Popular Science Monthly/Volume 14/March 1879/Sketch of Christian Gottfried Ehrenberg
By FREDERICK HOFFMANN.
AMONG the pioneers and master minds in the domain of natural science, during the first half of the nineteenth century, several have risen far above their contemporary co-laborers, and have attained to heroic prominence; while a few, transcending the limits of their own period, have largely contributed to giving shape and character to their time, opened and entered upon novel paths or new fields of inquiry, and thereby have immortalized their life-work, and their name in history's imperishable record. Among these sovereigns of science ranks Christian Gottfried Ehrenberg, whose labors and researches for more than sixty years have connected his name with the most illustrious scientific discoveries of modern times.
Ehrenberg was the son of a Lutheran minister, and was born April 19, 1795, at Delitsch, in Prussia. Having received a classical education at home, and at the famous Schulpforte Gymnasium, he entered the University of Leipsic in 1815 as a student of theology. During the three years' course of theology, he also occupied himself with the study of natural sciences, and, through his increasing interest in the wonders of the creation, took up the study of medicine in 1818 at the University of Berlin, then as now the greatest and foremost of German universities. His efforts and researches were soon directed toward the investigation of the minute organisms and the ultimate forms and phenomena of organic life. Since the time of that first remarkable triumvirate, Malpighi, Grew, and Leeuwenhoek, who toward the close of the seventeenth and in the opening of the eighteenth century had laid the scientific foundations of the microscopical method of investigation, hardly any substantial addition, beyond those awakening mere curiosity, had been made to the observations of those eminent investigators. At the beginning of the nineteenth century, Dutrochet, Mirbel, Saussure, and Knight had inaugurated a more searching investigation into anatomy and physiology. Link, Treviranus, and Rudolphi followed with still more elaborate and comprehensive researches, and paved the way to the discoveries early attained and rapidly accumulated by Ehrenberg's genius and industry. His master mind discerned the disconnected facts and details of his material in the light of uniformity and generalization. In lieu of the then prevailing belief in generatio equivoca, one of the first achievements of Ehrenberg was an account of a long series of investigations, at once strikingly acute, thorough, and convincing, of a large number of fungi, demonstrating that they, no less than the higher vegetable organisms, originated from seeds. He soon explored the cryptogamic flora of the environs of Berlin, and published a series of important discoveries in his dissertation entitled "Silvæ mycologicæ berolinenses" (1818), and in other essays. To the former he prefixed the motto, which became, as it were, the key-note of all his later labors and works:
While still a student, the novelty and exactness of his observations and researches, and the high order of his deductions, at once established their author's reputation; and many of the eminent scholars and professors of the Prussian capital encouraged and aided the rising investigator, among them Lichtenstein, Alexander von Humboldt, Rudolphi, Link, Klug, Von Schlechtendal, Adelbert von Chamisso, Carl Ritter, Kunze, E. Mitscherlich, and others. After having passed the state medical examination, he was proposed for a professorship at the University of Konigsberg, and also by the Berlin Academy of Sciences as a scientific attaché to an archæological expedition to the Nile countries, instituted by the Prussian General von Minutoli. He accepted the latter offer, together with his friend Dr. Hemprich, of Berlin. The expedition started from Alexandria in Egypt, in September, 1820, went through the Cyrenaica to the oasis of Jupiter Ammon, back to Cairo; in 1821 to Fajum, the pyramids of Sakhara, to Dongola in Nubia; in 1823 to the Sinai peninsula, to Syria, the Lebanon ranges, to Balbek and return by the way of Tripoli to Damietta. These expeditions were followed by others into Abyssinia, sailing down the Red Sea, stopping at and making trips to Tor, Djedda, Mecca, the islands of Gumfude, Ketumbul, Dalac, Farsan, etc. At Massauna the joint expedition came to an untimely end by the death of Dr. Hemprich in 1823. Ehrenberg then accomplished the plan of their mission alone.
To what hardships and dangers Ehrenberg was exposed for years while traveling through and exploring arid deserts, amid hostile tribes of marauding Arabs, during the prevalence of an epidemic of the plague, and unprovided with any of the comforts and conveniences of later expeditions, may be seen from the simple fact that the expedition lost seven of its members by death, and that of its scientific attachés Ehrenberg alone survived. He returned to Berlin in 1826, with magnificent collections of botanical, zoölogical, and geological specimens, embracing all departments of natural science, and an immense number of microscopical preparations until then unknown, and which remain for verification and ready inspection to this day. The extent and importance of these rare collections may be estimated by the mere statement that they included 46,000 botanical specimens, representing 3,000 species of plants; about 34,000 specimens from the animal kingdom, representing 4,000 species; while no less comprehensive were the geological and ethnographical collections, the geographical and meteorological observations, and other results of the expedition.
Considering such material mainly as requisite means for investigation and for comparative study, Ehrenberg now applied himself with unceasing zeal and diligence to his rich collections, assisted by eminent scholars and artists, for the illustration of microscopical objects. The results were published during the years 1828-1830, in a volume entitled "Scientific Travels through Northern Africa and Western Asia, by Ehrenberg and Hemprich," and in a series of elaborate, strictly scientific works, written in the Latin language, with more than eighty splendid illustrative plates, the principal ones being the following: "Symbolæ physicæ, seu icones et descriptiones mammalium" (1828), "Symbolæ physicæ avium" (1828), "Symbolæ physicæ insectorum" (1829-1834), "Symbolæ physicæ animalium evertebratorum sepositis insectis" (1829-1831).
