On January 30, 1860, the AcadÉmie des Sciences conferred on Pasteur the Prize for Experimental Physiology. Claude Bernard, who drew up the report, recalled how much Pasteur’s experiments in alcoholic fermentation, lactic fermentation, the fermentation of tartaric acid, had been appreciated by the AcadÉmie. He dwelt upon the great physiological interest of the results obtained. “It is,” he concluded, “by reason of that physiological tendency in Pasteur’s researches, that the Commission has unanimously selected him for the 1859 Prize for Experimental Physiology.”

That same January, Pasteur wrote to Chappuis: “I am pursuing as best I can these studies on fermentation which are of great interest, connected as they are with the impenetrable mystery of Life and Death. I am hoping to mark a decisive step very soon by solving, without the least confusion, the celebrated question of spontaneous generation. Already I could speak, but I want to push my experiments yet further. There is so much obscurity, together with so much passion, on both sides, that I shall require the accuracy of an arithmetical problem to convince my opponents by my conclusions. I intend to attain even that.”

This progress was depicted to his father in the following letter, dated February 7, 1860—

“I think I told you that I should read a second and last lecture on my old researches on Friday, at the Chemical Society, before several members of the Institute—amongst others, Messrs. Dumas and Claude Bernard. That lecture has had the same success as the first. M. Biot heard about it the next day through some distinguished persons who were in the audience, and sent for me in order to kindly express his great satisfaction.

“After I had finished, M. Dumas, who occupied the chair, rose and addressed me in these words. After praising the zeal I had brought to this novel kind of teaching at the Society’s request, and the so great penetration I had given proof of, in the course of the work I had just expounded, he added, ‘The AcadÉmie, sir, rewarded you a few days ago for other profound researches; your audience of this evening will applaud you as one of the most distinguished professors we possess.’

“All I have underlined was said in those very words by M. Dumas, and was followed by great applause.

“All the students of the scientific section of the Ecole Normale were present; they felt deeply moved and several of them have expressed their emotion to me.

“As for myself, I saw the realization of what I had foreseen. You know how I have always told you confidentially that time would see the growth of my researches on the molecular dissymmetry of natural organic products. Founded as they were on varied notions borrowed from divers branches of science—crystallography, physics, and chemistry—those studies could not be followed by most scientists so as to be fully understood. On this occasion I presented them in the aggregate with some clearness and power and every one was struck by their importance.

“It is not by their form that these two lectures have delighted my hearers, it is by their contents; it is the future reserved to those great results, so unexpected, and opening such entirely new vistas to physiology. I have dared to say so, for at these heights all sense of personality disappears, and there only remains that sense of dignity which is ever inspired by true love of science.

“God grant that by my persevering labours I may bring a little stone to the frail and ill-assured edifice of our knowledge of those deep mysteries of Life and Death where all our intellects have so lamentably failed.

“P.S.—Yesterday I presented to the Academy my researches on spontaneous generation; they seemed to produce a great sensation. More later.”

When Biot heard that Pasteur wished to tackle this study of spontaneous generation, he interposed, as he had done seven years before, to arrest him on the verge of his audacious experiments on the part played by dissymmetrical forces in the development of life. Vainly Pasteur, grieved at Biot’s disapprobation, explained that this question, in the course of such researches, had become an imperious necessity; Biot would not be convinced. But Pasteur, in spite of his quasi-filial attachment to Biot, could not stop where he was; he had to go through to the end.

“You will never find your way out,” cried Biot.

“I shall try,” said Pasteur modestly.

Angry and anxious, Biot wished Pasteur to promise that he would relinquish these apparently hopeless researches. J. B. Dumas, to whom Pasteur related the more than discouraging remonstrances of Biot, entrenched himself behind this cautious phrase—

“I would advise no one to dwell too long on such a subject.”

Senarmont alone, full of confidence in the ingenious curiosity of the man who could read nature by dint of patience, said that Pasteur should be allowed his own way.

It is regrettable that Biot—whose passion for reading was so indefatigable that he complained of not finding enough books in the library at the Institute—should not have thought of writing the history of this question of spontaneous generation. He could have gone back to Aristotle, quoted Lucretius, Virgil, Ovid, Pliny. Philosophers, poets, naturalists, all believed in spontaneous generation. Time went on, and it was still believed in. In the sixteenth century, Van Helmont—who should not be judged by that one instance—gave a celebrated recipe to create mice: any one could work that prodigy by putting some dirty linen in a receptacle, together with a few grains of wheat or a piece of cheese. Some time later an Italian, Buonanni, announced a fact no less fantastic: certain timberwood, he said, after rotting in the sea, produced worms which engendered butterflies, and those butterflies became birds.

Another Italian, less credulous, a poet and a physician, Francesco Redi, belonging to a learned society calling itself The Academy of Experience, resolved to carefully study one of those supposed phenomena of spontaneous generation. In order to demonstrate that the worms found in rotten meat did not appear spontaneously, he placed a piece of gauze over the meat. Flies, attracted by the odour, deposited their eggs on the gauze. From those eggs were hatched the worms, which had until then been supposed to begin life spontaneously in the flesh itself. This simple experiment marked some progress. Later on another Italian, a medical professor of Padua, Vallisneri, recognized that the grub in a fruit is also hatched from an egg deposited by an insect before the development of the fruit.

The theory of spontaneous generation, still losing ground, appeared to be vanquished when the invention of the microscope at the end of the seventeenth century brought fresh arguments to its assistance. Whence came those thousands of creatures, only distinguishable on the slide of the microscope, those infinitely small beings which appeared in rain water as in any infusion of organic matter when exposed to the air? How could they be explained otherwise than through spontaneous generation, those bodies capable of producing 1,000,000 descendants in less than forty-eight hours.

The world of salons and of minor courts was pleased to have an opinion on this question. The Cardinal of Polignac, a diplomat and a man of letters, wrote in his leisure moments a long Latin poem entitled the Anti-Lucretius. After scouting Lucretius and other philosophers of the same school, the cardinal traced back to one Supreme Foresight the mechanism and organization of the entire world. By ingenious developments and circumlocutions, worthy of the AbbÉ Delille, the cardinal, while vaunting the wonders of the microscope, which he called “eye of our eye,” saw in it only another prodigy offered us by Almighty Wisdom. Of all those accumulated and verified arguments, this simple notion stood out: “The earth, which contains numberless germs, has not produced them. Everything in this world has its germ or seed.”

Diderot, who disseminated so many ideas (since borrowed by many people and used as if originated by them), wrote in some tumultuous pages on nature: “Does living matter combine with living matter? how? and with what result? And what about dead matter?”

