Popular Science Monthly/Volume 17/September 1880/Sketch of Joseph Leidy

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PSM V17 D594 Joseph Leidy.jpg
JOSEPH LEIDY.
 

SKETCH OF JOSEPH LEIDY.
By EDWARD J. NOLAN.

IN 1849, Dr. Harvey, the author of the "Phycologia Britannica," describing his visit to the University of Pennsylvania, remarked, "There I met several persons, among whom was Dr. Leidy, a young man who will be famous if he lives and goes ahead according to present promises." The promises have been fulfilled. The young man of 1849 has gone ahead, and is now the most distinguished naturalist of America.

Joseph Leidy was born in Philadelphia, September 9, 1823. His father, Philip Leidy, was a native of Montgomery County, Pennsylvania, and his ancestors on both sides were Germans from the valley of the Rhine.

His taste for natural history was exhibited at a very early age, and received judicious encouragement from the master of the school where he acquired the rudiments of an English education. In his leisure moments he, like many other boys of his age, was fond of collecting colored pebbles and curiously shaped leaves long before he had ever heard the words mineralogy and botany. An itinerant lecturer, who described himself as belonging to he "Universal Lyceum," having one day been permitted to deliver a discourse to the school on minerals, his remarks being illustrated by specimens of quartz, mica, feldspar, etc., the boy's interest was so actively engaged that he procured for himself text-books of mineralogy and botany, and began the systematic study of the two branches without any further encouragement or assistance.

At the age of sixteen he left school, with the intention of becoming an artist, as his father proposed. It is evident, therefore, that the remarkable talent as a draughtsman, which has been of such service to Dr. Leidy in his scientific work, was apparent at this early age, and it is not improbable that the world in gaining a brilliant naturalist has lost a distinguished artist. In the mean time, however, much of his leisure had been passed in a wholesale drug-store near his home. His time here was so well spent that the proprietor did not hesitate, when an opportunity offered, to recommend him as competent to take temporary charge of a retail drug-store belonging to a customer. He was encouraged, by his success in filling the trust thus reposed in him, to study the properties and art of compounding drugs as a profession.

His study of nature while thus occupied had not been neglected. To botany and mineralogy he had added comparative anatomy, his first practical studies in that branch having been made on an ancient barn-door fowl and a common earthworm. So absorbed did he become in his anatomical studies, that at the suggestion of his mother, and with the consent of his father, he gave up all intention of becoming either artist or apothecary, and resolved to devote himself to that profession which would afford him the best opportunity of pursuing those studies from which it was now evident he could not easily withdraw himself.

In the autumn of 1840, therefore, he began the study of medicine, devoting his first year to practical anatomy. Having entered the office of Dr. Paul B. Goddard, he attended three full courses of lectures in the University of Pennsylvania, presented a thesis on "The Comparative Anatomy of the Eye of Vertebrated Animals," and graduated as Doctor of Medicine in the spring of 1844.

Immediately after receiving his degree, his first work in connection with the university was as assistant in the chemical laboratories of Drs. Hare and James B. Rogers. He began the practice of medicine in the fall of 1844, and continued it for two years, when he resolved to devote himself wholly to teaching. This course he has never had occasion to regret. His qualifications, natural and acquired, would undoubtedly have secured for him brilliant success as a practitioner, but his work as student and teacher has brought him not only satisfactory pecuniary reward, but also other things to which he attaches far more importance—peace of mind, sufficient leisure to pursue his favorite studies, and freedom from the toils and responsibilities which attend the daily life of the practicing physician.

In the winter of 1844, in addition to his work in the laboratory of Dr. Rogers, he assisted Dr. Goddard, who was then Demonstrator of Anatomy in the university. While yet a student he had attracted the attention of Dr. Horner, the Professor of Anatomy, by his success in making a beautiful preparation of the ducts of the lachrymal glands, and this interest was sufficient to secure his appointment as Prosector to the chair of Anatomy in the winter of 1845.

In the year 1846 Dr. Leidy was elected Demonstrator of Anatomy in the Franklin Medical College. He held this position, however, only during the first session, and the next spring again associated himself with Dr. Horner, and gave a private course of anatomical lectures to his students and others.

