Pathology is the science of disease in all its manifestations, whether structural or functional, progressive or regressive.
This subject brings the domain of pathology, however, into touch with that of variation, and we are profoundly ignorant as to the complex of external conditions which would decide in any given case how far a variation in form would be prejudicial or otherwise to the continued existence of a species.
It is when studied on these lines that pathology finds its proper place as a department of biology.
The only evidence we have in pathology of living structures in which apparently a differentiation into cell-body and nucleus does not exist, is in the case of bacteria, but then there comes the question whether they may not possess chromatin distributed through their substance, in the form of metachromatic points, as is the case in some infusoria (Trachelocerca, Gruber).
It includes five books; of which the first and second treat of physiology, pathology and hygiene, the third and fourth deal with the methods of treating disease, and the fifth describes the composition and preparation of remedies.
AUTH0RITne5.General and Historical.Berkeley, Vegetable Pathology, Gardeners Chronicle (1854) p. 4; Plowright, British Uredineae and Ustilagineae (1889); Erik,sson and Henning, Die Getreideroste (Stockholm, 1896); De Bary, Comparative Morph.
Despite the general recognition of these facts, the pharmacology of colchicum has hitherto thrown no light on the pathology of gout, and the pathology of gout has thrown no light upon the manner in which colchicum exerts its unique influence upon this disease.
The outstanding feature in the history of pathology during the 19th century, and more particularly of the latter half of it, was the completion of its rescue from the thraldom of abstract philosophy, and its elevation to the dignity of one of the natural sciences.
Influenced by the prevailing philosophy of the day, they interpreted the phenomena of disease through its lights, and endeavoured from time to time to reduce the study of pathology to philosophical order when the very elements of philosophical order were wanting.
The complexity and mystery of action inherent in living matter have probably been accountable for much of the vague philosophy of disease in the past, and have furnished one reason at least why pathology has been so long in asserting its independence as a science.
There are other factors, however, which have kept pathology in the background.
Progress in the study of pathology has been greatly facilitated by the introduction of improved methods of technique.
Experimental pathology has benefited by the use of antiseptic surgery in operations upon animals, and by the adoption of exact methods of recording; while the employment of solid culture media in bacteriology - the product of Koch's fertile genius - is responsible for a great part of the extraordinary development which has taken place in this department of pathological research.
The pathology of intra-cardiac and vascular murmurs has also been inquired into experimentally, the general impression being that these abnormal sounds result, in most cases at least, from the production of a sonorous liquid vein.
Our starting-point in this, as in all departments of biological study, must be the biological unit, and it is to the alterations to which this is subject, under varying conditions of nutrition and stimulation, that the science of pathology must apply itself.
From the foregoing it will be gathered that the problems in pathology are many-sided and require to be attacked from all points of vantage; and the subject falls naturally into certain great divisions, the chief of which are the following: I.
Assuming, with Sedgwick and others, this amassed and bound condition of the tissues to be true, it would be necessary to reject the cell-doctrine in pathology altogether, and to regard the living basis of the organism as a continuous substance whose parts are incapable of living independently of the whole.
This, one of the most difficult problems of pathology, is being attacked by many able workers, who are all striving from different standpoints to elucidate the nature of these new formations, which spring from the normal tissues in which they develop and which they destroy.
This phagocytal action of certain cells of the body is held by Metchnikoff and his followers to have an important bearing on the pathology of immunity.
Practical Applications Medicine and surgery have never been slow to appropriate and apply the biological facts of pathology, and at no period have they followed more closely in its wake than during the last quarter of the 19th century.
The recognition of the dangers accompanying the drinking of polluted water or milk, or of those attached to the breathing of a germ-polluted atmosphere, has been the natural sequence of an improved knowledge of pathology in its bacteriological relationships.
Medicina: sc. ars, art of healing, from mederi, to heal) may be used very widely, to include Pathology, the theory of the causation of disease, or, very narrowly, to mean only the drug or form of remedy prescribed by the physician - this being more properly the subject of Therapeutics (q.v.) and Pharmacology.
The treatment of wounds, injuries and deformities, with operative interference in general, is the special department of surgical practice (the corresponding parts of pathology, including inflammation, repair, and removable tumours, are sometimes grouped together as surgical pathology); and where the work of the profession is highly subdivided, surgery becomes the exclusive province of the surgeon, while internal medicine remains to the physician.
The importance in science of Bichat's classical works, especially of the Anatomie generale, cannot be estimated here; we can only point out their value as supplying a new basis for pathology or the science of disease.
Hippocrates had no opportunity of verification by necropsy, and Sydenham ignored pathology; yet the clinical features of many but recently described diseases, such, for example, as that named after Graves, and myxoedema, both associated with perversions of the thyroid gland, lay as open to the eye of physicians in the past as to our own.
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.
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 views opened by the discoveries of Pasteur on the side of pathogeny, and of J.
The pathology of aphasia, as worked out by a combination of the experimental, the pathological and the anatomical lines of inquiry is a favourable example of what has been accomplished.
The origin of the corpuscles, previously a matter of so much difference of opinion, is now pretty fairly set at rest, and has proved the key to the interpretation of the pathology of many diseases of the blood, such as the different forms of anaemia, of leucocythaemia, &c.
For the special pathological details of various diseases, see the separate articles on Parasitic Diseases; Neuro-Pathology; Digestive Organs; Respiratory System; Blood: Circulation; Metabolic Diseases; Fever; Bladder; Kidneys; Skin Diseases; EYE Diseases; Heart Disease; EAR, &c.; and the articles on different diseases and ailments under the headings of their common names.
418, also, Manual of General Pathology (London, 1898); Loeb, " Certain Activities of the Epithelial Tissue of Skin of Guinea-pig, &c.," Johns Hopkins Hosp. Bull., Balt.