MICROSCOPY IN MEDICAL PRACTICE.

118 NECESSITY IN THE INVESTIGATION OF DISEASE.

By G. H. MERKEL, M. D., Boston, Mass.

The present diagnosticating of diseases, is based almost exclusively upon physical examination. The subjective symptoms do not guide the practitioner, but chiefly those which he can count, measure, weigh, hear, touch, smell, and above all,

see.

For this purpose various instruments have been invented, in the last half-century, to aid the special organs of the practitioner in his diagnosis. As the thermometer tests the heat, so does the sphygmograph the pulse; the stethoscope, and now the microphone and telephone aid the hearing; the ophthalmoscope and laryngoscope, the sight. But neither of them has revealed as much to the medical practitioner as the microscope.

Until within a very few years, the scientific investigation of diseases, and the practical treatment and relief of the various maladies, to which humanity is subject, were held to be so entirely separated and distinct, that the medical practitioner was not expected to, nor did he, attempt to cultivate the knowledge of chemistry, materia medica, the therapeutic effects of drugs, histology, or microscopy. All these important and essential branches of the healing art, were looked upon as accessory, but by no means indispensable to the practice of medicine, or the attainment of the climax of the graduate's ambition-his diploma. Regardless of the fact that disease has its fundamental and irrevocable laws, and that those laws are equally within the comprehension of every student of medicine, the average practitioner, has seemingly contented himself with the temporary mitigation of the patient's sufferings, imagining that any time or talent spent in the investigation of its primary cause, was superfluous and unnecessary.

The developments of the last half-century, have shown most emphatically, that a practical and an intimate knowledge

of histology and microscropy, is as positively essential to the skillful and successful physician as an acquaintance with the principles of geometric and linear drawing would be to the architect or artist. Unless the medical attendant can diagnose the malady accurately, and trace the disease to its source, promptly watching, and even anticipating the chemical changes to which the human system in its abnormal condition is hourly subject, he cannot expect to be successful in his treatment, or to enjoy the confidence of his patients.

Even so early as the seventeenth and eighteenth centuries, the importance of histology and microscopy as auxiliaries to medical practice, began to be appreciated and acknowledged. The examination of the tissues, through the medium of crudelymade, but powerful magnifying lenses, is spoken of by Fallopius (1523-62). They were first introduced by Janssen (1590), an optician of Holland. The more minute structures of the human organism, were hidden from their gaze. They had neglected the marvels and mysteries of microscopic investigation, for the more elementary and comparatively simple branches of medical science, physiology, embryology, and comparative anatomy. Thus, with the exception of the work of Fontana, Muys, Lieberhuhn, Hewson and Prochasha, histology progressed but slowly during the whole of the seventeenth and eighteenth centuries, and its bibliography was little more than a disjointed collection of isolated observations. The first attempt to treat histology scientifically, and to award to microscopical investigation its proper position in medical practice, was made by M. Bichat, in 1801, when he published his far-famed Anatomie Generale. In this production he not only furnished a full and clear definition of the tissues, but gave perfect illustration of their physiological functions, and morbid alterations.

A few years afterward, (1809), Harting's achromatic microscope opened up a new and invaluable field of observation and research, and afforded an opportunity for the development of the law of cell-genesis and the molecular theory, so ably and satisfactorily systematized by Schwann and his successors, and brought to still greater perfection in the Cellular

Pathology of Virchow. The best, most popular, most comprehensive recent European work on general microscopy, is that of L. Dippel, (1867-69). Dr. Henry Frey's admirable work The Microscope and the Microscopical Technic as allied to the study of histology and clinical practice, is universally regarded by the medical and scientific world, as the highest and the most reliable authority on this important subject. It is translated into the English language by G. R. Cutter, M. D. The English work of L. Beale, The Microscope in Medicine, (4th edition, 1878), and the work of A. H. Hassall, Illustrations of the Microscopic Anatomy of the Human Body in Health and Disease, are to my mind an absolute necessity to the physician and student.

Microscopical investigation is so essentially a component part of histology, and of medicine generally, that the student cannot possibly study any one department of medical science without its aid as a sheet-anchor. Anatomy, physiology, pathology, chemistry, botany, toxicology and hygiene, are all more or less dependent for their demonstration and practical application to the human race on microscopic analysis.

