Chapter VI (1)

1865--1870

An epidemic was ruining in terrible proportions the industry of the cultivation of silkworms. J. B. Dumas had been desired, as Senator, to draw up a report on the wishes of over 3,500 proprietors in sericicultural departments, all begging the public authorities to study the question of the causes of the protracted epidemic. Dumas was all the more preoccupied as to the fate of sericiculture that he himself came from one of the stricken departments. He was born on July 14, 1800, in one of the back streets of the town of Alais, to which he enjoyed returning as a celebrated scientist and a dignitary of the Empire. He gave much attention to all the problems which interested the national prosperity and considered that the best judges in these matters were the men of science. He well knew the conscientious tenacity--besides other characteristics--which his pupil and friend brought into any undertaking, and anxiously urged him to undertake this study. “Your proposition,” wrote Pasteur in a few hurried lines, “throws me into a great perplexity; it is indeed most flattering and the object is a high one, but it troubles and embarrasses me! Remember, if you please, that I have never even touched a silkworm. If I had some of your knowledge on the subject I should not hesitate; it may even come within the range of my present studies. However, the recollection of your many kindnesses to me would leave me bitter regrets if I were to decline your pressing invitation. Do as you like with me.” On May 17, 1865, Dumas wrote: “I attach the greatest value to seeing your attention fixed on the question which interests my poor country; the distress is beyond anything you can imagine.”

Before his departure for Alais, Pasteur had read an essay on the history of the silkworm, published by one of his colleagues, Quatrefages, born like Dumas in the Gard. Quatrefages attributed to an Empress of China the first knowledge of the art of utilizing silk, more than 4,000 years ago. The Chinese, in possession of the precious insect, had jealously preserved the monopoly of its culture, even to the point of making it a capital offence to take beyond the frontiers of the Empire the eggs of the silkworm. A young princess, 2,000 years later, had the courage to infringe this law for love of her betrothed, whom she was going to join in the centre of Asia, and also through the almost equally strong desire to continue her fairy-like occupation after her marriage.

Pasteur appreciated the pretty legend, but was more interested in the history of the acclimatizing of the mulberry tree. From Provence Louis XI took it to Touraine: Catherine de Medici planted it in Orléanais. Henry IV had some mulberry trees planted in the park at Fontainebleau and in the Tuileries where they succeeded admirably. He also encouraged a _Treatise on the Gathering of Silk_ by Olivier de Serres. This earliest agricultural writer in France was much appreciated by the king, in spite of the opposition of Sully, who did not believe in this new fortune for France. Documentary evidence is lacking as to the development of the silk industry.

From 1700 to 1788, wrote Quatrefages, France produced annually about 6,000,000 kilogrammes of cocoons. This was decreased by one-half under the Republic; wool replaced silk perhaps from necessity, perhaps from affectation.

Napoleon I restored that luxury. The sericicultural industry prospered from the Imperial Epoch until the reign of Louis Philippe, to such an extent as to reach in one year a total of 20,000,000 kilogrammes of cocoons, representing 100,000,000 francs. The name of Tree of Gold given to the mulberry, had never been better deserved.

Suddenly all these riches fell away. A mysterious disease was destroying the nurseries. “Eggs, worms, chrysalides, moths, the disease may manifest itself in all the organs,” wrote Dumas in his report to the Senate. “Whence does it come? how is it contracted? No one knows. But its invasion is recognized by little brown or black spots.” It was therefore called “corpuscle disease”; it was also designated as “_gattine_” from the Italian _gattino_, kitten; the sick worms held up their heads and put out their hooked feet like cats about to scratch. But of all those names, that of “pébrine” adopted by Quatrefages was the most general. It came from the patois word _pébré_ (pepper). The spots on the diseased worms were, in fact, rather like pepper grains.

The first symptoms had been noticed by some in 1845, by others in 1847. But in 1849 it was a disaster. The South of France was invaded. In 1853, seed had to be procured from Lombardy. After one successful year the same disappointments recurred. Italy was attacked, also Spain and Austria. Seed was procured from Greece, Turkey, the Caucasus, but the evil was still on the increase; China itself was attacked, and, in 1864, it was only in Japan that healthy seed could be found.

Every hypothesis was suggested, atmospheric conditions, degeneration of the race of silkworms, disease of the mulberry tree, etc.--books and treatises abounded, but in vain.

When Pasteur started for Alais (June 16, 1865), entrusted with this scientific mission by the Minister of Agriculture, his mind saw but that one point of interrogation, “What caused these fatal spots?” On his arrival he sympathetically questioned the Alaisians. He received confused and contradictory answers, indications of chimerical remedies; some cultivators poured sulphur or charcoal powder on the worms, some mustard meal or castor sugar; ashes and soot were used, quinine powders, etc. Some cultivators preferred liquids, and syringed the mulberry leaves with wine, rum or absinthe. Fumigations of chlorine, of coal tar, were approved by some and violently objected to by others. Pasteur, more desirous of seeking the origin of the evil than of making a census of these remedies, unceasingly questioned the nursery owners, who invariably answered that it was something like the plague or cholera. Some worms languished on the frames in their earliest days, others in the second stage only, some passed through the third and fourth moultings, climbed the twig and spun their cocoon. The chrysalis became a moth, but that diseased moth had deformed antennæ and withered legs, the wings seemed singed. Eggs (technically called seed) from those moths were inevitably unsuccessful the following year. Thus, in the same nursery, in the course of the two months that a larva takes to become a moth, the pébrine disease was alternately sudden or insidious: it burst out or disappeared, it hid itself within the chrysalis and reappeared in the moth or the eggs of a moth which had seemed sound. The discouraged Alaisians thought that nothing could overcome pébrine.

