly on the surface of the graves containing carcases of animals which had fallen victims to the disease,—that sheep farmers should keep from the food of their animals plants such as thistles, ears of barley, and sharp pieces of straw; for the least scratch, usually harmless to sheep, became dangerous through the possible introduction of the germs of the disease.

“It would also be necessary” wrote Pasteur, “to avoid all probable diffusion of charbon germs through the carcases of animals dying of that disease, for it is likely that the department of Eure et Loir contains those germs in greater quantities than the other departments; splenic fever having long been established there, it always goes on, dead animals not being disposed of so as to destroy all germs of ulterior contagion.”

After finishing this report, Pasteur went to his little vineyard on the BesanÇon road, where he met with a disappointment; his precious grapes had not ripened, all the strength of the plant seemed to have gone to the wood and leaves. But the grapes had their turn at the end of September and in October, those bunches that were swathed in cotton wool as well as those which had remained free under the glass; there was a great difference of colour between them, the former being very pale. Pasteur placed grapes from the two series in distinct tubes. On October 10, he compared the grapes of the glass houses, free or swathed, with the neighbouring open-air grapes. “The result was beyond my expectations; the tubes of open-air grapes fermented with grape yeast after a thirty-six or forty-eight hours’ sojourn in a stove from 25° C. to 30° C.; not one, on the contrary, of the numerous tubes of grapes swathed in cotton wool entered into alcoholic fermentation, neither did any of the tubes containing grapes ripened free under glass. It was the experiment described in my Studies on Beer. On the following days I repeated these experiments with the same results.” He went on to another experiment. He cut some of the swathed bunches and hung them to the vines grown in the open air, thinking that those bunches—exactly similar to those which he had found incapable of fermentation—would thus get covered with the germs of alcoholic ferments, as did the bunches grown in the open air and their wood. After that, the bunches taken from under the glass and submitted to the usual rÉgime would ferment under the influence of the germs which they would receive as well as the others; this was exactly what happened.

The difficulty now was to bring to the AcadÉmie des Sciences these branches bearing swathed bunches of grapes; in order to avoid the least contact to the grapes, these vine plants, as precious as the rarest orchids, had to be held upright all the way from Arbois to Paris. Pasteur came back to Paris in a coupÉ carriage on the express train, accompanied by his wife and daughter, who took it in turns to carry the vines. At last, they arrived safely at the Ecole Normale, and from the Ecole Normale to the Institute, and Pasteur had the pleasure of bringing his grapes to his colleagues as he had brought his hens. “If you crush them while in contact with pure air,” he said, “I defy you to see them ferment.” A long discussion then ensued with M. Berthelot, which was prolonged until February, 1879.

“It is a characteristic of exalted minds,” wrote M. Roux, “to put passion into ideas.... For Pasteur, the alcoholic fermentation was correlative with the life of the ferment; for Bernard and M. Berthelot, it was a chemical action like any other, and could be accomplished without the participation of living cells.” “In alcoholic fermentation,” said M. Berthelot, “a soluble alcoholic ferment may be produced, which perhaps consumes itself as its production goes on.”

M. Roux had seen Pasteur try to “extract the soluble alcoholic ferment from yeast cells by crushing them in a mortar, by freezing them until they burst, or by putting them into concentrated saline solutions, in order to force by osmose the succus to leave its envelope.” Pasteur confessed that his efforts were vain. In a communication to the AcadÉmie des Sciences on December 30, 1878, he said—

“It ever is an enigma to me that it should be believed that the discovery of soluble ferments in fermentations properly so called, or of the formation of alcohol by means of sugar, independently of cells would hamper me. It is true—I own it without hesitation, and I am ready to explain myself more lengthily if desired—that at present I neither see the necessity for the existence of those ferments, nor the usefulness of their action in this order of fermentations. Why should actions of diastase, which are but phenomena of hydration, be confused with those of organized ferments, or vice versÂ? But I do not see that the presence of those soluble substances, if it were ascertained, could change in any way the conclusions drawn from my labours, and even less so if alcohol were formed by electrolysis.

“They agree with me who admit:

“Firstly. That fermentations, properly so called, offer as an essential condition the presence of microscopic organisms.

“Secondly. That those organisms have not a spontaneous origin.

“Thirdly. That the life of every organism which can exist away from free oxygen is suddenly concomitant with acts of fermentation; and that it is so with every cell which continues to produce chemical action without the contact of oxygen.”

