Makers of Modern Medicine

In a word, Müller owed the success of his career to the perfect poise of his intellect and the admirable critical faculty that guided him in the thorny path of knowledge at a time when there were so few landmarks of real scientific significance to show the investigator what the probable course and progress of real science must be. It was for this reason that, as Virchow has said, the reform of newer views became embodied in him, and in spite of the almost monastical retirement of the scholar, the influence of the method introduced by Müller was not limited to physiology, but continues to spread beyond that science in ever-widening circles into the domain of all the biological sciences.

Virchow concludes: "Müller vanquished mysticism and phantasms in the organic kingdom and he was most distinctly opposed to every dangerous tendency, whether it was pursued under the pretext of physiology or belief, or merely in accordance with conjectures. Müller did not discover, but he firmly established the exact method of investigating natural sciences: Hence, he did not found a school in the sense of dogmas–for he taught none, but only in the sense of methods. The school of natural science which Müller created knew no community of doctrine, but only of facts and still more of methods."

He did not confine himself in his studies, however, to the physiology and pathology, nor even to the anatomy and embryology of man. After 1840 he devoted himself to the study of invertebrates and investigated the starfish and the pentacrinites. While engaged in his work on the invertebrates he found that the fossil remains of animals had not been carefully explored, so for a time he devoted himself to paleontology. While his salary as professor was ample for his own support, it was not what would be called generous at the present time, yet Müller became so devoted to his science that he paid certain of the workmen to be on the lookout for fossil remains for him in the quarries of the Eifel. He became deeply interested, too, in life in the sea and made his vacations times of specially hard work, investigating the conditions of low life among marine organisms. He passed from one class of life to another. From sea-urchins and starfish to infusoria and polycystina, whose varieties he was himself the first to recognize and describe.

Müller was one of the first to point out that certain of the lower animals could propagate similar and dissimilar generations, that is, reproduce by alternate generations. He studied and demonstrated especially the metamorphoses in the echinodermata, and his broad vision and careful observation in this new and surprising scientific field cleared up many things that had been mysteries before.

In paleontology Müller worked with our own Agassiz, then a young man, or perhaps it should rather be said that Agassiz worked with Müller. A paper, for whose compilation they made a series of observations together, appeared at Neufchatel, in 1834. It was a note on the vertebrae of living and fossil dog fishes. At this time Müller was interested in fossil fishes of many kinds and wrote several articles in later years on this subject. Toward the end of Müller's life he studied especially the polycystina, certain of the radiolaria, and some of the many chambered specimens, fossil and living, that were attracting much attention at that time. As a matter of fact he went the day before his death to the zoological museum of Professor Peters in Berlin, in order to obtain some polythalamacea.

How open to advance in science and how ready to encourage the work of others Müller was, may be gathered from his attitude to parasites as the cause of disease, when these began to be discovered. After Professor Schoenlien's discovery of the parasite of favus, Müller became interested in it, confirmed Schoenlein's observations and added something to our knowledge of it. About this time, also, he discovered the psorosperm as a parasite of animals and possibly of man, and devoted considerable attention to it. His work was afterward greatly extended by one of his pupils, Lieberkühn, whose researches with regard to these minute organisms attracted the attention of the medical world.

It is not a little surprising how many of the investigations that afterward were to give fame to Virchow were initiated by his great teacher, Müller. It was Müller whose study of tumors led Virchow to devote himself to this subject and give us the best pathological work on it that has ever been written. Virchow himself notes with regret that Müller turned aside from pathology and never finished the promised work which was to have contained his theory of the origin of tumors. Another work in which Virchow followed in Müller's footsteps was the development of craniometry and, in general, the scientific investigations of skulls. Müller had interested himself very much in microcephalic skulls and Virchow assisted him in the investigations of them. Many years afterward Virchow established the science of craniology in the department of anthropology, and succeeded in throwing not a little light on the origins of races by his discoveries in this matter.