Pasteur did not admit such resignation. But he began by one aspect only of the problem. He resolved to submit those corpuscles of the silkworm which had been observed since 1849 to microscopical study. He settled down in a small _magnanerie_ near Alais; two series of worms were being cultivated. The first set was full grown; it came from some Japanese seed guaranteed as sound, and had produced very fine cocoons. The cultivator intended to keep the seed of the moths to compensate himself for the failure of the second set, also of Japanese origin, but not officially guaranteed. The worms of this second series were sickly and did not feed properly. And yet these worms, seen through the microscope, only exceptionally presented corpuscles; whilst Pasteur was surprised to find some in almost every moth or chrysalis from the prosperous nursery. Was it then elsewhere than in the worms that the secret of the pébrine was to be found?

Pasteur was interrupted in the midst of his experiments by a sudden blow. Nine days after his arrival, a telegram called him to Arbois: his father was very ill. He started, full of anguish, remembering the sudden death of his mother before he had had time to reach her, and that of Jeanne, his eldest daughter, who had also died far away from him in the little house at Arbois. His sad presentiment oppressed him during the whole of the long journey, and was fully justified; he arrived to find, already in his coffin, the father he so dearly loved and whose name he had made an illustrious one.

In the evening, in the empty room above the tannery, Pasteur wrote: “Dear Marie, dear children, the dear grandfather is no more; we have taken him this morning to his last resting place, close to little Jeanne’s. In the midst of my grief I have felt thankful that our little girl had been buried there.... Until the last moment I hoped I should see him again, embrace him for the last time ... but when I arrived at the station I saw some of our cousins all in black, coming from Salins; it was only then that I understood that I could but accompany him to the grave.

“He died on the day of your first communion, dear Cécile; those two memories will remain in your heart, my poor child. I had a presentiment of it when that very morning, at the hour when he was struck down, I was asking you to pray for the grandfather at Arbois. Your prayers will have been acceptable unto God, and perhaps the dear grandfather himself knew of them and rejoiced with dear little Jeanne over Cécile’s piety.

“I have been thinking all day of the marks of affection I have had from my father. For thirty years I have been his constant care, I owe everything to him. When I was young he kept me from bad company and instilled into me the habit of working and the example of the most loyal and best-filled life. He was far above his position both in mind and in character.... You did not know him, dearest Marie, at the time when he and my mother were working so hard for the children they loved, for me especially, whose books and schooling cost so much.... And the touching part of his affection for me is that it never was mixed with ambition. You remember that he would have been pleased to see me the headmaster of Arbois College? He foresaw that advancement would mean hard work, perhaps detrimental to my health. And yet I am sure that some of the success in my scientific career must have filled him with joy and pride; his son! his name! the child he had guided and cherished! My dear father, how thankful I am that I could give him some satisfaction!

“Farewell, dearest Marie, dear children. We shall often talk of the dear grandfather. How glad I am that he saw you all again a short time ago, and that he lived to know little Camille. I long to see you all, but must go back to Alais, for my studies would be retarded by a year if I could not spend a few days there now.

“I have some ideas on this disease, which is indeed a scourge for all those southern departments. The one _arrondissement_ of Alais has lost an income of 120,000,000 francs during the last fifteen years. M. Dumas is a million times right; it must be seen to, and I am going to continue my experiments. I am writing to M. Nisard to have the admission examinations in my absence, which can easily be done.”

Nisard wrote to him (June 19): “My dear friend, I heard of your loss, and I sympathize most cordially with you.... Take all the time necessary to you. You are away in the service of science, probably of humanity. Everything will be done according to your precise indications. I foresee no difficulty ... everything is going on well at the Ecole. In spite of your reserve--which is a part of your talent--I see that you are on the track, as M. Biot would have said, and that you will have your prey. Your name will stand next to that of Olivier de Serres in the annals of sericiculture.”

On his return to Alais Pasteur went back to his observations with his scientific ardour and his customary generous eagerness to lighten the burden of others. He wrote in the introduction to his _Studies on Silkworm Disease_ the following heartfelt lines--

“A traveller coming back to the Cévennes mountains after an absence of fifteen years would be saddened to see the change wrought in that countryside within such a short time. Formerly he might have seen robust men breaking up the rock to build terraces against the side and up to the summit of each mountain; then planting mulberry trees on these terraces. These men, in spite of their hard work, were then bright and happy, for ease and contentment reigned in their homes.

“Now the mulberry plantations are abandoned, the ‘golden tree’ no longer enriches the country, faces once beaming with health and good humour are now sad and drawn. Distress and hunger have succeeded to comfort and happiness.”