About the middle of the eighteenth century the problem was again raised on scientific ground. Two priests, one an Englishman, Needham, and the other an Italian, Spallanzani, entered the lists. Needham, a great partisan of spontaneous generation, studied with Buffon some microscopic animalculÆ. Buffon afterwards built up a whole system which became fashionable at that time. The force which Needham found in matter, a force which he called productive or vegetative, and which he regarded as charged with the formation of the organic world, Buffon explained by saying that there are certain primitive and incorruptible parts common to animals and to vegetables. These organic molecules cast themselves into the moulds or shapes which constituted different beings. When one of those moulds was destroyed by death, the organic molecules became free; ever active, they worked the putrefied matter, appropriating to themselves some raw particles and forming, said Buffon, “by their reunion, a multitude of little organized bodies, of which some, like earthworms, and fungi, seem to be fair-sized animals or vegetables, but of which others, in almost infinite numbers, can only be seen through the microscope.”

All those bodies, according to him, only existed through spontaneous generation. Spontaneous generation takes place continually and universally after death and sometimes during life. Such was in his view the origin of intestinal worms. And, carrying his investigations further, he added, “The eels in flour paste, those of vinegar, all those so-called microscopic animals, are but different shapes taken spontaneously, according to circumstances, by that ever active matter which only tends to organization.”

The AbbÉ Spallanzani, armed with a microscope, studied these infinitesimal beings. He tried to distinguish them and their mode of life. Needham had affirmed that by enclosing putrescible matter in vases and by placing those vases on warm ashes, he produced animalculÆ. Spallanzani suspected: firstly that Needham had not exposed the vases to a sufficient degree of heat to kill the seeds which were inside; and secondly, that seeds could easily have entered those vases and given birth to animalculÆ, for Needham had only closed his vases with cork stoppers, which are very porous.

“I repeated that experiment with more accuracy,” wrote Spallanzani. “I used hermetically sealed vases. I kept them for an hour in boiling water, and after having opened them and examined their contents within a reasonable time I found not the slightest trace of animalculÆ, though I had examined with the microscope the infusions from nineteen different vases.”

Thus dropped to the ground, in Spallanzani’s eyes, Needham’s singular theory, this famous vegetative force, this occult virtue. Yet Needham did not own himself beaten. He retorted that Spallanzani had much weakened, perhaps destroyed, the vegetative force of the infused substances by leaving his vases in boiling water during an hour. He advised him to try with less heat.

The public took an interest in this quarrel. In an opuscule entitled Singularities of Nature (1769), Voltaire, a born journalist, laughed at Needham, whom he turned into an Irish Jesuit to amuse his readers. Joking on this race of so-called eels which began life in the gravy of boiled mutton, he said: “At once several philosophers exclaimed at the wonder and said, ‘There is no germ; all is made, all is regenerated by a vital force of nature.’ ‘Attraction,’ said one; ‘Organized matter,’ said another, ‘they are organic molecules which have found their casts.’ Clever physicists were taken in by a Jesuit.”

In those pages, lightly penned, nothing remained of what Voltaire called “the ridiculous mistake, the unfortunate experiments of Needham, so triumphantly refuted by M. Spallanzani and rejected by whoever has studied nature at all.” “It is now demonstrated to sight and to reason that there is no vegetable, no animal but has its own germ.” In his Philosophic Dictionary, at the word God, “It is very strange,” said Voltaire, “that men should deny a creator and yet attribute to themselves the power of creating eels!” The AbbÉ Needham, meeting with these religious arguments, rather unexpected from Voltaire, endeavoured to prove that the hypothesis of spontaneous generation was in perfect accordance with religious beliefs. But both on Needham’s side and on Spallanzani’s there was a complete lack of conclusive proofs.

Philosophic argumentation always returned to the fore. As recently as 1846 Ernest Bersot (a moralist who became later a director of the Ecole Normale) wrote in his book on Spiritualism: “The doctrine of spontaneous generation pleases simplicity-loving minds; it leads them far beyond their own expectations. But it is yet only a private opinion, and, were it recognized, its virtue would have to be limited and narrowed down to the production of a few inferior animals.”

That doctrine was about to be noisily re-introduced.

On December 20, 1858, a correspondent of the Institute, M. Pouchet, director of the Natural History Museum of Rouen, sent to the AcadÉmie des Sciences a Note on Vegetable and Animal Proto-organisms spontaneously Generated in Artificial Air and in Oxygen Gas. The note began thus: “At this time when, seconded by the progress of science, several naturalists are endeavouring to reduce the domain of spontaneous generation or even to deny its existence altogether, I have undertaken a series of researches with the object of elucidating this vexed question.” Pouchet, declaring that he had taken excessive precautions to preserve his experiments from any cause of error, proclaimed that he was prepared to demonstrate that “animals and plants could be generated in a medium absolutely free from atmospheric air, and in which, therefore, no germ of organic bodies could have been brought by air.”

On one copy of that communication, the opening of a four years’ scientific campaign, Pasteur had underlined the passages which he intended to submit to rigorous experimentation. The scientific world was discussing the matter; Pasteur set himself to work.

A new installation, albeit a summary one, allowed him to attempt some delicate experiments. At one of the extremities of the faÇade of the Ecole Normale, on the same line as the doorkeeper’s lodge, a pavilion had been built for the school architect and his clerk. Pasteur succeeded in obtaining possession of this small building, and transformed it into a laboratory. He built a drying stove under the staircase; though he could only reach the stove by crawling on his knees, yet this was better than his old attic. He also had a pleasant surprise—he was given a curator. He had deserved one sooner, for he had founded the institution of agrÉgÉs prÉparateurs. Remembering his own desire, on leaving the Ecole Normale, to have a year or two for independent study, he had wished to facilitate for others the obtaining of those few years of research and perhaps inspiration. Thanks to him, five places as laboratory curators were exclusively reserved to Ecole Normale students who had taken their degree (agrÉgÉs). The first curator who entered the new laboratory was Jules Raulin, a young man with a clear and sagacious mind, a calm and tenacious character, loving difficulties for the sake of overcoming them.

Pasteur began by the microscopic study of atmospheric air. “If germs exist in atmosphere,” he said, “could they not be arrested on their way?” It then occurred to him to draw—through an aspirator—a current of outside air through a tube containing a little plug of cotton wool. The current as it passed deposited on this sort of filter some of the solid corpuscles contained in the air; the cotton wool often became black with those various kinds of dust. Pasteur assured himself that amongst various detritus those dusts presented spores and germs. “There are therefore in the air some organized corpuscles. Are they germs capable of vegetable productions, or of infusions? That is the question to solve.” He undertook a series of experiments to demonstrate that the most putrescible liquid remained pure indefinitely if placed out of the reach of atmospheric dusts. But it was sufficient to place in a pure liquid a particle of the cotton-wool filter to obtain an immediate alteration.

