# Popular Science Monthly/Volume 5/June 1874/Sketch of Professor Helmholtz

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HERMANN LUDWIG FERDINAND HELMHOLTZ
* SKETCH OF PROFESSOR HELMHOLTZ.
By G. A. F. VAN RHYN.
GERMANY assembled in 1869 her greatest savants to celebrate the centenary anniversary of the birth of Alexander von Humboldt, her greatest dead. The highest honor of this occasion was bestowed on Prof. Helmholtz, who delivered the opening oration. He reviewed the progress made in the natural sciences with special reference to the labors of German students, and said: "In Germany there has always been a greater fearlessness of the consequences resulting from speaking the whole truth than anywhere else. The eminent savants of England and France are still obliged to bow to the dictates of social and ecclesiastical prejudices, and, when they speak openly, they do it to the injury of their social standing. Germany is bolder; she confides in what has never proved false—that the whole truth is the best remedy for the evils of truth imperfectly stated."
The Academy of France lent new force to his statement by refusing to elect him a corresponding member, on account of the advanced ideas connected with his name. A French critic rebuked his country-men for hesitating to bestow on Helmholtz, the greatest living physicist of this century, so slight an honor, with the remark: "For his glory nothing is wanting; but he is wanting for ours." The Academy elected him in the following year.
Hermann Ludwig Ferdinand Helmholtz was born August 31, 1821, in Potsdam, the Prussian Versailles, the town of palaces, which gave birth to Alexander von Humboldt, and holds the ashes of Frederick the Great. His father was a teacher at the gymnasium in Potsdam, and a man possessed of a great store of knowledge. Under his guidance Hermann was soon prepared to enter the institution, where, as usual, too much Latin and Greek was taught for his youthful taste. He was, however, not permitted to shirk any of his studies, and, with that patient perseverance which is a dominant trait in his character, he ran through the whole curriculum of the gymnasium before he had ​reached his seventeenth year. He then went to Berlin, and entered the military school of medicine known as the Frederick William Institute, or as the Pépinière. It is true that, if medicine was the study of his choice, there were ample facilities for it at any German university. But there were reasons which rendered it advisable to send him to a military institution. Prussia demands of all her sons several years of active service in the army, to begin when they are twenty-one years of age. This regulation provides her with large available forces, but sadly interferes with the pursuits of the young men at a time when the foundation must be laid for their future career. To overcome this difficulty, and to create at the same time a comparatively cultured army, it is provided that those who attend for a short period some military institution, and pass a satisfactory examination of a certain literary grade, shall be more or less exempt from active service in time of peace. Young Helmholtz's parents considered it best that he should avail himself of this provision at an early age, in order to insure for him an uninterrupted season of study in subsequent years. But Hermann had also his own reason for entering the military school of medicine. He had been seized with that martial fever which is apt to attack the youth of countries where there is continually a gaudy display of soldiers.
He went to Berlin, and on the three years which he spent there Helmholtz still looks back as the most pleasant of his life. There were strict rules to be obeyed, and there was hard study to be done; but there were also short furloughs to be obtained for rambles through the city, and some even long enough for a journey to the old home at Potsdam. The constant feeling of being on duty developed in him that noble manliness which so deeply marks every feature of his face.
When he was twenty, he graduated from the Pépinière with an article prepared for his examination marked with all the learning that he has since made his own. His dissertation was on the subject of the nervous system of invertebrate animals, and is the only morphological investigation which he has ever made.
His treatise evinced such uncommon ability that he was at once ordered to attend as assistant surgeon the hospital of the Charité, in Berlin, and after a few months he was promoted to the rank of physician in a regiment of hussars, stationed at Potsdam. This was wise, as it placed the youth again under the wholesome restraints and the kindly influences of the family circle, instead of allowing his hard-earned knowledge and well-trained physique to run to waste, like those of most young officers.
Helmholtz published in the same year the first fruit of his independent researches. It was an article on the nature of fermentation, which contains several remarkable suggestions on the subject of spontaneous generation. The excellence of this production opened to him the pages of the prominent medical magazines, and gave him the ​honor of an engagement as contributor to the "Berlin Encyclopædic Lexicon of Medical Sciences." The most important among the numerous articles which he wrote during this period is one on the chemical analysis of the consumption of matter by muscular action; another on animal heat, especially in relation to the question whether the body of an animal throws out the same amount of heat which is produced by the combustion and transformation of its food; and a third, which treats of the development of heat through muscular action.