Pasteur thought with sorrow of the sufferings of the Cévenol populations. The scientific problem was narrowing itself down. Faced by the contradictory facts that one successful set of cocoons had produced corpuscled moths, while an apparently unsuccessful set of worms showed neither corpuscles nor spots, he had awaited the last period of these worms with an impatient curiosity. He saw, amongst those which had started spinning, some which as yet showed no spots and no corpuscles. But corpuscles were abundant in the chrysalides, those especially which were in full maturity, on the eve of becoming moths; and none of the moths were free from them. Perhaps the fact that the disease appeared in the chrysalis and moth only explained the failures of succeeding series. “It was a mistake,” wrote Pasteur (June 26, 1865), “to look for the symptom, the corpuscle, exclusively in the eggs or the worms; either might carry in themselves the germ of the disease, without presenting distinct and microscopically visible corpuscles.” The evil developed itself chiefly in the chrysalides and the moths, it was there that it should chiefly be sought. There should be an infallible means of procuring healthy seed by having recourse to moths free from corpuscles.

This idea was like a searchlight flashed into the darkness. Pasteur thus formulated his hypothesis: “Every moth containing corpuscles must give birth to diseased seed. If a moth only has a few corpuscles, its eggs will provide worms without any, or which will only develop them towards the end of their life. If the moth is much infected, the disease will show itself in the earliest stages of the worm, either by corpuscles or by other unhealthy symptoms.”

Pasteur studied hundreds of moths under the microscope. Nearly all, two or three couples excepted, were corpuscled, but that restricted quantity was increased by a precious gift. Two people, who had heard Pasteur ventilate his theories, brought him five moths born of a local race of silkworms and nurtured in the small neighbouring town of Anduze in the Turkish fashion, i.e. without any of the usual precautions consisting in keeping the worms in nurseries heated at an equal temperature. Everything having been tried, this system had also had its turn, without any appreciable success. By a fortunate circumstance, four out of those five moths were healthy.

Pasteur looked forward to the study in comparisons that the following spring would bring when worms were hatched both from the healthy and the diseased seed. In the meanwhile, only a few of the Alaisians, including M. Pagès, the Mayor, and M. de Lachadenède, really felt any confidence in these results. Most of the other silkworm cultivators were disposed to criticize everything, without having the patience to wait for results. They expressed much regret that the Government should choose a “mere chemist” for those investigations instead of some zoologist or silkworm cultivator. Pasteur only said, “Have patience.”

He returned to Paris, where fresh sorrow awaited him: Camille, his youngest child, only two years old, was seriously ill. He watched over her night after night, spending his days at his task in the laboratory, and returning in the evening to the bedside of his dying child. During that same period he was asked for an article on Lavoisier by J. B. Dumas, who had been requested by the Government to publish his works.

“No one,” wrote Dumas to Pasteur--“has read Lavoisier with more attention than you have; no one can judge of him better.... The chance which caused me to be born before you has placed me in communication with surroundings and with men in whom I have found the ideas and feelings which have guided me in this work. But, had it been yours, I should have allowed no one else to be the first in drawing the world’s attention to it. It is from this motive, also from a certain conformity of tastes and of principles which has long made you dear to me, that I now ask you to give up a few hours to Lavoisier.”

“My dear and illustrious master,” answered Pasteur (July 18, 1865), “in the face of your letter and its expressions of affectionate confidence, I cannot refuse to submit to you a paper which you must promise to throw away if it should not be exactly what you want. I must also ask you to grant me much time, partly on account of my inexperience, and partly on account of the fatigue both mental and bodily imposed on me by the illness of our dear child.”

Dumas replied: “Dear friend and colleague, I thank you for your kind acquiescence in Lavoisier’s interests, which might well be your own, for no one at this time represents better than you do his spirit and method,--a method in which reasoning had more share than anything else.

“The art of observation and that of experimentation are very distinct. In the first case, the fact may either proceed from logical reasons or be mere good fortune; it is sufficient to have some penetration and the sense of truth in order to profit by it. But the art of experimentation leads from the first to the last link of the chain, without hesitation and without a blank, making successive use of Reason, which suggests an alternative, and of Experience, which decides on it, until, starting from a faint glimmer, the full blaze of light is reached. Lavoisier made this art into a method, and you possess it to a degree which always gives me a pleasure for which I am grateful to you.

“Take your time. Lavoisier has waited seventy years! It is a century since his first results were produced! What are weeks and months?

“I feel for you with all my heart! I know how heartrending are those moments by the deathbed of a suffering child. I hope and trust this great sorrow will be spared you, as indeed you deserve that it should be.”

The promise made by Dumas to give to France an edition of Lavoisier’s works dated very far back. It was in May, 1836, in one of his eloquent lectures at the Collège de France, that Dumas had declared his intention of raising a scientific monument to the memory of this, perhaps the greatest of all French scientists. He had hoped that a Bill would be passed by the Government of Louis Philippe decreeing that this edition of Lavoisier’s works would be produced at the expense of the State. But the usual obstacles and formalities came in the way. Governments succeeded each other, and it was only in 1861 that Dumas obtained the decree he wished for and that the book appeared.

