Heroes of science

by P. Martin Duncan

Aristoteles founded the natural history of his age, and no one came near to him. He left nobody behind to follow his work.

In after years, Plinius wrote on beasts, fishes, birds, and insects, and on human and comparative anatomy, but he made no great advance on Aristoteles. Then there occurred as great a gap in the study of zoology as happened in botany, and many hundreds of years elapsed before progress was made.

Conrad Gesner, a Swiss, made the first great step in zoology after the ancients, and his life was a most remarkable one. A writer says of him, that he was a shining example of the truth of the remark, that those who have most to do, and are willing to work, find the most time. He was a great scholar, and a profound naturalist. He began life in extreme poverty, soon became an orphan, laboured whilst ill, and sacrificed himself for the sake of others. A son of a poor skinner and worker of hides, he was born in 1516, at Zurich, and had to suffer pinching poverty, with his numerous brothers and sisters. An uncle was kind to the boy, and began to educate him, but death stepped in and he lost his kind relation. When only thirteen years of age, Gesner was cast upon the world, his father having died fighting in the battle of Zug. The lad was seriously ill and dropsical, and his sole fortune was a little knowledge of classics, which he had picked up. Probably one of the professors at Zurich, Ammian by name, and who had instructed him, gave him introductions, for we find the lad at Strasbourg when fifteen years of age. His thoughts were to go into the Lutheran Church, and it is certain that the Lutheran Wolfgang Fabricius Capito gave him some employment, and enabled him to begin the study of Hebrew. Returning again to Zurich, the university there gave him a little pension, to enable him to travel, and he went into France to Bourges. There he taught at a school, and occupied his spare time in learning Greek and Latin. Then he went to Strasbourg again, hoping for employment, and finding none, was asked to return to Zurich, and to teach in the university. At the age of twenty he married, and, of course, much against the wishes of his friends, who do not appear to have done anything for him, except to have given gratuitous advice. Although the Church was to be the career of Gesner, he took much interest in the healing art, and resigning his position at Zurich, he went, having a small pension, to Basle as a medical student. Anxious to know the wisdom of the Greek physicians, he paid unusual attention to that language, and edited an edition of a dictionary of it. This study brought strange results, for he was offered a professorship of Greek at Lausanne, and he accepted the position. He was very young, and yet learned men found his friendship valuable. Going, subsequently, to Montpellier, he became acquainted with a naturalist named Rondelet, and he gradually began to earn enough money to be independent. So he returned to Basle, and in 1541, being twenty-five years old, took his degree in medicine. He settled in practice at Zurich, and occupied his spare time in studying zoology and botany, and soon became wealthy. Occasionally he travelled, and during one of these trips he became acquainted with the leading men at Venice and Augsburg, and at their instance began a great work, a kind of universal catalogue of Greek, Hebrew, and Latin works. All this time he was slowly and surely studying animals and plants, and in 1551 the first part of his “History of Animals” appeared, to be followed by others in 1554, 1555, and 1556. The volumes contained descriptions of viviparous quadrupeds, that is to say, four-footed beasts, whose young are born in active movement; of oviparous quadrupeds, or those which lay eggs; of birds and of fishes, and other aquatic animals. He wrote also upon insects. All agree that this book is a miracle of industry, having for its object no less than a general history of animated nature. It contains a careful criticism of the works of previous authors, and, besides much valuable and solid knowledge on zoology, many interesting remarks on the habits and medicinal uses of animals. He followed the method of Aristoteles, and the notion of the genus was, of course, not satisfactorily established; but the book was the source of much of modern zoology, from which succeeding writers drew largely.

