COMMEMORATION OF THE CENTENARY OF PASTEUR
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In 1923, Algeria commemorates the birth of Pasteur and celebrates with glare the "Centenary of the man of genius" that glorifie the whole humanity, and whose France can precisely enorgueillir itself. The notoriety of Mr. MAILLARD is well established and its withdrawal of the front of the scene would know in no manner of tarnishing its will have. It is quite naturally towards our hero that turns itself the General Governor to pay this homage amply deserved. Vis-a-vis to this frightening honor, Louis Camille will reveal us another facet of his immense talent. Its speech, made in front of the intellectual elite of the nation, will remain in annals.
With a technique tested of dialectical, our skilful talker develops the uncontested Master of Science. Its demonstrations on molecular dissymmetry fill with enthusiasm the assistance. Its limpid explanations transform the philistine lambda into informed physicochemist. Its comment on "fermentation, birth of the life" collects the audience with a rare happiness. You give pleasure, take five minutes to read this anthology. It is little of scientists of this level who transpose in so clear language some experiments of most difficult.
Doctor himself, it allows himself to scratch the Academy of Medicine for his behavior more than critical with regard to Pasteur. With a consumed art, he recalls the learned assembly that chemistry and physics-chemistry are essential sciences, even major. He does not forget to associate his Master, Mr Armand GAUTIER and all the chemists, with the homage presented at Pasteur.
This enthralling speech is read as a novel of adventure. It is a exercise of style of a great quality. Moreover, this vibrating homage is a true plea for science in general and physics-chemistry in particular.
Newspaper of Medicine and Surgery of North Africa
Commemoration of the CENTENARY of PASTEUR in ALGIERS June 3, 1923
Algeria was to celebrate with glare the Centenary of the man of genius that glorifie the whole humanity, and whose France can precisely enorgueillir itself. It did not miss there, and this ceremony was what it was to be, a perfect and serene communion in admiration and the recognition.
The?uvre of Pasteur extends on a so vast field that the spirit more cultivated malaisément embraces it in all its width. It thus appeared difficult to leave with only one vote the heavy task evoke the multiple aspects of them. This delicate care but also this invaluable honor reserved for several, and was extremely judiciously entrusted to the Masters most authorized for each branch of the science which the powerful spirit of Pasteur vivified. Thus, one could seize, in his logical, marvellous of boldness, prodigiously fertile sequence in his consequences, all the development of the brilliant thought which revolutionized the world.
To successively were exposed us:
Pasteur, the Academic and the Scientist, by Mr. the PR. Rouyer, Senior of the Faculty of Science
The chemical oeuvre of Pasteur, by Mr. DR Maillard, Professor with the Faculty of Medicine
Pasteur and Agriculture, by Mr. DR Trabut, Professor with the Faculty of Medicine
Pasteur and Surgery, by Mr. DR Goinard, Surgeon of the Hospitals of Algiers
Pasteur and Medicine, by Mr. DR Soulié, Professor with the Faculty of Medicine of Algiers
The Pasteurian Revolution, by Mr. DR Edmond Sergeant, Director of the Pasteur Institute
All these speeches, that the audience listened with meditation, and that each one will be happy to read again, could express the major worship which keep with the large initiator in each field that it fertilized, all those which continue with its the very continuation burning one and impassioned labour.
After them, Mr. general Governor, in a language of a noble rise, enjoyed to release the beneficial influence of the Pasteurian ideas on the development and the colonization of Algeria. Even, it implied that political sciences would have to gain in clearness and output if they wanted to agree to be renovated with vivifying the methods inaugurated by Pasteur: unexpected but largely desirable repercussion of infinitely small on the political life of the people...
With a perfect tact and a delicate taste, the organizers had known to spare pleasant rest in the desired austerity of this scientific ceremony. For an audience of elite, composed of all intellectual Algeria, the most beautiful pages of our French music, delicately interpreted by the orchestra Rivetted, could lay out the spirits with the highest emotions.