While histology relates to the form and general doctrine of the elementary part of the human system, microscopical anatomy is concerned with the understanding of the microscopic forms, and with the laws of their structure and development, and their condition in health and disease. A collection of microscopical preparations is indispensably necessary for the exact study of histology, but it is a great mistake to suppose that any microscope will serve the purpose. The value of a microscope consists in its clearness of definition and objective power; many are in the market of inferior quality. Those made by Hartnack, of Potsdam; Smith, Beck, and Ross, of London; Spencer, of Wales; Dentmayer, and in particular, Tolles, of Boston, and Carl Jeiss, of Jena, have thus far exceeded them all by their constructions of the oil and homogenious immersion objectives, and being the most effective and reliable in my opinion.

Every practitioner and every student should not only possess a good microscope, but he should also know how to use it,

prepare his specimens for examination, and make accurate and careful drawings of his observations; for no amount of oral instructions or study, however good the teaching or textbook may be, will afford him that tangible or practical acquaintance with the microscopic character of objects, presented to his notice, which the personal preparation and examination of those objects would ensure.

It would be Impossible for me within the brief limits of this paper, to describe in detail, or even to enumerate the manifold uses of the microscope in the various departments of medicine and surgery. But in order that the physician of to-day may be enabled to keep pace with the demands of society, and the rapid studies which every other department of science has made;-in order that every practitioner of medicine may see the necessity of becoming his own microscopist, and appreciate its essential importance as the basis of his studies in pathology, physiology and therapeutics;-in order that he may avoid the errors, omissions and false conclusions into which our fathers in medicine have unwittingly fallen,—I will cursorily enumerate some of the uses and advantages attendant upon the introduction of microscopical investigation as a substantial and indispensable element in the practice of medicine.

Had Jenner known and understood the value of microscopy, he would not have outraged common sense and violated the first principies of nature, by the introduction of that insidious poison, vaccine, into the human system.

Had Harvey been thoroughly acquainted with the form and character of the blood-corpuscles, the changes to which they were subject, the method of enumerating them, and their importance as an element of diagnosis, his immortal discovery would have been immeasurably enhanced in value; thousands of lives might have been saved, or their lives prolonged; and the divine art of healing would have been brought to a far greater pitch of perfection than it yet has reached.

Neither in this country nor in England, despite the practical character of the people, has the public feeling been thoroughly awakened to the necessity of combining scientific investigation of disease with the treatment of the sick. As a natural

consequence, the amount of real knowledge concerning the origin, nature and properties of contagious poisons on the human organism, the morbific and chemical changes arising from the various abnormalities to which that organism is subject from atmospheric and other influences, and the influence exercised by constitutional or hereditary tendencies to disease is very scanty and fragmentary in its character.

Even the statistical information, periodically obtained by the local municipal organizations in the great cities on either. side of the Atlantic, were, and still are, incomplete and unreliable, from the fact that they signally fail in tracing the several diseases to their origin, and therefore, leave the great underlying evil unremedied and obscure. Whereas, were only one-third of the generous contribution for the relief of the sick poor, in the shape of benefactions to hospitals, dispensaries, and diet-kitchens, set apart to the investigation of the primary cause of disease by the organization of a microscopical and pathological laboratory in connection with every public institution, the inmates would be saved from a vast amount of suffering; the rate of mortality would be materially lessened; the taxation of the community would be reduced to a minimum; and the scientific skill of the medical faculty, as a whole, would be raised to an elevation which would command and obtain the universal confidence, and esteem, of the community generally.

These considerations bring us to the great question of the methods by which microscopical investigation, may be made available to the requirements of the medical science at the present time; and how far it is an imperative necessity in the treatment of disease.

In the study of the elementary parts of the muscular system, its structure and mode of action, and the general arrangement of the nervous organism, the plan of its distribution and reflex action, and the nature of nerve-force, microscopical examination is the only practical medium by which we can arrive at a knowledge of the phenomena of nervous affections generally, or discover efficient methods of treatment.

Then again, in ascertaining the nature of contagious dis