A year before starting any discussion Pasteur wrote to Pouchet that the results which he had attained were “not founded on facts of a faultless exactitude. I think you are wrong, not in believing in spontaneous generation (for it is difficult in such a case not to have a preconceived idea), but in affirming the existence of spontaneous generation. In experimental science it is always a mistake not to doubt when facts do not compel affirmation.... In my opinion, the question is whole and untouched by decisive proofs. What is there in air which provokes organization? Are they germs? is it a solid? is it a gas? is it a fluid? is it a principle such as ozone? All this is unknown and invites experiment.”

After a year’s study, Pasteur reached this conclusion: “Gases, fluids, electricity, magnetism, ozone, things known or things occult, there is nothing in the air that is conditional to life, except the germs that it carries.”

Pouchet defended himself vigorously. To suppose that germs came from air seemed to him impossible. How many millions of loose eggs or spores would then be contained in a cubic millimetre of atmospheric air?

“What will be the outcome of this giant’s struggle?” grandiloquently wrote an editor of the Moniteur Scientifique (April, 1860). Pouchet answered this anonymous writer by advising him to accept the doctrine of spontaneous generation adopted of old by so many “men of genius.” Pouchet’s principal disciple was a lover of science and of letters, M. Nicolas Joly, an agrÉgÉ of natural science, doctor of medicine, and professor of physiology at Toulouse. He himself had a pupil, Charles Musset, who was preparing a thesis for his doctor’s degree under the title: New Experimental Researches on Heterogenia, or Spontaneous Generation. By the words heterogenia or spontaneous generation Joly and Musset agreed in affirming that “they did not mean a creation out of nothing, but the production of a new organized being, lacking parents, and of which the primordial elements are drawn from ambient organic matter.”

Thus supported, Pouchet multiplied objections to the views of Pasteur, who had to meet every argument. Pasteur intended to narrow more and more the sphere of discussion. It was an ingenious operation to take the dusts from a cotton-wool filter, to disseminate them in a liquid, and thus to determine the alteration of that liquid; but the cotton wool itself was an organic substance and might be suspected. He therefore substituted for the cotton wool a plug of asbestos fibre, a mineral substance. He invented little glass flasks with a long curved neck; he filled them with an alterable liquid, which he deprived of germs by ebullition; the flask was in communication with the outer air through its curved tube, but the atmospheric germs were deposited in the curve of the neck without reaching the liquid; in order that alteration should take place, the vessel had to be inclined until the point where the liquid reached the dusts in the neck.

But Pouchet said, “How could germs contained in the air be numerous enough to develop in every organic infusion? Such a crowd of them would produce a thick mist as dense as iron.” Of all the difficulties this last seemed to Pasteur the hardest to solve. Could it not be that the dissemination of germs was more or less thick according to places? “Then,” cried the heterogenists, “there would be sterile zones and fecund zones, a most convenient hypothesis, indeed!” Pasteur let them laugh whilst he was preparing a series of flasks reserved for divers experiments. If spontaneous generation existed, it should invariably occur in vessels filled with the same alterable liquid. “Yet it is ever possible,” affirmed Pasteur, “to take up in certain places a notable though limited volume of ordinary air, having been submitted to no physical or chemical change, and still absolutely incapable of producing any alteration in an eminently putrescible liquor.” He was ready to prove that nothing was easier than to increase or to reduce the number either of the vessels where productions should appear or of the vessels where those productions should be lacking. After introducing into a series of flasks of a capacity of 250 cubic centimetres a very easily corrupted liquid, such as yeast water, he submitted each flask to ebullition. The neck of those vessels was ended off in a vertical point. Whilst the liquid was still boiling, he closed, with an enameller’s lamp, the pointed opening through which the steam had rushed out, taking with it all the air contained in the vessel. Those flasks were indeed calculated to satisfy both partisans or adversaries of spontaneous generation. If the extremity of the neck of one of these vessels was suddenly broken, all the ambient air rushed into the flask, bringing in all the suspended dusts; the bulb was closed again at once with the assistance of a jet of flame. Pasteur could then carry it away and place it in a temperature of 25-30° C., quite suitable for the development of germs and mucors.

In those series of tests some flasks showed some alteration, others remained pure, according to the place where the air had been admitted. During the beginning of the year 1860 Pasteur broke his bulb points and enclosed ordinary air in many different places, including the cellars of the Observatory of Paris. There, in that zone of an invariable temperature, the absolutely calm air could not be compared to the air he gathered in the yard of the same building. The results were also very different: out of ten vessels opened in the cellar, closed again and placed in the stove, only one showed any alteration; whilst eleven others, opened in the yard, all yielded organized bodies.

In a letter to his father (June, 1860), Pasteur wrote: “I have been prevented from writing by my experiments, which continue to be very curious. But it is such a wide subject that I have almost too many ideas of experiments. I am still being contradicted by two naturalists, M. Pouchet of Rouen and M. Joly of Toulouse. But I do not waste my time in answering them; they may say what they like, truth is on my side. They do not know how to experiment; it is not an easy art; it demands, besides certain natural qualities, a long practice which naturalists have not generally acquired nowadays.”

When the long vacation approached, Pasteur, who intended to go on a voyage of experiments, laid in a store of glass flasks. He wrote to Chappuis, on August 10, 1860: “I fear from your letter that you will not go to the Alps this year.... Besides the pleasure of having you for a guide, I had hoped to utilize your love of science by offering you the modest part of curator. It is by some study of air on heights afar from habitations and vegetation that I want to conclude my work on so-called spontaneous generation. The real interest of that work for me lies in the connection of this subject with that of ferments which I shall take up again November.”

Pasteur started for Arbois, taking with him seventy-three flasks; he opened twenty of them not very far from his father’s tannery, on the road to DÔle, along an old road, now a path which leads to the mount of the BergÈre. The vine labourers who passed him wondered what this holiday tourist could be doing with all those little phials; no one suspected that he was penetrating one of nature’s greatest secrets. “What would you have?” merrily said his old friend, Jules Vercel; “it amuses him!” Of those twenty vessels, opened some distance away from any dwelling, eight yielded organized bodies.

Pasteur went on to Salins and climbed Mount Poupet, 850 metres above the sea-level. Out of twenty vessels opened, only five were altered. Pasteur would have liked to charter a balloon in order to prove that the higher you go the fewer germs you find, and that certain zones absolutely pure contain none at all. It was easier to go into the Alps.