And it is in a homage of deep admiration for the large thinker, of infinite
gratitude for its?uvre of kindness and charity that this solemnity finished.
The chemical research of PASTEUR
by Doctor Louis Camille MAILLARD
Science Doctor
Member corresponding of the Academy of Medicine
- - - - - -
Mister the General Governor,
By entrusting the mission to me of evoking in a few words the chemical?uvre of Pasteur, you made me very great honor, an honor larger than do not think much of the people who surround us, because if general public knows the importance that one have for the restoration of medicine the discoveries of the great man, its?uvre chemical is known less, even in the most cultivated mediums.
However it is perhaps the chemical part of work of Pasteur who is most beautiful, most penetrating, highest by its scientific range and also by its consequences. The very whole series of work of Pasteur is not other thing only one logical and uninterrupted sequence, where each discovery results directly from the meditations of the Master on the preceding discoveries. These are the chemical work which constitutes the origin of the series, the end of this marvellous wire whose imperturbable unfolding will remain marked in the history, and without his initial chemical discoveries, Pasteur had undoubtedly not been guided towards the others.
From there comes, Mister the General Governor, whom you wanted to place, at the beginning of this evocation of the Pasteurian?uvre, chemical work. But if the honor is large, the task is delicate to have to recall them in a few words too short: I will thus ask you, Mesdames and you, Messrs, to help itself by your benevolent attention, of which I will misuse the least possible.
As of the Teacher training school, the noble curiosity of Pasteur had been put in awakening by a bizarrery of the nature, whose incomplete explanation could not satisfy the critical direction of its young brain. One described two very close substances, the tartaric acid and the racemic or paratartric acid, which had exactly the same composition and the same chemical functions, the same physical properties and until the same crystalline form; indeed, the most qualified scientists, studying the various plane faces which limit the crystals of the one and the other body, and measuring with precision the angles which between them these facets form, found exactly the same faces being cut under identical angles. However the tartaric acid was more soluble than the acid paratartric, and, moreover, its aqueous solution enjoyed the optical activity, i.e. of the property curious to make turn (towards the line) the plan of polarization of a beam of polarized light which crosses it.
Pasteur did not resign himself to admit that two so similar substances by the whole of their properties could be different only by some; there was something which ran up against its robust good direction, and Pasteur thought that something had had to escape from the preceding observations. He thus solved to resume this study, and started to remake all crystallographic measurements.
First of all it could only confirm former measurements which had been carefully made. But here that on the crystals of tartaric acid, beside beautiful and large already given facets, it saw others of them smaller and so negligible that one often needed the magnifying glass to examine them, if unimportant seemingly that they had remained unperceived, or had neglected, other scientists.
Curious thing, Pasteur noticed that its small additional facets existed only on one side of the crystal, and not of the other, contrary usually, because, in general, all the faces appear by symmetrical couples on both sides center of a crystal, one on the left, the other on the right, one in top, the other in bottom, one ahead, the other behind, being done during like the accessories of a mantelpiece ornament which, in the middle-class living rooms of our fathers, were done during with an imperturbable symmetry. In the case of the tartaric acid, the large faces are well places from there like the massive torches at the two ends of the chimney, and what misses are only the small facets of the one of the ends, like if, on a side only of the chimney, one had concealed a tiny curio by leaving in place his/her twin brother on other side. The curio is so tiny that its disappearance is not noticed immediately, and the predecessors of Pasteur had not seen the unilateral facets; but their unilateral character does not introduce of it less dissymmetry into a crystal whose essential character was precisely, up to that point, a perfect symmetry.
But, you will say, Messrs, whom with the walk of the world these tiny scratches can make well that an old scientist has fun to contemplate on a crystal --- because a scientist is always a "old scientist", are not it true, Mesdames, were it in all the superb enthusiasm of its twenty years! --- And that us these puerile plays of large children import who have fun to align small facets, as others play to align small stones!
In truth, I you say it, it is to have meditated on these humble facets that Pasteur transformed medicine and renovated industries of fermentation. And I would be happy if my short explanations had the chance of you to convince some.