Gesner’s botanical works were as great as those relating to animals, and he designed and painted fifteen hundred figures of plants, which were of great use to his successors. As if he had not enough to do, he translated the Greek works of Aelian, on animals, in 1556. Scientific and industrious, he had much to contend with, and was short-sighted. He was the first person who used concaved glasses to remedy this defect in his sight. As years rolled on, Gesner was much liked and honoured in his native town; he was very amiable, a great peacemaker, and a liberal citizen. He established a botanic garden, and gave employment to artists. Whilst in the full vigour of life, and in active practice as a physician, the plague attacked Zurich, and Gesner successfully combated the contagious disorder in many cases. He exposed himself without fear, after the fashion of most medical men, and unfortunately caught the disease. When the worst symptoms came, he knew his hour was at hand, and asked to be carried into his library and museum, where all the treasures he had collected and described, to the delight of his students and friends, were deposited. There he breathed his last, in the arms of his affectionate wife, for whose love contagion had no terrors. He died with the calmness of a Christian philosopher, on the fifth day of his attack, at the early age of forty-nine. His remains rest, much honoured, in the cloister of the Greek church at Zurich. Not only did Gesner consolidate the knowledge of the animal and vegetable kingdom of his day, but he also influenced other authors to do good work, and to avoid unkind criticism. His calm, candid, and equable temper enabled him to soothe the angry feelings of others, under their real and imaginary wrongs. He laid aside his own labour to assist others, and he devoted much time to the supervision and publication of a work which was left incomplete, by a deceased friend, so as to provide for the family.

Gesner’s life is a very good proof that where there is a will there is a way, and that poverty does not impede the path of a thoroughly industrious and earnest man. The poor skinner’s son’s name is respected at the present day, and will be so, as long as science lasts.

The interesting life of Ray has already been given amongst those of the heroes of botany; he was, however, a zoologist of the first class, and his devotion to that part of natural history was part of his great friendship for Mr. Willughby. This promising young man studied under Ray, at Cambridge, and whilst the master took plants under his care and study, the pupil began to work at animals. They made a tour together, visiting France, Spain, Italy, Germany, and the Low Countries. Ichthyology, or the study of fishes, and ornithology, or the study of birds, occupied the attention of Willughby. Having collected a vast number of specimens and observations, they returned to England, and Willughby immediately commenced working with a view to the publication of a great work on the animal kingdom. He even contemplated a visit to America; but health failed, and he died in the prime of life, on July 3rd, 1672. The education of his two infant sons was confided to Mr. Ray, who was one of his executors. Willughby thought his works too imperfect for publication, but Ray felt otherwise, and urged it upon him for three reasons: first, the glory of God; secondly, the assistance of others in the same studies; thirdly, the honour of his native land. Upon these grounds he gave his consent, and Ray became their editor. A book on birds, “The Ornithologia,” was the result, and it contains a large amount of original observation, and is a full and exact description of the habits and maladies of birds, and the best means of domesticating them. Excellent anatomical descriptions are added. Subsequently, a book on the fishes of the Mediterranean appeared.

The merits of Willughby as a natural historian still continue to be recognized. He was a most accomplished zoologist, and he gave Ray and Linnæus the method of classification of animals which is usually associated with their names. Ray acknowledged this, and he says that he found among his friend’s manuscripts the histories of beasts and insects, no less than of birds and fishes, “digested with a method of his own.” He was not a simple wealthy and intelligent amateur, for he was master to one of the greatest naturalists. Ray, in editing Willughby’s “Book on Birds,” gives a most touching preface to the memory of his friend. He says, “He was from childhood addicted to study, and ever since he came to the use of reason, so great a husbander of his time, as not willingly to lose, or let slip unoccupied, the least fragment of it; detesting no vice more than idleness, which he looked on as the parent and source of all others. Of his skill in natural philosophy, chiefly the history of animals, I shall say no more at present, but that it hath not yet been my hap to meet with any man, whether in England or beyond seas, of so general and comprehensive knowledge therein.”