Certainly Pasteur knew and admired as much as any one the discoveries of Lavoisier. But, in the presence of the series of labours accomplished, in spite of many other burdens, during that life cut off in its prime by the Revolutionary Tribunal (1792), labours collated for the first time by Dumas, Pasteur was filled with a new and vivid emotion. His logic in reasoning and his patience in observing nature had in no wise diminished the impetuous generosity of his feelings; a beautiful book, a great discovery, a brilliant exploit or a humble act of kindness would move him to tears. Concerning such a man as Lavoisier, Pasteur’s curiosity became a sort of worship. He would have had the history of such a life spread everywhere. “Though one discovery always surpasses another, and though the chemical and physical knowledge accumulated since his time has gone beyond all Lavoisier’s dreams,” wrote Pasteur, “his work, like that of Newton and a few other rare spirits, will remain ever young. Certain details will age, as do the fashions of another time, but the foundation, the method, constitute one of those great aspects of the human mind, the majesty of which is only increased by years....”

Pasteur’s article appeared in the _Moniteur_ and was much praised by the celebrated critic Sainte Beuve, whose literary lectures were often attended by Pasteur, between 1857 and 1861. The chronological order that we are following in this history of Pasteur’s life allows us to follow the ideas and feelings with which he lived his life of hard daily work combined with daily devotion to others. Joys and sorrows can be chronicled, thanks to the confidences of those who loved him. His fame is indeed part of the future, but the tenderness which he inspired revives the memories of the past.

In September, 1865, little Camille died. Pasteur took the tiny coffin to Arbois and went back to his work. A letter written in November alludes to the depth of his grief.

It was à propos of a candidature to the Académie des Sciences, Sainte Beuve was asked to help that of a young friend of his, Charles Robin. Robin occupied a professor’s chair specially created for him at the _Faculté de Médecine_; he had made a deep microscopical study of the tissues of living bodies, of cellular life, of all which constitutes histology. He was convinced that outside his own studies, numerous questions would fall more and more into the domain of experimentation, and he believed that the faith in spiritual things could not “stand the struggle against the spirit of the times, wholly turned to positive things.” He did not, like Pasteur, understand the clear distinction between the scientist on the one hand and the man of sentiment on the other, each absolutely independent. Neither did he imitate the reserve of Claude Bernard who did not allow himself to be pressed by any urgent questioner into enrolment with either the believers or the unbelievers, but answered: “When I am in my laboratory, I begin by shutting the door on materialism and on spiritualism; I observe facts alone; I seek but the scientific conditions under which life manifests itself.” Robin was a disciple of Auguste Comte, and proclaimed himself a Positivist, a word which for superficial people was the equivalent of materialist. The same efforts which had succeeded in keeping Littré out of the Académie Française in 1863 were now attempted in order to keep Robin out of the Académie des Sciences in 1865.

Sainte Beuve, whilst studying medicine, had been a Positivist; his quick and impressionable nature had then turned to a mysticism which had inspired him to pen some fine verses. He had now returned to his former philosophy, but kept an open mind, however, criticism being for him not the art of dictating, but of understanding, and he was absolutely averse to irrelevant considerations when a candidature was in question.

The best means with Pasteur, who was no diplomat, was to go straight to the point. Sainte Beuve therefore wrote to him: “Dear Sir, will you allow me to be indiscreet enough to solicit your influence in favour of M. Robin, whose work I know you appreciate?

“M. Robin does not perhaps belong to the same philosophical school as you do; but it seems to me--from an outsider’s point of view--that he belongs to the same scientific school. If he should differ essentially--whether in metaphysics or otherwise--would it not be worthy of a great scientist to take none but positive work into account? Nothing more, nothing less.

“Forgive me; I have much resented the injustice towards you of certain newspapers, and I have sometimes asked myself if there were not some simple means of showing up all that nonsense, and of disproving those absurd and ill-intentioned statements. If M. Robin deserves to be of the Académie why should he not attain to it through you?...

“My sense of gratitude towards you for those four years during which you have done me the honour of including such a man as you are in my audience, also a feeling of friendship, are carrying me too far. I intended to mention this to you the other day at the Princess’s; she had wished me to do so, but I feel bolder with a pen....”

The Princess in question was Princess Mathilde. Her salon, a rendezvous of men of letters, men of science and artists, was a sort of second Academy which consoled Théophile Gautier for not belonging to the other. Sainte Beuve prided himself on being, so to speak, honorary secretary to this accomplished and charming hostess.

Pasteur answered by return of post. “Sir and illustrious colleague, I feel strongly inclined towards M. Robin, who would represent a new scientific element at the Academy--the microscope applied to the study of the human organism. I do not trouble about his philosophical school save for the harm it may do to his work.... I confess frankly, however, that I am not competent on the question of our philosophical schools. Of M. Comte I have only read a few absurd passages; of M. Littré I only know the beautiful pages you were inspired to write by his rare knowledge and some of his domestic virtues. My philosophy is of the heart and not of the mind, and I give myself up, for instance, to those feelings about eternity which come naturally at the bedside of a cherished child drawing its last breath. At those supreme moments, there is something in the depths of our souls which tells us that the world may be more than a mere combination of phenomena proper to a mechanical equilibrium brought out of the chaos of the elements simply through the gradual action of the forces of matter. I admire them all, our philosophers! We have experiments to straighten and modify our ideas, and we constantly find that nature is other than we had imagined. They, who are always guessing, how can they know!...”