When Pasteur related this discussion, and formed of it an appendix to his book, Critical Examination of a Posthumous Work of Claude Bernard on Fermentations, his painful feelings in opposing a friend who was no more were so clearly evidenced that Sainte Claire Deville wrote to him (June 9, 1879): “My dear Pasteur, I read a few passages of your new book yesterday to a small party of professors and savants. We all were much moved by the expressions with which you praise our dear Bernard, and by your feelings of friendship and pure fraternity.”

Sainte Claire Deville often spoke of his admiration for Pasteur’s precision of thought, his forcible speech, the clearness of his writings. As for J. B. Dumas, he called the attention of his colleagues at the AcadÉmie FranÇaise to certain pages of that Critical Examination. Though unaccustomed to those particular subjects, they could not but be struck by the sagacity and ingenuity of Pasteur’s researches, and by the eloquence inspired by his genius. A propos of those ferment germs, which turn grape juice into wine, and from which he had preserved his swathed bunches, Pasteur wrote—

“What meditations are induced by those results! It is impossible not to observe that, the further we penetrate into the experimental study of germs, the more we perceive sudden lights and clear ideas on the knowledge of the causes of contagious diseases! Is it not worthy of attention that, in that Arbois vineyard (and it would be true of the million hectares of vineyards of all the countries in the world), there should not have been, at the time when I made the aforesaid experiments, one single particle of earth which would not have been capable of provoking fermentation by a grape yeast, and that, on the other hand, the earth of the glass houses I have mentioned should have been powerless to fulfil that office? And why? Because, at a given moment, I covered that earth with some glass. The death, if I may so express it, of a bunch of grapes thrown at that time on any vineyard, would infallibly have occurred through the saccharomyces parasites of which I speak; that kind of death would have been impossible, on the contrary, on the little space enclosed by my glass houses. Those few cubic yards of air, those few square yards of soil, were there, in the midst of a universal possible contagion, and they were safe from it.”

And suddenly looking beyond those questions of yeast and vintage, towards the germs of disease and of death: “Is it not permissible to believe, by analogy, that a day will come when easily applied preventive measures will arrest those scourges which suddenly desolate and terrify populations; such as the fearful disease (yellow fever) which has recently invaded Senegal and the valley of the Mississippi, or that other (bubonic plague), yet more terrible perhaps, which has ravaged the banks of the Volga.”

Pasteur, with his quick answers, his tenacious refutations, was looked upon as a great fighter by his colleagues at the Academy, but in the laboratory, while seeking Claude Bernard’s soluble ferment, he tackled subjects from which he drew conclusions which were amazing to physicians.

A worker in the laboratory had had a series of furuncles. Pasteur, whose proverb was “Seek the microbe,” asked himself whether the pus of furuncles might not have an organism, which, carried to and fro,—for it may be said that a furuncle never comes alone—would explain the centre of inflammation and the recurrence of the furuncles. After abstracting—with the usual purity precautions—some pus from three successive furuncles, he found in some sterilized broth a microbe, formed of little rounded specks which clustered to the sides of the culture vessel. The same was observed on a man whom Dr. Maurice Raynaud, interested in those researches on furuncles, had sent to the laboratory, and afterwards on a female patient of the LariboisiÈre Hospital, whose back was covered with furuncles. Later on, Pasteur, taken by Dr. Lannelongue to the Trousseau Hospital, where a little girl was about to be operated on for that disease of the bones and marrow called osteomyelitis, gathered a few drops of pus from the inside and the outside of the bone, and again found clusters of microbes. Sown into a culture liquid, this microbe seemed so identical with the furuncle organism that “it might be affirmed at first sight,” said Pasteur, “that osteomyelitis is the furuncle of bones.”

The hospital now took as much place in Pasteur’s life as the laboratory. “Chamberland and I assisted him in those studies,” writes M. Roux. “It was to the HÔpital Cochin or to the MaternitÉ that we went most frequently, taking our culture tubes and sterilized pipets into the wards or operating theatres. No one knows what feelings of repulsion Pasteur had to overcome before visiting patients and witnessing post-mortem examinations. His sensibility was extreme, and he suffered morally and physically from the pains of others; the cut of the bistoury opening an abscess made him wince as if he himself had received it. The sight of corpses, the sad business of necropsies, caused him real disgust; we have often seen him go home ill from those operating theatres. But his love of science, his desire for truth were the stronger; he returned the next day.”

