CHAPTER XVI

SCIENCE AND WAR—PASTEUR, LISTER

In the history of science war is no mere interruption, but a great stimulating influence, promoting directly or indirectly the liberties of the people, calling into play the energy of artisan and manufacturer, and increasing the demand for useful and practical studies. In the activities of naval and military equipment and organization this influence is obvious enough; it is no less real in the reaction from war which impels all to turn with new zest to the arts and industries of peace and to cherish whatever may tend to culture and civil progress. Not infrequently war gives rise, not only to new educational ideals, but to new institutions and to new types of institution favorable to the advancement of science. As we have already seen, the Royal Society and Milton's Academies owed their origin to the Great Rebellion. Similarly the Ecole Polytechnique, mother of many scientific discoveries, rose in answer to the needs of the French Revolution. No less noteworthy was the reconstruction of education under the practical genius of Napoleon I, the division of France into académies, the founding of the lycées, the reëstablishment of the great Ecole Normale, and the organization of the Imperial University with new science courses and new provincial Faculties at Rennes, Lille, and elsewhere. With all these different forms in which the influence of war makes itself felt in the progress of science the life and career of Louis Pasteur (1822-1895), the founder of bacteriology, stood intimately associated.

He was born at Dôle, but the family a few years later settled at Arbois. For three generations the Pasteurs had been tanners in the Jura, and they naturally adhered to that portion of the population which hailed the Revolution as a deliverance. The great-grandfather was the first freeman of Pasteur's forbears, having purchased with money his emancipation from serfdom. The father in 1811, at the age of twenty, was one of Napoleon's conscripts, and in 1814 received from the Emperor, for valor and fidelity, the Cross of the Legion of Honor. The directness and endurance of the influence of this trained veteran on his gifted son a hundred fine incidents attest. In 1848—year of revolt in the monarchies of Europe—the young scientist enrolled himself in the National Guard, and, seeing one day in the Place du Panthéon a structure inscribed with the words autel de la patrie, he placed upon it all the humble means—one hundred and fifty francs—then at his disposal.

It was in that same year that Pasteur put on record his discovery of the nature of racemic acid, his first great service to science, from which all his other services were to proceed. As a boy he had attended the collège at Arbois where his teacher had inspired him with an ambition to enter the great Ecole Normale. Before reaching that goal he took his bachelor's degree in science as well as in arts at the Besançon college. At Paris he came in contact with the leaders of the scientific world—Claude Bernard, Balard, Dumas, Biot.

J. B. Biot had entered the ranks of science by way of the Ecole Polytechnique and the artillery service. In 1819 he had announced that the plane of polarized light—for example, a ray passed through Iceland spar—is deflected to right or left by various chemical substances. Among these is common tartaric acid—the acid of grape-juice, obtained from wine lees. Racemic acid, however, which is identical with tartaric acid in its chemical constituents, is optically inactive, rotating the plane of polarized light neither to the right nor the left. This substance Pasteur subjected to special investigation. He scrutinized the crystals of sodium ammonium racemate obtained from aqueous solution. These he observed to be of two kinds differing in form as a right glove from a left, or as an object from its mirror-image. Separating the crystals according to the difference of form, he made a solution from each group. One solution, tested in the polarized-light apparatus, turned the plane to the right; the other solution turned it to the left. He had made a capital discovery of far-reaching importance, namely, that racemic acid is composite, consisting of dextro-tartaric and lævo-tartaric acids. Biot hesitated to credit a mere tyro with such an achievement. The experiment was repeated in his presence. Convinced by ocular demonstration, he was almost overcome with emotion. "My dear boy," he exclaimed, "I have loved the sciences so much my life through that that makes my heart jump."

Pasteur began his regular professional experience as a teacher of physics in the Dijon lycée, but he was soon transferred to the University of Strasburg (1849). There he married the daughter of the rector of the académie, and three years later became Professor of Chemistry. In 1854 he was appointed Dean of the Faculty of Sciences at Lille, a town then officially described as the richest center of industrial activity in the north of France. In his opening address he showed the value and attractiveness of practical studies. He believed as an educator in the close alliance of laboratory and factory. Application should always be the aim, but resting on the severe and solid basis of scientific principles; for it is theory alone which can bring forth and develop the spirit of invention.