Sainte Beuve was probably not astonished at Pasteur’s somewhat hasty epithet applied to Auguste Comte, whom he had himself defined as “an obscure, abstruse, often diseased brain.” After Robin’s election he wrote to his “dear and learned colleague”--

“I have not allowed myself to thank you for the letter, so beautiful, if I may say so, so deep and so exalted in thought, which you did me the honour of writing in answer to mine. Nothing now forbids me to tell you how deeply I am struck with your way of thinking and with your action in this scientific matter.”

That “something in the depths of our souls” of which Pasteur spoke in his letter to Sainte Beuve, was often perceived in his conversation; absorbed as he was in his daily task, he yet carried in himself a constant aspiration towards the Ideal, a deep conviction of the reality of the Infinite and a trustful acquiescence in the Mystery of the universe.

During the last term of the year 1865, he turned from his work for a time in order to study cholera. Coming from Egypt, the scourge had lighted on Marseilles, then on Paris, where it made in October more than two hundred victims per day; it was feared that the days of 1832 would be repeated, when the deaths reached twenty-three per 1,000. Claude Bernard, Pasteur, and Sainte Claire Deville went into the attics of the Lariboisière hospital, above a cholera ward.

“We had opened,” said Pasteur, “one of the ventilators communicating with the ward; we had adapted to the opening a glass tube surrounded by a refrigerating mixture, and we drew the air of the ward into our tube, so as to condense into it as many as we could of the products of the air in the ward.”

Claude Bernard and Pasteur afterwards tried blood taken from patients, and many other things; they were associated in those experiments, which gave no result. Henri Sainte Claire Deville once said to Pasteur, “Studies of that sort require much courage.” “What about duty?” said Pasteur simply, in a tone, said Deville afterwards, worth many sermons. The cholera did not last long; by the end of the autumn all danger had disappeared.

Napeoleon the Third loved science, and found in it a sense of assured stability which politics did not offer him. He desired Pasteur to come and spend a week at the Palace of Compiègne.

The very first evening a grand reception took place. The diplomatic world was represented by M. de Budberg, ambassador of Russia, and the Prussian ambassador, M. de Goltz. Among the guests were: Dr. Longet, celebrated for his researches and for his _Treatise on Physiology_, a most original physician, whose one desire was to avoid patients and so have more time for pure science; Jules Sandeau, the tender and delicate novelist, with his somewhat heavy aspect of a captain in the Garde Nationals; Paul Baudry, the painter, then in the flower of his youth and radiant success; Paul Dubois, the conscientious artist of the _Chanteur Florentin_ exhibited that very year; the architect, Viollet le Duc, an habitué of the palace. The Emperor drew Pasteur aside towards the fireplace, and the scientist soon found himself instructing his Sovereign, talking about ferments and molecular dissymmetry.

Pasteur was congratulated by the courtiers on the favour shown by this immediate confidential talk, and the Empress sent him word that she wished him to talk with her also. Pasteur remembered this conversation, an animated one, a little disconnected, chiefly about animalculæ, infusories and ferments. When the guests returned to the immense corridor into which the rooms opened, each with the name of the guests on the door, Pasteur wrote to Paris for his microscope and for some samples of diseased wines.

The next morning a stag hunt was organized; riders in handsome costumes, open carriages drawn by six horses and containing guests, entered the forest; a stag was soon brought to bay by the hounds. In the evening, after dinner, there was a torchlight procession in the great courtyard. Amid a burst of trumpets, the footmen in state livery, standing in a circle, held aloft the flaming torches. In the centre, a huntsman held part of the carcase of the stag and waved it to and fro before the greedy eyes of the hounds, who, eager to hurl themselves upon it, and now restrained by a word, then let loose, and again called back all trembling at their discomfiture, were at length permitted to rush upon and devour their prey.

The next day offered another item on the programme, a visit to the castle of Pierrefonds, marvellously restored by Viollet le Duc at the expense of the Imperial purse. Pasteur, who, like the philosopher, might have said, “I am never bored but when I am being entertained,” made his arrangements so that the day should not be entirely wasted. He made an appointment for his return with the head butler, hoping to find a few diseased wines in the Imperial cellar. That department, however, was so well administered that he was only able to find seven or eight suspicious-looking bottles. The tall flunkeys, who scarcely realized the scientific interest offered by a basketful of wine bottles, watched Pasteur more or less ironically as he returned to his room, where he had the pleasure of finding his microscope and case of instruments sent from the Rue d’Ulm. He remained upstairs, absorbed as he would have been in his laboratory, in the contemplation of a drop of bitter wine revealing the tiny mycoderma which caused the bitterness.

In the meanwhile some of the other guests were gathered in the smoking room, smilingly awaiting the Empress’s five o’clock tea, whilst others were busy with the preparations for the performance of Racine’s _Plaideurs_, which Provost, Regnier, Got, Delaunay, Coquelin, and Mademoiselle Jouassain were going to act that very evening in the theatre of the palace.

On the Sunday, at 4 p.m., he was received privately by their Majesties, for their instruction and edification. He wrote in a letter to a friend: “I went to the Emperor with my microscope, my wine samples, and all my paraphernalia. When I was announced, the Emperor came up to meet me and asked me to come in. M. Conti, who was writing at a table, rose to leave the room, but was invited to stay. Then he fetched the Empress, and I began to show their Majesties various objects under the microscope and to explain them; it lasted a whole hour.”