The great variety of subjects treated in his short publications during these years excludes the hypothesis that there was in his studies a gradual growth toward the discoveries which uphold his worldwide fame, and for which every branch of study related to the physical sciences is so greatly indebted to him. There are, however, impressions which every reader of these papers receives. Helmholtz is nobody's pupil; he stands on the basis of personal observation, and speaks whatever he believes to be true. To show how independently his mind was developed, it may be stated that he could not be induced to attend a single lecture on physical science while a student in Berlin.
In 1847, being consequently only twenty-six years of age, he published his important work, "The Conservation of Force." The discovery of this principle of Nature has been of the greatest moment to the progress of the whole range of physical sciences. This law is, in fact, indispensable to a sound understanding of any and every phenomenon in the animate and inanimate world. And Helmholtz opened his scientific career with a production that would have worthily closed a long life of study and fame.
After the publication of "The Conservation of Force," he was appointed prosector at the Anatomical Institute in Berlin, where he remained about a year. In 1849 he was called to the chair of Physiology at the University of Königsberg. He accepted it, and filled it for a period of nearly six years, in which he made some brilliant discoveries and inventions, which have proved a blessing to thousands of sufferers.
It had been generally held that the time needed for conceiving a thought, and experiencing sensations, could not be measured. Prof. Helmholtz (1850-'51) invented, however, a series of highly-ingenious processes for measuring the duration of any action, however swift, and demonstrated, in a number of papers, that there is a lapse of time before a sensation caused on one end of a nerve is felt at the other. He proved, for example, that, when we touch a thing, it takes a little time before we know that we touched it, and that, however rapid and seemingly instantaneous our actions be, some small period of time must elapse before we can begin to execute the mandates of our will. In 1851 he invented a mirror with which to examine the retina of the eye in living beings, and in the following year he described an ​ophthalmometer, or an instrument for measuring the eye, which has proved of much service. His next researches were on the field of spectro-analysis, and he demonstrated that the results obtained by painters in mixing colors do not correspond with those of mingling the pure spectral colors of solar light or of other lights decomposed with a prism. He showed, for example, that, when yellow and blue rays of light are combined, the color produced is white, and not green. In connection with this subject, he entered into an admirable analysis of the extent and limits of human observation, and totally refuted at the same time Sir David Brewster's alleged decomposition of solar light.
In 1855 Helmholtz was called to the University of Bonn as Professor of Anatomy and Physiology, and director of the Anatomical and Physiological Institute. Three years later he removed to the University of Heidelberg, to fill a chair of Physiology, which he continued to occupy for more than twelve years. It would be tedious to enumerate every thing that his patient labor and the unerring logic of his mind demolished, while there, in the snug but shaky edifices of conservative science. He scattered the results of his researches with a liberal hand all over Germany. Every scientific periodical was honored by him with a contribution on its own specialty. There is, however, one class of his articles that appeared during this period which must not be overlooked. He had rendered valuable services toward an exact understanding of the mechanism of the eye, and had observed the physical laws of vision. He now turned his attention to a subject of equal importance. He investigated the mechanism of the ear, and searched for the laws of sound. His discoveries are laid down in his "Doctrine of the Sensations of Sound, as a Physiological Basis for the Theory of Music." It contains a complete analysis of the conditions of harmony, and reduces its aesthetic principles to a few fundamental physical laws.
Helmholtz's new doctrines of sight and sound have been universally received, and his fame will last as long as they continue to be among the main pillars of physical science. His name is also inseparably connected with the doctrine of the conservation of force, which subsequent investigation at the hands of others has shown to be the key-note of every law of Nature. Its bearing on the doctrine of evolution is, however, so strong and favorable that, like that doctrine, it will need much time before it receives an unreserved acceptance. Helmholtz tested, a few years ago, the progress which the doctrine of evolution has made, by asking the congress of natural philosophers, assembled at Speier, to declare, openly, who of them were in favor of, and who against, Darwinism. The roll was called, and there was not one against it. Helmholtz removed, in 1871, to Berlin, and holds there a professorship in the University.