His own study of racemic acid, begun in the laboratories of Paris, and followed up in the factories of Leipzig, Prag, and Vienna, had led to his theory of molecular dissymmetry, the starting point of modern stereo-chemistry. It now gave rise on Pasteur's part to new studies and to new applications to the industries. He tried an experiment which seems almost whimsical, placing ammonium racemate in the ordinary conditions of fermentation, and observed that only one part—the dextro-rotatory—ferments or putrefies. Why? "Because the ferments of that fermentation feed more easily on the right hand than on the left hand molecules." He succeeded in keeping alive one of the commonest moulds on the surface of ashes and racemic acid, and saw the lævo-tartaric acid appear. It was thus that he passed from the study of crystals to the study of ferments.

In the middle of the nineteenth century little was known of the nature of fermentation, though some sought to explain by this ill-understood process the origin of various diseases and of putrefaction. Why does fruit-juice produce alcohol, wine turn to vinegar, milk become sour, and butter rancid? Pasteur's interest in these problems of fermentation was stimulated by one of the industries of Lille. He was accustomed to visit with his students the factories of that place as well as those of neighboring French and Belgian cities. The father of one of his students was engaged in the manufacture of alcohol from beetroot sugar, and Pasteur came to be consulted when difficulties arose in the manufacturing process. He discovered a relationship between the development of the yeast and the success or failure of the fermentation, the yeast globules as seen under the microscope showing an alteration of form when the fermentation was not proceeding satisfactorily. In 1857 Pasteur on the basis of this study was able to demonstrate that alcoholic fermentation, that is, the conversion of sugar into alcohol, carbonic acid, and other compounds, depends on the action of yeast, the cells of which are widely disseminated in the atmosphere.

In this year of his second great triumph Pasteur was appointed director of science studies in the Ecole Normale, from which he had graduated in 1847. Two years later the loss of his daughter by a communicable disease—typhoid fever—had a great effect on his sensitive and profound mind. Many of his opponents, it is true, found Pasteur implacable in controversy. Undoubtedly he had the courage of his convictions, and his belief that, for the sake of human welfare, right views—his views won by tireless experiment—must prevail, gained him the name of a fighter. But in all the intimate relations of life his essential tenderness was manifest. Like Darwin he had a horror of inflicting pain, and always insisted, when operations on animals were necessary in the laboratory, on the use of anæsthetics (our command of which had been greatly advanced by Simpson in 1847). Emile Roux said that Pasteur's agitation at witnessing the slightest exhibition of pain would have been ludicrous if, in so great a man, it had not been touching.

A few months after his daughter's death Pasteur wrote to one of his friends: "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 make a decisive advance very soon, by solving without the least lack of clearness the famous question of spontaneous generation." Two years previously a scientist had claimed that animals and plants could be generated in a medium of artificial air or oxygen, from which all atmospheric air and all germs of organized bodies had been precluded. Pasteur now filtered atmospheric air through a plug of cotton or asbestos (a procedure which had been followed by others in 1854), and proved that in air thus treated no fermentation takes place. Nothing in the atmosphere causes life except the micro-organisms it contains. He even demonstrated that a putrescible fluid like blood will remain unchanged in an open vessel so constructed as to exclude atmospheric dust.

Pasteur's critics maintained that if putrefaction and fermentation be caused solely by microscopic organisms, then these must be found everywhere and in such quantities as to encumber the air. He replied that they were less numerous in some parts of the atmosphere than in others. To prove his contention he set out for Arbois with a large number of glass bulbs each half filled with a putrescible liquid. The necks of the bulbs had been drawn out and hermetically sealed after the contents had been boiled. In case the necks were broken (to be again sealed immediately), the air would rush in, and (if it held the requisite micro-organisms) furnish the conditions for putrefaction. It was found that in every trial the contents of a certain number of the bulbs always escaped alteration. Twenty were opened in the country near Arbois free from human habitations. Eight out of the twenty showed signs of putrefaction. Twenty were exposed to the air on the heights of the Jura at an altitude of eight hundred and fifty meters above sea-level; the contents of five of these subsequently putrefied. Twenty others were opened near Mont Blanc at an altitude of two thousand meters and while a wind was blowing from the Mer de Glace; in this case the contents of only one of the bulbs became putrefied.

While his opponents still professed to believe in the creation of organized beings lacking parents, Pasteur was under the influence of the theory of "the slow and progressive transformation of one species into another," and was becoming aware of phases of the struggle for existence hitherto shrouded in mystery. He wished he said to push these studies far enough to prepare the way for a serious investigation of the origin of disease.

