they followed more closely in its wake than during the last quarter of the 19th century. When, for instance, the cause of septic infection had been revealed, the prophylaxis of the disease became a possibility. Seldom has it happened, since the discovery of the law of gravity, that so profound an impression has been made upon the scientific world at large as by the revelation of the part played by germ-life in nature; seldom has any discovery been fraught with such momentous issues in so many spheres of science and industry.
The names of Pasteur and Lister will descend to posterity as those of two of the greatest figures in the annals of medical science, and indeed of science in general, during the 19th century. The whole system of treatment of tubercular disease has been altered by the discovery of the tubercle microphyte. Previously consumptive individuals were carefully excluded from contact with fresh air, and were advised to live in rooms almost hermetically sealed and kept at a high temperature. The treatment of the disease has now gone off in the opposite direction. Sanatoria have started up all over Europe and elsewhere for its treatment on the open-air principle. Individuals suffering from pulmonary phthisis are encouraged to live night and day in the open, and with the best results. The rapid diagnosis of diphtheria, by recognizing its bacillus, has enabled the practitioner of medicine to commence the treatment early, and it has also enabled the medical officer of health to step in and insist on the isolation of affected persons before the disease has had time to spread. The discovery of the parasite of malaria by Laveran, and of the method by which it gains entrance to the human body, through the bite of a particular variety of mosquito, by Manson and Ross, promises much in the way of eradication of the disease in the future. One of the most remarkable practical outcomes of germ-pathology, however, has been the production of the immunized sera now employed so extensively in the treatment of diphtheria and other contagious diseases. By the continuous injections under the skin, in increasing doses, of the toxins of certain pathogenic micro-organisms, such as that of diphtheria, an animal—usually the horse—may be rendered completely refractory to the disease. Its serum in course of time is found to contain something (antitoxin) which has the power of neutralizing the toxin secreted by the organism when parasitical upon the body. This immunity can be transferred to a fresh host (e.g. man) by injecting such serum subcutaneously. The modern system of hygiene is in great part founded upon recent pathology. 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. Skin-grafting and regeneration of bone are among not the least remarkable applications of pathological principles to the combat with disease in recent times; and in this connexion may also be mentioned the daring acts of surgery for the relief of tumours of the brain, rendered practicable by improved methods of localization, as well as operations upon the serous cavities for diseased conditions within them or in their vicinity.
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.
Authorities.—Adami, “Inflammation,” Allbutt’s System of Med. (London, 1896), vol. i.; Afanassieff, “Granulation Tissue and Infection,” Centralbl. f. allg. Path. u. path. Anat. (1896), vii. 456; Arnold, “Finer Structure of the Cell,” Arch. f. path. Anat. (1879), lxxvii. 181; Beyerinck, Beobachtungen üb. d. ersten Entwicklungsphasen einiger Cynipidengallen (Amsterdam, 1882); Bordet, “Phagocytosis,” Ann. de l’inst. Pasteur (1895), x. 104; Buchner, “Chemiotaxis of Leucocytes,” Berl. klin. Wochenschr. (1890), xxvii. 1084; Cancer: synopsis of recent literature. See The Practitioner (1899), vol. ix.; Chatin, “Direct Cellular Division,” Compt. rend. acad. d. sc. (1898), cxxvi. 1163; Coats, Manual of Pathology (London, 1895); Cohnheim, Vorlesungen üb. allg. Path. Berlin (1877-1880); Cornil, “Organization of Clot within Vessels,” J. de l’anat. et physiol. (1897), xxxiii. 201; Davidsohn, “Experimental Amyloid,” Arch. f. path. Anat. (1897), cl. 16; Delage, “Studies in Merogony,” Arch. de zool. expér. et gen. (1899), vii. 383; Ehrlich, “Mastzellen,” Arch. f. mik. Anat. (1877), xiii. 263; Engelmann, “Chemiotaxis of Oxygen for Bacteria,” Arch. f. d. ges. Physiol. (1881), xxv. 285; Farmer, “Present Position of some Cell Problems,” Nature (1898), lviii. 