The Empress had been much interested, and wished that her five o’clock friends--who were waiting in the room where tea was served--should also acquire some notions of these studies. She merrily took up the microscope, laughing at her new occupation of laboratory attendant, and arrived thus laden in the drawing-room, much to the surprise of her privileged guests. Pasteur came in behind her, and gave a short and simple account of a few general ideas and precise discoveries.

In the same way, the preceding week, Le Verrier[25] had spoken of his planet, and Dr. Longet had given a lecture on the circulation of the blood. That butterfly world of the Court, taking a momentary interest in scientific things, did not foresee that the smallest discovery made in the poor laboratory of the Rue d’Ulm would leave a more lasting impression than the fêtes of the Tuileries of Fontainebleau and of Compiègne.

In the course of their private interview, Napoleon and Eugénie manifested some surprise that Pasteur should not endeavour to turn his discoveries and their applications to a source of legitimate profit. “In France,” he replied, “scientists would consider that they lowered themselves by doing so.”

He was convinced that a man of pure science would complicate his life, the order of his thoughts, and risk paralysing his inventive faculties, if he were to make money by his discoveries. For instance, if he had followed up the industrial results of his studies on vinegar, his time would have been too much and too regularly occupied, and he would not have been free for new researches.

“My mind is free,” he said. “I am as full of ardour for the new question of silkworm disease as I was in 1863, when I took up the wine question.”

What he most wished was to be able to watch the growth of the silkworms from the very first day, and to pursue without interruption this serious study in which the future of France was interested. That, and the desire to have one day a laboratory adequate to the magnitude of his works were his only ambitions. On his return to Pam he obtained leave to go back to Alais.

“My dear Raulin,” wrote Pasteur to his former pupil in January, 1866. “I am again entrusted by the Minister of Agriculture with a mission for the study of silkworm disease, which will last at least five months, from February 1 to the end of June. Would you care to join me?”

Raulin excused himself; he was then preparing, with his accustomed slow conscientiousness, his doctor’s thesis, a work afterwards considered by competent judges to be a masterpiece.

“I must console myself,” wrote Pasteur, expressing his regrets, “by thinking that you will complete your excellent thesis.”

One of Raulin’s fellow students at the Ecole Normale, M. Gernez, was now a professor at the Collège Louis le Grand. His mind was eminently congenial to Pasteur’s. Duruy, then Minister of Public Instruction, was ever anxious to smooth down all difficulties in the path of science: he gave a long leave of absence to M. Gernez, in order that he might take Raulin’s place. Another young _Normalien_, Maillot, prepared to join the scientific party, much to his delight. The three men left Paris at the beginning of February. They began by spending a few days in an hotel at Alais, trying to find a suitable house where they would set up their temporary laboratory. After a week or two in a house within the town, too far, to be convenient, from the restaurant where they had their meals, Maillot discovered a lonely house at the foot of the Mount of the Hermitage, a mountain once covered with flourishing mulberry trees, but now abandoned, and growing but a few olive trees.

This house, at Pont Gisquet, not quite a mile from Alais, was large enough to hold Pasteur, his family and his pupils; a laboratory was soon arranged in an empty orangery.

“Then began a period of intense work,” writes M. Gernez. “Pasteur undertook a great number of trials, which he himself followed in their minutest details; he only required our help over similar operations by which he tested his own. The result was that above the fatigues of the day, easily borne by us strong young men, he had to bear the additional burden of special researches, importunate visitors, and an equally importunate correspondence, chiefly dealing out criticisms....”

Madame Pasteur, who had been detained in Paris for her children’s education, set out for Alais with her two daughters. Her mother being then on a visit to the rector of the Chambéry Academy, M. Zevort, she arranged to spend a day or two in that town. But hardly had she arrived when her daughter Cécile, then twelve years old, became ill with typhoid fever. Madame Pasteur had the courage not to ask her husband to leave his work and come to her; but her letters alarmed him, and the anxious father gave up his studies for a few days and arrived at Chambéry. The danger at that time seemed averted, and he only remained three days at Chambéry. Cécile, apparently convalescent, had recovered her smile, that sweet, indefinable smile which gave so much charm to her serious, almost melancholy face. She smiled thus for the last time at her little sister Marie-Louise, about the middle of May, lying on a sofa by a sunny window.

On May 21, her doctor, Dr. Flesschutt, wrote to Pasteur: “If the interest I take in the child were not sufficient to stimulate my efforts, the mother’s courage would keep up my hopes and double my ardent desire for a happy issue.” Cécile died on May 23 after a sudden relapse. Pasteur only arrived at Chambéry in time to take to Arbois the remains of the little girl, which were buried near those of his mother, of his two other daughters, Jeanne and Camille, and of his father, Joseph Pasteur. The little cemetery indeed represented a cup of sorrows for Pasteur.

“Your father has returned from his sad journey to Arbois,” wrote Madame Pasteur from Chambéry to her son who was at school in Paris. “I did think of going back to you, but I could not leave your poor father to go back to Alais alone after this great sorrow.” Accompanied by her who was his greatest comfort, and who gave him some of her own courage, Pasteur came back to the Pont Gisquet and returned to his work. M. Duclaux in his turn joined the hard-working little party.