He returned to the study of lactic fermentation, showed that butyric fermentation may be caused by organisms which live in the absence of oxygen, while vinegar is produced from wine through the agency of bacteria freely supplied with the oxygen of the air. Pasteur was seeing ever more clearly the part played by the infinitesimally small in the economy of nature. Without these microscopic beings life would become impossible, because death would be incomplete. On the basis of Pasteur's study of fermentation, his demonstration that decomposition is owing to living organisms and that minute forms of life spring from parents like themselves, his disciple Joseph Lister began in 1864 to develop antiseptic surgery.

Pasteur's attention was next directed to the wine industry, which then had an annual value to France of 500,000,000 francs. Might not the acidity, bitterness, defective flavor, which were threatening the foreign sale of French wines, be owing to ferments? He discovered that this was, indeed, the case, and that the diseases of wine could be cured by the simple expedient of heating the liquor for a few moments to a temperature of 50° to 60° C. Tests on a considerable scale were made by order of the naval authorities. The ship Jean Bart before starting on a voyage took on board five hundred liters of wine, half of which had been heated under Pasteur's directions. At the end of ten months the pasteurized wine was mellow and of good color, while the wine which had not been heated had an astringent, almost bitter, taste. A more extensive test—seven hundred hectoliters, of which six hundred and fifty had been pasteurized—was carried out on the frigate la Sibylle with satisfactory results. Previously wines had been preserved by the addition of alcohol, which made them both dearer and more detrimental to health.

In 1865 Pasteur was called upon to exercise his scientific acumen on behalf of the silk industry. A disease—pébrine—had appeared among silkworms in 1845. In 1849 the effect on the French industry was disastrous. In the single arrondissement of Alais an annual income of 120,000,000 francs was lost for the subsequent fifteen years. The mulberry plantations of the Cévennes were abandoned and the whole region was desolate. Pasteur, at the instigation of the Minister of Agriculture, undertook an investigation. After four or five years, in spite of repeated domestic afflictions and the breakdown of his own health, he arrived at a successful conclusion. Pébrine, due to "corpuscles" readily detected under the microscope, could be recognized at the moment of the moth's formation. A second disease, flacherie, was due to a micro-organism found in the digestive cavity of the moth. Measures were taken to select the seed of the healthy moths and to destroy the others. These investigations revealed the infinitesimally small as disorganizers of living tissue, and brought Pasteur nearer his purpose "of arriving," as he had expressed it to Napoleon III in 1863, "at the knowledge of the causes of putrid and contagious diseases."

Returning in July, 1870, from a visit to Liebig at Munich, Pasteur heard at Strasburg of the imminence of war. All his dreams of conquest over disease and death seemed to vanish. He hurried to Paris. His son, eighteen years of age, set out with the army. Every student of the Ecole Normale enlisted. Pasteur's laboratory was used to house soldiers. He himself wished to be enrolled in the National Guard, and had to be told that a half-paralyzed man could not render military service. He was obsessed with horror of wanton bloodshed and with indignation at the insolence of armed injustice. Trained to serve his country only in one way he tried, but in vain, to resume his researches. He retired to the old home town of Arbois, and sought to distract his mind from the contemplation of human baseness. Arbois was entered by the enemy in January with the usual atrocities of war. Pasteur accompanied by wife and daughter had gone in search of his son, sick at Pontarlier. The boy was restored to health and returned to his regiment the following month.

During this crisis Pasteur and his friends felt, as many English scientists feel in 1917, in reference to ignorance in high places. "We are paying the penalty," he said, "of fifty years' forgetfulness of science, and of its conditions of development." Again he speaks, as Englishmen to-day very well might, of the neglect, disdain even, of the country for great intellectual men, especially in the realm of exact science. In the same strain his friend Bertin said that after the war everything would have to be rebuilt from the top to the bottom, the top especially. Pasteur recalled the period of 1792 when Lavoisier, Berthollet, Monge, Fourcroy, Guyton de Morveau, Chaptal, Clouet, and other scientists had furnished France with gunpowder, steel, cannon, fortifications, balloons, leather, and other means to repel unjust invasion.

