A new microbe now became the object of the same studies of culture and inoculation as the bacillus anthracis. Readers of this book may have had occasion to witness the disasters caused in a farmyard by a strange and sudden epidemic. Hens, believed to be good sitters, are found dead on their nests. Others, surrounded by their brood, allow the chicks to leave them, giving them no attention; they stand motionless in the centre of the yard, staggering under a deadly drowsiness. A young and superb cock, whose triumphant voice was yesterday heard by all the neighbours, falls into a sudden agony, his beak closed, his eyes dim, his purple comb drooping limply. Other chickens, respited till the next day, come near the dying and the dead, picking here and there grains soiled with excreta containing the deadly germs: it is chicken cholera.

An Alsatian veterinary surgeon of the name of Moritz had been the first to notice, in 1869, some “granulations” in the corpses of animals struck down by this lightning disease, which sometimes kills as many as ninety chickens out of a hundred, those who survive having probably recovered from a slight attack of the cholera. Nine years after Moritz, Perroncito, an Italian veterinary surgeon, made a sketch of the microbe, which has the appearance of little specks. Toussaint studied it, and demonstrated that this microbe was indeed the cause of virulence in the blood. He sent to Pasteur the head of a cock that had died of cholera. The first thing to do, after isolating the microbe, was to try successive cultures; Toussaint had used neutralized urine. This, though perfect for the culture of the bacillus anthracis, proved a bad culture medium for the microbe of chicken cholera; its multiplication soon became arrested. If sown in a small flask of yeast water, equally favourable to bacteridia, the result was worse still: the microbe disappeared in forty-eight hours.

“Is not that” said Pasteur—with the gift of comparison which made him turn each failure into food for reflection—“an image of what we observe when a microscopic organism proves to be harmless to a particular animal species? It is harmless because it does not develop within the body, or because its development does not reach the organs essential to life.”

After trying other culture mediums, Pasteur found that the one which answered best was a broth of chicken gristle, neutralized with potash and sterilized by a temperature of 110° C. to 115° C.

“The facility of multiplication of the micro-organism in that culture medium is really prodigious,” wrote Pasteur in a duplicate communication to the Academies of Sciences and of Medicine (February, 1880), entitled Of Virulent Diseases, and in particular that commonly called Chicken Cholera. “In a few hours, the most limpid broth becomes turgid and is found to be full of little articles of an extreme tenuity, slightly strangled in their middle and looking at first sight like isolated specks; they are incapable of locomotion. Within a few days, those beings, already so small, change into a multitude of specks so much smaller, that the culture liquid, which had at first become turgid, almost milky, becomes nearly clear again, the specks being of such narrow diameter as to be impossible to measure, even approximately.

“This microbe certainly belongs to quite another group than that of the vibriones. I imagine that it will one day find a place with the still mysterious virus, when the latter are successfully cultivated, which will be soon, I hope.”

Pasteur stated that the virulence of this microbe was such that the smallest drop of recent culture, on a few crumbs, was sufficient to kill a chicken. Hens fed in this way contracted the disease by their intestinal canal, an excellent culture medium for the micro-organism, and perished rapidly. Their infected excreta became a cause of contagion to the hens which shared with them the laboratory cages. Pasteur thus described one of these sick hens—

“The animal suffering from this disease is powerless, staggering, its wings droop and its bristling feathers give it the shape of a ball; an irresistible somnolence overpowers it. If its eyes are made to open, it seems to awake from a deep sleep, and death frequently supervenes after a dumb agony, before the animal has stirred from its place; sometimes there is a faint fluttering of the wings for a few seconds.”

Pasteur tried the effect of this microbe on guinea-pigs which had been brought up in the laboratory, and found it but rarely mortal; in general it merely caused a sore, terminating in an abscess, at the point of inoculation. If this abscess were opened, instead of being allowed to heal of its own accord, the little microbe of chicken cholera was to be found in the pus, preserved in the abscess as it might be in a phial.

“Chickens or rabbits,” remarked Pasteur, “living in the society of guinea-pigs presenting these abscesses, might suddenly become ill and die without any alteration being seen in the guinea-pigs’ health. It would suffice for this purpose that those abscesses should open and drop some of their contents on the food of the chickens and rabbits.

“An observer witnessing those facts, and ignorant of the above-mentioned cause, would be astonished to see hens and rabbits decimated without apparent cause, and would believe in the spontaneity of the evil; for he would be far from supposing that it had its origin in the guinea-pigs, all of them in good health. How many mysteries in the history of contagions will one day be solved as simply as this!!!”

A chance, such as happens to those who have the genius of observation, was now about to mark an immense step in advance and prepare the way for a great discovery. As long as the culture flasks of chicken-cholera microbe had been sown without interruption, at twenty-four hours’ interval, the virulence had remained the same; but when some hens were inoculated with an old culture, put away and forgotten a few weeks before, they were seen with surprise to become ill and then to recover. These unexpectedly refractory hens were then inoculated with some new culture, but the phenomenon of resistance recurred. What had happened? What could have attenuated the activity of the microbe? Researches proved that oxygen was the cause; and, by putting between the cultures variable intervals of days, of one, two or three months, variations of mortality were obtained, eight hens dying out of ten, then five, then only one out of ten, and at last, when, as in the first case, the culture had had time to get stale, no hens died at all, though the microbe could still be cultivated.

“Finally,” said Pasteur, eagerly explaining this phenomenon, “if you take each of these attenuated cultures as a starting-point for successive and uninterrupted cultures, all this series of cultures will reproduce the attenuated virulence of that which served as the starting-point; in the same way non-virulence will reproduce non-virulence.”

And, while hens who had never had chicken-cholera perished when exposed to the deadly virus, those who had undergone attenuated inoculations, and who afterwards received more than their share of the deadly virus, were affected with the disease in a benign form, a passing indisposition, sometimes even they remained perfectly well; they had acquired immunity. Was not this fact worthy of being placed by the side of that great fact of vaccine, over which Pasteur had so often pondered and meditated?

He now felt that he might entertain the hope of obtaining, through artificial culture, some vaccinating-virus against the virulent diseases which cause great losses to agriculture in the breeding of domestic animals, and, beyond that, the greater hope of preserving humanity from those contagious diseases which continually decimate it. This invincible hope led him to wish that he might live long enough to accomplish some new discoveries and to see his followers step into the road he had marked out.

Strong in his experimental method which enabled him to produce proofs and thus to demonstrate the truth; able to establish the connection between a virulent and a microbian disease; finally, ready to reproduce by culture, in several degrees of attenuation, a veritable vaccine, could he not now force those of his opponents who were acting in good faith to acknowledge the evidence of facts? Could he not carry all attentive minds with him into the great movement which was about to replace old ideas by new and precise notions, more and more accessible?

Pasteur enjoyed days of incomparable happiness during that period of enthusiasm, joys of the mind in its full power, joys of the heart in all its expansion; for good was being done. He felt that nothing could arrest the course of his doctrine, of which he said—“The breath of Truth is carrying it towards the fruitful fields of the future.” He had that intuition which makes a great poet of a great scientist. The innumerable ideas surging through his mind were like so many bees all trying to issue from the hive at the same time. So many plans and preconceived ideas only stimulated him to further researches; but, when he was once started on a road, he distrusted each step and only progressed in the train of precise, clear and irrefutable experiments.

A paper of his on the plague, dated April, 1880, illustrates his train of thought. The preceding year the Academy of Medicine had appointed a commission composed of eight members, to draw up a programme of research relative to the plague. The scourge had appeared in a village situated on the right bank of the Volga, in the district of Astrakhan. There had been one isolated case at first, followed ten days later by another death; the dread disease had then invaded and devoured the whole village, going from house to house like an inextinguishable fire; 370 deaths had occurred in a population of 1,372 inhabitants; thirty or forty people died every day. In one of those sinister moments when men forget everything in their desire to live, parents and relations had abandoned their sick and dying among the unburied dead, with 20° C. of frost!! The neighbouring villages were contaminated; but, thanks to the Russian authorities, who had established a strict sanitary cordon, the evil was successfully localized. Some doctors, meeting in Vienna, declared that that plague was no other than the Black Death of the fourteenth century, which had depopulated Europe. The old pictures and sculptures of the time, which represent Death pressing into his lugubrious gang children and old men, beggars and emperors, bear witness to the formidable ravages of such a scourge. In France, since the epidemic at Marseilles in 1720, it seemed as if the plague were but a memory, a distant nightmare, almost a horrible fairy tale. Dr. Rochard, in a report to the AcadÉmie de MÉdecine, recalled how the contagion had burst out in May, 1720; a ship, having lost six men from the plague on its journey, had entered Marseilles harbour. The plague, after an insidious first phase, had raged in all its fury in July.

“Since the plague is a disease,” wrote Pasteur (whose paper was a sort of programme of studies), “the cause of which is absolutely unknown, it is not illogical to suppose that it too is perhaps produced by a special microbe. All experimental research must be guided by some preconceived ideas, and it would probably be very useful to tackle the study of that disease with the belief that it is due to a parasite.

“The most decisive of all the proofs which can be invoked in favour of the possible correlation between a determined affection and the presence of a micro-organism, is that afforded by the method of cultures of organisms in a state of purity; a method by which I have solved, within the last twenty-two years, the chief difficulties relative to fermentations properly so called; notably the important question, much debated formerly, of the correlation which exists between those fermentations and their particular ferments.”

He then pointed out that if, after gathering either blood or pus immediately before or immediately after the death of a plague patient, one could succeed in discovering the micro-organism, and then in finding for that microbe an appropriate culture medium, it would be advisable to inoculate with it animals of various kinds, perhaps monkeys for preference, and to look for the lesions capable of establishing relations from cause to effect between that organism and the disease in mankind.

He did not hide from himself the great difficulties to be met with in experimenting; for, after discovering and isolating the organism, there is nothing to indicate a priori to the experimentalist an appropriate culture medium. Liquids which suit some microbes admirably are absolutely unsuitable to others. Take, for instance, the microbe of chicken-cholera, which will not develop in beer yeast; a hasty experimentalist might conclude that the chicken-cholera is not produced by a micro-organism, and that it is a spontaneous disease with unknown immediate causes. “The fallacy would be a fatal one,” said Pasteur, “for in another medium, say, for instance, in chicken-broth, there would be a virulent culture.”

In these researches on the plague, then, various mediums should be tried; also the character, either aËrobic or anaËrobic, of the microbe should be present to the mind.