In the spring of 1848 he accompanied Dr. Horner to Europe, and enjoyed, for the first time, a long-desired opportunity of examining the museums and hospitals of England, Germany, and France.

On his return he gave a course of lectures on microscopic anatomy, and in the spring of 1849 began a course on physiology in the Medical Institute, but owing to ill health, induced by incessant labor, he was obliged to take a rest extending over several months.

In the spring of 1850 Dr. George B. Wood was transferred from the chair of Materia Medica to that of Practice of Medicine in the University of Pennsylvania. Desiring to form an illustrative collection of specimens, models, and drawings, he was accompanied to Europe by Dr. Leidy, whose services in the selection of the material required will be evident to those who visit the museum of the university.

In the winter of 1852 Dr. Horner, who had been in ill health for some time, was unable to continue his course. With the consent of the Board of Trustees, he appointed Dr. Leidy as his substitute, and so acceptable to faculty, trustees, and students were the lectures delivered in completion of the course, that, on the death of Dr. Horner, Dr. Leidy was elected Professor of Anatomy in the spring of 1853.

During the war he was surgeon to Satterlee Military Hospital. His special duty was to report on the more important post-mortem examinations made, and several of these reports, with beautiful illustrative drawings, are published in the "Medical and Surgical History of the War."

In 1871 he was appointed Professor of Natural History in Swarthmore College, a position which his natural aptitude for imparting scientific information makes pleasant to him.

Apart from the record of his intellectual activity there is but little more to be stated regarding Dr. Leidy, for we are of the opinion that in an article of this kind a eulogium would be out of place, although in the present instance there is every temptation to write a warm one. Since his election to his professorship in the University of Pennsylvania, Dr. Leidy's life has been the placid one of the student. At the earliest possible moment he had resolved to depend wholly on his own efforts for a livelihood. The struggle had been severe, the work incessant, and the success achieved at the early age of thirty years was due, not at all to social or family influence, but solely to personal merit. Since 1853 his published works have been his "footprints on the sands of time," and it only remains to allude briefly to the more important of these, and to his connection with an institution which in no small degree has been instrumental in enabling him to secure his present enviable position in the scientific world.

In 1844 Dr. Amos Binney, who then contemplated the publication of his superb work on the terrestrial air-breathing mollusks of the United States, was desirous of employing an anatomist who was also an artist, to dissect and draw the internal organs of the species to be described. On the recommendation of Dr. Goddard, Dr. Leidy was selected to take charge of the work. The result was the production of sixteen plates, giving the anatomy of thirty-eight species of native mollusks with a beauty of finish and accuracy of detail which have never been excelled. Dr. Leidy afterward wrote the chapter of the introduction entitled "Special Anatomy of the Terrestrial Mollusks of the United States."

Dr. Binney's intention, after the work had progressed sufficiently to demonstrate the ability of the artist to render much higher service than that of a mere draughtsman, was that Dr. Leidy should give a complete anatomical and physiological description of the terrestrial gasteropoda of the United States, including the special and general anatomy, with the embryology of the several genera. Before the special anatomy was completed, however, the death of Dr. Binney put a stop to the work. Referring to Dr. Leidy's dissections and drawings, Dr. Binney very justly remarks in his preface, "They constitute the most novel and important accession to science contained in the work, and are an honorable evidence of a skill and industry which entitle him to a high rank among philosophical zoölogists."

Dr. Leidy's studies of the terrestrial gasteropods excited the attention of the leading naturalists of Philadelphia, and quickly brought him into communication with Cassin, Morton, Phillips, Bridges, Griddon, Gambel, Conrad, Vaux, Pickering, and other leading members of the Academy of Natural Sciences. Community of interests led to an intimate association with those gentlemen, and he was elected a member of the Academy in July, 1845.

His first published communication, entitled "Notes on White Pond, Warren County, New Jersey," was presented to the Academy in October of the same year, and so active from that time was his work in connection with the society that, at the annual election, in 1846, he was elected chairman of the Curators, a position which he has since uninterruptedly occupied. With characteristic modesty he has frequently declined the presidency of the society, and has contented himself with the quiet, unostentatious performance of the very important duties of chairman of the Curators. The respect and personal affection with which Dr. Leidy inspires every one brought into intimate communication with him, together with his practical good sense and knowledge of the needs of a large collection of objects of natural history, have enabled him to act with great efficiency in his office for the good of every department and interest of the society. He has been also a number of years chairman of the Library and Publication Committees.

