ARTICLE III.

THE RELATIONS BETWEEN THE STUDY OF THE EXACT SCIENCES AND THE STUDY OF MEDICINE.

BY PROF. J. E. DAVIES, OF THE STATE UNIVERSITY.

I feel that in coming before so purely practical a body as the State Medical Society, some apology is due from me whose actual work is merely one of preparation and education in the fundamentals, and not of actual work in applying these principles to the amelioration or cure of disease. My apology is that I every year see the ranks of the medical profession filled with a greater or less number of those who enter it with a very inadequate conception of what constitutes science in general, and who look upon the whole art of the physician as merely the putting into practice certain precepts they have learned for certain contingencies, and whose whole originality will ever consist in the impulse that first led them to conceive themselves fitted for a profession which really demands wider preparation, greater mental activity, quicker perceptions and more true originality than any other profession among men.

It is because I am anxious to contribute my share to the effort to raise the standard of medical education in this country, and to place the study of medicine, and consequently its practice, more nearly upon what I conceive to be its true basis, that I have ventured to appear before you with these hastily written, and I fear, too crudely presented remarks, upon the relations which, it seems to me, ought to hold between the study of the exact sciences in general and the study of medicine in particular. Generalization and specialization may seem to work against each other. Knowledge may sometimes be too general for practical utility, or on the other hand, so purely practical as to give no philosophical grasp of the subject; nevertheless, power to generalize is one of the most important powers of man and ought to be obtained in some way, and

mere nurse.

general studies may give it. Something of course depends upon the end to be ultimately attained, whether physician, surgeon, or The training involved in a Helmholtz, or Donders, is very different from that required by the ordinary physician; for one Claude Bernard there will be many many mere doctors of the liver, and but one Charcot to hosts of ordinary neurologists. Something also depends upon the special department of work which the medical student may ultimately take up. Yet it seems to me that for all alike there must always be two great points to be observed in the study of medicine, and the preparation for its practice. One is the attainment of the requisite special and technical knowledge and skill; the other, that cultivation of the judgment and power of logical deduction so much needed everywhere in the affairs of life, but nowhere more than in the accidents and emergencies of disease.

I speak now only of necessities, and not of accomplishments. Early youth would seem to be the appropriate time for the latter. It is certainly the time for the cultivation of the languages, and all depending most upon the memory. It is also the time for the right training of the affections. Later, when the reasoning powers are more developed, should come the study of the Sciences. For medicine this study should be accurate and far-reaching, and as far as possible specifically directed towards the bettering of the judgment in all matters bearing on the growth, development and disease of the human body. The "mystery of life" is certainly as great a problem as any that can interest the mind of man, and everything that can in the remotest degree throw light upon the organic processes or explain their perversions in disease is worth of study.

Now for the attainment of special and technical knowledge and skill. I wish to raise my voice aloud in favor of prolonged, careful, minute and accurate study of Anatomy, descriptive and microscopical, experimental physiology in all its details, the fundamental principles of optics especially those that underlie the construction and use of the microscope, the essential principles of Botany, the modern theory of heat and the modes of measuring it, the elementary principles of Chemistry (particularly of the so-called organic chemistry), the methods of chemical analysis, and so much of physics as shall make it utterly impossible for many of the existing humbuggeries to find any tolerance from medical men. This is especially true for the principles of electricity and magnetism. It

ought to be impossible for the venders of electric belts for example, to obtain certificates of their efficacy when the merest tyro knows that a closed circuit of a fraction of an ohm's resistance will be chosen by an electric current in preference to one of many thousand ohms, and by many experiments, I have found that almost the entire resistance of the body to the electrical current is offered by the passage into and out of the skin, so that no matter how near the electrodes are to each other, the resistance offered is from 3,000 to 13,000 ohms, according to the dryness and thickness of the skin.

Trousseau, somewhere in his lectures on Clinical Medicine, (the exact place I cannot now recall) has said in effect that the more completely the medical practitioner lets Physics alone, and the less help he expects therapeutically from it, the better will be his practice and success.