“The sterility of a culture liquid may come from the presence of air and not from its own constitution; the septic vibrio, for instance, is killed by oxygen in air. From this last circumstance it is plain that culture must be made not only in the presence of air but also in a vacuum or in the presence of pure carbonic acid gas. In the latter case, immediately after sowing the blood or humour to be tested, a vacuum must be made in the tubes, they must be sealed by means of a lamp, and left in a suitable temperature, usually between 30° C. and 40° C.” Thus he prepared landmarks for the guidance of scientific research on the etiology of the plague.

Desiring as Pasteur did that the public in general should take an interest in laboratory research, he sent to his friend Nisard the number of the Bulletin of the AcadÉmie de MÉdecine which contained a first communication on chicken-cholera, and also his paper on the plague.

“Read them if you have time,” he wrote (May 3, 1880): “they may interest you, and there should be no blanks in your education. They will be followed by others.

“To-day at the Institute, and to-morrow at the AcadÉmie de MÉdecine, I shall give a new lecture.

“Do repeat to me every criticism you hear; I much prefer them to praise, barren unless encouragement is wanted, which is certainly not my case; I have a lasting provision of faith and fire.”

Nisard answered on May 7: “My very dear friend, I am almost dazed with the effort made by my ignorance to follow your ideas, and dazzled with the beauty of your discoveries on the principal point, and the number of secondary discoveries enumerated in your marvellous paper. You are right not to care for barren praise; but you would wrong those who love you if you found no pleasure in being praised by them when they have no other means of acknowledging your notes.

“I am reading the notice on chicken-cholera for the second time, and I observe that the writer is following the discoverer, and that your language becomes elevated, supple and coloured, in order to express the various aspects of the subject.

“It gives me pleasure to see the daily growth of your fame, and I am indeed proud of enjoying your friendship.”

Amidst his researches on a vaccine for chicken-cholera, the etiology of splenic fever was unceasingly preoccupying Pasteur. Did the splenic germs return to the surface of the soil, and how? One day, in one of his habitual excursions with Messrs. Roux and Chamberland to the farm of St. Germain, near Chartres, he suddenly perceived an answer to that enigma. In a field recently harvested, he noticed a place where the colour of the soil differed a little from the neighbouring earth. He questioned M. Maunoury, the proprietor of the farm, who answered that sheep dead of anthrax had been buried there the preceding year. Pasteur drew nearer, and was interested by the mass of little earth cylinders, those little twists which earthworms deposit on the ground. Might that be, he wondered, the explanation of the origin of the germs which reappear on the surface? Might not the worms, returning from their subterranean journeys in the immediate neighbourhood of graves, bring back with them splenic spores, and thus scatter the germs so exhumed? That would again be a singular revelation, unexpected but quite simple, due to the germ theory. He wasted no time in dreaming of the possibilities opened by that preconceived idea, but, with his usual impatience to get at the truth, decided to proceed to experiment.

On his return to Paris Pasteur spoke to Bouley of this possible part of germ carriers played by earthworms, and Bouley caused some to be gathered which had appeared on the surface of pits where animals dead of splenic fever had been buried some years before. Villemin and Davaine were invited as well as Bouley to come to the laboratory and see the bodies of these worms opened; anthrax spores were found in the earth cylinders which filled their intestinal tube.

At the time when Pasteur revealed this pathogenic action of the earthworm, Darwin, in his last book, was expounding their share in agriculture. He too, with his deep attention and force of method, able to discover the hidden importance of what seemed of little account to second-rate minds, had seen how earthworms open their tunnels, and how, by turning over the soil, and by bringing so many particles up to the surface by their “castings,” they ventilate and drain the soil, and, by their incessant and continuous work, render great services to agriculture. These excellent labourers are redoubtable grave-diggers; each of those two tasks, the one beneficent and the other full of perils, was brought to light by Pasteur and Darwin, unknowingly to each other.

Pasteur had gathered earth from the pits where splenic cows had been buried in July, 1878, in the Jura. “At three different times within those two years,” he said to the AcadÉmie des Sciences and to the AcadÉmie de MÉdecine in July, 1880, “the surface soil of those same pits has presented charbon spores.” This fact had been confirmed by recent experiments on the soil of the Beauce farm; particles of earth from other parts of the field had no power of provoking splenic fever.

Pasteur, going on to practical advice, showed how grazing animals might find in certain places the germs of charbon, freed by the loosening by rain of the little castings of earthworms. Animals are wont to choose the surface of the pits, where the soil, being richer in humus, produces thicker growth, and in so doing risk their lives, for they become infected, somewhat in the same manner as in the experiments when their forage was poisoned with a few drops of splenic culture liquid. Septic germs are brought to the surface of the soil in the same way.

“Animals,” said Pasteur, “should never be buried in fields intended for pasture or the growing of hay. Whenever it is possible, burying-grounds should be chosen in sandy or chalky soils, poor, dry, and unsuitable to the life of earthworms.”

Pasteur, like a general with only two aides de camp, was obliged to direct the efforts of Messrs. Chamberland and Roux simultaneously in different parts of France. Sometimes facts had to be checked which had been over-hastily announced by rash experimentalists. Thus M. Roux went, towards the end of the month of July, to an isolated property near Nancy, called Bois le Duc Farm, to ascertain whether the successive deaths of nineteen head of cattle were really, as affirmed, due to splenic fever. The water of this pasture was alleged to be contaminated; the absolute isolation of the herd seemed to exclude all idea of contagion. After collecting water and earth from various points on the estate M. Roux had returned to the laboratory with his tubes and pipets. He was much inclined to believe that there had been septicÆmia and not splenic fever.

M. Chamberland was at Savagna, near Lons-le-Saulnier, where, in order to experiment on the contamination of the surface of pits, he had had a little enclosure traced out and surrounded by an open paling in a meadow where victims of splenic fever had been buried two years previously. Four sheep were folded in this enclosure. Another similar fold, also enclosing four sheep, was placed a few yards above the first one. This experiment was intended to occupy the vacation, and Pasteur meant to watch it from Arbois.

A great sorrow awaited him there. “I have just had the misfortune of losing my sister,” he wrote to Nisard at the beginning of August, “to see whom (as also my parents’ and children’s graves) I returned yearly to Arbois. Within forty-eight hours I witnessed life, sickness, death and burial; such rapidity is terrifying. I deeply loved my sister, who, in difficult times, when modest ease even did not reign in our home, carried the heavy burden of the day and devoted herself to the little ones of whom I was one. I am now the only survivor of my paternal and maternal families.”

In the first days of August, Toussaint, the young professor of the Toulouse Veterinary School, declared that he had succeeded in vaccinating sheep against splenic fever. One process of vaccination (which consisted in collecting the blood of an animal affected with charbon just before or immediately after death, defibrinating it and then passing it through a piece of linen and filtering it through ten or twelve sheets of paper) had been unsuccessful; the bacteridia came through it all and killed instead of preserving the animal. Toussaint then had recourse to heat to kill the bacteridia: “I raised,” he said, “the defibrinated blood to a heat of 55° C. for ten minutes; the result was complete. Five sheep inoculated with three cubic cent. of that blood, and afterwards with very active charbon blood, have not felt it in the least.” However, several successive inoculations had to be made.

“All ideas of holidays must be postponed; we must set to work in Jura as well as in Paris,” wrote Pasteur to his assistants. Bouley, who thought that the goal was reached, did not hide from himself the difficulties of interpretation of the alleged fact. He obtained from the Minister of Agriculture permission to try at Alfort this so-called vaccinal liquid on twenty sheep.

“Yesterday,” wrote Pasteur to his son-in-law on August 13, “I went to give M. Chamberland instructions so that I may verify as soon as possible the Toussaint fact, which I will only believe when I have seen it, seen it with my own eyes. I am having twenty sheep bought, and I hope to be satisfied as to the exactitude of this really extraordinary observation in about three weeks’ time. Nature may have mystified M. Toussaint, though his assertions seem to attest the existence of a very interesting fact.”

Toussaint’s assertion had been hasty, and Pasteur was not long in clearing up that point. The temperature of 55° C. prolonged for ten minutes was not sufficient to kill the bacteridia in the blood; they were but weakened and retarded in their development; even after fifteen minutes’ exposure to the heat, there was but a numbness of the bacteridium. Whilst these experiments were being pursued in the Jura and in the laboratory of the Ecole Normale, the Alfort sheep were giving Bouley great anxiety. One died of charbon one day after inoculation, three two days later. The others were so ill that M. Nocard wanted to sacrifice one in order to proceed to immediate necropsy; Bouley apprehended a complete disaster. But the sixteen remaining sheep recovered gradually and became ready for the counter test of charbon inoculation.

Whilst Pasteur was noting the decisive points, he heard from Bouley and from Roux at the same time, that Toussaint now obtained his vaccinal liquid, no longer by the action of heat, but by the measured action of carbolic acid on splenic fever blood. The interpretation by weakening remained the same.

“What ought we to conclude from that result?” wrote Bouley to Pasteur. “It is evident that Toussaint does not vaccinate as he thought, with a liquid destitute of bacteridia, since he gives charbon with that liquid; but that he uses a liquid in which the power of the bacteridium is reduced by the diminished number and the attenuated activity. His vaccine must then only be charbon liquid of which the intensity of action may be weakened to the point of not being mortal to a certain number of susceptible animals receiving it. But it may be a most treacherous vaccine, in that it might be capable of recuperating its power with time. The Alfort experiment makes it probable that the vaccine tested at Toulouse and found to be harmless, had acquired in the lapse of twelve days before it was tried at Alfort, a greater intensity, because the bacteridium, numbed for a time by carbolic acid, had had time to awaken and to swarm, in spite of the acid.”

Whilst Toussaint had gone to Rheims (where sat the French Association for the Advancement of Science) to state that it was not, as he had announced, the liquid which placed the animal into conditions of relative immunity and to epitomize Bouley’s interpretation, to wit, that it was a bearable charbon which he had inoculated, Pasteur wrote rather a severe note on the subject. His insisting on scrupulous accuracy in experiment sometimes made him a little hard; though the process was unreliable and the explanation inexact, Toussaint at least had the merit of having noted a condition of transitory attenuation in the bacteridium. Bouley begged Pasteur to postpone his communication out of consideration for Toussaint.

One of the sheep folded over splenic-fever pits had died on August 25, its body, full of bacteridia, proving once more the error of those who believed in the spontaneity of transmissible diseases. Pasteur informed J. B. Dumas of this, and at the same time expressed his opinion on the Toussaint fact. This letter was read at the AcadÉmie des Sciences.