He arrived at Chamonix on September 20, and engaged a guide to make the ascent of the Montanvert. The very next morning this novel sort of expedition started. A mule carried the case of thirty-three vessels, followed very closely by Pasteur, who watched over the precious burden and walked alongside of precipices supporting the case with one hand so that it should not be shaken.

When the first experiments were started an incident occurred. Pasteur has himself related this fact in his report to the AcadÉmie. “In order to close again the point of the flasks after taking in the air, I had taken with me an eolipyle spirit-lamp. The dazzling whiteness of the ice in the sunlight was such that it was impossible to distinguish the jet of burning alcohol, and as moreover that was slightly moved by the wind, it never remained on the broken glass long enough to hermetically seal my vessel. All the means I might have employed to make the flame visible and consequently directable would inevitably have given rise to causes of error by spreading strange dusts into the air. I was therefore obliged to bring back to the little inn of Montanvert, unsealed, the flasks which I had opened on the glacier.”

The inn was a sort of hut, letting in wind and rain. The thirteen open vessels were exposed to all the dusts in the room where Pasteur slept; nearly all of them presented alterations.

In the meanwhile the guide was sent to Chamonix where a tinker undertook to modify the lamp in view of the coming experiment.

The next morning, twenty flasks, which have remained celebrated in the world of scientific investigators, were brought to the Mer de Glace. Pasteur gathered the air with infinite precautions; he used to enjoy relating these details to those people who call everything easy. After tracing with a steel point a line on the glass, careful lest dusts should become a cause of error, he began by heating the neck and fine point of the bulb in the flame of the little spirit-lamp. Then raising the vessel above his head, he broke the point with steel nippers, the long ends of which had also been heated in order to burn the dusts which might be on their surface and which would have been driven into the vessel by the quick inrush of the air. Of those twenty flasks, closed again immediately, only one was altered. “If all the results are compared that I have obtained until now,” he wrote, on March 5, 1880, when relating this journey to the AcadÉmie, “it seems to me that it can be affirmed that the dusts suspended in atmospheric air are the exclusive origin, the necessary condition of life in infusions.”

And in an unnoticed little sentence, pointing already then to the goal he had in view, “What would be most desirable would be to push those studies far enough to prepare the road for a serious research into the origin of various diseases.” The action of those little beings, agents not only of fermentation but also of disorganization and putrefaction, already dawned upon him.

While Pasteur was going from the Observatoire cellars to the Mer de Glace, Pouchet was gathering air on the plains of Sicily, making experiments on Etna, and on the sea. He saw everywhere, he wrote, “air equally favourable to organic genesis, whether surcharged with detritus in the midst of our populous cities, or taken on the summit of a mountain, or on the sea, where it offers extreme purity. With a cubic decimetre of air, taken where you like, I affirm that you can ever produce legions of microzoa.”

And the heterogenists proclaimed in unison that “everywhere, strictly everywhere, air is constantly favourable to life.” Those who followed the debate nearly all leaned towards Pouchet. “I am afraid,” wrote a scientific journalist in La Presse (1860), “that the experiments you quote, M. Pasteur, will turn against you.... The world into which you wish to take us is really too fantastic....”

And yet some adversaries should have been struck by the efforts of a mind which, while marching forward to establish new facts, was ever seeking arguments against itself, and turned back to strengthen points which seemed yet weak. In November, Pasteur returned to his studies on fermentations in general and lactic fermentation in particular. Endeavouring to bring into evidence the animated nature of the lactic ferment, and to indicate the most suitable surroundings for the self-development of that ferment, he had come across some complications which hampered the purity and the progress of that culture. Then he had perceived another fermentation, following upon lactic fermentation and known as butyric fermentation. As he did not immediately perceive the origin of this butyric acid—which causes the bad smell in rancid butter—he ended by being struck by the inevitable coincidence between the (then called) infusory animalculÆ and the production of this acid.

“The most constantly repeated tests,” he wrote in February, 1861, “have convinced me that the transformation of sugar, mannite and lactic acid into butyric acid is due exclusively to those Infusories, and they must be considered as the real butyric ferment.” Those vibriones that Pasteur described as under the shape of small cylindric rods with rounded ends, sliding about, sometimes in a chain of three or four articles, he sowed in an appropriate medium, as he sowed beer yeast. But, by a strange phenomenon, “those infusory animalculÆ,” he said, “live and multiply indefinitely, without requiring the least quantity of air. And not only do they live without air, but air actually kills them. It is sufficient to send a current of atmospheric air during an hour or two through the liquor where those vibriones were multiplying to cause them all to perish and thus to arrest butyric fermentation, whilst a current of pure carbonic acid gas passing through that same liquor hindered them in no way. Thence this double proposition,” concluded Pasteur; “the butyric ferment is an infusory; that infusory lives without free oxygen.” He afterwards called anaËrobes those beings which do not require air, in opposition to the name of aËrobes given to other microscopic beings who require air to live.

Biot, without knowing all the consequences of these studies, had not been long in perceiving that he had been far too sceptical, and that physiological discoveries of the very first rank would be the outcome of researches on so-called spontaneous generation. He would have wished, before he died, not only that Pasteur should be the unanimously selected candidate for the 1861 Zecker prize in the Chemistry Section, but also that his friend, forty-eight years younger than himself, should be a member of the Institute. At the beginning of 1861, there was one vacancy in the Botanical Section. Biot took advantage of the researches pursued by Pasteur within the last three years, to say and to print that he should be nominated as a candidate. “I can hear the commonplace objection: he is a chemist, a physicist, not a professional botanist.... But that very versatility, ever active and ever successful, should be a title in his favour.... Let us judge of men by their works and not by the destination more or less wide or narrow that they have marked out for themselves. Pasteur made his dÉbut before the AcadÉmie in 1848, with the remarkable treatise which contained by implication the resolution of the paratartaric acid into its two components, right and left. He was then twenty-six; the sensation produced is not forgotten. Since then, during the twelve years which followed, he has submitted to your appreciation twenty-one papers, the last ten relating to vegetable physiology. All are full of new facts, often very unexpected, several very far reaching, not one of which has been found inaccurate by competent judges. If to-day, by your suffrage, you introduce M. Pasteur into the Botanical Section, as you might safely have done for ThÉodore de Saussure or Ingenhousz, you will have acquired for the AcadÉmie and for that particular section an experimentalist of the same order as those two great men.”

Balard, who in this academic campaign made common cause with Biot, was also making efforts to persuade several members of the Botanical Section. He was walking one day in the Luxembourg with Moquin-Tandon, pouring out, in his rasping voice, arguments in favour of Pasteur. “Well,” said Moquin-Tandon, “let us go to Pasteur’s, and if you find a botanical work in his library I shall put him on the list.” It was a witty form given to the scruples of the botanists. Pasteur only had twenty-four votes; Duchartre was elected.