A very different career, but one which has had a greater general influence on natural history, was that of John Swammerdam, who was born at Amsterdam, in 1637, his father being an apothecary. His grandfather, Jacob Dirkz, was born in the village of Swammerdam, near Leyden, and his father, a well-to-do apothecary, lived there and took his name from the village. He married Berendina Corvera and settled at Amsterdam. The family lived in comfort, and the little one was destined, like many other naturalists, to the Church. His education consisted of sound Latin and Greek, and when he became old enough, he began to feel that there were responsibilities about his future office as a clergyman, which he did not think he could fulfil. Holland at that time was in a religious ferment, and sects of all kinds existed, religion being more talked about than practised. The lad, as he grew up, desired to follow in his father’s footsteps, and to learn the healing art; but his genius led him to the study of nature. Before he was fifteen years of age, he began to make collections of natural history objects, and whenever he could get away from home, and spare time from his medical studies, he pursued his favourite employment, searching the woods and fields, the sand-hills and muddy shores, the lakes, rivers, and canals, for insects, worms, and molluscs, until he acquired, even as a youth, a more extensive knowledge of the lower animals than all the naturalists who had preceded him. In 1661 he went to Leyden and studied surgery and anatomy. In this last he excelled, and became celebrated for his methods of preserving dissections. Then he went to Saumur, in France, and to Paris, where he gained the friendship of Thévenot the traveller, who was his patron subsequently, and assisted him when in Amsterdam in after years, by obtaining permission for him to dissect human bodies. His fellow-pupil was Nicholas Steno, of whom more will be said under the title of “Heroes of Geology.” On his return to Leyden, Swammerdam discovered the method of injecting arteries with coloured wax, and of keeping the internal organs in a dry condition for purposes of study, and investigated the nature of the lymphatics. He graduated soon after, and after receiving his diploma, returned to his old love, nature, and occupied nearly all his time in the anatomy and physiology of insects.

Swammerdam worked so incessantly, that he got into bad health, and was obliged to relinquish the medical profession for a time. He followed up his researches into the minute construction of insects, and really never ceased them until death. The Grand Duke of Tuscany visited Amsterdam at this time, and examined Swammerdam’s collections. Greatly impressed with their value, and with the splendid dissections, he offered a home to the young naturalist in his palace, and twelve thousand florins for the collection. Swammerdam, however, did not care to wear a collar; and loving freedom of thought, which he did not think he would have in Italy, declined the offer. He knew that he would be expected to change his religious tenets, and said that he would not sell his soul for money. He published a “General History of Insects,” in 1669, and soon afterwards broke down, entirely, in health, so that he had to go into the country to rest and do nothing. But this was impossible; and he began to study bees, and their natural history. Probably it was this constant weak health, and the solitude necessary for the peculiar nature of his work and observations, that had a very remarkable influence on the mind and emotions of this great investigator. Always religious, he longed more and more for communion with his Maker and the author of all the wonders he was constantly studying. When in better health he was happy in his thoughts, and considered that it was his duty to study nature; but when ill, from the effects of overwork, he began to think that his labours were leading him astray, and that to seek the good opinion of his fellow-creatures and to become famous, was a sin. Sometimes he gave up science, to begin again with fresh zeal, and then he would neglect it, giving up his whole time to religion. Unfortunately he was unreasonable in his method of working. Boerhaave, the great physician, thus wrote of Swammerdam: “He laboured so assiduously at this work as to destroy his constitution, nor did he ever recover a shadow of his former strength. The labour, in fact, was beyond the power of ordinary men—all day he was employed in examining objects, and at night described and delineated what he had seen by day. At six in the morning, in summer, he began to receive sufficient light from the sun to enable him to trace the objects of his examination. He continued dissecting until twelve, with his hat removed lest it should impede the light, and in the full blaze of the sun, the heat of which caused his head to be constantly covered with profuse perspiration. His eyes being constantly exposed to a strong light, the effect of which was increased by the microscope, they were so affected by it, that after midday he could no longer trace the minute bodies which he examined, although he had then as bright a light as in the forenoon.”

Swammerdam investigated the nature of the changes of outside form and internal structure which accompany insect life. Some of his drawings of the escape of the ephemera fly from its sheath of delicate skin on the surface of the water, and out of the wingless or nymph condition, are very beautiful. But his accuracy regarding the minute internal changes of the tissues and organs in the larva, pupa, and perfect insect is being more and more acknowledged. He taught that these changes were not sudden, but that a continuous growth of organs and tissues culminated at certain times of the life of the insect. The larva, or caterpillar, admirably adapted for its course of life, was a stage of the life cycle of a more perfect form, the imago or flying insect. Swammerdam stated that all the organs of the perfect insect—a butterfly, for instance—were in a visible yet only slightly developed condition in the caterpillar. And late researches are leading to prove that he was right, for the wings of the future fly are to be detected in the body of the tiny crawling thing that escapes from the egg.