At the beginning of June, Duruy, with the solicitude of a Minister who found time to be also a friend, wrote affectionately to Pasteur--

“You are leaving me quite in the dark, yet you know the interest I take in your work. Where are you? and what are you doing? Finding out something I feel certain....”

Pasteur answered, “Monsieur le Ministre, I hasten to thank you for your kind reminder. My studies have been associated with sorrow; perhaps your charming little daughter, who used to play sometimes at M. Le Verrier’s, will remember Cécile Pasteur among other little girls of her age that she used to meet at the Observatoire. My dear child was coming with her mother to spend the Easter holidays with me at Alais, when, during a few days’ stay at Chambéry, she was seized with an attack of typhoid fever, to which she succumbed after two months of painful suffering. I was only able to be with her for a few days, being kept here by my work, and full of deceiving hopes for a happy issue from that terrible disease.

“I am now wholly wrapped up in my studies, which alone take my thoughts from my deep sorrow.

“Thanks to the facilities which you have put in my way, I have been able to collect a quantity of experimental observations, and I think I understand on many points this disease which has been ruining the South for fifteen or twenty years. I shall be able on my return to propose to the Commission of Sericiculture a practical means of fighting the evil and suppressing it in the course of a few years.

“I am arriving at this result that there is no silkworm disease. There is but an exaggeration of a state of things which has always existed, and it is not difficult, in my view, to return to the former situation, even to improve on it. The evil was sought for in the worm and even in the seed; that was something, but my observations prove that it develops chiefly in the chrysalis, especially in the mature chrysalis, at the moment of the moth’s formation, on the eve of the function of reproduction. The microscope then detects its presence with certitude, even when the seed and the worm seem very healthy. The practical result is this: you have a nursery full; it has been successful or it has not; you wish to know whether to smother the cocoons or whether to keep them for reproduction. Nothing is simpler. You hasten the development of about 100 moths through an elevation of temperature, and you examine these moths through the microscope, which will tell you what to do.

“The sickly character is then so easy to detect that a woman or a child can do it. If the cultivator should be a peasant, without the material conditions required for this study, he can do this: instead of throwing away the moths after they have laid their eggs, he can bottle a good many of them in brandy and send them to a testing office or to some experienced person who will determine the value of the seed for the following year.”

The Japanese Government sent some cases of seed supposed to be healthy to Napoleon III, who distributed them in the silkworm growing departments. Pasteur, in the meanwhile, was stating the results he had arrived at, and they were being much criticized. In order to avoid the pébrine, which was indeed the disease caused by the corpuscles so clearly visible through the microscope, he averred that no seed should be used that came from infected moths. In order to demonstrate the infectious character of the pébrine he would give to some worms meals of leaves previously contaminated by means of a brush dipped in water containing corpuscles. The worms absorbed the food, and the disease immediately appeared and could be found in the chrysalides and moths from those worms.

“I hope I am in the right road--close to the goal, perhaps, but I have not yet reached it,” wrote Pasteur to his faithful Chappuis; “and as long as the final proof is not acquired complications and errors are to be feared. Next year, the growth of the numerous eggs I have prepared will obviate my scruples, and I shall be sure of the value of the preventive means I have indicated. It is tiresome to have to wait a year before testing observations already made; but I have every hope of success.”

While awaiting the renewal of the silkworm season, he was busy editing his book on wine, full of joy at contributing to the national riches through practical application of his observations. It was, in fact, sufficient to heat the wines by the simple process already at that time known in Austria as _pasteurisation_, to free them from all germs of disease and make them suitable for keeping and for exportation. He did not accord much attention to the talk of old gourmets who affirmed that wines thus “mummified” could not mellow with age, being convinced on the contrary that the most delicate wines could only be improved by heating. “The ageing of wines,” he said, “is due, not to fermentation, but to a slow oxidation which is favoured by heat.”

He alluded in his book to the interest taken by Napoleon III in those researches which might be worth millions to France. He also related how the Imperial solicitude had been awakened, and acknowledged gratitude for this to General Favé, one of the Emperor’s aides de camp.

The General, on reading the proofs, declared that his name must disappear. Pasteur regretfully gave in to his scruples, but wrote the following words on the copy presented to General Favé: “General, this book contains a serious omission--that of your name: it would be an unpardonable one had it not been made at your own request, according to your custom of keeping your good works secret. Without you, these studies on wine would not exist; you have helped and encouraged them. Leave me at least the satisfaction of writing that name on the first page of this copy, of which I beg you to accept the homage, while renewing the expression of my devoted gratitude.”

Another incident gives us an instance of Pasteur’s kindness of heart. In the year 1866 Claude Bernard suffered from a gastric disease so serious that his doctors, Rayer and Davaine, had to admit their impotence. Bernard was obliged to leave his laboratory and retire to his little house at St. Julien (near Villefranche), his birthplace. But the charm of his recollections of childhood was embittered by present sadness. His mind full of projects, his life threatened in its prime, he had the courage, a difficult thing to unselfish people, of resolutely taking care of himself. But preoccupied solely with his own diet, his own body now a subject for experiments, he became a prey to a deep melancholia. Pasteur, knowing to what extent moral influences react on the physique, had the idea of writing a review of his friend’s works, and published it in the _Moniteur Universel_ of November 7, 1866, under the following title: _Claude Bernard: the Importance of his Works, Teaching and Method_. He began thus: “Circumstances have recently caused me to re-peruse the principal treatises which have founded the reputation of our great physiologist, Claude Bernard.