He was highly interested in the study of puerperal fever, which was still enveloped in profound darkness. Might not the application of his theories to the progress of surgery be realized in obstetrics? Could not those epidemics be arrested which passed like scourges over lying-in hospitals? It was still remembered with horror how, in the Paris Maternity Hospital, between April 1 and May 10, 1856, 64 fatalities had taken place out of 347 confinements. The hospital had to be closed, and the survivors took refuge at the LariboisiÈre Hospital, where they nearly all succumbed, pursued, it was thought, by the epidemic.

Dr. Tarnier, a student residing at the MaternitÉ during that disastrous time, related afterwards how the ignorance of the causes of puerperal fever was such that he was sometimes called away, by one of his chiefs, from some post-mortem business, to assist in the maternity wards; nobody being struck by the thought of the infection which might thus be carried from the theatre to the bed of the patient.

The discussion which arose in 1858 at the AcadÉmie de MÉdecine lasted four months, and hypotheses of all kinds were brought forward. Trousseau alone showed some prescience of the future by noticing an analogy between infectious surgical accidents and infectious puerperal accidents; the idea of a ferment even occurred to him. Years passed; women of the lower classes looked upon the MaternitÉ as the vestibule of death. In 1864, 310 deaths occurred out of 1,350 confinement cases; in 1865, the hospital had to be closed. Works of cleansing and improvements gave rise to a hope that the “epidemic genius” might be driven away. “But, at the very beginning of 1866,” wrote Dr. TrÉlat, then surgeon-in-chief at the MaternitÉ, “the sanitary condition seemed perturbed, the mortality rose in January, and in February we were overwhelmed.” Twenty-eight deaths had occurred out of 103 cases.

TrÉlat enumerated various causes, bad ventilation, neighbouring wards, etc., but where was the origin of the evil?

“Under the influence of causes which escape us,” wrote M. LÉon Le Fort about that time, “puerperal fever develops in a recently delivered woman; she becomes a centre of infection, and, if that infection is freely exercised, the epidemic is constituted.”

Tarnier, who took TrÉlat’s place at the MaternitÉ, in 1867, had been for eleven years so convinced of the infectious nature of puerperal fever that he thought but of arresting the evil by every possible means of defence, the first of which seemed to him isolation of the patients.

In 1874, Dr. Budin, then walking the hospitals, had noted in Edinburgh the improvement due to antisepsis, thanks to Lister. Three or four years later, in 1877 and 1878, after having seen that, in the various maternity hospitals of Holland, Germany, Austria, Russia and Denmark, antisepsis was practised with success, he brought his impressions with him to Paris. Tarnier hastened to employ carbolic acid at the MaternitÉ with excellent results, and his assistant, M. Bar, tried sublimate. While that new period of victory over fatal cases was beginning, Pasteur came to the AcadÉmie de MÉdecine, having found, in certain puerperal infections, a microbe in the shape of a chain or chaplet, which lent itself very well to culture.

“Pasteur,” wrote M. Roux, “does not hesitate to declare that that microscopic organism is the most frequent cause of infection in recently delivered women. One day, in a discussion on puerperal fever at the Academy, one of his most weighty colleagues was eloquently enlarging upon the causes of epidemics in lying-in hospitals; Pasteur interrupted him from his place. ‘None of those things cause the epidemic; it is the nursing and medical staff who carry the microbe from an infected woman to a healthy one.’ And as the orator replied that he feared that microbe would never be found, Pasteur went to the blackboard and drew a diagram of the chain-like organism, saying: ‘There, that is what it is like!’ His conviction was so deep that he could not help expressing it forcibly. It would be impossible now to picture the state of surprise and stupefaction into which he would send the students and doctors in hospitals, when, with an assurance and simplicity almost disconcerting in a man who was entering a lying-in ward for the first time, he criticized the appliances, and declared that all the linen should be put into a sterilizing stove.”

Pasteur was not satisfied with offering advice and criticism, making for himself irreconcilable enemies amongst those who were more desirous of personal distinction than of the progress of Science. In order the better to convince those who still doubted, he affirmed that, in a badly infected patient—what he usually and sorrowfully called an invaded patient—he could bring the microbe into evidence by a simple pin prick on the finger tip of the unhappy woman doomed to die the next day.