The study of a microscopic fungus, capable by itself of transforming wine into vinegar, the bringing to light of the action of that mycoderma, endowed with the power of taking oxygen from air and fixing it upon alcohol, thus transforming the latter into acetic acid; the most ingenious experiments to demonstrate the absolute and exclusive power of the little plant, all gave reason to Biot’s affirmation that such skill in the observation of inferior vegetables equalled any botanist’s claim. Pasteur, showing that the interpretations of the causes which act in the formation of vinegar were false, and that alone the microscopic fungus did everything, was constantly dwelling on this power of the infinitesimally small. “Mycoderma,” he said, “can bring the action of combustion of the oxygen in air to bear on a number of organic materia. If microscopic beings were to disappear from our globe, the surface of the earth would be encumbered with dead organic matter and corpses of all kinds, animal and vegetable. It is chiefly they who give to oxygen its powers of combustion. Without them, life would become impossible because death would be incomplete.”

Pasteur’s ideas on fermentation and putrefaction were being adopted by disciples unknown to him. “I am sending you,” he wrote to his father, “a treatise on fermentation, which was the subject of a recent competition at the Montpellier Faculty. This work is dedicated to me by its author, whom I do not know at all, a circumstance which shows that my results are spreading and exciting some attention.

“I have only read the last pages, which have pleased me; if the rest is the same, it is a very good rÉsumÉ, entirely conceived in the new direction of my labours, evidently well understood by this young doctor.

“M. Biot is very well, only suffering a little from insomnia. He has, fortunately for his health, finished that great account of my former results which will be the greatest title I can have to the esteem of scientists.”

Biot died without having realized his last wish, which was to have Pasteur for a colleague. It was only at the end of the year 1862 that Pasteur was nominated by the Mineralogical Section for the seat of Senarmont. This new candidature did not go without a hitch. In his study on tartrates, Pasteur, as will be remembered, had discovered that their crystalline forms were hemihedral. When he examined the characteristic faces, he held the crystal in a particular way and said: “It is hemihedral on the right side.” A German mineralogist, named Rammelsberg, holding the crystal in the opposite direction, said: “It is hemihedral on the left side.” It was a mere matter of conventional orientation; nothing was changed in the scientific results announced by Pasteur. But some adversaries made a weapon of that inverted crystal; not a dangerous weapon, thought Pasteur at first, fancying that a few words would clear the misunderstanding. But the campaign persisted, with insinuations, murmurs, whisperings. When Pasteur saw this simple difference in the way the crystal was held stigmatised as a cause of error, he desired to cut short this quarrel made in Germany. He then had with him no longer Raulin, but M. Duclaux, who was beginning his scientific life. M. Duclaux remembers one day when Pasteur, seeing that incontrovertible arguments were required, sent for a cabinet maker with his tools. He superintended the making of a complete wooden set of the crystalline forms of tartrates, a gigantic set, such as Gulliver might have seen in Brobdingnag if he had studied geometrical forms in that island. A coating of coloured paper finished the work; green paper marked the hemihedral face. A member of the Philomathic Society, Pasteur asked the Society to give up the meeting of November 8, 1862, to the discussion of that subject. Several of his colleagues vainly endeavoured to dissuade him from that intention; Pasteur hearkened to no one. He took with him his provision of wooden crystals, and gave a vivid and impassioned lecture. “If you know the question,” he asked his adversaries, “where is your conscience? If you know it not, why meddle with it?” And with one of his accustomed sudden turns, “What is all this?” he added. “One of those incidents to which we all, more or less, are exposed by the conditions of our career; no bitterness remains behind. Of what account is it in the presence of those mysteries, so varied, so numerous, that we all, in divers directions, are working to clear? It is true I have had recourse to an unusual means of defending myself against attacks not openly published, but I think that means was safe and loyal, and deferential towards you. And,” he added, thinking of Biot and Senarmont, “will you have my full confession? You know that I had during fifteen years the inestimable advantage of the intercourse of two men who are no more, but whose scientific probity shone as one of the beacons of the AcadÉmie des Sciences. Before deciding on the course I have now followed, I questioned my memory and endeavoured to revive their advice, and it seemed to me that they would not have disowned me.”

M. Duclaux said about this meeting: “Pasteur has since then won many oratorical victories. I do not know of a greater one than that deserved by that acute and penetrating improvisation. He was still much heated as we were walking back to the Rue d’Ulm, and I remember making him laugh by asking him why, in the state of mind he was in, he had not concluded by hurling his wooden crystals at his adversaries’ heads.”

On December 8, 1862, Pasteur was elected a member of the AcadÉmie des Sciences; out of sixty voters he received thirty-six suffrages.

The next morning, when the gates of the Montparnasse cemetery were opened, a woman walked towards Biot’s grave with her hands full of flowers. It was Mme. Pasteur who was bringing them to him who lay there since February 5, 1862, and who had loved Pasteur with so deep an affection.

A letter picked up at a sale of autographs, one of the last Biot wrote, gives a finishing touch to his moral portrait. It is addressed to an unknown person discouraged with this life. “Sir,—The confidence you honour me with touches me. But I am not a physician of souls. However, in my opinion, you could not do better than seek remedies to your moral suffering in work, religion, and charity. A useful work taken up with energy and persevered in will revive by occupation the forces of your mind. Religious feelings will console you by inspiring you with patience. Charity manifested to others will soften your sorrows and teach you that you are not alone to suffer in this life. Look around you, and you will see afflicted ones more to be pitied than yourself. Try to ease their sufferings; the good you will do to them will fall back upon yourself and will show you that a life which can thus be employed is not a burden which cannot, which must not be borne.”

On his entering the AcadÉmie des Sciences, Balard and Dumas advised Pasteur to let alone his wooden crystals and to continue his studies on ferments. He undertook to demonstrate that “the hypothesis of a phenomenon of mere contact is not more admissible than the opinion which placed the ferment character exclusively in dead albuminoid matter.” Whilst continuing his researches on beings which could live without air, he tried, as he went along, À propos of spontaneous generation, to find some weak point in his work. Until now the liquids he had used, however alterable they were, had been brought up to boiling point. Was there not some new and decisive experiment to make? Could he not study organic matter as constituted by life and expose to the contact of air deprived of its germs some fresh liquids, highly putrescible, such as blood and urine? Claude Bernard, joining in these experiments of Pasteur’s, himself took some blood from a dog. This blood was sealed up in a glass phial, with every condition of purity, and the phial remained in a stove constantly heated up to 30°C. from March 3 until April 20, 1862, when Pasteur laid it on the AcadÉmie table. The blood had suffered no sort of putrefaction; neither had some urine treated in the same way. “The conclusions to which I have been led by my first series of experiments,” said Pasteur before the AcadÉmie, “are therefore applicable in all cases to organic substances.”