On the day after Sedan the Quaker surgeon Lister had published directions for the use of aqueous solutions of carbolic acid to destroy septic particles in wounds, and of oily solutions "to prevent putrefactive fermentation from without." He recognized that the earlier the case comes from the field the greater the prospect of success. Sédillot (the originator of the term "microbe"), at the head of an ambulance corps in Alsace, was a pioneer in the rapid transport of wounded from the field of battle. He knew the horrors of purulent infection in military hospitals, and regretted that the principles of Pasteur and Lister were not more fully applied.

After the war was over, Pasteur kept repeating his life-long exhortation: We must work—"Travaillez, travaillez toujours!" He applied himself to a study of the brewing industry. He did not believe in spontaneous alterations, but found that every marked change in the quality of beer coincides with the development of micro-organisms. He was able to tell the English brewers the defects in their output by a microscopic examination of their yeast. ("We must make some friends for our beloved France," he said.) Bottled beer could be pasteurized by bringing it to a temperature of 50° to 55° C. Whenever beer contains no ferments it is unalterable. His scrupulous mind was coming ever closer to the goal of his ambition. This study of the diseases of beer led him nearer to a knowledge of infections. Many micro-organisms may, must, be detrimental to the health of man and animals.

In 1874 the Government conferred upon Pasteur a life annuity of twelve thousand francs, an equivalent of his salary as Professor of Chemistry at the Sorbonne. (He had received appointment in 1867, but had been compelled by ill-health to relinquish his academic functions.) The grant was in all respects wise. Huxley remarked that Pasteur's discoveries alone would suffice to cover the war indemnity of five milliards paid by France to Germany in 1871. Moreover, all his activities were dictated by patriotic motives. He felt that science is of no country and that its conquests belong to mankind, but that the scientist must be a patriot in the service of his native land.

Pasteur now applied his energies to the study of virulent diseases, following the principles of his earlier investigations. He opposed those physicians who believed in the spontaneity of disease, and he wished to wage a war of extermination against all injurious organisms. As early as 1850 Davaine and Rayer had shown that a rod-like micro-organism was always present in the blood of animals dying of anthrax, a disease which was destroying the flocks and herds of France. Dr. Koch, who had served in the Franco-Prussian War, succeeded in 1876 in obtaining pure cultures of this bacillus and in defining its relation to the disease. Pasteur took up the study of anthrax in 1877, verified previous discoveries, and, as we shall see, sought means for the prevention of this pest. He discovered (with Joubert and Chamberland) the bacillus of malignant edema. He applied the principles of bacteriology to the treatment of puerperal fever, which in 1864 had rendered fatal 310 cases out of 1350 confinements in the Maternité in Paris. Here he had to fight against conservatism in the medical profession, and he fought strenuously, one of his disciples remarking that it is characteristic of lofty minds to put passion into ideas. Swine plague, which in the United States in 1879 destroyed over a million hogs, and chicken cholera, also engaged his attention.

Cultures of chicken cholera virus kept for some time became less active. A hen that chanced to be inoculated with the weakened virus developed the disease, but, after a time, recovered (much as patients after the old-time smallpox inoculations). It was then inoculated with a fresh culture supposed sufficient to cause death. It again recovered. The use of the weakened inoculation had developed its resistance to infection. A weakened virus recovered its strength when passed through a number of sparrows, the second being inoculated with virus from the first, the third from the second, and so on (this species being subject to the disease). Hens that had not had chicken cholera could be rendered immune by a series of attenuated inoculations gradually increasing in strength. In the case of anthrax the virus could be weakened by keeping it at a certain temperature, while it could be strengthened by passage through a succession of guinea-pigs. There are of course many instances where pathogenic bacteria lose virulence in passing from one animal to another, the human smallpox virus, for example, producing typical cowpox in an inoculated heifer. These facts help to explain why certain infections have grown less virulent in the course of history, and why infections of which civilized man has become tolerant prove fatal when imparted to the primitive peoples of Australia.

Pasteur's preventive inoculation for anthrax was tested under dramatic circumstances at Melun in June, 1881. Sixty sheep and a number of cows were subjected to experiment. None of the sheep that had been given the preventive treatment died from the crucial inoculation; while all those succumbed which had not received previous treatment. The test for the cows was likewise successful. Pasteur thought that in places where sheep dead of anthrax had been buried, the microbes were brought to the surface in the castings of earthworms. Hence he issued certain directions to prevent the transmission of the disease. He also aided agriculture by discovering a vaccine for swine plague.