“Allow me, before I finish, to tell you another secret. I have hastened, again with the assistance of Messrs. Chamberland and Roux, to verify the extraordinary facts recently announced to the Academy by M. Toussaint, professor at the Toulouse Veterinary School.

“After numerous experiments leaving no room for doubt, I can assure you that M. Toussaint’s interpretations should be gone over again. Neither do I agree with M. Toussaint on the identity which he affirms as existing between acute septicÆmia and chicken-cholera; those two diseases differ absolutely.”

Bouley was touched by this temperate language after all the verifying experiments made at the Ecole Normale and in the Jura. When relating the Alfort incidents, and while expressing a hope that some vaccination against anthrax would shortly be discovered, he revealed that Pasteur had had “the delicacy of abstaining from a detailed criticism, so as to leave M. Toussaint the care of checking his own results.”

The struggle against virulent diseases was becoming more and more the capital question for Pasteur. He constantly recurred to the subject, not only in the laboratory, but in his home conversations, for he associated his family with all the preoccupations of his scientific life. Now that the oxygen of air appeared as a modifying influence on the development of a microbe in the body of animals, it seemed possible that there might be a general law applicable to every virus! What a benefit it would be if the vaccine of every virulent disease could thus be discovered! And in his thirst for research, considering that the scientific history of chicken-cholera was more advanced than that of variolic and vaccinal affections—the great fact of vaccination remaining isolated and unexplained—he hastened on his return to Paris (September, 1880) to press physicians on this special point—the relations between small-pox and vaccine. “From the point of view of physiological experimentation,” he said, “the identity of the variola virus with the vaccine virus has never been demonstrated.” When Jules GuÉrin—a born fighter, still desirous at the age of eighty to measure himself successfully with Pasteur—declared that “human vaccine is the product of animal variola (cow pox and horse pox) inoculated into man and humanised by its successive transmissions on man,” Pasteur answered ironically that he might as well say, “Vaccine is—vaccine.”

Those who were accustomed to speak to Pasteur with absolute sincerity advised him not to let himself be dragged further into those discussions when his adversaries, taking words for ideas, drowned the debate in a flood of phrases. Of what good were such debates to science, since those who took the first place among veterinary surgeons, physicians and surgeons, loudly acknowledged the debt which science owned to Pasteur? Why be surprised that certain minds, deeply disturbed in their habits, their principles, their influence, should feel some difficulty, some anger even in abandoning their ideas? If it is painful to tenants to leave a house in which they have spent their youth, what must it be to break with one’s whole education?

Pasteur, who allowed himself thus to be told that he lacked philosophical serenity, acknowledged this good advice with an affectionate smile. He promised to be calm; but when once in the room, his adversaries’ attacks, their prejudices and insinuations, enervated and irritated him. All his promises were forgotten.

“To pretend to express the relation between human variola and vaccine by speaking but of vaccine and its relations with cow pox and horse pox, without even pronouncing the word small-pox, is mere equivocation, done on purpose to avoid the real point of the debate.” Becoming excited by GuÉrin’s antagonism, Pasteur turned some of GuÉrin’s operating processes into ridicule with such effect that GuÉrin started from his place and rushed at him. The fiery octogenarian was stopped by Baron Larrey; the sitting was suspended in confusion. The following day, GuÉrin sent two seconds to ask for reparation by arms from Pasteur. Pasteur referred them to M. BÉclard, Permanent Secretary to the AcadÉmie de MÉdicine, and M. Bergeron, its Annual Secretary, who were jointly responsible for the Official Bulletin of the Academy. “I am ready,” said Pasteur, “having no right to act otherwise, to modify whatever the editors may consider as going beyond the rights of criticism and legitimate defence.”

In deference to the opinion of Messrs. BÉclard and Bergeron, Pasteur consented to terminate the quarrel by writing to the chairman of the Academy that he had no intention of offending a colleague, and that in all discussions of that kind, he never thought of anything but to defend the exactitude of his own work.

The Journal de la MÉdecine et de la Chimie, edited by M. Lucas-ChampionniÈre, said À propos of this very reasonable letter—“We, for our part, admire the meekness of M. Pasteur, who is so often described as combative and ever on the warpath. Here we have a scientist, who now and then makes short, substantial and extremely interesting communications. He is not a medical man, and yet, guided by his genius, he opens new paths across the most arduous studies of medical science. Instead of being offered the tribute of attention and admiration which he deserves, he meets with a raging opposition from some quarrelsome individuals, ever inclined to contradict after listening as little as possible. If he makes use of a scientific expression not understood by everybody, or if he uses a medical expression slightly incorrectly, then rises before him the spectre of endless speeches, intended to prove to him that all was for the best in medical science before it was assisted by the precise studies and resources of chemistry and experimentation.... Indeed, M. Pasteur’s expression of equivocation seemed to us moderate!”

How many such futile incidents, such vain quarrels, traverse the life of a great man! Later on, we only see glory, apotheosis, and the statues in public places; the demi-gods seemed to have marched in triumph towards a grateful posterity. But how many obstacles and oppositions are there to retard the progress of a free mind desirous of bringing his task to a successful conclusion and incited by the fruitful thought of Death, ever present to spirits preoccupied with interests of a superior order? Pasteur looked upon himself as merely a passing guest of those homes of intellect which he wished to enlarge and fortify for those who would come after him.

Confronted with the hostility, indifference and scepticism which he found in the members of the Medical Academy, he once appealed to the students who sat on the seats open to the public.

“Young men, you who sit on those benches, and who are perhaps the hope of the medical future of the country, do not come here to seek the excitement of polemics, but come and learn Method.”

His method, as opposed to vague conceptions and a priori speculations, went on fortifying itself day by day. Artificial attenuation, that is, virus modified by the oxygen of air, which weakens and abates virulence; vaccination by the attenuated virus—those two immense steps in advance were announced by Pasteur at the end of 1880. But would the same process apply to the microbe of charbon? That was a great problem. The vaccine of chicken-cholera was easy to obtain; by leaving pure cultures to themselves for a time in contact with air, they soon lost their virulence. But the spores of charbon, very indifferent to atmospheric air, preserved an indefinitely prolonged virulence. After eight, ten or twelve years, spores found in the graves of victims of splenic fever were still in full virulent activity. It was therefore necessary to turn the difficulty by a culture process which would act on the filament-shaped bacteridium before the formation of spores. What may now be explained in a few words demanded long weeks of trials, tests and counter tests.

In neutralized chicken broth, the bacteridium can no longer be cultivated at a temperature of 45° C.; it can still be cultivated easily at a temperature of 42° C. or 43° C., but the spores do not develop.

“At that extreme temperature,” explains M. Chamberland, “the bacteridia yet live and reproduce themselves, but they never give any germs. Thenceforth, when trying the virulence of the phials after six, eight, ten or fifteen days, we have found exactly the same phenomena as for chicken-cholera. After eight days, for instance, our culture, which originally killed ten sheep out of ten, only kills four or five; after ten or twelve days it does not kill any; it merely communicates to animals a benignant malady which preserves them from the deadly form.

“A remarkable thing is that the bacteridia whose virulence has been attenuated may afterwards be cultivated in a temperature of 30° C. to 35° C., at which temperature they give germs presenting the same virulence as the filaments which formed them.”

Bouley, who was a witness of all these facts, said, in other words, that “if that attenuated and degenerated bacteridium is translated to a culture medium in a lower temperature, favourable to its activity, it becomes once again apt to produce spores. But those spores born of weakened bacteridia, will only produce bacteridia likewise weakened in their swarming faculties.”

Thus is obtained and enclosed in inalterable spores a vaccine ready to be sent to every part of the world to preserve animals by vaccination against splenic fever.

On the day when he became sure of this discovery, Pasteur, returning to his rooms from his laboratory, said to his family, with a deep emotion—“Nothing would have consoled me if this discovery, which my collaborators and I have made, had not been a French discovery.”

He desired to wait a little longer before proclaiming it. Yet the cause of the evil was revealed, the mode of propagation indicated, prophylaxis made easy; surely, enough had been achieved to move attentive minds to enthusiasm and to deserve the gratitude of sheep owners!

So thought the Society of French Agricultors, when it decided, on February 21, 1881, to offer to Pasteur a medal of honour. J. B. Dumas, detained at the AcadÉmie des Sciences, was unable to attend the meeting. He wrote to Bouley, who had been requested to enumerate Pasteur’s principal discoveries at that large meeting—“I had desired to make public by my presence my heartfelt concurrence in your admiration for him who will never be honoured to the full measure of his merits, of his services and of his passionate devotion to truth and to our country.”

On the following Monday, Bouley said to Dumas, as they were walking to the AcadÉmie des Sciences, “Your letter assures me of a small share of immortality.”

“See,” answered Dumas, pointing to Pasteur, who was preceding them, “there is he who will lead us both to immortality.”

On that Monday, February 28, Pasteur made his celebrated communication on the vaccine of splenic fever and the whole graduated scale of virulence. The secret of those returns to virulence lay entirely in some successive cultures through the body of certain animals. If a weakened bacteridium was inoculated into a guinea-pig a few days old it was harmless; but it killed a new-born guinea-pig.

“If we then go from one new-born guinea-pig to another,” said Pasteur, “by inoculation of the blood of the first to the second, from the second to a third, and so on, the virulence of the bacteridium—that is: its adaptability to development within the economy—becomes gradually strengthened. It becomes by degrees able to kill guinea-pigs three or four days old, then a week, a month, some years old, then sheep themselves; the bacteridium has returned to its original virulence. We may affirm, without hesitation, though we have not had the opportunity of testing the fact, that it would be capable of killing cows and horses; and it preserves that virulence indefinitely if nothing is done to attenuate it again.

“As to the microbe of chicken-cholera, when it has lost its power of action on hens, its virulence may be restored to it by applying it to small birds such as sparrows or canaries, which it kills immediately. Then by successive passages through the bodies of those animals, it gradually assumes again a virulence capable of manifesting itself anew on adult hens.

“Need I add, that, during that return to virulence, by the way, virus-vaccines can be prepared at every degree of virulence for the bacillus anthracis and for the chicken-cholera microbe.

“This question of the return to virulence is of the greatest interest for the etiology of contagious diseases.”

Since charbon does not recur, said Pasteur in the course of that communication, each of the charbon microbes attenuated in the laboratory constitutes a vaccine for the superior microbe. “What therefore is easier than to find in those successive virus, virus capable of giving splenic fever to sheep, cows and horses, without making them perish, and assuring them of ulterior immunity from the deadly disease? We have practised that operation on sheep with the greatest success. When the season comes for sheep-folding in the Beauce, we will try to apply it on a large scale.”