“I have derived from them so great a satisfaction, and my admiration for his talent has been confirmed and increased to such an extent that I cannot resist the somewhat rash desire of communicating my impressions....”

Amongst Claude Bernard’s discoveries, Pasteur chose that which seemed to him most instructive, and which Claude Bernard himself appreciated most: “When M. Bernard became in 1854 a candidate for the Académie des Sciences, his discovery of the glycogenic functions of the liver was neither the first nor the last among those which had already placed him so high in the estimation of men of science; yet it was by that one that he headed his list of the claims which could recommend him to the suffrages of the illustrious body. That preference on the part of the master decides me in mine.”

Claude Bernard had begun by meditating deeply on the disease known as diabetes and which is characterized, as everybody knows, by a superabundance of sugar in the whole of the organism, the urine often being laden with it. But how is it, wondered Claude Bernard, that the quantity of sugar expelled by a diabetic patient can so far surpass that with which he is provided by the starchy or sugary substances which form part of his food? How is it that the presence of sugary matter in the blood and its expulsion through urine are never completely arrested, even when all sugary or starchy alimentation is suppressed? Are there in the human organism sugar-producing phenomena unknown to chemists and physiologists? All the notions of science were contrary to that mode of thinking; it was affirmed that the vegetable kingdom only could produce sugar, and it seemed an insane hypothesis to suppose that the animal organism could fabricate any. Claude Bernard dwelt upon it however, his principle in experimentation being this: “When you meet with a fact opposed to a prevailing theory, you should adhere to the fact and abandon the theory, even when the latter is supported by great authorities and generally adopted.”

This is what he imagined, summed up in a few words by Pasteur--

“Meat is an aliment which cannot develop sugar by the digestive process known to us. Now M. Bernard having fed some carnivorous animals during a certain time exclusively with meat, he assured himself, with his precise knowledge of the most perfect means of investigation offered him by chemistry, that the blood which enters the liver by the portal vein and pours into it the nutritive substances prepared and rendered soluble by digestion is absolutely devoid of sugar; whilst the blood which issues from the liver by the hepatic veins is always abundantly provided with it.... M. Claude Bernard has also thrown full light on the close connection which exists between the secretion of sugar in the liver and the influence of the nervous system. He has demonstrated, with a rare sagacity, that by acting on some determined portion of that system it was possible to suppress or exaggerate at will the production of sugar. He has done more still; he has discovered within the liver the existence of an absolutely new substance which is the natural source whence this organ draws the sugar that it produces.”

Pasteur, starting from this discovery of Claude Bernard’s, spoke of the growing close connection between medicine and physiology. Then, with his constant anxiety to incite students to enthusiasm, he recommended them to read the lectures delivered by Bernard at the Collège de France. Speaking of the _Introduction to the Study of Experimental Medicine_, Pasteur wrote: “A long commentary would be necessary to present this splendid work to the reader; it is a monument raised to honour the method which has constituted Physical and Chemical Science since Galileo and Newton, and which M. Bernard is trying to introduce into physiology and pathology. Nothing so complete, so profound, so luminous has ever been written on the true principles of the difficult art of experimentation.... This book will exert an immense influence on medical science, its teaching, its progress, its language even.” Pasteur took pleasure in adding to his own tribute praise from other sources. He quoted, for instance, J. B. Dumas’ answer to Duruy, who asked him, “What do you think of this great physiologist?” “He is not a great physiologist; he is Physiology itself.” “I have spoken of the man of science,” continued Pasteur. “I might have spoken of the man in everyday life, the colleague who has inspired so many with a solid friendship, for I should seek in vain for a weak point in M. Bernard; it is not to be found. His personal distinction, the noble beauty of his physiognomy, his gentle kindliness attract at first sight; he has no pedantry, none of a scientist’s usual faults, but an antique simplicity, a perfectly natural and unaffected manner, while his conversation is deep and full of ideas....” Pasteur, after informing the public that the graver symptoms of Bernard’s disease had now disappeared, ended thus: “May the publicity now given to these thoughts and feelings cheer the illustrious patient in his enforced idleness, and assure him of the joy with which his return will be welcomed by his friends and colleagues.”

The very day after this article reached him (November 19, 1860) Bernard wrote to Pasteur: “My dear friend,--I received yesterday the _Moniteur_ containing the superb article you have written about me. Your great praise indeed makes me proud, though I feel I am yet very far from the goal I would reach. If I return to health, as I now hope I may do, I think I shall find it possible to pursue my work in a more methodical order and with more complete means of demonstration, better indicating the general idea towards which my various efforts converge. In the meanwhile it is a very precious encouragement to me to be approved and praised by a man such as you. Your works have given you a great name, and have placed you in the first rank among experimentalists of our time. The admiration which you profess for me is indeed reciprocated; and we must have been born to understand each other, for true science inspires us both with the same passion and the same sentiments.

“Forgive me for not having answered your first letter; but I was really not equal to writing the notice you wanted. I have deeply felt for you in your family sorrow; I have been through the same trial, and I can well understand the sufferings of a tender and delicate soul such as yours.”