When Pasteur at the age of fifteen was in Paris, overcome with homesickness, he had exclaimed, "If I could only get a whiff of the old tannery yard, I feel I should be cured." Certainly every time he came in contact with the industries—silk, wine, beer, wool—his scientific insight, Antæus-like, seemed to revive. All his life he had preached the doctrine of interchange of service between theory and practice, science and the occupations. What he did is more eloquent than words. His theory of molecular dissymmetry, that the atoms in a molecule may be arranged in left-hand and right-hand spirals or other tridimensional figures corresponding to asymmetrical crystals, touches the abstruse question of the constitution of matter. His preventive treatment breathes new life into the old dictum similia similibus curantur. The view he adopted of the gradual transformation of species offers a new interpretation of the speculations of philosophy in reference to being and becoming and the relation of the real to the concrete. Yet Pasteur felt he could learn much of value from the simplest shepherd or vine-dresser.

He was complete in the simplicity of his affections, in his compassion for all suffering, in the warmth of his religious faith, and in his devotion to his country. He thought France was to regain her place in the world's esteem through scientific progress. He was therefore especially gratified in August, 1881, at the thunders of applause which greeted his appearance at the International Medical Congress in London. There he was introduced to the Prince of Wales (fondateur de l'Entente Cordiale), "to whom I bowed, saying that I was happy to salute a friend of France."

Pasteur's investigation of rabies began in this same year. Difficulty was found in isolating the microbe of the rabic virus, but an inoculation from the medulla oblongata of a mad dog injected into one of the brain membranes (dura mater) of another dog invariably brought on the symptoms of rabies. To obtain attenuation of the virus it was sufficient to dry the medulla taken from an infected rabbit. The weakened virus increased in strength when cultivated in a series of rabbits. Pasteur obtained in inoculations of graded virulence, which could be administered hypodermically, a means of prophylaxis after bites. He conjectured that in vaccinal immunity the virus is accompanied by a substance which makes the nervous tissue unfavorable for the development of the microbe.

It was not till 1885 that he ventured to use his discovery to prevent hydrophobia. On July 6 a little boy, Joseph Meister, from a small place in Alsace was brought by his mother to Paris for treatment. He had been severely bitten by a mad dog. Pasteur, with great trepidation, but moved by his usual compassion, undertook the case. The inoculations of the attenuated virus began at once. The boy suffered little inconvenience, playing about the laboratory during the ten days the treatment lasted. Pasteur was racked with fears alternating with hopes, his anxiety growing more intense as the virulence of the inoculations increased. On August 20, however, even he was convinced that the treatment was a complete success. In October a shepherd lad, who, though badly bitten himself, had saved some other children from the attack of a rabid dog, was the second one to benefit by the great discovery. Pasteur's exchange of letters with these boys after they had returned to their homes reveals the kindliness of his disposition. His sentiment toward children had regard both to what they were and to what they might become. One patient, brought to him thirty-seven days after being bitten, he failed to save. By March 1 Pasteur reported that three hundred and fifty cases had been treated with only one death.

When subscriptions were opened for the erection and endowment of the Pasteur Institute, a sum of 2,586,680 francs was received in contributions from many different parts of the world. Noteworthy among the contributors were the Emperor of Brazil, the Czar of Russia, the Sultan of Turkey, and the peasants of Alsace. On November 14, 1888, President Carnot opened the institution, which was soon to witness the triumphs of Roux, Yersin, Metchnikoff, and other disciples of Pasteur. In the address prepared for this occasion the veteran scientist wrote:—

"If I might be allowed, M. le Président, to conclude by a philosophical remark, inspired by your presence in this home of work, I should say that two contrary laws seem to be wrestling with each other at the present time; the one a law of blood and death, ever devising new means of destruction and forcing nations to be constantly ready for the battlefield—the other, a law of peace, work, and health, ever developing new means of delivering man from the scourges which beset him.

"The one seeks violent conquests, the other the relief of humanity. The latter places one human life above any victory; while the former would sacrifice hundreds and thousands of lives to the ambition of one. The law of which we are the instruments seeks, even in the midst of carnage, to cure the sanguinary ills of the law of war; the treatment inspired by our antiseptic methods may preserve thousands of soldiers. Which of these two laws will ultimately prevail God alone knows. But we may assert that French science will have tried, by obeying the law of humanity, to extend the frontiers of life."