The means of doing this were given to Pasteur before long; assistance was offered to him by various people for various reasons; some desired to see a brilliant demonstration of the truth; others whispered their hopes of a signal failure. The promoter of one very large experiment was a Melun veterinary surgeon, M. Rossignol.

In the Veterinary Press, of which M. Rossignol was one of the editors, an article by him might have been read on the 31st January, 1881, less than a month before that great discovery on charbon vaccine, wherein he expressed himself as follows: “Will you have some microbe? There is some everywhere. Microbiolatry is the fashion, it reigns undisputed; it is a doctrine which must not even be discussed, especially when its Pontiff, the learned M. Pasteur, has pronounced the sacramental words, I have spoken. The microbe alone is and shall be the characteristic of a disease; that is understood and settled; henceforth the germ theory must have precedence of pure clinics; the Microbe alone is true, and Pasteur is its prophet.”

At the end of March, M. Rossignol began a campaign, begging for subscriptions, pointing out how much the cultivators of the Brie—whose cattle suffered almost as much as that of the Beauce—were interested in the question. The discovery, if it were genuine, should not remain confined to the Ecole Normale laboratory, or monopolized by the privileged public of the AcadÉmie des Sciences, who had no use for it. M. Rossignol soon collected about 100 subscribers. Did he believe that Pasteur and his little phials would come to a hopeless fiasco in a farmyard before a public of old practitioners who had always been powerless in the presence of splenic fever? Microbes were a subject for ceaseless joking; people had hilarious visions of the veterinary profession confined some twenty years hence in a model laboratory assiduously cultivating numberless races, sub-races, varieties and sub-varieties of microbes.

It is probable that, if light comes from above, a good many practitioners would not have been sorry to see a strong wind from below putting out Pasteur’s light.

M. Rossignol succeeded in interesting every one in this undertaking. When the project was placed before the Melun Agricultural Society on the 2nd April, they hastened to approve of it and to accord their patronage.

The chairman, Baron de la Rochette, was requested to approach Pasteur and to invite him to organize public experiments on the preventive vaccination of charbon in the districts of Melun, Fontainebleau and Provins.

“The noise which those experiments will necessarily cause,” wrote M. Rossignol, “will strike every mind and convince those who may still be doubting; the evidence of facts will have the result of ending all uncertainty.”

Baron de la Rochette was a typical old French gentleman; his whole person was an ideal of old-time distinction and courtesy. Well up to date in all agricultural progress, and justly priding himself, with the ease of a great landowner, that he made of agriculture an art and a science, he could speak in any surroundings with knowledge of his subject and a winning grace of manner. When he entered the laboratory, he was at once charmed by the simplicity of the scientist, who hastened to accept the proposal of an extensive experiment.

At the end of April, Pasteur wrote out the programme which was to be followed near Melun at the farm of Pouilly le Fort. M. Rossignol had a number of copies of that programme printed, and distributed them, not only throughout the Department of Seine et Marne, but in the whole agricultural world. This programme was so decidedly affirmative that some one said to Pasteur, with a little anxiety: “You remember what Marshal Gouyion St. Cyr said of Napoleon, that ‘he liked hazardous games with a character of grandeur and audacity.’ It was neck or nothing with him; you are going on in the same way!”

“Yes,” answered Pasteur, who meant to compel a victory.

And as his collaborators, to whom he had just read the precise and strict arrangements he had made, themselves felt a little nervous, he said to them, “What has succeeded in the laboratory on fourteen sheep will succeed just as well at Melun on fifty.”

This programme left him no retreat. The Melun Agricultural Society put sixty sheep at Pasteur’s disposal; twenty-five were to be vaccinated by two inoculations, at twelve or fifteen days’ interval, with some attenuated charbon virus. Some days later those twenty-five and also twenty-five others would be inoculated with some very virulent charbon culture.

“The twenty-five unvaccinated sheep will all perish,” wrote Pasteur, “the twenty-five vaccinated ones will survive.” They would afterwards be compared with the ten sheep which had undergone no treatment at all. It would thus be seen that vaccination did not prevent sheep from returning to their normal state of health after a certain time.

Then came other prescriptions, for instance, the burying of the dead sheep in distinct graves, near each other and enclosed within a paling.

“In May, 1882,” added Pasteur, “twenty new sheep, that is, sheep never before used for experimentation, will be shut within that paling.”

And he predicted that the following year, 1882, out of those twenty-five sheep fed on the grass of that little enclosure or on forage deposited there, several would become infected by the charbon germs brought to the surface by earthworms, and that they would die of splenic fever. Finally, twenty-five other sheep might be folded in a neighbouring spot, where no charbon victims had ever been buried, and under these conditions none would contract the disease.

M. de la Rochette having expressed a desire that cows should be included in the programme, Pasteur answered that he was willing to try that new experiment, though his tests on vaccine for cows were not as advanced as those on sheep vaccine. Perhaps, he said, the results may not be as positive, though he thought they probably would be. He was offered ten cows; six were to be vaccinated and four not vaccinated. The experiments were to begin on the Thursday, 5th May, and would in all likelihood terminate about the first fortnight in June.

At the time when M. Rossignol declared that all was ready for the fixed time, an editor’s notice in the Veterinary Press said that the laboratory experiments were about to be repeated in campo, and that Pasteur could thus “demonstrate that he had not been mistaken when he affirmed before the astonished Academy that he had discovered the vaccine of splenic fever, a preventative to one of the most terrible diseases with which animals and even men could be attacked.” This notice ended thus, with an unexpected classical reminiscence: “These experiments are solemn ones, and they will become memorable if, as M. Pasteur asserts, with such confidence, they confirm all those he has already instituted. We ardently wish that M. Pasteur may succeed and remain the victor in a tournament which has now lasted long enough. If he succeeds, he will have endowed his country with a great benefit, and his adversaries should, as in the days of antiquity, wreathe their brows with laurel leaves and prepare to follow, chained and prostrate, the chariot of the immortal Victor. But he must succeed: such is the price of triumph. Let M. Pasteur not forget that the Tarpeian Rock is near the Capitol.”

On May 5 a numerous crowd arriving from Melun station or from the little station of Cesson, was seen moving towards the yard of Pouilly le Fort farm; it looked like a mobilisation of Conseillers GÉnÉraux, agricultors, physicians, apothecaries, and especially veterinary surgeons. Most of these last were full of scepticism—as was remarked by M. Thierry, who represented the Veterinary Society of the Yonne, and one of his colleagues, M. Biot, of Pont-sur-Yonne. They were exchanging jokes and looks to the complete satisfaction of Pasteur’s adversaries. They were looking forward to the last and most virulent inoculation.

Pasteur, assisted not only by Messrs. Chamberland and Roux, but also by a third pupil of the name of Thuillier, proceeded to the arrangement of the subjects. At the last moment, two goats were substituted for two of the sheep.

Vaccination candidates and unvaccinated test sheep were divided under a large shed. For the injection of the vaccinal liquid, Pravaz’s little syringe was used; those who have experienced morphia injections know how easily the needle penetrates the subcutaneous tissues. Each of the twenty-five sheep received, on the inner surface of the right thigh, five drops of the bacteridian culture which Pasteur called the first vaccine. Five cows and one ox substituted for the sixth cow were vaccinated in their turn, behind the shoulder. The ox and the cows were marked on the right horn, and the sheep on the ear.

Pasteur was, after this, asked to give a lecture on splenic fever in the large hall of the Pouilly farm. Then, in clear, simple language, meeting every objection half-way, showing no astonishment at ignorance or prejudice, knowing perfectly well that many were really hoping for a failure, he methodically described the road already travelled, and pointed to the goal he would reach. For nearly an hour he interested and instructed his mixed audience; he made them feel the genuineness of his faith, and, besides his interest in the scientific problem, his desire to spare heavy losses to cultivators. After the lecture, some, better informed than others, were admiring the logical harmony of that career, mingling with pure science results of incalculable benefit to the public, an extraordinary alliance which gave a special moral physiognomy to this man of prodigious labours.

An appointment was made for the second inoculation. In the interval—on May 6, 7, 8 and 9—Messrs. Chamberland and Roux came to Pouilly le Fort to take the temperature of the vaccinated animals, and found nothing abnormal. On May 17 a second inoculation was made with a liquid which, though still attenuated, was more virulent than the first. If that liquid had been inoculated to begin with it would have caused a mortality of 50 per 100.

“On Tuesday, May 31,” wrote Pasteur to his son-in-law, “the third and last inoculation will take place—this time with fifty sheep and ten cows. I feel great confidence—for the two first, on the 5th and the 17th, have been effected under the best conditions without any mortality amongst the twenty-five vaccinated subjects. On June 5 at latest the final result will be known, and should be twenty-five survivors out of twenty-five vaccinated, and six cows. If the success is complete, this will be one of the finest examples of applied science in this century, consecrating one of the greatest and most fruitful discoveries.”

This great experiment did not hinder other studies being pursued in the laboratory. The very day of the second inoculation at Pouilly le Fort, Mme. Pasteur wrote to her daughter, “One of the laboratory dogs seems to be sickening for hydrophobia; it seems that that would be very lucky, in view of the interesting experiment it would provide.”

On May 25, another letter from Mme. Pasteur shows how deeply each member of the family shared Pasteur’s preoccupations and hopes and was carried away with the stream of his ideas: “Your father has just brought great news from the laboratory. The new dog which was trephined and inoculated with hydrophobia died last night after nineteen days’ incubation only. The disease manifested itself on the fourteenth day, and this morning the same dog was used for the trephining of a fresh dog, which was done by Roux with unrivalled skill. All this means that we shall have as many mad dogs as will be required for experiments, and those experiments will become extremely interesting.

“Next month one of the master’s delegates will go to the south of France to study the ‘rouget’ of swine, which ordinarily rages at this time.

“It is much hoped that the vaccine of that disease will be found.”

The trephining of that dog had much disturbed Pasteur. He, who was described in certain anti-vivisectionist quarters as a laboratory executioner, had a great horror of inflicting suffering on any animal.

