intricate and beautiful machines, was unable to answer the great new question: " What effect will this symptom or sign exercise on the field of battle?"
The whole weakness of the purely laboratory point of view was exposed in a flash. As a means of diagnosis this branch of medicine was of enormous value; as a means of arriving at a prognosis its value was much less. The new task of medicine was to interpret the findings of the laboratory and of the senses in terms of active life.
At the beginning there were many failures, and an outcry against the medical boards arose. Instances were cited of men who had broken down badly, though they had been passed " fit," and these made a considerable effect on the public mind. Nor did the retort that medicine had failed to find any sign of disease avail much. The layman replied that it was the doctor's duty to make a reasonable prognosis.
Clinical Medicine. This difficulty led with great rapidity to a new orientation. Clinical medicine the study of abnormal functioning at the bedside of the patient became really im- portant again; and the clinical revival which began at that time spread with amazing rapidity. Within a few years workers in every school of thought were adopting what are spoken of as " functional " standards. 1
Heart Disease. In no direction was progress so rapid as in the study of heart disease. This disease had escaped to some extent the bacteriological obsession. It remained a clinical problem because no definite infective agent had been found. In consequence old ideas prevailed and the shadow of the post- mortem room lay over every sign and symptom.
Popular apprehension of heart disease caused physicians, moreover, to stickle at sending any patient with a " murmur " to the fighting line. Happily, the British army medical authori- ties took a firm line, called to their help the leaders of what was then spoken of as the New Cardiology, who boldly applied their functional tests, and on the strength of them formed conclusions as to fitness for service. In spite of some anxious protests the views expressed were carried into effect, and men sent to fight who, in peace time, might possibly have been sent to bed. The result fully justified the method. Heart diseases, instead of proving the bugbear they had been in the early days of the war,
1 There was founded in 1920 by Sir James Mackenzie in the town of St. Andrews, Scotland, an Institute for Clinical Research which had hitherto no counterpart in the world. The reasons for taking this step were twofold: (i) While the signs of organic disease are well known and more or less easily recognizable, those of disease before organ damage occurs are almost entirely unknown. Disease before organic breakdown is thus an uncharted country. (2) I n order to chart it, it is necessary to study carefully and extensively the so-called " trivial " symptoms. Only by such an investigation can light be obtained on the real meaning of those symptoms. The town of St. Andrews was chosen for the site of the work because it is small and self-contained. It was felt that, if the history of any given symptom was to be followed up, and its progress into the future the only final proof of its seriousness or triviality to be determined, a resident and non-shifting population must be studied. Moreover, the work must be carried out by general practitioners because they alone are consulted by sufferers from trivial ailments, and so alone see the earliest manifestations of disease.
Sir James Mackenzie gathered around him the local medical men at St. Andrews, and they all became research workers in the institute. The methods employed are those of the bedside amplified and extended. Every symptom of which a patient complains is carefully observed and noted down and the records are filed, in- dexed and classified. Any laboratory examination which may be necessary can be carried out in the institution, but for the most part such instruments as the X rays are inapplicable, there being no ob- jective signs of disease. Periodically a particular symptom is studied intensively, for example exhaustion. By 1921, several important papers had come from the research workers. Their work revealed the fact that all symptoms depend for their production on disturb- ances of the normal reflexes of the body, another way of saying that they are exaggerations of physiological events. As most reflexes depend on the presence of a stimulating agent, a nervous mechanism and an organ or region stimulated, it is evident that a new pathway to the study of disease had been suggested. Thus, a morbid condi- tion may fall under the heading of one or other of the three factors mentioned : it may be an excessive or extraordinary stimulus (a stone in the ureter), or an agent acting in the nervous mechanism (the toxin of a disease) or actual involvement of organic structure.
ceased to give much trouble. This news spread rapidly, and a new era in the medical study of the heart began. Incidentally it was found that exercise greatly helped many sufferers from so-called heart affections, and later still many of those affections were traced back to bacterial diseases. Thus the so-called toxic theory of heart disease was strengthened. It came to be under- stood that with the advent of an infection disturbances take place in the mechanism of the heart and result in a depreciation of functional efficiency. This can be restored by two methods: destruction of the invading germ (e.g. in syphilis) or increase in the human resisting power (e.g. exercise).
Thus modern medicine achieved its two great principles the understanding of the meaning of signs and symptoms in terms of active life, and the necessity of conserving and buiHing up natural resistance against the enemies of the body. These principles, it will be seen, are complementary to one another. For prognosis must always vary with treatment. In the days before antidiphtheria serum was discovered the prognosis in diphtheria was very bad. Since the use of serum has become general it is, on the whole, good.
General Immunity. The early days of the bacteriological period had seen a movement away from drugs whose uses are directed to restoring the patient's strength. Instead, great search was made for substances capable of killing bacteria in the human body, and antiseptics and specifics of many kinds were introduced e.g. salvarsan, new combinations of quinine, sera. Later still the extension of methods of vaccination, for increasing specific natural immunity, occupied the forefront of research. Now general immunity, health in the broad sense, commanded attention. There was a revival of physical culture, and this was applied to the diseased as well as to the healthy.
Inevitably such a movement brought the study of physiology into new prominence and this indeed is another of the land- marks in a very interesting period. One of the applications was the work of Sir Almroth Wright and his assistants in war wounds. When the war began, surgery had passed back again from anti- septicism to asepticism. It had been found that the technique introduced and used by Lister was not necessary, that antiseptics were troublesome, and that absolute cleanliness secured all the advantages which these bacterial and protoplasmic poisons had gained for us.
Treatment of Wounds. The treatment of wounds made by a surgeon in a modern hospital and the treatment of wounds made by shells on the battlefields of France were two very different things. Asepsis was no use when sepsis was already present. As a consequence the cry " Back to Lister " was raised, and the wounds of war were deluged with strong solutions of carbolic acid, iodine and other substances. This procedure naturally resulted in some trouble, and at length Almroth Wright was commissioned to make an investigation of the whole subject.
His conclusions were that antiseptics are largely useless be- cause they fail to kill the germs of septic poisoning but do injure and weaken the tissues in which these germs are embedded. They thus interfere with a physiological process of repair and cleansing. Wright conducted some most delicate experiments, the object of which was to determine how wounds tend to heal and how deleterious matter is got rid of. He studied the lymph, or natural fluid, which flows out when a wound is made, and came to the conclusion that this, so long as it is fresh and un- contaminated, is an agent capable of destroying bacteria. If, however, the flow of lymph is dammed up, the fluid becomes corrupted and then forms an excellent pabulum for bacteria.
The case against antiseptics was that they tended to cause coagulation of the lymph and so produced " crusts " which dammed up the lymph flow. Thus more harm than good resulted. Wright, on the contrary, used salt solutions of various strengths, which increase lymph flow, and was able by this means to make wounds cleanse themselves. His views were received with im- mense interest, and were soon under discussion in every theatre of war and indeed in every civilized country. By some they were hotly contested, but they served effectually to put an end to the rash and indiscriminate use of antiseptics. Meanwhile, however,