While studying putrefaction, which is itself but a fermentation applied to animal materia, while showing the marvellous power of the infinitesimally small, he foresaw the immensity of the domain he had conquered, as will be proved by the following incident. Some time after the AcadÉmie election, in March, 1863, the Emperor, who took an interest in all that took place in the small laboratory of the Rue d’Ulm, desired to speak with Pasteur. J. B. Dumas claimed the privilege of presenting his former pupil, and the interview took place at the Tuileries. Napoleon questioned Pasteur with a gentle, slightly dreamy insistence. Pasteur wrote the next day: “I assured the Emperor that all my ambition was to arrive at the knowledge of the causes of putrid and contagious diseases.”

In the meanwhile, the chapter on ferments was not yet closed; Pasteur was attracted by studies on wine. At the beginning of the 1863 holidays, just before starting for Arbois, he drew up this programme with one of his pupils: “From the 20th to the 30th (August) preparation in Paris of all the vessels, apparatus, products, that we must take. September 1, departure for the Jura; installation; purchase of the products of a vineyard. Immediate beginning of tests of all kinds. We shall have to hurry; grapes do not keep long.”

Whilst he was preparing this vintage tour, which he intended to make with three “Normaliens,” Duclaux, Gernez and Lechartier, the three heterogenists, Pouchet, Joly and Musset, proposed to use that same time in fighting Pasteur on his own ground. They started from BagnÈres-de-Luchon followed by several guides and taking with them all kinds of provisions and some little glass flasks with a slender pointed neck. They crossed the pass of Venasque without incident, and decided to go further, to the Rencluse. Some isard-stalkers having come towards the strange-looking party, they were signalled away; even the guides were invited to stand aside. It was necessary to prevent any dusts from reaching the bulbs, which were thus opened at 8 p.m. at a height of 2,083 metres. But eighty-three metres higher than the Montanvert did not seem to them enough, they wished to go higher. “We shall sleep on the mountain,” said the three scientists. Fatigue and bitter cold, they withstood everything with the courage inspired by a problem to solve. The next morning they climbed across that rocky chaos, and at last reached the foot of one of the greatest glaciers of the Maladetta, 3,000 metres above the sea-level. “A very deep narrow crevasse,” says Pouchet, “seemed to us the most suitable place for our experiments.” Four phials (filled with a decoction of hay) were opened and sealed again with precautions that Pouchet considered as exaggerated.

Pouchet, in his merely scientific report, does not relate the return journey, yet more perilous than the ascent. At one of the most dangerous places, Joly slipped, and would have rolled into a precipice, but for the strength and presence of mind of one of the guides. All three at last came back to Luchon, forgetful of dangers run, and glorying at having reached 1,000 metres higher than Pasteur. They triumphed when they saw alteration in their flasks! “Therefore,” said Pouchet, “the air of the Maladetta, and of high mountains in general, is not incapable of producing alteration in an eminently putrescible liquor; therefore heterogenia or the production of a new being devoid of parents, but formed at the expense of ambient organic matter, is for us a reality.”

The Academy of Sciences was taking more and more interest in this debate. In November, 1863, Joly and Musset expressed a wish that the Academy should appoint a Commission, before whom the principal experiments of Pasteur and of his adversaries should be repeated. On this occasion Flourens expressed his opinion thus: “I am blamed in certain quarters for giving no opinion on the question of spontaneous generation. As long as my opinion was not formed, I had nothing to say. It is now formed, and I give it: M. Pasteur’s experiments are decisive. If spontaneous generation is real, what is required to obtain animalculÆ? Air and putrescible liquor. M. Pasteur puts air and putrescible liquor together and nothing happens. Therefore spontaneous generation is not. To doubt further is to misunderstand the question.”

Already in the preceding year, the AcadÉmie itself had evidenced its opinion by giving Pasteur the prize of a competition proposed in these terms: “To attempt to throw some new light upon the question of so-called spontaneous generation by well-conducted experiments.” Pasteur’s treatise on Organized Corpuscles existing in Atmosphere had been unanimously preferred. Pasteur might have entrenched himself behind the suffrages of the Academy, but begged it, in order to close those incessant debates, to appoint the Commission demanded by Joly and Musset.

The members of the Commission were Flourens, Dumas, Brongniart, Milne-Edwards, and Balard. Pasteur wished that the discussion should take place as soon as possible, and it was fixed for the first fortnight in March. But Pouchet, Joly and Musset asked for a delay on account of the cold. “We consider that it might compromise, perhaps prevent, our results, to operate in a temperature which often goes below zero even in the south of France. How do we know that it will not freeze in Paris between the first and fifteenth of March?” They even asked the Commission to adjourn experiments until the summer. “I am much surprised,” wrote Pasteur, “at the delay sought by Messrs. Pouchet, Joly and Musset; it would have been easy with a stove to raise the temperature to the degree required by those gentlemen. For my part I hasten to assure the Academy that I am at its disposal, and that in summer, or in any other season, I am ready to repeat my experiments.”

Some evening scientific lectures had just been inaugurated at the Sorbonne; such a subject as spontaneous generation was naturally on the programme. When Pasteur entered the large lecture room of the Sorbonne on April 7, 1864, he must have been reminded of the days of his youth, when crowds came, as to a theatrical performance, to hear J. B. Dumas speak. Dumas’ pupil, now a master, in his turn found a still greater crowd invading every corner. Amongst the professors and students, such celebrities as Duruy, Alexandre Dumas senior, George Sand, Princess Mathilde, were being pointed out. Around them, the inevitable “smart” people who must see everything and be seen everywhere, without whom no function favoured by fashion would be complete; in short what is known as the “Tout Paris.” But this “Tout Paris” was about to receive a novel impression, probably a lasting one. The man who stood before this fashionable audience was not one of those speakers who attempt by an insinuating exordium to gain the good graces of their hearers; it was a grave-looking man, his face full of quiet energy and reflective force. He began in a deep, firm voice, evidently earnestly convinced of the greatness of his mission as a teacher: “Great problems are now being handled, keeping every thinking man in suspense; the unity or multiplicity of human races; the creation of man 1,000 years or 1,000 centuries ago, the fixity of species, or the slow and progressive transformation of one species into another; the eternity of matter; the idea of a God unnecessary. Such are some of the questions that humanity discusses nowadays.”