“He could assist without too much effort,” writes M. Roux, “at a simple operation such as a subcutaneous inoculation, and even then, if the animal screamed at all, Pasteur was immediately filled with compassion, and tried to comfort and encourage the victim, in a way which would have seemed ludicrous if it had not been touching. The thought of having a dog’s cranium perforated was very disagreeable to him; he very much wished that the experiment should take place, and yet he feared to see it begun. I performed it one day when he was out. The next day, as I was telling him that the intercranial inoculation had presented no difficulty, he began pitying the dog. ‘Poor thing! His brain is no doubt injured, he must be paralysed!’ I did not answer, but went to fetch the dog, whom I brought into the laboratory. Pasteur was not fond of dogs, but when he saw this one, full of life, curiously investigating every part of the laboratory, he showed the keenest pleasure, and spoke to the dog in the most affectionate manner. Pasteur was infinitely grateful to this dog for having borne trephining so well, thus lessening his scruples for future trephining.”

As the day was approaching for the last experiments at Pouilly le Fort, excitement was increasing in the veterinary world. Every chance meeting led to a discussion; some prudent men said “Wait.” Those that believed were still few in number.

One or two days before the third and decisive inoculation, the veterinary surgeon of Pont-sur-Yonne, M. Biot, who was watching with a rare scepticism the Pouilly le Fort experiments, met Colin on the road to Maisons-Alfort. “Our conversation”—M. Biot dictated the relation of this episode to M. Thierry, his colleague, also very sceptical and expecting the Tarpeian Rock—“our conversation naturally turned on Pasteur’s experiments. Colin said: ‘You must beware, for there are two parts in the bacteridia-culture broth: one upper part which is inert, and one deep part very active, in which the bacteridia become accumulated, having dropped to the bottom because of their weight. The vaccinated sheep will be inoculated with the upper part of the liquid, whilst the others will be inoculated with the bottom liquid, which will kill them.’” Colin advised M. Biot to seize at the last moment the phial containing the virulent liquid and to shake it violently, “so as to produce a perfect mixture rendering the whole uniformly virulent.”

If Bouley had heard such a thing, he would have lost his temper, or he would have laughed heartily. A year before this, in a letter to M. Thierry, who not only defended but extolled Colin, Bouley had written:

“No doubt Colin is a man of some value, and he has cleverly taken advantage of his position of Chief of the Anatomy department at Alfort to accomplish some important labours. But it is notable that his negative genius has ever led him to try and demolish really great work. He denied Davaine, Marey, Claude Bernard, Chauveau; now he is going for Pasteur.” Bouley, to whom Colin was indebted for his situation at Alfort, might have added, “And he calls me his persecutor!” But Biot refused to believe in Colin’s hostility and only credited him with scruples on the question of experimental physiology. Colin did not doubt M. Pasteur’s bona fides, M. Biot said, but only his aptitude to conduct experiments in anima vili.

On May 31, every one was at the farm. M. Biot executed Colin’s indications and shook the virulent tube with real veterinary energy. He did more: still acting on advice from Colin, who had told him that the effective virulence was in direct proportion to the quantity injected, he asked that a larger quantity of liquid than had been intended should be inoculated into the animals. A triple dose was given. Other veterinary surgeons desired that the virulent liquid should be inoculated alternatively into vaccinated and unvaccinated animals. Pasteur lent himself to these divers requests with impassive indifference and without seeking for their motives.

At half-past three everything was done, and a rendezvous fixed for June 2 at the same place. The proportion between believers and unbelievers was changing. Pasteur seemed so sure of his ground that many were saying “He can surely not be mistaken.” One little group had that very morning drunk to a fiasco. But, whether from a sly desire to witness a failure, or from a generous wish to be present at the great scientific victory, every man impatiently counted the hours of the two following days.

On June 4, Messrs. Chamberland and Roux went back to Pouilly le Fort to judge of the condition of the patients. Amongst the lot of unvaccinated sheep, several were standing apart with drooping heads, refusing their food. A few of the vaccinated subjects showed an increase of temperature; one of them even had 40° C. (104° Fahrenheit); one sheep presented a slight oedema of which the point of inoculation was the centre; one lamb was lame, another manifestly feverish, but all, save one, had preserved their appetite. All the unvaccinated sheep were getting worse and worse. “In all of them” noted M. Rossignol, “breathlessness is at its maximum; the heaving of the sides is now and then interrupted by groans. If the most sick are forced to get up and walk, it is with great difficulty that they advance a few steps, their limbs being so weak and vacillating.” Three had died by the time M. Rossignol left Pouilly le Fort. “Everything leads me to believe,” he wrote, “that a great number of sheep will succumb during the night.”

Pasteur’s anxiety was great when Messrs. Chamberland and Roux returned, having noticed a rise in the temperature of certain vaccinated subjects. It was increased by the arrival of a telegram from M. Rossignol announcing that he considered one sheep as lost. By a sudden reaction, Pasteur, who had drawn up such a bold programme, leaving no margin for the unexpected, and who the day before seemed of an imperturbable tranquillity among all those sheep, the life or death of whom was about to decide between an immortal discovery and an irremediable failure, now felt himself beset with doubts and anguish.

Bouley, who had that evening come to see his master, as he liked to call him, could not understand this reaction—the result of too much strain on the mind, said M. Roux, whom it did not astonish. Pasteur’s emotional nature, strangely allied to his fighting temperament, was mastering him. “His faith staggered for a time,” writes M. Roux, “as if the experimental method could betray him.” The night was a sleepless one.

“This morning, at eight o’clock,” wrote Mme. Pasteur to her daughter, “we were still very much excited and awaiting the telegram which might announce some disaster. Your father would not let his mind be distracted from his anxiety. At nine o’clock the laboratory was informed, and the telegram handed to me five minutes later. I had a moment’s emotion, which made me pass through all the colours of the rainbow. Yesterday, a considerable rise of temperature had been noticed with terror in one of the sheep; this morning that same sheep was well again.”

On the arrival of the telegram Pasteur’s face lighted up; his joy was deep, and he desired to share it immediately with his absent children. Before starting for Melun, he wrote them this letter:

“June 2, 1881.

“It is only Thursday, and I am already writing to you; it is because a great result is now acquired. A wire from Melun has just announced it. On Tuesday last, 31st May, we inoculated all the sheep, vaccinated and non-vaccinated, with very virulent splenic fever. It is not forty-eight hours ago. Well, the telegram tells me that, when we arrive at two o’clock this afternoon, all the non-vaccinated subjects will be dead; eighteen were already dead this morning, and the others dying. As to the vaccinated ones, they are all well; the telegram ends by the words ‘stunning success’; it is from the veterinary surgeon, M. Rossignol.

“It is too early yet for a final judgment; the vaccinated sheep might yet fall ill. But when I write to you on Sunday, if all goes well, it may be taken for granted that they will henceforth preserve their good health, and that the success will indeed have been startling. On Tuesday, we had a foretaste of the final results. On Saturday and Sunday, two sheep had been abstracted from the lot of twenty-five vaccinated sheep, and two from the lot of twenty-five non-vaccinated ones, and inoculated with a very virulent virus. Now, when on Tuesday all the visitors arrived, amongst whom were M. Tisserand, M. Patinot, the Prefect of Seine et Marne, M. Foucher de Careil, Senator, etc., we found the two unvaccinated sheep dead, and the two others in good health. I then said to one of the veterinary surgeons who were present, ‘Did I not read in a newspaper, signed by you, À propos of the virulent little organism of saliva, “There! one more microbe; when there are 100 we shall make a cross”?’ ‘It is true,’ he immediately answered, honestly. ‘But I am a converted and repentant sinner.’ ‘Well,’ I answered, ‘allow me to remind you of the words of the Gospel: Joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons which need no repentance.’ Another veterinary surgeon who was present said, ‘I will bring you another, M. Colin.’ ‘You are mistaken,’ I replied. ‘M. Colin contradicts for the sake of contradicting, and does not believe because he will not believe. You would have to cure a case of neurosis, and you cannot do that!’ Joy reigns in the laboratory and in the house. Rejoice, my dear children.”

When Pasteur arrived, at two o’clock in the afternoon, at the farmyard of Pouilly le Fort, accompanied by his young collaborators, a murmur of applause arose, which soon became loud acclamation, bursting from all lips. Delegates from the Agricultural Society of Melun, from medical societies, veterinary societies, from the Central Council of Hygiene of Seine et Marne, journalists, small farmers who had been divided in their minds by laudatory or injurious newspaper articles—all were there. The carcases of twenty-two unvaccinated sheep were lying side by side; two others were breathing their last; the last survivors of the sacrificed lot showed all the characteristic symptoms of splenic fever. All the vaccinated sheep were in perfect health.

Bouley’s happy face reflected the feelings which were so characteristic of his attractive personality: enthusiasm for a great cause, devotion to a great man. M. Rossignol, in one of those loyal impulses which honour human nature, disowned with perfect sincerity his first hasty judgment; Bouley congratulated him. He himself, many years before, had allowed himself to judge too hastily, he said, of certain experiments of Davaine’s, of which the results then appeared impossible. After having witnessed these experiments, Bouley had thought it a duty to proclaim his error at the AcadÉmie de MÉdecine, and to render a public homage to Davaine. “That, I think,” he said, “is the line of conduct which should always be observed; we honour ourselves by acknowledging our mistakes and by rendering justice to neglected merit.”

No success had ever been greater than Pasteur’s. The veterinary surgeons, until then the most incredulous, now convinced, desired to become the apostles of his doctrine. M. Biot spoke of nothing less than of being himself vaccinated and afterwards inoculated with the most active virus. Colin’s absence was much regretted. Pasteur was not yet satisfied. “We must wait until the 5th of June,” he said, “for the experiment to be complete, and the proof decisive.”

M. Rossignol and M. Biot proceeded on the spot to the necropsy of two of the dead sheep. An abundance of bacteridia was very clearly seen in the blood through the microscope.

Pasteur was accompanied back to the station by an enthusiastic crowd, saluting him—with a luxury of epithets contrasting with former ironies—as the immortal author of the magnificent discovery of splenic fever vaccination, and it was decided that the farm of Pouilly le Fort would henceforth bear the name of Clos Pasteur.

The one remaining unvaccinated sheep died that same night. Amongst the vaccinated lot one ewe alone caused some anxiety. She was pregnant, and died on the 4th of June, but from an accident due to her condition, and not from the consequences of the inoculation, as was proved by a post-mortem examination.

Amongst the cattle, those which had been vaccinated showed no sign whatever of any disturbance; the others presented enormous oedemata.

Pasteur wrote to his daughter: “Success is definitely confirmed; the vaccinated animals are keeping perfectly well, the test is complete. On Wednesday a report of the facts and results will be drawn up which I shall communicate to the AcadÉmie des Sciences on Monday, and on Tuesday to the AcadÉmie de MÉdecine.”