After Schoenlien's discovery of the parasite of favus, Müller became interested in the parasitology of human beings, and with Retzius, the famous Swedish anatomist, investigated certain molds which occur in the respiratory passages of birds. They succeeded in demonstrating that these vegetable parasitic growths were a form of Aspergillus. Their studies in the white owl particularly called general attention to the possibility of such molds occurring as parasites of animals. Later on, Virchow showed that these same molds occur occasionally in the respiratory passages of men. Virchow found them in three bodies at autopsy, all of them being run down individuals, two of them old subjects, and all sufferers from chronic bronchitis. Usually, when the parasites were found, there was a distinct tendency to very low resistive vitality in the tissues, sometimes proceeding even to the extent of beginning pulmonary gangrene. In reviewing the subject Virchow7 said that the light thrown upon it by the investigations of Müller and Retzius was of the greatest possible assistance in enabling him to identify the parasite when he found it in human subjects.

The number of positive facts which Müller brought to light in the most diverse departments of science is almost beyond calculation, and yet it is astonishing how seldom the slightest error, or even an incomplete observation, can be found in his work. On the other hand, it has happened, over and over again, that when the correctness of his observations in the beginning seemed according to other investigators to be dubious, they have come eventually to be acknowledged as representing the truth. As a rule, he went over every set of observations three times. During the second series he wrote about them. He always repeated the experiments on which his observations were founded while his material was going through the press. His manuscripts were a mass of corrections; notwithstanding this, his proof sheets were the despair of the printers.

Müller accomplished all this only by the most careful husbanding of his time. He knew how to make use even of the ends of hours and brief intervals which others waste without a thought about them. He used to call these periods of short duration between the duties "the gold-dust of time," and said that he did not wish to lose a particle of it. In the quarter of an hour between two lectures it was not an unusual thing to find that he took up some dissection at which he was engaged, or continued his work sketching the observations that he had been making during the previous day.

How thorough was Müller's work in everything that he devoted himself to can be gathered from certain excursions into pathology, which was, after all, only a side issue in his work, and to which he gave very little serious attention. Müller's assistant in the Museum of Berlin, and one of his favorite pupils, Schwann, made a series of what Virchow calls comprehensive and magnificent investigations on the cell structures of the animal tissues, on which progress in pathology so essentially depends. Müller followed up these discoveries, and, to quote Virchow once more, he was in this matter the authority of authorities; for the medical world owes to him practically all its knowledge of tumors. Müller first demonstrated the harmony which existed between the pathological and the embryonic development of tumors.

This physiological observation is of the highest importance. It came at a time when tumors were considered to have nothing of the physiological about them, but to be entirely manifestations of morbid processes foreign to all natural functions of the body. Müller's observation of the identity of the pathological and the embryonic development of tumors is really the key to the whole doctrine of morbid formations. Virchow assures us that Müller's labors gave the strongest impulse to the employment of the microscope in pathological investigations. Undoubtedly this was his most important contribution to scientific medicine. With this he laid the foundation of the explanations of tumors–a work that his great pupil was destined to carry on. Some of Müller's work in this line, his study of enchondromata for instance, Virchow confesses to have been part of the inspiration that led to his own later work. Müller was occupied, however, with too many things to devote himself to the study of pathology in the way that would have been necessary to make great discoveries in the science. He promised that he would sometime settle down to make a classification of tumors, and that the principle of such a classification would not be based either on their fineness of structure or on their chemical composition, but that their physiological nature and tendency to grow must be taken into account. When he died, however, he left behind him nothing unfinished except the long-expected conclusion of his book on tumors.

Müller's most important work in physiology, and his most far-reaching influence on the biological sciences, which were just then beginning their modern development, came from his assertion of vital force as a thing entirely different from and absolutely independent of the physical or chemical forces which it directs and makes use of. Vital force for Müller was the ultimate cause and supreme ruler of vital phenomena, so that all the energies of an organism follow a definite plan. It was for him the complete explanation of all the physical manifestations of life. It disappears in death without producing any corresponding effect. Without losing anything of itself it hands over in multiplication or reproduction a force equal to itself to the new being that is born from it. This vital force that is thus handed over need not necessarily manifest itself at once, but may lie dormant for a long time to be awakened to manifestations of life by the concurrence of proper conditions in its environment.