Crystalline dissymmetry that Pasteur had just noted at the tartaric acid could not miss approaching in its spirit, of another dissymmetrical property of the same body, the dextrogyre rotation which prints with the polarized light a tartaric acid solution. If there is well correlation between these two manifestations of dissymmetry, the acid paratartric, whose solution does not enjoy the optical activity, does not have to carry on its crystals the dissymmetrical facets, "hemihedral" as say the crystallographers.
And it is well what Pasteur checked. Extending its observations to salts which the tartaric acid and the acid paratartric with various bases form, it noted that the tartrates, which deviate the plan of polarization, have the hemihedral facets, while the paratartrates, inactive on the polarized light, are deprived by it. To enclose the series with dignity, Pasteur decided to take again all crystallographic measurements on remarkable salts by the beauty of their crystals and the facility with which one obtains them: double the ammonium and sodium tartrate and paratartrate.
The tartrate, dextrogyre, shows the hemihedral facets well. A supreme checking, and all is regulated: Pasteur takes the crystals of the double ammonium and sodium paratartrate, which does not have optical activity, and... still finds the facets hemihedral! ... Despair! All is broken!!!... And while Pasteur, destroyed in front of his crystals of paratartrate, cries the collapse of expensive sound dreams, here suddenly that it observes that on some of the crystals the hemihedral facets are left side of the crystal, while on other crystals they are on the right. Feverishly Pasteur seizes right crystals, left crystals, separately dissolves them in water and runs to the polarimeter: the solution of the right crystals deviates on the right, the solution of the left crystals deviates on the left; the mixture is inactive, following the example initial paratartre.
It is told that Pasteur was transported of an emotion so strong that it leaps of its laboratory and started to run in the corridors, where it failed to choke under his embrassades the first colleague which it met. Then it went to repeat the experiment in the old Master BIOT, with whom one owed the discovery even of the optical activity of the solutions. Hardly the tube placed on the polarimeter, Biot saw at once that there was a strong deviation on the left, but it was if moved him also that it could not read the graduation of its apparatus and says gently: "My child, I liked sciences in my life as well, as your discovery makes me beat the c?ur!"
Since the dissymmetrical character that betrayed the hemihedral facets still expresses, by the optical activity, in the solution, it is that this dissymmetry does not come not from a certain arrangement of the molecules in the crystal, but many characteristics of the molecule itself: it is a molecular dissymmetry. Developed, deepened, studied in its details, built in body of doctrines, schematized in formulas, the molecular dissymmetry of Pasteur became stereochemistry, chapter important of the science which built our compatriot the Beautiful one and the Dutchman Van' T Hoff. With it only, molecular dissymmetry is a discovery of genius and would be enough to make live the name of Pasteur, even if the wire of its days had been distinct prematurely.
But it is the molecular dissymmetry which launched Pasteur in the study of the phenomena of the life, and it is thus it which is with the source of the immense services rendered by this man of genius to hard-working and suffering humanity.
Since the study of tartrates, one knows that all the gifted bodies of the optical activity are likely to exist in two forms, one right, the other left, two "antipodes optical" like one says, whose properties are similar except this that one deviates the on the right polarized light and the other on the left but of the same quantity. The association of both antipodes in equal proportions does not have any more any optical activity, and their coupling establishes the symmetry which missed with each one of them; one gave to these couples the general name the "racemic ones" in remembering the racemic acid which was, between the hands of Pasteur, the object of the discovery.
If your thought wishes to make use of a familiar comparison, that Pasteur himself proposed, you will notice that the optical antipodes are, by their molecular structure, comparable with an object and its image in the ice, or with our two hands, the right-hand side and the left, which are well consisted the same number of fingers, but laid out in opposite directions, symmetrical and nonsuperposable. To be able to join the two hands, they should be turned over one compared to the other: at this point in time they join exactly, and their unit forms a symmetrical, symmetrical grouping compared to the plan of their joining, following the example racemic couple.