He had now, he continued, entered upon a subject accessible to experimentation, and which he had made the object of the strictest and most conscientious studies. Can matter organize itself? Can living beings come into the world without having been preceded by beings similar to them? After showing that the doctrine of spontaneous generation had gradually lost ground, he explained how the invention of the microscope had caused it to reappear at the end of the seventeenth century, “in the face of those beings, so numerous, so varied, so strange in their shapes, the origin of which was connected with the presence of all dead vegetable and animal matter in a state of disorganization.” He went on to say how Pouchet had taken up this study, and to point out the errors that this new partisan of an old doctrine had committed, errors difficult to recognize at first. With perfect clearness and simplicity, Pasteur explained how the dusts which are suspended in air contain germs of inferior organized beings and how a liquid preserved, by certain precautions, from the contact of these germs can be kept indefinitely, giving his audience a glimpse of his laboratory methods.

“Here,” he said, “is an infusion of organic matter, as limpid as distilled water, and extremely alterable. It has been prepared to-day. To-morrow it will contain animalculÆ, little infusories, or flakes of mouldiness.

“I place a portion of that infusion into a flask with a long neck, like this one. Suppose I boil the liquid and leave it to cool. After a few days, mouldiness or animalculÆ will develop in the liquid. By boiling, I destroyed any germs contained in the liquid or against the glass; but that infusion being again in contact with air, it becomes altered, as all infusions do. Now suppose I repeat this experiment, but that, before boiling the liquid, I draw (by means of an enameller’s lamp) the neck of the flask into a point, leaving, however, its extremity open. This being done, I boil the liquid in the flask, and leave it to cool. Now the liquid of this second flask will remain pure not only two days, a month, a year, but three or four years—for the experiment I am telling you about is already four years old, and the liquid remains as limpid as distilled water. What difference is there, then, between those two vases? They contain the same liquid, they both contain air, both are open! Why does one decay and the other remain pure? The only difference between them is this: in the first case, the dusts suspended in air and their germs can fall into the neck of the flask and arrive into contact with the liquid, where they find appropriate food and develop; thence microscopic beings. In the second flask, on the contrary, it is impossible, or at least extremely difficult, unless air is violently shaken, that dusts suspended in air should enter the vase; they fall on its curved neck. When air goes in and out of the vase through diffusions or variations of temperature, the latter never being sudden, the air comes in slowly enough to drop the dusts and germs that it carries at the opening of the neck or in the first curves.

“This experiment is full of instruction; for this must be noted, that everything in air save its dusts can easily enter the vase and come into contact with the liquid. Imagine what you choose in the air—electricity, magnetism, ozone, unknown forces even, all can reach the infusion. Only one thing cannot enter easily, and that is dust, suspended in air. And the proof of this is that if I shake the vase violently two or three times, in a few days it contains animalculÆ or mouldiness. Why? because air has come in violently enough to carry dust with it.

“And, therefore, gentlemen, I could point to that liquid and say to you, I have taken my drop of water from the immensity of creation, and I have taken it full of the elements appropriated to the development of inferior beings. And I wait, I watch, I question it, begging it to recommence for me the beautiful spectacle of the first creation. But it is dumb, dumb since these experiments were begun several years ago; it is dumb because I have kept it from the only thing man cannot produce, from the germs which float in the air, from Life, for Life is a germ and a germ is Life. Never will the doctrine of spontaneous generation recover from the mortal blow of this simple experiment.”

The public enthusiastically applauded these words, which ended the lecture:

“No, there is now no circumstance known in which it can be affirmed that microscopic beings came into the world without germs, without parents similar to themselves. Those who affirm it have been duped by illusions, by ill-conducted experiments, spoilt by errors that they either did not perceive or did not know how to avoid.”

In the meanwhile, besides public lectures and new studies, Pasteur succeeded in “administering” the Ecole Normale in the most complete sense of the word. His influence was such that students acquired not a taste but a passion for study; he directed each one in his own line, he awakened their instincts. It was already through his wise inspiration that five “Normaliens agrÉgÉs” should have the chance of the five curators’ places; but his solicitude did not stop there. If some disappointment befell some former pupil, still in that period of youth which doubts nothing or nobody, he came vigorously to his assistance; he was the counsellor of the future. A few letters will show how he understood his responsibility.

A Normalien, Paul Dalimier, received 1st at the agrÉgation of Physics in 1858, afterwards Natural History curator at the Ecole, and who, having taken his doctor’s degree, asked to be sent to a Faculty, was ordered to go to the LycÉe of Chaumont.

In the face of this almost disgrace he wrote a despairing letter to Pasteur. He could do nothing more, he said, his career was ruined. “My dear sir,” answered Pasteur, “I much regret that I could not see you before your departure for Chaumont. But here is the advice which I feel will be useful to you. Do not manifest your just displeasure; but attract attention from the very first by your zeal and talent. In a word, aggravate, by your fine discharge of your new duties, the injustice which has been committed. The discouragement expressed in your last letter is not worthy of a man of science. Keep but three objects before your eyes: your class, your pupils and the work you have begun.... Do your duty to the best of your ability, without troubling about the rest.”

Pasteur undertook the rest himself. He went to the Ministry to complain of the injustice and unfairness, from a general point of view, of that nomination.

“Sir,” answered the Chaumont exile, “I have received your kind letter. My deep respect for every word of yours will guarantee my intention to follow your advice. I have given myself up entirely to my class. I have found here a Physics cabinet in a deplorable state, and I have undertaken to reorganise it.”

He had not time to finish: justice was done, and Paul Dalimier was made maÎtre des confÉrences at the Ecole Normale. He died at twenty-eight.

The wish that masters and pupils should remain in touch with each other after the three years at the Ecole Normale had already in 1859 inspired Pasteur to write a report on the desirableness of an annual report entitled, Scientific Annals of the Ecole Normale.

The initiative of pregnant ideas often is traced back to France. But, through want of tenacity, she allows those same ideas to fall into decay and they are taken up by other nations, transplanted, developed, until they come back unrecognized to their mother country. Germany had seen the possibilities of such a publication as Pasteur’s projected Annals. Renan wrote about that time to the editors of the Revue Germanique, a Review intended to draw France and Germany together: “In France, nothing is made public until achieved and ripened. In Germany, a work is given out provisionally, not as a teaching, but as an incitement to think, as a ferment for the mind.”

Pasteur felt all the power of that intellectual ferment. In the volume entitled Centenary of the Ecole Normale, M. Gernez has recalled Pasteur’s enthusiasm when he spoke of those Annals. Was it not for former pupils, away in the provinces, a means of collaborating with their old masters and of keeping in touch with Paris?

