disease in its static aspects only, and also for the most part in the particular aspect of final demolition; and it became manifest as pathology and clinical medicine became more and more thoroughly integrated, that the processes which initiate and are concerned in this dissolution were not revealed by the scalpel.
Again, the physician as naturalist, though stimulated by the pathologist to delineate disease in its fuller manifestations, yet was hampered in a measure by the didactic method of constructing “types” which should command the attention of the disciple and rivet themselves on his memory; thus too often those incipient and transitory phases which initiate the paths of dissolution were missed. Not only so, but the physician, thus fascinated by “types,” and impressed by the silent monuments of the pathological museum, was led to localize disease too much, to isolate the acts of nature, and to forget not only the continuity of the phases which lead up to the exemplary forms, or link them together, but to forget also that even between the types themselves relations of affinity must exist—and these oftentimes none the less intimate for apparent diversities of form, for types of widely different form may be, and indeed often are, more closely allied than types which have more superficial resemblance—and to forget, moreover, how largely negative is the process of abstraction by which types are imagined. Upon this too static a view, both of clinical type and of post-mortem-room pathology, came a despairing spirit, almost of fatalism, which in the contemplation of organic ruins lost the hope of cure of organic diseases. So prognosis became pessimistic, and the therapeutics of the abler men negative, until fresh hopes arose of stemming the tides of evil at their earliest flow.
Such was medicine, statically ordered in pathology, statically ordered in its clinical concepts, when, on the 24th of November 1859, the Origin of Species was published. It is no exaggeration to say that this epoch-making work brought to birth a world of conceptions as new as the work of Copernicus. For the natural philosopher the whole Influence of Darwin. point of view of things was changed; in biology not only had the anthropocentric point of view been banished, but the ancient concept of perpetual flux was brought home to ordinary men, and entered for good into the framework of thought. The study of comparative pathology, yet in an inchoate stage, and of embryology, illuminated and enlarged biological conceptions, both normal and abnormal; and the ens reale subsistens in corpore disappeared for ever—at any rate from physiology and medicine. Before Darwin—if the name of Darwin may be used to signify the transformation of thought of which he was the chief artificer—natural objects were regarded, not in medicine and pathology only, as a set of hidebound events; and natural operations as moving in fixed grooves, after a fashion which it is now difficult for us to realize. With the melting of the ice the more daring spirits dashed into the new current with such ardour that for them all traditions, all institutions, were thrown into hotchpot; even elderly and sober physicians took enough of the infection to liberate their minds, and, in the field of the several diseases and in that of post-mortem pathology, the hollowness of classification by superficial resemblance, the transitoriness of forms, and the flow of processes, broke upon the view. Thus it came about not only that classifications of disease based on superficial likeness—such as jaundice, dropsy, inflammation—were broken up, and their parts redistributed, but also that even more set diseases began to lose their settlements, and were recognized as terms of series, as transitory or culminating phases of perturbations which might be traced to their origins, and in their earlier stages perhaps withstood.
The doctrine of heredity in disease thus took a larger aspect; the view of morbid series was no longer bounded even by the life of the individual; and the propagation of taints, and of morbid varieties of man, from generation to generation proved to be no mere repetition of fixed features but, even more frequently, to be modes of development or of dissolution betraying themselves often in widely dissimilar forms, in series often extending over many lives, the terms of which at first sight had seemed wholly disparate. Thus, for example, as generations succeed one another, nervous disorders appear in various guise; epilepsy, megrim, insanity, asthma, hysteria, neurasthenia, a motley array at first sight, seemed to reveal themselves as terms of a morbid series; not only so, but certain disorders of other systems also might be members of the series, such as certain diseases of the skin, and even peculiar susceptibilities or immunities in respect of infections from without. On the other hand, not a few disorders proved to be alien to classes to which narrower views of causation had referred them; of such are tabes dorsalis, neuritis, infantile palsy or tetanus, now removed from the category of primary nervous diseases and placed in one or other of the class of infections; or, conversely, certain forms of disease of the joints are now regarded with some certainty as members of more than one series of diseases chiefly manifest in the nervous system. In the effects of simpler poisons the recognition of unity in diversity, as in the affiliation of a peripheral neuritis to arsenic, illustrated more definitely this serial or etiological method of classifying diseases. On the other hand, inheritance was dismissed, or survived only as a “susceptibility,” in the cases of tubercle, leprosy and some other maladies now recognized as infectious; while in others, as in syphilis, it was seen to consist in a translation of the infectious element from parent to offspring. These new conceptions of the multiplicity in unity of disease, and of the fluidity and continuity of morbid processes, might have led to vagueness and over-boldness in speculation and reconstruction, had not the experimental method been at hand with clues and tests for the several series. Of this method the rise and wonderful extension of the science of bacteriology also furnished no inconsiderable part.
In the disease of the scalp called favus, Schönlein had discovered a minute mycelial fungus; a remarkable discovery, for it was the first conspicuous step in the attribution of diseases to the action of minute parasites. Schönlein thus did something to introduce new and positive conceptions and exacter methods into Germany; but unfortunately Bacteriology. his own mind retained the abstract habit of his country, and his abilities were dissipated in the mere speculations of Schelling. Similarly Karl Hoffmann of Würzburg wasted his appreciations of the newer schools of developmental biology in fanciful notions of human diseases as reversions to normal stages of lower animals; scrofula being for him a reversion to the insect, rickets to the mollusc, epilepsy to the oscillaria, and so forth. Even that distinguished physiologist Johannes Müller, remained a staunch vitalist. Fortunately Germany, which at the beginning of the century was delivered over to Brownism and vitalism and was deaf to Bichat, was rescued from this sort of barrenness by the brilliant experimental work of Claude Bernard and Pasteur in France—work which, as regards the attenuated virus, was a development of that of Edward Jenner, and indeed of Schwann, Robert Koch worthily following Pasteur with his work on the bacillus of anthrax and with his discovery of that of tuberculosis; and by the cellular doctrine and abundant labours in pathology of Virchow. Ludwig Brieger then discovered the toxins of certain infections; and Emil A. von Behring completed the sphere of the new study by his discovery of the antitoxins of diphtheria and tetanus. In practical medicine the subsequent results of Behring and his followers have in diphtheria attained a signal therapeutical success. If the striking conceptions of Paul Ehrlich and Emil Fischer continue to prove as fertile in inspiring and directing research as at present they seem to be, another wide sphere of conceptions will be opened out, not in bacteriology only, but also in biological chemistry and in molecular physics. Again, besides giving us the clue to the nature of many diseases and to the continuity of many morbid series, by bacteriology certain diseases, such as actinomycosis, have been recognized for the first time.
As the prevalence of the conceptions signified and inspired by the word “phlogiston” kept alive ontological notions of disease, so the dissipation of vitalistic conceptions in the field of physics prepared men’s minds in pathology for the new