“And he did so,” writes M. Roux. “In spite of the tyranny of medical education which weighed down the public mind, some students were attracted, and came to the laboratory to examine more closely those matters, which allowed of such precise diagnosis and such confident prognosis.”

What struggles, what efforts, were necessary before it could be instilled into every mind that a constant watch must be kept in the presence of those invisible foes, ready to invade the human body through the least scratch—that surgeons, dressers and nurses may become causes of infection and propagators of death through forgetfulness! and before the theory of germs and the all powerfulness of microbes could be put under a full light À propos of that discussion on puerperal fever!

But Pasteur was supported and inspired during that period, perhaps the most fruitful of his existence, by the prescience that those notions meant the salvation of human lives, and that mothers need no longer be torn by death from the cradle of their new-born infants.

“I shall force them to see; they will have to see!” he repeated with a holy wrath against doctors who continued to talk, from their study or at their clubs, with some scepticism, of those newly discovered little creatures, of those ultra-microscopic parasites, trying to moderate enthusiasm and even confidence.

An experimental fact which occurred about that time was followed with interest, not only by the AcadÉmie des Sciences, but by the general public, whose attention was beginning to be awakened. A professor at the Nancy Faculty, M. Feltz, had announced to the AcadÉmie des Sciences in March, 1879, that, in the blood abstracted from a woman, who had died at the Nancy Hospital of puerperal fever, he had found motionless filaments, simple or articulated, transparent, straight or curved, which belonged, he said, to the genus leptothrix. Pasteur, who in his studies on puerperal fever had seen nothing of the kind, wrote to Dr. Feltz, asking him to send him a few drops of that infected blood. After receiving and examining the sample, Pasteur hastened to inform M. Feltz that that leptothrix was no other than the bacillus anthracis. M. Feltz, much surprised and perplexed, declared himself ready to own his error and to proclaim it if he were convinced by examining blood infected by charbon, and which, he said, he should collect wherever he could find it. Pasteur desired to save him that trouble, and offered to send him three little guinea-pigs alive, but inoculated, the one with the deceased woman’s blood, the other with the bacteridia of charbon-infected blood from Chartres, the third with some charbon-infected blood from a Jura cow.

The three rodents were inoculated on May 12, at three o’clock in the afternoon, and arrived, living, at Nancy, on the morning of the thirteenth. They died on the fourteenth, in the laboratory of M. Feltz, who was thus able to observe them with particular attention until their death.

“After carefully examining the blood of the three animals after their death, I was unable,” said M. Feltz, “to detect the least difference; not only the blood, but the internal organs, and notably the spleen, were affected in the same manner.”... “It is a certainty to my mind,” he wrote to Pasteur, “that the contaminating agent has been the same in the three cases, and that it was the bacteridium of what you call anthrax.”

There was therefore no such thing as a leptothrix puerperalis. And it was at a distance, without having seen the patient, that Pasteur said: “That woman died of charbon.” With an honourable straightforwardness, M. Feltz wrote to the AcadÉmie des Sciences relating the facts.

“It is doubly regrettable,” he concluded, “that I should not have known charbon already last year, for, on the one hand, I might have diagnosed the redoubtable complication presented by the case, and, on the other hand, sought for the mode of contamination, which at present escapes me almost completely.” All he had been able to find was that the woman, a charwoman, lived in a little room near a stable belonging to a horse dealer. Many animals came there; the stable might have contained diseased ones; M. Feltz had been unable to ascertain the fact. “I must end,” he added, “with thanks to M. Pasteur for the great kindness he has shown me during my intercourse with him. Thanks to him, I was able to convince myself of the identity between the bacillus anthracis and the bacteridium found in the blood of a woman who presented all the symptoms of grave puerperal fever.”

At the time when that convincing episode was taking place, other experiments equally precise were being undertaken concerning splenic fever. The question was to discover whether it would be possible to find germs of charbon in the earth of the fields which had been contaminated purposely, fourteen months before, by pouring culture liquids over it. It seemed beyond all probability that those germs might be withdrawn and isolated from the innumerable other microbes contained in the soil. It was done, however; 500 grammes of earth were mixed with water, and infinitesimal particles of it isolated. The spore of the bacillus anthracis resists a temperature of 80° C. or 90° C., which would kill any other microbe; those particles of earth were accordingly raised to that degree of heat and then injected into some guinea-pigs, several of which died of splenic fever. It was therefore evident that flocks were exposed to infection merely by grazing over certain fields in that land of the Beauce. For it was sufficient that some infected blood should have remained on the ground, for germs of bacteridia to be found there, perhaps years later. How often was such blood spilt as a dead animal was being taken to the knacker’s yard or buried on the spot! Millions of bacteridia, thus scattered on and below the surface of the soil, produced their spores, seeds of death ready to germinate.