Shortly after assuming his position in the university, Dr. Leidy edited an edition of Sharpey and Quain's "Anatomy," with a view to supplying the wants of his class while preparing a manual of his own. The latter was published in 1861, and for clearness and accuracy of statement and convenience of arrangement has not been equaled by any other elementary treatise on human anatomy in the English language.

Dr. Leidy's earlier scientific work was confined to no specialty. The whole field of Nature lay extended before him, and innumerable were the objects of interest which engaged his attention. Hence one is surprised to find how almost encyclopedic is Dr. Leidy's knowledge of natural history. Although he has published little or nothing upon either mineralogy or botany, his knowledge of both these sciences is rather that of one who devotes himself specially to them than that of the casual student. The pages of the "Proceedings" of the Academy for 1845 and 1846, however, indicate that his favorite field of research during that time was among the lower animal forms, and that his microscope was often brought into use. The anatomy of spectrum femoratum (Say), new species of entozoa, the mechanism which closes the wings of grasshoppers, the situation of the olfactory sense in the gasteropods, and new species of planarian worms, were among the subjects upon which communications were published in rapid succession during the first two years of his connection with the Academy.

In October, 1846, he recorded the occurrence of a species of trichina in the hog, and stated that he could perceive no distinction between it and Trichina spiralis which he had met with in several human subjects in the dissecting-room, since attention had been directed to it by Mr. Hilton and Professor Owen. Leuckart afterward acknowledged that he was indebted to this communication for his success in tracing the development of trichina in the hog and man.

In September, 1847, he published his first paleontological paper, entitled "On the Fossil Horse of America," in the "Proceedings" of the Academy. The existence of remains of extinct horses on the American Continent had been regarded with incredulity, in consequence of the entire disappearance of these animals in after-ages. The paper consists of descriptions and figures of specimens contained in the Museum of the Academy of Natural Sciences of Philadelphia, some of which the author regarded as belonging to the South American form, described by Owen under the name Equus curvidens, and others as indicating a new species, for which he proposed the name Equus Americanus.

His investigations on the development of cartilage-cells, the structure of the liver, of the nettling organs in hydra, the presence of the first indication of muscular fiber in the gregarines, the discovery of the eye in the perfect condition of the cirrhopoda, together with descriptions of many new forms of entozoa and entophita, miscellaneous anatomical and zoölogical notes, and a continuous series of papers entitled "Helminth ological Contributions," enriched the pages of the "Proceedings" of the Academy during the next four or five years. His elaborate memoir on the "Anatomy of Corydalus Cornutus in its Three Stages of Existence," published in the "Memoirs of the American Academy of Arts and Sciences," and his beautifully illustrated monograph entitled "A Flora and Fauna within Living Animals," issued as part of the fifth volume of the Smithsonian contributions to knowledge, merit special mention.

These communications, laboriously prepared as many of them were, did not, however, indicate the full extent of Dr. Leidy's industry. Since the publication of his paper on the fossil horses of America, much of his time had been occupied in the study of the vertebrate fossils in the museum of the Academy, or which were brought to his notice from time to time by collectors. Long before the active exploration of the West had added so immensely to our knowledge of the extinct fauna of that region, he had determined the former existence, in a tropical climate on our western slope, of the lion, the tiger, the camel, the horse, the rhinoceros, and many other forms having no immediate existing representatives.

In 1853 the Smithsonian Institution published his memoir on the extinct species of American ox, and in the following year the elaborate "Ancient Fauna of Nebraska." Other paleontological papers were published in the "Transactions of the American Philosophical Society," and many new genera and species were announced in the "Proceedings" of the Academy. The extent to which Dr. Leidy was absorbed in his paleontological studies, between the years 1854 and 1872, may be judged by the fact that, out of seventy-two communications published during that period, only thirteen were on the subjects to which he had formerly devoted his attention, and these were, for the most part, brief reports of verbal communications made before the meetings of the Academy.