And, that same day, he addressed a joyful telegram to Bouley, who, in his quality of General Inspector of Veterinary Schools, had been obliged to go to Lyons. Bouley answered by the following letter:

“Lyons, June 5, 1881. Dearest Master, your triumph has filled me with joy. Though the days are long past now when my faith in you was still somewhat hesitating, not having sufficiently impregnated my mind with your spirit, as long as the event—which has just been realized in a manner so rigorously in conformity with your predictions—was still in the future, I could not keep myself from feeling a certain anxiety, of which you were yourself the cause, since I had seen you also a prey to it, like all inventors on the eve of the day which reveals their glory. At last your telegram, for which I was pining, has come to tell me that the world has found you faithful to all your promises, and that you have inscribed one more great date in the annals of Science, and particularly in those of Medicine, for which you have opened a new era.

“I feel the greatest joy at your triumph; in the first place, for you, who are to-day receiving the reward of your noble efforts in the pursuit of Truth; and—shall I tell you?—for myself too, for I have so intimately associated myself with your work that I should have felt your failure absolutely as if it had been personal to me. All my teaching at the Museum consists in relating your labours and predicting their fruitfulness.”

Those experiments at Pouilly le Fort caused a tremendous sensation; the whole of France burst out in an explosion of enthusiasm. Pasteur now knew fame under its rarest and purest form; the loving veneration, the almost worship with which he inspired those who lived near him or worked with him, had become the feeling of a whole nation.

On June 13, at the AcadÉmic des Sciences, he was able to state as follows his results and their practical consequences: “We now possess virus vaccines of charbon, capable of preserving from the deadly disease, without ever being themselves deadly—living vaccines, to be cultivated at will, transportable anywhere without alteration, and prepared by a method which we may believe susceptible of being generalized, since it has been the means of discovering the vaccine of chicken-cholera. By the character of the conditions I am now enumerating, and from a purely scientific point of view, the discovery of the vaccine of anthrax constitutes a marked step in advance of that of Jenner’s vaccine, since the latter has never been experimentally obtained.”

On all sides, it was felt that something very great, very unexpected, justifying every sort of hope, had been brought forth. Ideas of research were coming up. On the very morrow of the results obtained at Pouilly le Fort, Pasteur was asked to go to the Cape to study a contagious disease raging among goats.

“Your father would like to take that long journey,” wrote Mme. Pasteur to her daughter, “passing on his way through Senegal to gather some good germs of pernicious fever; but I am trying to moderate his ardour. I consider that the study of hydrophobia should suffice him for the present.”

He was at that time “at boiling point,” as he put it—going from his laboratory work to the Academies of Sciences and Medicine to read some notes; then to read reports at the Agricultural Society; to Versailles, to give a lecture to an Agronomic Congress, and to Alfort to lecture to the professors and students. His clear and well-arranged words, the connection between ideas and the facts supporting them, the methodical recital of experiments, allied to an enthusiastic view of the future and its prospects—especially when addressing a youthful audience—deeply impressed his hearers. Those who saw and heard him for the first time were the more surprised that, in certain circles, a legend had formed round Pasteur’s name. He had been described as of an irritable, intolerant temper, domineering and authoritative, almost despotic; and people now saw a man of perfect simplicity, so modest that he did not seem to realize his own glory, pleased to answer—even to provoke—every objection, only raising his voice to defend Truth, to exalt Work, and to inspire love for France, which he wished to see again in the first rank of nations. He did not cease to repeat that the country must regain her place through scientific progress. Boys and youths—ever quick to penetrate the clever calculations of those who seek their own interest instead of accomplishing a duty—listened to him eagerly and, very soon conquered, enrolled themselves among his followers. In him they recognized the three rarely united qualities which go to form true benefactors of humanity: a mighty genius, great force of character, and genuine goodness.

The Republican Government, desirous of recognizing this great discovery of splenic fever vaccination, offered him the Grand Cordon of the Legion of Honour. Pasteur put forward one condition; he wanted, at the same time, the red ribbon for his two collaborators. “What I have most set my heart upon is to obtain the Cross for Chamberland and Roux,” he wrote to his son-in-law on June 26; “only at that price will I accept the Grand Cross. They are taking such trouble! Yesterday they went to a place fifteen kilometres from Senlis, to vaccinate ten cows and 250 sheep. On Thursday we vaccinated 300 sheep at Vincennes. On Sunday they were near Coulommiers. On Friday we are going to Pithiviers. What I chiefly wish is that the discovery should be consecrated by an exceptional distinction to two devoted young men, full of merit and courage. I wrote yesterday to Paul Bert, asking him to intervene most warmly in their favour.”

One of Pasteur’s earliest friends, who, in 1862, had greeted with joy his election to the AcadÉmie des Sciences, and who had never ceased to show the greatest interest in the progress due to the experimental method, entered the Ecole Normale laboratory with a beaming face. Happy to bring good tidings, he took his share of them like the devoted, hardworking, kindly man that he was. “M. Grandeau,” wrote Mme. Pasteur to her children, “has just brought to the laboratory the news that Roux and Chamberland have the Cross and M. Pasteur the Grand Cross of the Legion of Honour. Hearty congratulations were exchanged in the midst of the rabbits and guinea-pigs.”

Those days were darkened by a great sorrow. Henri Sainte Claire Deville died. Pasteur was then reminded of the words of his friend in 1868: “You will survive me, I am your senior; promise that you will pronounce my funeral oration.” When formulating this desire, Sainte Claire Deville had no doubt been desirous of giving another direction to the presentiments of Pasteur, who believed himself death-stricken. But, whether it was from a secret desire, or from an affectionate impulse, he felt that none understood him better than Pasteur. Both loved Science after the same manner; they gave to patriotism its real place; they had hopes for the future of the human mind; they were moved by the same religious feelings before the mysteries of the Infinite.

Pasteur began by recalling his friend’s wish: “And here am I, before thy cold remains, obliged to ask my memory what thou wert in order to repeat it to the multitude crowding around thy coffin. But how superfluous! Thy sympathetic countenance, thy witty merriment and frank smile, the sound of thy voice remain with us and live within us. The earth which bears us, the air we breathe, the elements, often interrogated and ever docile to answer thee, could speak to us of thee. Thy services to Science are known to the whole world, and every one who has appreciated the progress of the human mind is now mourning for thee.”

He then enumerated the scientist’s qualities, the inventive precision of that eager mind, full of imagination, and at the same time the strictness of analysis and the fruitful teaching so delightedly recognized by those who had worked with him, Debray, Troost, FouquÉ, Grandeau, Hautefeuille, Gernez, Lechartier. Then, showing that, in Sainte Claire Deville, the man equalled the scientist:

“Shall I now say what thou wert in private life? Again, how superfluous! Thy friends do not want to be reminded of thy warm heart. Thy pupils want no proofs of thy affection for them and thy devotion in being of service to them! See their sorrow.

“Should I tell thy sons, thy five sons, thy joy and pride, of the preoccupations of thy paternal and prudent tenderness? And can I speak of thy smiling goodness to her, the companion of thy life, the mere thought of whom filled thy eyes with a sweet emotion?

“Oh! I implore thee, do not now look down upon thy weeping wife and afflicted sons: thou wouldst regret this life too much! Wait for them rather in those divine regions of knowledge and full light, where thou knowest all now, where thou canst understand the Infinite itself, that terrible and bewildering notion, closed for ever to man in this world, and yet the eternal source of all Grandeur, of all Justice and all Liberty.”

Pasteur’s voice was almost stifled by his team, as had been that of J. B. Dumas speaking at PÉclet’s tomb. The emotions of savants are all the deeper that they are not enfeebled, as in so many writers or speakers, by the constant use of words which end by wearing out the feelings.

Little groups slowly walking away from a country churchyard seem to take with them some of the sadness they have been feeling, but the departure from a Paris cemetery gives a very different impression. Life immediately grasps again and carries away in its movement the mourners, who now look as if they had been witnessing an incident in which they were not concerned. Pasteur felt such bitter contrasts with all his tender soul, he had a cult for dear memories; Sainte Claire Deville’s portrait ever remained in his study.

The adversaries of the new discovery now had recourse to a new mode of attack. The virus which had been used at Pouilly le Fort to show how efficacious were the preventive vaccinations was, they said, a culture virus—some even said a Machiavellian preparation of Pasteur’s. Would vaccinated animals resist equally well the action of the charbon blood itself, the really malignant and infallibly deadly blood? Those sceptics were therefore impatiently awaiting the result of some experiments which were being carried out near Chartres in the farm of Lambert. Sixteen Beauceron sheep were joined to a lot of nineteen sheep brought from Alfort and taken from the herd of 300 sheep vaccinated against charbon three weeks before, on the very day of the lecture at Alfort. On July 16, at 10 o’clock in the morning, the thirty-five sheep, vaccinated and non-vaccinated, were gathered together. The corpse of a sheep who had died of charbon four hours before, in a neighbouring farm, was brought into the field selected for the experiments. After making a post-mortem examination and noting the characteristic injuries of splenic fever, ten drops of the dead sheep’s blood were injected into each of the thirty-five sheep, taking one vaccinated at Alfort and one non-vaccinated Beauceron alternately. Two days later, on July 18, ten of the latter were already dead, most of the others were prostrated. The vaccinated sheep were perfectly well.

While the ten dead sheep were being examined, two more died, and three more on the 19th. Bouley, informed by the veterinary surgeon, Boutet, of those successive incidents, wrote on the 20th to Pasteur: “My dear Master, Boutet has just informed me of the Chartres event. All has been accomplished according to the master’s words; your vaccinated sheep have triumphantly come through the trial, and all the others save one are dead. That result is of special importance in a country-side where incredulity was being maintained in spite of all the demonstrations made. It seems that the doctors especially were refractory. They said it was too good to be true, and they counted on the strength of the natural charbon to find your method in default. Now they are converted, Boutet writes, and the veterinary surgeon too—one amongst others, whose brain, it seems, was absolutely iron-clad—also the agricultors. There is a general Hosannah in your honour.”

After congratulating Pasteur on the Grand Cross, he added, “I was also very glad of the reward you have obtained for your two young collaborators, so full of your spirit, so devoted to your work and your person, and whose assistance is so self-sacrificing and disinterested. The Government has honoured itself by so happily crowning with that distinction the greatness of the discovery in which they took part.”

Henceforth, and for a time, systematic opposition ceased. Thousands and thousands of doses were used of the new vaccine, which afterwards saved millions to agriculture.