In a word, Müller appreciated fully the mystery of life, faced the problem of it directly, stated it in unequivocal terms, and by so doing saved the rising science of biology from wandering off into speculations which were seductive enough at that time, but which would have proved vain and wasteful of time and investigative energy. Müller's influence on his students was sufficient in this matter to set the seal of vitalism, as it is called, on most of the biological work done in Germany about the middle of the century, and it was a recurrence to his observations and his methods which led the reaction to vitalistic theories that characterized the concluding years of the nineteenth century.

With regard to the significance of Müller's work, Professor Du Bois-Reymond, himself a pupil of Müller, in his memorial address delivered before the Royal Academy of Sciences of Berlin in 1859,8 says: "It has been objected by those who insist on the greatness of Müller's reputation that he himself made no discovery that can be said to be of the first rank. Müller's fame is great enough for us to allow that there is something true in this objection. He accomplished more in developing the ideas of others than in original research of his own. That he did not make any great discovery is, however, rather due to the fact that he came at a time when great discoveries were no longer lying around loose as they had been in the preceding century, waiting to be made, as it were; and what he accomplished was of more value than one or two single discoveries of primary importance. He made the original ideas of other men so clear that they were at once accepted by all the medical and scientific world. In this way he furthered the progress of medicine better than any devotion, however successful, to one single feature could possibly have accomplished.

"Müller made mistakes, but then who ever fails to make mistakes in the face of nature? As a rule, however, he hit the nail on the head. There are many suggestive thoughts from him that the investigators of later times have proved to be true. He suggested, for instance, that there must necessarily be some connection between the ganglionic bodies and the nerve stems. He suggested, also, that there must be a special nerve system for the intestinal tract. Later discoveries in physiology have established both of these thoughts and have shown that Müller had so entered into the spirit of nature and her processes as to be able to think her thoughts. There is no doubt that there are suggestions in his writings, especially those of the later years of his life, which will give a series of triumphal substantiations of the same kind."

Du Bois-Reymond's final judgment is of special interest, because it tries to point out the comparative place that will be occupied by three great men in the biological sciences of a century ago:

"Haller and Müller must be considered as giants of earlier days, though when future generations compare them with Cuvier they will occupy somewhat of the position that Galileo and Newton hold in comparison to La Place and Gauss, or Lavoisier in comparison to Berzelius. The first of these men had the opportunity to do great things while it was yet possible to do them, and left to their successors only the possibility of developing their thoughts."9

It is as a teacher that Müller did his best work. He was not by nature a good talker and never said much, but he was very direct; and, as he spoke from the largest possible and most progressive knowledge of the subject, his lectures were always interesting to serious students. There seems to be a more or less general agreement that for the mass of his students he was uninteresting because likely to be above their heads. For the talented members of his class, however, he was an ideal teacher–always suggestive, always to the point, and eminently complete. Du Bois-Reymond says that he never was confused, never repeated himself, and never contradicted himself.

He was able to illustrate his lectures by sketches on the board in a way that enabled students to follow every step of even a complex, embryological developmental process. He could trace, step by step, with the chalk, every stage of evolution in the organism and bring it clearly before his students. To a narrow circle of the best men within his class he became a personal friend, whose inspiration led them on to the deepest original researches. Among his students were some of the men who made German medicine and German science known all over the world in the last fifty years. Chief among them may be mentioned Virchow, Helmholtz, Du Bois-Reymond, Schwann, Lieberkuhn, the discoverer of the follicles in the intestines; Max Schultze, whose work in histology and physiology are well known; Claparede, Remak, Guido, Wagener, Lachmann and Reichert.