Like all other sweeping statements there is much to be said on both sides. Mathematical precision is undoubtedly not now to be attained in many subjects save as to a few of the fundamental points involved. Most results as we find them are the effects of a vast complication of causes, any one of which simply might possibly be expressed mathematically if we so desired. But as Sir John Herschel has remarked, if we should attempt to put into one mathematical expression the whole of what is involved in the simplest of the phenomena of organic life, we should probably have equations, any one of which would belt the earth. And so we need not attempt such vast generalities in a mathematically precise way. A line of battle may be confused and broken, swayed hither and thither, even broken as at Shiloh-into many detached parts, and yet be after all a line-possibly too, a very effective line. So too, many of the crude and hasty earth works thrown up in the late war, were very effective barriers against shot and shell, and saved many a valuable life, although but little engineering skill was displayed in their planning or arrangement. Indeed in most cases they had no plan, and were only the instinctive efforts of brave men to save themselves from useless destruction, and they well accomplished their purpose. Mathematically precise lines would have been useless under these circumstances, and anything would do so long as it met the needs of the hour. It is often thus in the ordinary affairs of life, and still more so in the exigencies that arise in medical practice.

Nevertheless as matters now stand, it would seem that while a very profound study of the exact sciences may not be necessary as a preliminary or as an accompaniment of the study of medicine (a few fundamental principles often having a very wide range of application in practice), the spirit and method of the exact sciences ought to enter more and more into medical traming. One has only to observe the conflict of opinions concerning the nature of many diseases, as evidenced in the discussions of medical societies and elsewhere, to see how little the methods—whatever may be true of the spirit—of these sciences are observed. Vague general impression without positive proof, an extraordinary attention to some features of a disease and a total neglect of others, an almost total neglect of the microscope and of chemical analysis in cases where they might apply, a lack of definition as to what exactly shall constitute a given disease, and even where a disease is well defined a lack of rigid observation as to whether all its features were present in a given case or not, all these things do certainly seem to indicate a wide departure from the methods which seem essential to the attainment of truth in the exact sciences, and without which apparently no real science can be built up.

On the other hand, what do we not owe to Microscopical Anatomy and its methods, to the exact analyses of chemical products of health and disease, to the experiments upon the relation of waste and work, of fever and heat, to the sphygmograph, the stethoscope, the ophthalmoscope, and all those other appliances for supplanting vague conjecture by reliable measurement, which the progress of the exact sciences has brought out during recent years.

There are very many questions in science at the present time which cannot be settled by experiments performed by single individuals. One man can, like Professor Ferrell, work out what must be the general influence of the earth's rotation upon all objects moving upon or above its surface, and thus explain the general laws of storms, but it requires a vast mass of observations taken all over the world, to verify these conclusions, and to give exactly the conditions of the atmosphere preceding, during and following storms. In other words, something of the nature of statistical knowledge must come in-knowledge wherein the experience of the many is made to correct the possibly too narrow conclusions of the few. One clear crucial experiment may settle a law where the conditions are

uncomplicated, but where many causes conspire to produce a result, as in disease, or in the functions of organic life generally, there may be so many chances of error that nothing but the widest possible deductions, made under a great variety of conditions can, with certainty lead to the truth. In this manner there has grown up within the domain of exact science itself a science of the sciences, a science of how the truth can best possibly be eliminated from error and the most probable results ascertained—the so-called theory of errors or the science of probability-the science of the discussion of observations. But this science presupposes observations of the most rigid and painstaking kind, done with instruments of the greatest precision, and by experienced observers. It assumes the elimination of all constant sources of error, i. e. those conditions that impress a certain bias in determinate directions upon the results, like heat or cold, dryness or moisture, wind or calm, etc., etc.

So there are in medicine hosts of questions which it does not seem possible to settle by easy or rapid experiment of individuals, but for the determination of which are required the widest possible inductions of many minds all over the world, making full use of all the appliances known to science, and that in the most scientific way.

I have said that a profound study of the exact sciences is not necessary for a medical man. Let me explain: First it is very hard to say exactly now-a-days, which are the exact sciences. It is generally customary, among scientific men to confine this term to the various mathematical and physical branches, but certainly, in these days, not only Chemistry, but Physiology, Histology, and even Pathology deserve to come in this rank. But it is the former particularly that I mean should not be pursued too far by the medical student. A knowledge of the Differential Calculus is very essential for the complete study of diffraction images and polarized light. But the medical student may thoroughly understand in a general way how the resolving power of his microscope may depend upon the ability of his objectives to combine diffraction images into ordinary ones, or how the plane of polarization is rotated by solutions of grape sugar, without knowing anything of the differential calculus. There is danger that if he once becomes absorbed in the mathematical portions of his work, and the sublime questions that arise from this side, he may be tempted away from his legitimate work, and