It was in June, 1864, that Pasteur presented the first number of this publication to the AcadÉmie des Sciences. M. Gernez, who was highly thought of by Pasteur, has not related in the Centenary that the book opened with some of his own researches on the rotatory power of certain liquids and their steam.

At that same time, the heterogenists had at last placed themselves at the disposal of the AcadÉmie and were invited to meet Pasteur before the Natural History Commission at M. Chevreul’s laboratory. “I affirm,” said Pasteur, “that in any place it is possible to take up from the ambient atmosphere a determined volume of air containing neither egg nor spore and producing no generation in putrescible solutions.” The Commission declared that, the whole contest bearing upon one simple fact, one experiment only should take place. The heterogenists wanted to recommence a whole series of experiments, thus reopening the discussion. The Commission refused, and the heterogenists, unwilling to concede the point, retired from the field, repudiating the arbiters that they had themselves chosen.

And yet Joly had written to the AcadÉmie, “If one only of our flasks remains pure, we will loyally own our defeat.” A scientist who later became Permanent Secretary of the AcadÉmie des Sciences, Jamin, wrote about this conflict: “The heterogenists, however they may have coloured their retreat, have condemned themselves. If they had been sure of the fact—which they had solemnly engaged to prove or to own themselves vanquished,—they would have insisted on showing it, it would have been the triumph of their doctrine.”

The heterogenists appealed to the public. A few days after their defeat, Joly gave a lecture at the Faculty of Medicine. He called the trial, as decided on by the Commission, a “circus competition”; he was applauded by those who saw other than scientific questions in the matter. The problem was now coming down from mountains and laboratories into the arena of society discussions. If all comes from a germ, people said, whence came the first germ? We must bow before that mystery, said Pasteur; it is the question of the origin of all things, and absolutely outside the domain of scientific research. But an invincible curiosity exists amongst most men which cannot admit that science should have the wisdom to content itself with the vast space between the beginning of the world and the unknown future. Many people transform a question of fact into a question of faith. Though Pasteur had brought into his researches a solely scientific preoccupation, many people approved or blamed him as the defender of a religious cause.

Vainly had he said, “There is here no question of religion, philosophy, atheism, materialism, or spiritualism. I might even add that they do not matter to me as a scientist. It is a question of fact; when I took it up I was as ready to be convinced by experiments that spontaneous generation exists as I am now persuaded that those who believe it are blindfolded.”

It might have been thought that Pasteur’s arguments were in support of a philosophical theory! It seemed impossible to those whose ideas came from an ardent faith, from the influence of their surroundings, from personal pride or from interested calculations to understand that a man should seek truth for its own sake and with no other object than to proclaim it. Hostilities were opened, journalists kept up the fire. A priest, the AbbÉ Moigno spoke of converting unbelievers through the proved non-existence of spontaneous generation. The celebrated novelist, Edmond About, took up Pouchet’s cause with sparkling irony. “M. Pasteur preached at the Sorbonne amidst a concert of applause which must have gladdened the angels.”

Thus, among the papers and reviews of that time we can follow the divers ideas brought out by these discussions. Guizot, then almost eighty, touched on this problem with the slightly haughty assurance of one conscious of having given much thought to his beliefs and destiny. “Man has not been formed through spontaneous generation, that is by a creative and organizing force inherent in matter; scientific observation daily overturns that theory, by which, moreover, it is impossible to explain the first appearance upon the earth of man in his complete state.” And he praised “M. Pasteur, who has brought into this question the light of his scrupulous criticism.”

Nisard was a wondering witness of what took place in the small laboratory of the Ecole Normale. Ever preoccupied by the relations between science and religion, he heard with some surprise Pasteur saying modestly, “Researches on primary causes are not in the domain of Science, which only recognizes facts and phenomena which it can demonstrate.”

Pasteur did not disinterest himself from the great problems which he called the eternal subjects of men’s solitary meditations. But he did not admit the interference of religion with science any more than that of science with religion.

His eagerness during a conflict was only equalled by his absolute forgetfulness after the conflict was over. He answered some one who, years later, reminded him of that past so full of attacks and praises. “A man of science should think of what will be said of him in the following century, not of the insults or the compliments of one day.”

Pasteur, anxious to regain lost time, hurried to return to his studies on wine. “Might not the diseases of wines,” he said at the AcadÉmie des Sciences in January, 1864, “be caused by organized ferments, microscopic vegetations, of which the germs would develop when certain circumstances of temperature, of atmospheric variations, of exposure to air, would favour their evolution or their introduction into wines?... I have indeed reached this result that the alterations of wines are co-existent with the presence and multiplication of microscopic vegetations.” Acid wines, bitter wines, “ropy” wines, sour wines, he had studied them all with a microscope, his surest guide in recognizing the existence and form of the evil.

As he had more particularly endeavoured to remedy the cause of the acidity which often ruins the Jura red or white wines in the wood, the town of Arbois, proud of its celebrated rosy and tawny wines, placed an impromptu laboratory at his disposal during the holidays of 1864; the expenses were all to be covered by the town. “This spontaneous offer from a town dear to me for so many reasons,” answered Pasteur to the Mayor and Town Council, “does too much honour to my modest labours, and the way in which it is made covers me with confusion.” He refused it however, fearing that the services he might render should not be proportionate to the generosity of the Council. He preferred to camp out with his curators in an old coffee room at the entrance of the town, and they contented themselves with apparatus of the most primitive description, generally made by some local tinker or shoeing smith.

The problem consisted, in Pasteur’s view, in opposing the development of organized ferments or parasitic vegetations, causes of the diseases of wines. After some fruitless endeavours to destroy all vitality in the germs of these parasites, he found that it was sufficient to keep the wine for a few moments at a temperature of 50° C. to 60° C. “I have also ascertained that wine was never altered by that preliminary operation, and as nothing prevents it afterwards from undergoing the gradual action of the oxygen in the air—the only cause, as I think, of its improvement with age—it is evident that this process offers every advantage.”

It seems as if that simple and practical means, applicable to every quality of wine, now only had to be tried. But not so. Every progress is opposed by prejudice, petty jealousies, indolence even. A devoted obstinacy is required in order to overcome this opposition. Pasteur’s desire was that his country should benefit by his discovery. An Englishman had written to him: “People are astonished in France that the sale of French wines should not have become more extended here since the Commercial Treaties. The reason is simple enough. At first we eagerly welcomed those wines, but we soon had the sad experience that there was too much loss occasioned by the diseases to which they are subject.”

Pasteur was in the midst of those discussions, experimental sittings, etc., when J. B. Dumas suddenly asked of him the greatest of sacrifices, that of leaving the laboratory.