A few days later, came a change in Pasteur’s surroundings. He was invited by the Organizing Committee to attend the International Medical Congress in London, and desired by the Government of the Republic to represent France.

On August 3, when he arrived in St. James’ Hall, filled to overflowing, from the stalls to the topmost galleries, he was recognized by one of the stewards, who invited him to come to the platform reserved for the most illustrious members of the Congress. As he was going towards the platform, there was an outburst of applause, hurrahs and acclamations. Pasteur turned to his two companions, his son and his son-in-law, and said, with a little uneasiness: “It is no doubt the Prince of Wales arriving; I ought to have come sooner.”

“But it is you that they are all cheering,” said the President of the Congress, Sir James Paget, with his grave, kindly smile.

A few moments later, the Prince of Wales entered, accompanying his brother-in-law, the German Crown Prince.

In his speech, Sir James Paget said that medical science should aim at three objects: novelty, utility and charity. The only scientist named was Pasteur; the applause was such that Pasteur, who was sitting behind Sir James Paget, had to rise and bow to the huge assembly.

“I felt very proud,” wrote Pasteur to Mme. Pasteur in a letter dated that same day, “I felt inwardly very proud, not for myself—you know how little I care for triumph!—but for my country, in seeing that I was specially distinguished among that immense concourse of foreigners, especially of Germans, who are here in much greater numbers than the French, whose total, however, reaches two hundred and fifty. Jean Baptiste and RenÉ were in the Hall; you can imagine their emotion.

“After the meeting, we lunched at Sir James Paget’s house; he had the Prussian Crown Prince on his right and the Prince of Wales on his left. Then there was a gathering of about twenty-five or thirty guests in the drawing-room. Sir James presented me to the Prince of Wales, to whom I bowed, saying that I was happy to salute a friend to France. ‘Yes,’ he answered, ‘a great friend.’ Sir James Paget had the good taste not to ask me to be presented to the Prince of Prussia; though there is of course room for nothing but courtesy under such circumstances, I could not have brought myself to appear to wish to be presented to him. But he himself came up to me and said, ‘M. Pasteur, allow me to introduce myself to you, and to tell you that I had great pleasure in applauding you just now,’ adding some more pleasant things.”

In the midst of the unexpected meetings brought about by that Congress, it was an interesting thing to see this son of a King and Emperor, the heir to the German crown, thus going towards that Frenchman whose conquests were made over disease and death. Of what glory might one day dream this Prince, who became Frederic III!

His tall and commanding stature, the highest position in the Prussian army conferred on him by his father, King William, in a solemn letter dated from Versailles, October, 1870—everything seemed to combine in making a warlike man of this powerful-looking prince. And yet was it not said in France that he had protested against certain barbarities, coldly executed by some Prussian generals during that campaign of 1870? Had he not considered the clauses of the Treaty of Frankfort as Draconian and dangerous? If he had been sole master, would he have torn Alsace away from France? What share would his coming reign bear in the history of civilization?... Fate had already marked this Prince, only fifty years old, for an approaching death. In his great sufferings, before the inexorable death which was suffocating him, he was heroically patient. His long agony began at San Remo, amongst the roses and sunshine; he was an Emperor for less than one hundred days, and, on his death-bed, words of peace, peace for his people, were on his lips.

As Pasteur, coming to this Congress, was not only curious to see what was the place held in medicine and surgery by the germ-theory, but also desirous to learn as much as possible, he never missed a discussion and attended every meeting. It was in a simple sectional meeting that Bastian attempted to refute Lister. After his speech, the President suddenly said, “I call on M. Pasteur,” though Pasteur had not risen. There was great applause; Pasteur did not know English; he turned to Lister and asked him what Bastian had said.

“He said,” whispered Lister, “that microscopic organizations in disease were formed by the tissues themselves.”

“That is enough for me,” said Pasteur. And he then invited Bastian to try the following experiment:

“Take an animal’s limb, crush it, allow blood and other normal or abnormal liquids to spread around the bones, only taking care that the skin should neither be torn nor opened in any way, and I defy you to see any micro-organism formed within that limb as long as the illness will last.”

Pasteur, desired to do so by Sir James Paget at one of the great General Meetings of the Congress, gave a lecture on the principles which had led him to the attenuation of virus, on the methods which had enabled him to obtain the vaccines of chicken-cholera and of charbon, and, finally, on the results obtained. “In a fortnight,” he said, “we vaccinated, in the Departments surrounding Paris, nearly 20,000 sheep, and a great many oxen, cows and horses....

“Allow me,” he continued, “not to conclude without telling you of the great joy that I feel in thinking that it is as a member of the International Medical Congress sitting in London that I have made known to you the vaccination of a disease more terrible perhaps for domestic animals than is small-pox for man. I have given to the word vaccination an extension which I hope Science will consecrate as a homage to the merit and immense services rendered by your Jenner, one of England’s greatest men. It is a great happiness to me to glorify that immortal name on the very soil of the noble and hospitable city of London!”

“Pasteur was the greatest success of the Congress,” wrote the correspondent of the Journal des DÉbats, Dr. Daremberg, glad as a Frenchman and as a physician to hear the unanimous hurrahs which greeted the delegate of France. “When M. Pasteur spoke, when his name was mentioned, a thunder of applause rose from all benches, from all nations. An indefatigable worker, a sagacious seeker, a precise and brilliant experimentalist, an implacable logician, and an enthusiastic apostle, he has produced an invincible effect on every mind.”

The English people, who chiefly look in a great man for power of initiative and strength of character, shared this admiration. One group only, alone in darkness, away from the Congress, was hostile to the general movement and was looking for an opportunity for direct or indirect revenge; it was the group of anti-vaccinators and anti-vivisectionists. The influence of the latter was great enough in England to prevent experimentation on animals. At a general meeting of the Congress, Virchow, the German scientist, spoke on the use of experimenting in pathology.

Already at a preceding Congress held in Amsterdam, Virchow had said amid the applause of the Assembly: “Those who attack vivisection have not the faintest idea of Science, and even less of the importance and utility of vivisection for the progress of medicine.” But to this just argument, the international leagues for the protection of animals—very powerful, like everything that is founded on a sentiment which may be exalted—had answered by combative phrases. The physiological laboratories were compared to chambers of torture. It seemed as if, through caprice or cruelty, quite uselessly at any rate, this and that man of science had the unique desire of inflicting on bound animals, secured on a board, sufferings of which death was the only limit. It is easy to excite pity towards animals; an audience is conquered as soon as dogs are mentioned. Which of us, whether a cherished child, a neglected old maid, a man in the prime of his youth or a misanthrope weary of everything, has not, holding the best place in his recollections, the memory of some example of fidelity, courage or devotion given by a dog? In order to raise the revolt, it was sufficient for anti-vivisectionists to evoke amongst the ghosts of dog martyrs the oft-quoted dog who, whilst undergoing an experiment, licked the hand of the operator. As there had been some cruel abuses on the part of certain students, those abuses alone were quoted. Scientists did not pay much heed to this agitation, partly a feminine one: they relied on the good sense of the public to put an end to those doleful declamations. But the English Parliament voted a Bill prohibiting vivisection; and, after 1876, English experimentalists had to cross the Channel to inoculate a guinea-pig.

Virchow did not go into details; but, in a wide exposÉ of Experimental Physiological Medicine, he recalled how, at each new progress of Science—at one time against the dissection of dead bodies and now against experiments on living animals—the same passionate criticisms had been renewed. The Interdiction Bill voted in England had filled a new Leipzig Society with ardour; it had asked the Reichstag in that same year, 1881, to pass a law punishing cruelty to animals under pretext of scientific research, by imprisonment, varying between five weeks and two years, and deprivation of civil rights. Other societies did not go quite so far, but asked that some of their members should have a right of entrance and inspection into the laboratories of the Faculties.

“He who takes more interest in animals than in Science and in the knowledge of truth is not qualified to inspect officially things pertaining to Science,” said Virchow. With an ironical gravity on his quizzical wrinkled face, he added, “Where shall we be if a scientist who has just begun a bon fide experiment finds himself, in the midst of his researches, obliged to answer questions from a new-comer and afterwards to defend himself before some magistrate for the crime of not having chosen another method, other instruments, perhaps another experiment?...

“We must prove to the whole world the soundness of our cause,” concluded Virchow, uneasy at those “leagues” which grew and multiplied, and scattered through innumerable lecture halls the most fallacious judgments on the work of scientists.

Pasteur might have brought him, to support his statements relative to certain deviations of ideas and sentiments, numberless letters which reached him regularly from England—letters full of threats, insults and maledictions, devoting him to eternal torments for having multiplied his crimes on the hens, guinea-pigs, dogs and sheep of the laboratory. Love of animals carries some women to such lengths!

It would have been interesting, if, after Virchow’s speech, some French physician had in his turn related a series of facts, showing how prejudices equally tenacious had had to be struggled against in France, and how savants had succeeded in enforcing the certainty that there can be no pathological science if Physiology is not progressing, and that it can only progress by means of the experimental method. Claude Bernard had expressed this idea under so many forms that it would almost have been enough to give a few extracts from his works.

In 1841, when he was Magendie’s curator, he was one day attending a lesson on experimental physiology, when he saw an old man come in, whose costume—a long coat with a straight collar and a hat with a very wide brim—indicated a Quaker.

“Thou hast no right,” he said, addressing Magendie, “to kill animals or to make them suffer. Thou givest a wicked example and thou accustomest thy fellow creatures to cruelty.”

Magendie replied that it was a pity to look at it from that point of view, and that a physiologist, when moved by the thought of making a discovery useful to Medicine, and consequently useful to his fellow creatures, did not deserve that reproach.

“Your countryman Harvey,” said he, hoping to convince him, “would not have discovered the circulation of the blood if he had not made some experiments in vivisection. That discovery was surely worth the sacrifice of a few deer in Charles the First’s Park?”

But the Quaker stuck to his idea; his mission, he said, was to drive three things from this world: war, hunting and shooting, and experiments on live animals. Magendie had to show him out.

Three years later, Claude Bernard, in his turn, was taxed with barbarity by a Police Magistrate. In order to study the digestive properties of gastric juice, it had occurred to him to collect it by means of a cannula, a sort of silver tap which he adapted to the stomach of live dogs. A Berlin surgeon, M. Dieffenbach, who was staying in Paris, expressed a wish to see this application of a cannula to the stomach. M. Pelouze, the chemist, had a laboratory in the Rue Dauphine; he offered it to Claude Bernard. A stray dog was used as a subject for the experiment and shut up in the yard of the house, where Claude Bernard wished to keep a watch on him. But, as the treatment in no wise hindered the dog from running about, the door of the yard was hardly opened when he escaped, cannula and all.