In 1869 his memoir entitled "The Extinct Mammalian Fauna of Dakota and Nebraska" appeared as the seventh volume of the journal of the Academy. The work, a quarto of 472 pages, illustrated by thirty lithographic plates, is the result of the gradual accumulation of material during twenty-three years. This elaborate work was followed in 1873 by one of equal importance, under the title "Contributions to the Extinct Vertebrate Fauna of the Western Territories." It forms the first volume of the superb quarto reports of the survey of the Territories, under Dr. Hayden, and consists of 354 pages and thirty-seven plates.

For many years after the publication of his paper on fossil horses, in 1847, Dr. Leidy was almost the only American author whose attention was given to the study of the extinct vertebrata. The wonderful remains brought to light by the explorations under the direction of Dr. Hayden had, however, excited the interest of others, and private expeditions, as well as the official surveys, had collected rich stores of vertebrate fossils, in some cases from the same localities whence came the material submitted to Dr. Leidy's examination. The anxiety to obtain early publication of descriptions of supposed new forms became so great that, in at least one instance, such description was telegraphed to a learned society from the field. The dispatch was published with as little delay as possible, but the paragraph contained so many errors that the experiment has not, we believe, been repeated. In the attempt to settle questions of priority, the published arguments became so bitter and the personalities indulged in so pronounced that Dr. Leidy, who had been able to refrain from taking part in the controversy, finally withdrew from the field. With characteristic amiability, he had remarked in the preface to his last-named work: "The investigations and descriptions of some fossils from the same localities have been so nearly contemporary with my own that, for want of the opportunity of comparison of specimens, we have no doubt in some cases described the same things under different names, and thus produced some confusion which can only be corrected in future." And, while others were making anxious inquiries regarding dates of issue, and personal bulletins were followed rapidly by bitter little notes of reclamation, he placidly held to the belief that the future would undoubtedly award the credit where it belonged, and withdrew to resume the studies which he had prosecuted so successfully in former years. The only paleontological communication of importance which he has since published is his "Description of Vertebrate Remains, chiefly from the Phosphate Beds of South Carolina," in the eighth volume of the journal of the Academy.

Finding that the activity and enthusiasm of the younger naturalists, who had taken up the study of the extinct fauna of the West, were quite sufficient to guarantee the prompt use of the fine collections which still continue to be received from that region, and constitutionally indisposed to take part in the battle for priority, Dr. Leidy availed himself with pleasure of the opportunity to study a group of minute organisms to which he had already given some attention. For the next four years he devoted all his spare time to collecting, studying and delineating the fresh-water rhizopods of America, and the results of his work are embodied in the twelfth volume of the report of the United States Geological Survey of the Territories. The memoir is entitled "Fresh-water Rhizopods of North America," and is perhaps the best illustration of Dr. Leidy's qualities as a naturalist, and the most enduring monument to his industry, which has yet appeared. While preparing the work he spent the greater portion of two seasons in the West, under the auspices of the Survey, and made careful explorations of the country about Fort Bridger, the Uintah Mountains, and the Salt Lake Basin, in search of materials for the memoir.

Since the issue of this superb monograph, Dr. Leidy has been engaged in preparing a new edition of his manual of human anatomy. When this is finished, he intends collecting material for an elaborate illustrated work on parasites. He will probably publish, in the next number of the journal of the Academy, a paper on the parasites of the white ant, many curious forms of which were brought to his notice during his studies of the rhizopods.

The value of Dr. Leidy's scientific work has lately been substantially recognized by the Council of the Boston Society of Natural History, which awarded him the Walker Prize. On account of the extraordinary merit of his researches, the prize, which usually consists of the sum of $500, was on the occasion increased to $1,000.

In the performance of the great scientific work thus imperfectly recorded, Dr. Leidy has confined himself to the duty of accurately describing what he has seen. He very rarely draws inferences from his accumulated facts, and his innate truthfulness is such as to deter him from theorizing. As a lecturer he rarely indulges in figures of speech or flights of fancy. He is deliberate and lucid in his statements, some of his word-pictures being so nearly perfect as to make the fine blackboard drawings with which he often illustrates his remarks almost unnecessary. His delight at acquiring knowledge of a new fact is only equaled by his pleasure in communicating it to others.