And yet negative facts were being opposed to these positive facts, and the theory of spontaneity invoked! “It is with deep sorrow,” said Pasteur at the AcadÉmie de MÉdecine on November 11, 1873, “that I so frequently find myself obliged to answer thoughtless contradiction; it also grieves me much to see that the medical Press speaks of these discussions in apparent ignorance of the true principles of experimental method....

“That aimlessness of criticism seems explicable to me, however, by this circumstance—that Medicine and Surgery are, I think, going through a crisis, a transition. There are two opposite currents, that of the old and that of the new-born doctrine; the first, still followed by innumerable partisans, rests on the belief in the spontaneity of transmissible diseases; the second is the theory of germs, of the living contagium with all its legitimate consequences....”

The better to point out that difference between epochs, Pasteur respectfully advised M. Bouillaud, who was taking part in the discussion, to read over LittrÉ’s Medicine and Physicians, and to compare with present ideas the chapter on epidemics written in 1836, four years after the cholera which had spread terror over Paris and over France. “Poisons and venoms die out on the spot after working the evil which is special to them,” wrote LittrÉ, “and are not reproduced in the body of the victim, but virus and miasmata are reproduced and propagated. Nothing is more obscure to physiologists than those mysterious combinations of organic elements; but there lies the dark room of sickness and of death which we must try to open.” “Among epidemic diseases,” said LittrÉ in another passage equally noted by Pasteur, “some occupy the world and decimate nearly all parts of it, others are limited to more or less wide areas. The origin of the latter may be sought either in local circumstances of dampness, of marshy ground, of decomposing animal or vegetable matter, or in the changes which take place in men’s mode of life.”

“If I had to defend the novelty of the ideas introduced into medicine by my labours of the last twenty years,” wrote Pasteur from Arbois in September, 1879, “I should invoke the significant spirit of LittrÉ’s words. Such was then the state of Science in 1836, and those ideas on the etiology of great epidemics were those of one of the most advanced and penetrating minds of the time. I would observe, contrarily to LittrÉ’s opinion, that nothing proves the spontaneity of great epidemics! As we have lately seen the phylloxera, imported from America, invade Europe, so it might be that the causes of great pests were originated, unknowingly to stricken countries, in other countries which had had fortuitous contact with the latter. Imagine a microscopic being, inhabiting some part of Africa and existing on plants, on animals, or even on men, and capable of communicating a disease to the white race; if brought to Europe by some fortuitous circumstance, it may become the occasion of an epidemic....”

And, writing later, about the same passage: “Nowadays, if an article had to be written on the same subject, it would certainly be the idea of living ferments and microscopic beings and germs which would be mentioned and discussed as a cause. That is the great progress,” added Pasteur with legitimate pride, “in which my labours have had so large a share. But it is characteristic of Science and Progress that they go on opening new fields to our vision; the scientist, who is exploring the unknown, resembles the traveller who perceives further and higher summits as he reaches greater altitudes. In these days, more infectious diseases, more microscopic beings appear to the mind as things to be discovered, the discovery of which will render a wonderful account of pathological conditions and of their means of action and propagation, of self-multiplication within and destruction of the organism. The point of view is very different from LittrÉ’s!!”

On his return to Paris, Pasteur, his mind overflowing with ideas, had felt himself impelled to speak again, to fight once more the fallacious theory of the spontaneity of transmissible diseases. He foresaw the triumph of the germ theory arising from the ruin of the old doctrines—at the price, it is true, of many efforts, many struggles, but those were of little consequence to him.

The power of his mind, the radiating gifts that he possessed, were such that his own people were more and more interested in the laboratory, every one trying day by day to penetrate further into Pasteur’s thoughts. His family circle had widened; his son and his daughter had married, and the two new-comers had soon been initiated into past results and recent experiments. He had, in his childhood and youth, been passionately loved by his parents and sisters, and now, in his middle age, his tenderness towards his wife and children was eagerly repaid by the love they bore him. He made happiness around him whilst he gave glory to France.