What he demanded of his students above all was that they should learn to help themselves. He set them tasks, gave them suggestions, directed their work, corrected their errors, but he wanted them to do work for themselves. His very presence was an inspiration. Both Virchow and Du Bois-Reymond speak of the power of his eye. Du Bois-Reymond says that there was in him an almost demoniac magic, and that students looked to him as the soldiers of the first Napoleon did when the great Emperor's words were in their ears–"Soldiers, the Emperor has his eye on you." Du Bois-Reymond adds that, consciously or unconsciously, every student felt the winning influence of his great personality. With all this he knew how to unbend, especially with favorite students, and many a joke from him found its way around the laboratory even during working hours. He was not one to stand on his dignity, and Virchow tells of him that even when nearly fifty he was known to race with a student down the corridor from one class-room door to another. He took up skating at the age of forty-five, and though he had not many friends and was too entirely devoted to his work to make many acquaintances, it was always a source of pleasure to young men to be allowed to associate with him, and many eagerly sought the privilege.

How impressive a figure Müller made in his character of teacher can be gathered best, perhaps, from a note added to Virchow's panegyric during its progress through the press, in which the pupil tells his impressions of the master:

"I must confess that Müller, in his lectures and in his manner, reminded me of a Catholic priest, which might be accounted for by the impressions of his early childhood. When as the dean of the Faculty he mounted the cathedra superior, dressed in his official robes, and pronounced the Latin formulary of the proclamation of the doctors of medicine, with short, broken and contracted words; when he began his ordinary lectures in almost murmured syllables; or, when with religious earnestness he was discussing any of the abstruse questions of physiology, his tone and manner, his gestures and looks, all betrayed the traditional training of the Catholic priest."

Virchow adds, "Müller himself was what he styled one of his greatest predecessors–perpetually a priest of nature. The religion which he served attached his pupils to him as it were by a sacred bond; and the earnest, priest-like manner of his speech and gestures completed the feeling of veneration with which everyone regarded him."

In the recently issued life of von Helmholtz, the great German physicist, his biographer makes it very clear how much Helmholtz thought of Müller, one of the earliest teachers.10 Helmholtz, Brücke, and Du Bois-Reymond were warm personal friends (college chums we would call them in America), and all fervent admirers of their greatest master, who showed them, as Helmholtz says, "how thoughts arise in the brains of independent thinkers." A half-century later, in his recollections of the time, he said: "He who has come in contact with one or more men of the first rank has his mental intellectual standard for all time broadened, and such contact is the most interesting thing that life can hold." Curiously enough, one of the most interesting things in Helmholtz's recollections is that, despite the fact that the poverty of his parents made it advisable for him to get through his medical studies as soon as possible, Müller persuaded him to take another year's medical work before going up for his graduation. This was mainly for the purpose of having his pupil complete an essay in physiology on which he was engaged. Müller offered him the use of his own laboratory and all his instruments for this purpose. His judgment was justified by Helmholtz's wonderful work on the conservation of energy made within a few years after his graduation.

Müller's death was sudden, though not entirely unexpected. He had been ailing for many months and had resolved to give up his lectureship. He had made most of his preparations for settling up his affairs, and had even sent for his son, who was practising medicine at Cologne, to come up to see him. He made a special engagement for a consultation with his physician for a certain morning, and having gone to bed in reasonably good spirits, in fact, feeling better than he had for a long while, was found dead in the morning. Some time before he had made his will forbidding an autopsy, and so the exact cause of death will never be known, though it is rather easy to surmise that it was due to apoplexy, as arteriosclerosis–that is, degeneration of arteries–had been noticeable in Müller for some years, and his temporal artery particularly had become hard and tortuous.

Müller was buried with all the rites of the Church, and as in Germany the ecclesiastical authorities are very strict in this matter, there can be no doubt that the great physiologist had been a faithful Catholic. He was known for his edifying attendance at Mass on all the Sundays of the year. Many years afterward, in the midst of the Kulturkampf in the early seventies, a monument was erected to him in his native Coblentz, and the occasion of its unveiling was taken by the Catholic Rhineland for a celebration in honor of their great scientist.