However, all the substances in solution at which Biot had discovered the optical activity, came from the alive beings. Pasteur insists on this fact and notes that all the substances with molecular dissymmetry were, without any exception, worked out by an alive being. It is with the living matter, and it only, which is reserved the privilege to print with a substance the dissymmetrical character, and that because the living matter is itself affected of a dissymmetry which it propagates.
"the artificial products", said Pasteur in a famous conference made to the Chemical Company in 1860, the artificial products do not have any molecular dissymmetry, and I could not indicate the existence of a more major separation between the products born under the influence of the life and all the others. Let us insist a little, because you will see in the continuation of this lesson releasing more and more the physiological side from its studies. Let us review the principal classes of natural organic materials:
Cellulose, starches, gums, sugars..., acids tartaric, malic, quinic, tannic..., morphine, codeine, quinine, strychnin, brucine..., spirits of turpentine, of lemon..., albumin, fibrin, gelatine... All these immediate principles are moléculairement dissymmetrical. All these matters have the optical activity with the state of dissolution: character necessary and sufficient to establish their dissymmetry, at the time same as, by the absence of possible crystallization, hemihedrism would be missing for the recognition of this property.
In this enumeration all the most essential substances of the animal and vegetable organization appear "
Since Pasteur, a great number of substances rigorously identical to those which provide the alive beings, were artificially reproduced by the synthesis in the laboratory of the chemists, and in particular of his famous rival, Marcelin Berthelot. And it was really a beautiful spectacle which noble emulation of these two great men, of which one proclaimed inébranlablement the chemical specificity of the life, and of which the other inlassablement brought new organic materials reconstituted by the art of the chemist!
But a capital difference remains. Always the artificial preparation gives the racemic couple, i.e. both antipodes in equal quantities, because the synthesizing forces others that those of the life are very of nature symmetrical, and impotent to support one of asymmetrical isomers rather than the other. Pasteur himself had thought well of subjecting the matters being developed synthetic to the action of forces dissymmetrical, able to perhaps direct the synthesis in a unilateral direction. To imitate nature, he wanted "to make act of the actions of solenoid, magnetism, luminous dissymmetrical movement". But from Pasteur to our days, all the attempts at this kind remained unfruitful.
We well admittedly know to duplicate the racemic ones in their dissymmetrical components. But for that it is always essential to utilize an auxiliary of vital origin. Thus one can separate, with the example of Pasteur, the two shapes antipodes of a synthetic acid, thanks to solubility different from salts which they give with various bases, such as cinchonidine, quinicine, strychnin, yohimbine or other alkaloids; but precisely these bases are asymmetrical substances provided by the alive beings. Or one can, always like Pasteur, to deliver in grazing ground the racemic couple to an alive being which, will be able to choose to him, like a yeast or a mould which consume the tartaric acid right and give up the left acid with the hands of the chemist.
He thus seems well that as of the mysterious origins of the life, the living matter was marked of an original dissymmetry whose cause escapes to us and who is transmitted in heritage through the centuries of centuries. There would not be more spontaneous asymmetrical synthesis than of spontaneous generation; the first asymmetrical synthesis would not be explained than the origin of the first alive germ.
You include/understand now why one can say that never no man in the world, in any country nor in any time, knew to penetrate only Pasteur more closely the structure and the operation of the living matter. These are the crystallographic beginnings which pushed it directly, and as under the irresistible pressure of a logic relentless, in the study of the life, physiology, medicine. The pious evocation of its work which we try today could be entitled "Crystallography with Medicine", and it is really, as I proclaimed it a few moments ago, to have contemplated with a brilliant patience of negligible crystalline facets, than Pasteur was registered in the forefront of the benefactors of humanity.