“A few days later,” writes Claude Bernard in the course of an otherwise grave report concerning the progress of general physiology in France (1867), “I was still in bed, early one morning, when I received a visit from a man who came to tell men that the Police Commissary of the Medicine School District wished to speak to me, and that I must go round to see him. I went in the course of the day to the Police Commissariat of the Rue du Jardinet; I found a very respectable-looking little old man, who received me very coldly at first and without saying anything. He took me into another room and showed me, to my great astonishment, the dog on whom I had operated in M. Pelouze’s laboratory, asking me if I confessed to having fixed that instrument in his stomach. I answered affirmatively, adding that I was delighted to see my cannula, which I thought I had lost. This confession, far from satisfying the Commissary, apparently provoked his wrath, for he gave me an admonition of most exaggerated severity, accompanied with threats for having had the audacity to steal his dog to experiment on it.

“I explained that I had not stolen his dog, but that I had bought it of some individuals who sold dogs to physiologists, and who claimed to be employed by the police in picking up stray dogs. I added that I was sorry to have been the involuntary cause of the grief occasioned in his household by the misadventure to the dog, but that the animal would not die of it; that the only thing to do was to let me take away my silver cannula and let him keep his dog. Those last words altered the Commissary’s language and completely calmed his wife and daughter. I removed my instrument and left, promising to return, which I did the next and following days. The dog was perfectly cured in a day or two, and I became a friend of the family, completely securing the Commissary’s future protection. It was on that account that I soon after set up my laboratory in his District, and for many years continued my private classes of experimental physiology, enjoying the protection and warnings of the Commissary and thus avoiding much unpleasantness, until the time when I was at last made an assistant to Magendie at the CollÈge de France.”

The London Society for the Protection of Animals had the singular idea of sending to Napoleon III complaints, almost remonstrances, on the vivisection practised within the French Empire. The Emperor simply sent on those English lamentations to the Academy of Medicine. The matter was prolonged by academical speeches. In a letter addressed to M. Grandeau, undated, but evidently written in August, 1863, Claude Bernard showed some irritation, a rare thing with him. Declaring that he would not go to the Academy and listen to the “nonsense” of “those who protect animals in hatred of mankind” he gave his concluding epitome: “You ask me what are the principal discoveries due to vivisection, so that you can mention them as arguments for that kind of study. All the knowledge possessed by experimental physiology can be quoted in that connection; there is not a single fact which is not the direct and necessary consequence of vivisection. From Galen, who, by cutting the laryngeal nerves, learnt their use for respiration and the voice, to Harvey, who discovered circulation; Pecquet and Aselli, the lymphatic vessels; Haller, muscular irritability; Bell and Magendie, the nervous functions, and all that has been learnt since the extension of that method of vivisection, which is the only experimental method; in biology, all that is known on digestion, circulation, the liver, the sympathetic system, the bones, Development—all, absolutely all, is the result of vivisection, alone or combined with other means of study.”

In 1875, he again returned to this idea in his experimental medicine classes at the CollÈge de France: “It is to experimentation that we owe all our precise notions on the functions of the viscera and a fortiori on the properties of such organs as muscles, nerves, etc.”

One more interesting quotation might have been offered to the members of the Congress. A Swede had questioned Darwin on vivisection, for the anti-vivisectionist propaganda was spreading on every side. Darwin, who, like Pasteur, did not admit that useless suffering should be inflicted on animals (Pasteur carried this so far that he would never, he said, have had the courage to shoot a bird for sport)—Darwin, in a letter dated April 14th, 1881, approved any measures that could be taken to prevent cruelty, but he added: “On the other hand, I know that physiology can make no progress if experiments on living animals are suppressed, and I have an intimate conviction that to retard the progress of physiology is to commit a crime against humanity.... Unless one is absolutely ignorant of all that Science has done for humanity, one must be convinced that physiology is destined to render incalculable benefits in the future to man and even to animals. See the results obtained by M. Pasteur’s work on the germs of contagious diseases: will not animals be the first to profit thereby? How many lives have been saved, how much suffering spared by the discovery of parasitic worms following on experiments made by Virchow and others on living animals!”

The London Congress marked a step on the road of progress. Besides the questions which were discussed and which were capable of precise solution, the scientific spirit showed itself susceptible of permeating other general subjects. Instead of remaining the impassive Sovereign we are wont to fancy her, Science—and this was proved by Pasteur’s discoveries and their consequences, as Paget, Tyndall, Lister, and Priestley loudly proclaimed—Science showed herself capable of associating with pure research and perpetual care for Truth a deep feeling of compassion for all suffering and an ever-growing thirst for self-sacrifice.

Pasteur’s speech at the London Medical Congress was printed at the request of an English M.P. and distributed to all the members of the House of Commons. Dr. H. Gueneau de Mussy, who had spent part of his life in England, having followed the Orleans family into exile, wrote to Pasteur on August 15, “I have been very happy in witnessing your triumph; you are raising us up again in the eyes of foreign nations.”

Applause was to Pasteur but a stimulus to further efforts. He was proud of his discoveries, but not vain of the effect they produced; he said in a private letter: “The Temps again refers, in a London letter, to my speech at the Congress. What an unexpected success!”

Having heard that yellow fever had just been brought into the Gironde, at the Pauillac lazaretto by the vessel CondÉ from Senegal, Pasteur immediately started for Bordeaux. He hoped to find the microbe in the blood of the sick or the dead, and to succeed in cultivating it. M. Roux hastened to join his master.

If people spoke to Pasteur of the danger of infection, “What does it matter?” he said. “Life in the midst of danger is the life, the real life, the life of sacrifice, of example, of fruitfulness.”

He was vexed to find his arrival notified in the newspapers; it worried him not to be able to work and to travel incognito.

On September 17, he wrote to Mme. Pasteur: “...We rowed out to a great transport ship which is lying in the Pauillac roads, having just arrived. From our boat, we were able to speak to the men of the crew. Their health is good, but they lost seven persons at St. Louis, two passengers and five men of the crew. Save the captain and one engineer, they are all Senegalese negroes on that ship. We have been near another large steamboat, and yet another; their health is equally good....

“The most afflicted ship is the CondÉ, which is in quarantine in the Pauillac roads, and near which we have not been able to go. She has lost eighteen persons, either at sea or at the lazaretto....”

No experiment could be attempted—the patients were convalescent. “But,” he wrote the next day, “the Richelieu will arrive between the 25th and 28th, I think with some passengers.... It is more than likely that there will have been deaths during the passage, and patients for the lazaretto. I am therefore awaiting the arrival of that ship with the hope—God forgive a scientist’s passion!!—that I may attempt some researches at the Pauillac lazaretto, where I will arrange things in consequence. You may be sure I shall take every precaution. In the meanwhile, what shall I do in Bordeaux?

“I have made the acquaintance of the young librarian of the town library, which is a few doors from the HÔtel Richelieu, in the Avenues of Tourny. The library is opened to me at all hours: I am there even now, alone and very comfortably seated, surrounded with more LittrÉ than I can possibly get through.”

For some months, several members of the AcadÉmie FranÇaise—according to the traditions of the Society which has ever thought it an honour to number among its members scientists such as Cuvier, Flourens, Biot, Claude Bernard, J. B. Dumas—had been urging Pasteur to become a candidate to the place left vacant by LittrÉ. Pasteur was anxious to know not only the works, but the life of him whose place he might be called upon to fill. It was with some emotion that he first came upon the following lines printed on the title-page of the translation of the works of Hippocrates; they are a dedication by LittrÉ to the memory of his father, a sergeant-major in the Marines under the Revolution.

“...Prepared by his lessons and by his example, I have been sustained through this long work by his ever present memory. I wish to inscribe his name on the first page of this book, in the writing of which he has had so much share from his grave, so that the work of the father should not be forgotten in the work of the son, and that a pious and just gratitude should connect the work of the living with the heritage of the dead....”

Pasteur in 1876 had obeyed a similar filial feeling when he wrote on the first page of his Studies on Beer—

“To the memory of my father, a soldier under the first Empire, and a knight of the Legion of Honour. The more I have advanced in age, the better I have understood thy love and the superiority of thy reason. The efforts I have given to these Studies and those which have preceded them are the fruit of thy example and advice. Wishing to honour these pious recollections, I dedicate this work to thy memory.”

The two dedications are very similar. Those two soldiers’ sons had kept the virile imprint of the paternal virtues. A great tenderness was also in them both; LittrÉ, when he lost his mother, had felt a terrible grief, comparable to Pasteur’s under the same circumstances.

In spite of Pasteur’s interest in studying LittrÉ in the Bordeaux library, he did not cease thinking of yellow fever. He often saw M. Berchon, the sanitary director, and inquired of him whether there were any news of the Richelieu. A young physician, Dr. Talmy, had expressed a desire to join Pasteur at Bordeaux and to obtain permission, when the time came, to be shut up with the patients in the lazaretto. Pasteur wrote on December 25 to Mme. Pasteur: “There is nothing new save the Minister’s authorization to Dr. Talmy to enter the lazaretto; I have just telegraphed to him that he might start. The owners of the Richelieu still suppose that she will reach Pauillac on Tuesday. M. Berchon, who is the first to be informed of what takes place in the roads, will send me a telegram as soon as the Richelieu is signalled, and we shall then go—M. Talmy, Roux and I—to ascertain the state of the ship, of course without going on board, which we should not be allowed to do if it has a suspicious bill of health.”

And, as Mme. Pasteur had asked what happened when a ship arrived, he continued in the same letter: “From his boat to windward, M. Berchon receives the ship’s papers, giving the sanitary state of the ship day by day. Before passing from the hands of the captain of the vessel to those of the sanitary director, the papers are sprinkled over with chloride of lime.

“If there are cases of illness, all the passengers are taken to the lazaretto; only a few men are left on board the ship, which is henceforth in quarantine, no one being allowed to leave or enter it.

“God permit that, in the body of one of those unfortunate victims of medical ignorance, I may discover some specific microscopic being. And after that? Afterwards, it would be really beautiful to make that agent of disease and death become its own vaccine. Yellow fever is one of the three great scourges of the East—bubonic plague, cholera, and yellow fever. Do you know that it is already a fine thing to be able to put the problem in those words!”

The Richelieu arrived, but she was free from fever. The last passenger had died during the crossing and his body had been thrown into the sea.

Pasteur left Bordeaux and returned to his laboratory.