For a time, in his younger years, Müller appears to have been not all unaffected by the materialistic tendencies so rife in the science of the time. His early anatomical investigations seem to have clouded somewhat his faith in things spiritual. One of the expressions attributed to him before his twenty-fifth year is that nothing exists in the human being which cannot be discovered by the scalpel. It was not long, however, before Müller repudiated this expression and came back to a realization of the importance of the immaterial. Another expression attributed to him, "Nemo psychologus, nisi physiologus," "No one can be a psychologist, unless he is a physiologist," has been often repeated as if Müller meant it in an entirely materialist sense. As a matter of fact, however, it is intended to convey only the idea that no one can really exhaust the science of psychology unless he knows the physiology of the brain, the organ which the mind uses in its functions in this life. The expression is really the foundation of the modern physiological psychology, which is by no means necessarily materialistic in its tendency, and has become a favorite subject of study even with those who appreciate thoroughly the importance of the immaterial side of psychology.

Müller seems never to have gotten so far away from the Church as that other great physiologist of the succeeding generation in France, Claude Bernard, who for many years allowed himself to be swamped by the wave of materialism so likely to seem irresistible to a scientist engaged in physiological researches. But, even Claude Bernard came back to the Church before the end, and, under the guidance of the great Dominican, Père Didon, reached the realization that the only peace in the midst of the mysterious problem of life and the question of a hereafter is to be found in a submissive faith of the doctrines of Christianity.

Many years ago, when Virchow took it upon himself to say harsh words in public of Catholic scholarship, and to put forward the hampering influence of the Church on intellectual development as a reason for not allowing Catholics to have any weight in educational matters, the organ of the Catholics of Germany, Germania, reminded him that his own teacher, the great Johann Müller, the acknowledged father of modern German medicine, and the founder of the fecund scientific method to which so many discoveries in the biological and medical sciences are due, had been brought up and educated a Catholic, had lived all the years of his productive scholarship and fruitful investigation in her bosom, and had died as an acknowledged son of the great mother Church.

Müller is certainly one of the great names of nineteenth century science. When many another that seems now as well, or perhaps even better known, shall have been lost, his will endure, for his original researches represent the primal step in the great movement that has made possible the advances in nineteenth century medicine. He was honored by his contemporaries, venerated by the men of science who succeeded him; he has been enshrined in a niche for himself by posterity, and his name will remain as that of one of the great geniuses to whose inventive faculty the world owes some of those steps across the borderland into the hitherto unknown which seem so obvious once made, yet require a master mind to make and mean so much for human progress.

THEODORE SCHWANN, FATHER OF THE CELL DOCTRINE

My message is chiefly to you, Students of Medicine, since with the ideals entertained now your future is indissolubly bound. The choice lies open, the paths are plain before you. Always seek your own interests, make of a high and sacred calling a sordid business, regard your fellow-creatures as so many tools of trade, and, if your heart's desire is for riches, they may be yours; but you will have bartered away the birthright of a noble heritage, traduced the physician's well-deserved title of the Friend of Man, and falsified the best traditions of an ancient and honorable Guild. On the other hand, I have tried to indicate some of the ideals which you may reasonably cherish. No matter though they are paradoxical in comparison with the ordinary conditions in which you work, they will have, if encouraged, an ennobling influence, even if it be for you only to say with Rabbi Ben Ezra, "What I aspired to be and was not, comforts me." And though this course does not necessarily bring position or renown, consistently followed it will at any rate give to your youth an exhilarating zeal and a cheerfulness which will enable you to surmount all obstacles–to your maturity a serene judgment of men and things, and that broad charity without which all else is naught–to your old age that greatest of blessings, peace of mind, a realization, maybe, of the prayer of Socrates for the beauty in the inward soul and for unity of the outer and the inner man; perhaps, of the promise of St. Bernard, "Pax sine crimine, pax sine turbine, pax sine rixa."