The first of the major biological problems to which it was attacked was that of fermentation. Although the brewers' yeast was known, and that Cagniard-Latour, recognizing it like an alive being, since 1835 the opinion had emitted that it is undoubtedly by some effect of its vegetation that it transforms the juices sweetened into spirituous liquors, Berzélius refused to see in the different yeast globules thing that a simple chemical precipitate, and classified fermentations among the phenomena of contact due to a catalytic action. Liebig as refused with fermentations any vital character, noticing besides as sugar can ferment not only out of alcohol, but as in lactic acid or butyric acid, and as here one observes no yeast, proof, believed it, that these chemical conversions do not have any relationship with the life. Fermentation would have been only one kind of molecular shock born from the decomposition of the nitrogenized matters and communicating itself with the close substances.
In 1856, Pasteur, who was then a senior, of the Faculty of Science of Lille, was consulted by a distiller whose fermentations went badly, and often gave lactic acid, instead of awaited alcohol. This advised industrialist named Mr. Bigo, and after soon three quarter centuries, its name deserves to be preserved, in homage to its intelligence or quite simply to its robust good direction. Because it should be enough to the good direction to understand that null industry cannot thrive without the help of the scientist. But it should be believed that, with due respect to the philosopher, the good direction is not the thing of the world best divided, since one too often meets still insufficiently convinced industrialists or farmers, seizing badly that, of all the businesses whom a businessman can dream, mirifique is the loan with science, because it brings back thousand for one.
Pasteur started to examine the tanks of Mr. Bigo by his usual method, without preconceived ideas, with his legendary patience, and most thoroughly possible, i.e. while arming himself with the microscope. And in addition to the globules of yeast, it observed others of them much smaller, in the shape of small short sticks, which seemed to pullulate all the more in the tanks that those provided more lactic acid.
Pasteur had the brilliant intuition that these two kinds of the globules, smallest like largest, were not other thing that alive beings, species different, of which one had as a property to make alcohol, and the other from the lactic acid, after both had nourished sugar, with some less copious food which brought nitrogen, sulphur, phosphorus and metals to them. But to establish this design on experimental bases inébranlables, it was necessary to insulate each one of these species independently of the other, independently also of any foreign germ which could have come to involve itself unduly in the experiments; it was necessary to prepare for these species of the nutritive mediums where one could cultivate them as plants of big size would be cultivated; it was necessary that these culture media were pure of any foreign vital intrusion, and such until the moment fixed by the will of the experimenter were preserved to sow the species there to be cultivated, in short, it had "to be sterilized".
And it is celebrates it "Memory on the fermentation known as lactic" which shows us how Pasteur, for the needs for his chemical studies, created of all parts and simultaneously bacteriological science and bacteriological technology, as it would have imagined an unspecified apparatus for an experiment. My eminent colleagues will say to you better than me the incalculable consequences of this invention for agronomy and medicine. But it is to the chemist that it rested to recall how, such Pallas Athéné springing, very armed with foot in course, the brain of Zeus, bacteriology, invaluable girl of chemistry, left very a blow of the brain of Pasteur, very alive and very armed with his techniques, that one since developed in their details, but without y nothing to find to change in the principles.
Here thus our hero in measurement studied with leisure each fermentation caused by various micro-organisms, because fermentation, it is not death, as nebulas Germanic designs believed it: fermentation it is the life, as Pasteur proves it triumphantly. And as it was to show it later, it is the life of the microbes which repairs the death of the plants and the higher animals. It is them whose various species, attacking the organic matter of the corpses, disaggregate the complex molecules quickly of them to bring back them to molecules much simpler, acid carbonic and water, ammonia, nitrates, i.e. with the state of mineral substances returned in the universal medium, where new alive beings take them again without delay to constitute their substance of it, maintaining without truce the new lives. Perhaps without the microbes, the regression of the organic matter could be made under the action of the air and of water helped by solar radiation in its luminous or heating form, but this regression would take place with such a slowness that the face of the world would be radically changed it.
The surface of the sphere would be soon encumbered almost indestructibles corpses, retaining in them essential carbon and nitrogen with the new beings which would not find any more what to constitute themselves; and the most sinister imagination of the most horrific storyteller never still dreamed this appalling nightmare of the last man having eaten the last green sheet, and dying of inanition in the medium of a desert of corpses.