The continuation of these consummate researches and labors was interrupted for about one year, when in 1829 Alexander von Humboldt, Ehrenberg, and Gustav Rose, on invitation of the Russian Government, undertook an expedition to the Ural and Altaï regions, with the special aim of exploring their mineral resources. After the return from this exploration, Ehrenberg entered upon the most fruitful epoch of his labors and career: he accepted a professorship at the Berlin University, but still continued his original researches with unceasing assiduity. His first publications had already attracted the attention of the learned throughout Europe, and secured for the young investigator a reputation among the remarkable array of savants then in Berlin. When that severe critic, Cuvier, in 1830, presented Ehrenberg's first publications to the "Institute of France," he accompanied them with these words: "Ces découvertes changent entièrement les idées et renversent surtout bien des systèmes, elles sont du nombre de celles qui font époque dans les sciences."
The continuous series of publications founded on and recording his discoveries and researches, had reference principally to such problems and objects as the phosphorescence of the ocean, corals, fossil as well as living deposits of minute organic remains in the strata of the earth's crust, the minute organic life in the atmosphere, the phenomena of blood rain and snow, dust-showers and the "Bleeding Host," which latter one, during the middle ages, was the cause of the most barbarous excesses of the Inquisition. All these investigations and works were followed by his splendid exploration, beginning with 1840, of the minute organic creation, and by the disclosure of the influence of that "realm of littleness" in the development of the present condition of the earth's crust, and on the whole organic life of nature.
In consummate generalizations he laid down the results of his life-long, profound, and comprehensive observations and researches in the most famous of his many works, "Microgeology" (1854). Henceforth governments, travelers, and scientists, from all parts of the globe, submitted specimens and problematic objects to the investigation or the verdict of the Berlin microscopist and savant. Deep-sea soundings, which began about this time, were especially fruitful in material for research; and the surprising result was brought to view that organic beings exist even at the greatest depth of the earth's submarine declivities, previously believed to be void of life.
Those who, in common with the writer, during Ehrenberg's most productive years, have witnessed and participated in the ardor and enthusiasm of the great and genial scholar and teacher, will ever remember with veneration the originality and conscientiousness of his methods of research, his wonderful skill, elegance, and acuteness in microscopical observation, and, above all, the lucid and graphic description of the master whose eyes undoubtedly had done more close and critical microscopical research than those of any contemporary. In him were fully and harmoniously blended the strictest sense of duty and truthfulness, the highest order of intellectual attainments, the exquisite taste of the accomplished classical scholar, and the charm of religious faith, genial disposition, and a generous heart.
Ehrenberg continued his work steadily and unfailingly to the end of his life, even when his eyesight had become impaired by protracted application, and when almost all of his famous contemporary co-laborers at the Berlin University had passed away.
In reviewing the discoveries, the works, and achievements of Ehrenberg, one is strongly impressed by their vast number and their high order in a domain at once so abstruse and so unlimited. In his hands, microscopical research first attained its proper application and a definite character, and revealed new fields of inquiry, afterward successfully trodden by others; his physiological and biological investigations paved the way for those discoveries which, in rapid succession, have been since effected in the structure and processes of the human body in health and disease, and which have shed much light upon the progress of every branch of the healing art. His researches and achievements contributed to every department of the physical sciences; the minute organic creation became, for the first time in our knowledge, a new link in the scale of animated beings, and its influence upon the formation of the strata of the earth's crust and their geological history was recognized. All the writings of Ehrenberg, the occasional orations and addresses delivered by him as Rector Magnificus of the University, as Permanent Secretary of the Berlin Academy of Sciences, etc, are masterpieces of learning, of exquisite style, replete with exalted ideas, and form enduring evidences of their illustrious author's eminence. His name will ever be honored as the father of modern microscopy.
How profoundly faith and rare modesty were congenial to his mind, will appear from the following brief passage from one of his latest rectoral orations; "Investigators and writers who, because at the limit of their knowledge and powers, conclude that there is no soul, ergo no immortal life, may from their own point of view be quite right; but they are not on that account by any means to be accepted as representative men of science. The proper sentiment of the naturalist is this, that so far from pretending to inspiration or infallibility, he humbly recognizes the limitations inherent in his own intellectual powers, and imposed upon him and his time; while with all the faculties of his mind and soul, and with faith, he labors unbiased and assuredly, aiming at truth and confident of the usefulness of his life-work to his own or to subsequent generations, who sooner or later will recognize every true contribution to the stock of knowledge and to a purer and profounder insight into the wonders of the creation. The true investigator of nature should never divest himself of the idea that he is, as it were, a son in his Father's house and a co-worker, in his own humble sphere, with the great Ordainer of the universe."
The universal appreciation of Ehrenberg and his achievements found a spontaneous expression on the occasion of the celebration of the fiftieth anniversary of his doctorate in medicine, on November 5, 1868, when felicitations and honors poured in upon the veteran savant from all countries. The United States were represented in official congratulation by their Minister Plenipotentiary, Mr. George Bancroft, and in addresses from the American Association for the Advancement of Science, the American Medical Association, the American Pharmaceutical Association, and also in a poem by Dr. O. W. Holmes. These tributes were presented by Mr. Bancroft, who afterward had them all printed in a pamphlet.
Devoted and faithful to his life-work, he maintained his powers and his activity to the end. As stirring and brilliant as the day of his life had been, was its evening serene and hopeful; gently and without pain he passed away, on the 28th of June, 1876, in his eighty-second year.
His large and invaluable collections he bequeathed to the Museums of the University of Berlin.