Let us return to alcoholic fermentation. The chemical mechanism appears of it to us better, at once that the carbon dioxide and alcohol are considered like products of disassimilation of the protoplasm living of yeast: Pasteur supplements the equation of Lavoisier besides, by showing that alcohol and carbon dioxide are not the only products of yeast, but that it is necessary to join to it other substances such as glycerin, succinic acid, etc, whose whole represents approximately 5 % of consumed sugar.
But in his first experiments, Pasteur had found, beside the lactic acid, a little butyric acid, and that in extremely irregular proportion, circumstance which gave rise to him to think perhaps that it acted of a parasitic phenomenon, which had of some butyric fermentation which would have slipped insidiously among the germs of the lactic leaven. By seeking the butyric leaven, Pasteur found it. But this new leaven was presented in mobile sticks, slipping, undulating, being balanced, swivelling, so that Pasteur did not compare it with a plant, like yeast, but rather with an animal infusoire: we know today that these distinctions hardly any more have of importance to the eyes of the biologists.
However, if one examines in a drop of liquid these butyric "vibrios", one sees that those of the center are trémoussent with agility; but at once that the vibrio approaches the edges of the drop, in the vicinity of the air, it is immobilized and does not move more than one corpse. Whereas for all the alive beings hitherto known, the absorption of atmospheric oxygen is a paramount need such as its urgency erases all the others, would there be thus beings for which the air, far from being the fundamental vivificator, would be only one mortal poison? If formidable that was the assumption, Pasteur did not hesitate, and many experimental evidence gave him reason. It had just discovered the anaerobic life, discovered capital in biological chemistry, and that with the great amazement of the physiologists: physiologists and doctors were not at the end of their astonishments.
These amazements, I will leave to colleagues particularly qualified the privilege to tell them to you. However the chemist, humble disciple of the famous ancestor, will put some corporative pride to say to you that when we commemorated with the Academy of Medicine, two years ago, the centenary of our Company, some of my eminent fellow-members undertook to evoke "one century of medicine", "one century of surgery", "one century of biology", "one century of hygiene", "one century of veterinary art". And none them, each one in its field, for glorifier the secular prestige of French medicine, found better only Pasteur, still Pasteur, always Pasteur, always the Pasteur chemist!
Bright revenge of the rough hostility and the indecent contempt with which had accomodated the majority of the doctors of his time, and the Academy itself, not admitting that a vulgar chemist dared to interfere himself medicine, and throwing to him to the face the scornful one: "sutor, ultra crepidam*!" Because in these times, already remote, Messrs, there were people who believed that to lead humanity in the ways of progress, it was enough to speak Latin *Cordonnier, not higher than the shoe, the chemist cannot speak about medicine
Never Pasteur let himself dazzle by words, if prestigious that they could be. With torrents of eloquence, it answered by experiments, cold, but decisive. And of this still we must know liking to him, to have proven in the world that the French, very in love that it is noble speeches and harmonious periods, can also, when it is necessary, listen to the voice of reason initially.
But if were needed, so that Medicine let itself fertilize by the chemist, a true rape, which thus would now dare to regret it? And if, our piles homage towards Pasteur, we associate some famous shades, Lavoisier and Fourcroy, the Gay-Lussac and the J.-B. Dumas, the Claude Bernard and Marcelin Berthelot, the Armand Gautier and Pierre Curie, let us not have not the right to say that they are the chemists --- the French chemists --- who had in modern medicine the really creative role?
How this great lesson is not lost! Can the example of the genius of which we glorifions the marvellous epopee today, clarify the future generations, and make that never again medicine is mislaid to treat in "additional" sciences physicochemical sciences, which are at the base even of its fundamental bases!.
Chymia not ancilla medicine: not alia
melior and magis egregia dominated !
Chemistry is not the maidservant of medicine: it is best and the most famous of the mistresses