63; Flemming, “Studies in Regeneration of the Tissues,” Arch. f. mik. Anat. (1885), xxiv. 371; Frank, Die Krankheiten der Pflanzen (Breslau, 1895); Galeotti, “Experimental Production of Irregular Karyokinetic Processes,” Beitr. z. path. Anat. u. z. allg. Path. (1893), xiv. 288; Grawitz, “Slumber Cells,” Arch. f. path. Anat. (1892), cxxvii. 96; Hahn, “Increase of Natural Resistance by Production of Hyperleucocytosis,” Berl. klin. Wochenschr. (1896), xxxiii. 864; Hamilton, “Process of Healing,” Journ. Anat. Physiol. and Path. (1879), xiii. 518, also “Organization of Sponge,” Edin. Med. Journ. (1882), xxvii. 385; Text-Book of Pathology (London, 1894); Hansemann, “Pathological Mitosis,” Arch. f. path. Anat. (1891), cxxiii. 356; Hartig, Text-Book of the Diseases of Trees (Eng. trans., London, 1894); Heidenhain, “Action of Poisons on Nerves of Submaxillary Gland,” Arch. f. d. ges. Physiol. (1872) v. 309, also, “Question of Lymph Production,” ibid. (1891), xlix. 209, also, “Central-Body of Giant-cells,” Morph. Arb. (1897), vii. 225; O. Hertwig, Die Zelle u. d. Gewebe (1898, also Eng. trans., 1895); Heukelom, “Sarcoma and Plastic Inflammation,” Arch. f. path. Anat. (1887), cvii. 393; Justi, “Unna’s Plasma-Cells in Granulations,” Arch. f. path. Anat. (1897), cl. 197; Jürgelünas, “Protective Action of Granulations,” Beiträge z. path. Anat. u. z. allg. Path., Ziegler (1901), xxix. 92; Kickhefel, “Histology of Mucoid,” Arch. f. path. Anat. (1892), cxxix. 450; Krawkow, “Chemistry of Amyloid,” Arch. f. exper. Path. u. Pharmakol. (1897) xl. 195, also “Experimental Amyloid,” Arch. f. path. Anat. (1898), clii. 162; Krompecher, “Plasma-Cells,” Beitr. z. path. Anat. u. z. allg. Path. (1898), xxiv. 163; Labbé, La Cytologie expérimentale (Paris, 1898); Lazarus-Barlow, “Lymph Formation,” Journ. Physiol. Camb. (1895-1896), xix. 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. (1898), ix. 1, also “Artificial Production of Normal Larvae,” Amer. Journ. Physiol. (1899), iii. 135; Löwit, “Relationship of Leucocytes to Bacterial Action,” Beitr. z. path. Anat. u. z. allg. Path. (1897), xxii. 172; Lubarsch, “Experimental Amyloid,” Arch. f. path. Anat. (1897), cl. 471; Lubarsch and Ostertag, Ergebnisse der spec. path. Morphologie u. Physiologie des Menschen (Wiesbaden, 1896); Ludwig, Lehrbuch der Physiol. vol. ii.; Marshall Ward, Timber and some of its Diseases (London, 1889); Massart and Bordet, “Irritability of Leucocytes,” Journ. publ. par la soc. des sci. med. et nat. de Bruxelles (1890), vol. v.; Metchnikoff, Lectures on Comp. Path. of Inflammation (Eng. trans., London, 1893); Notkin, “Nature of Colloid in Thyroid Gland,” Arch. f. path. Anat. (1896), cxliv. 224 (Suppl. Hft.); Nowak, “Experimental Researches on Amyloidosis,” Arch. f. path. Anat. (1898), clii. 162; Oddi, “Nature of Amyloid,” Arch. f. Path. u. Pharmakol. (1894), xxxiii. 376; Paget, “Address on Healing,” Brit. Med. Journ. (1880), ii. 611; Pelagatti, “Blastomycetes and Hyaline degeneration,” Arch. f. path. Anat. (1897), cl. 247; Penzo, “Influence of Temperature on Cellular Regeneration,” Archivios per le scienze mediche (1892); Pfeffer, “Chemiotaxis,” Unters. aus d. bot. Inst., zu Tübingen (1884), i. 363; ibid. (1888); Pickardt, “Chemistry of Pathological Exudates,” Berl. klin. Wochenschr. (1897), xxxiv. 844; Plimmer, “Aetiology and Histology of Cancer,” Practitioner (1899), ix. 430; Ruffer and Plimmer, “Cancer Bodies,” Journ. Path. and Bacteriol. (1892-1893), i. 395; Runeberg, “Filtration of Albuminous Liquids,” Arch. f. d. ges. Physiol. (1885), xxxv. 54, also “Diagnostic Value of Proteid in Dropsical Liquids,” Deutsch. Arch. f. klin. Med. (1883), xxxiv. 1; Russell, “Fuchsin Bodies,” Brit. Med. Journ. (1890), ii. 1356; Salvioli, “Production of Oedema,” Virchow and Hirsch’s Jahresbericht (1885), i. 252; Schottländer, “Nuclear and Cell Division in Epithelium of Inflamed Skin,” Arch. f. mik. Anat. (1888), xxxi. 426; Sczawinska, “Reticular Structure of Nerve-Cells,” Compt. rend. acad. d. sc. (1896), cxxiii. 379; Senator, “On Transudation,” Arch. f. path. Anat. (1888), cxi. 219; Shattock, “Healing of Incisions in Vegetable Tissues,” Journ. Path. and Bacteriol. (1898), v. 39; v. Sicherer, “Chemiotaxis of Leucocytes of Warm-blooded Animals outside the Body,” Münch. med. Wochenschr. (1896), xliii. 976; Siegert, “Corpora Amylacea,” Arch. f. path. Anat. (1892), cxxix. 513; Starling, “Mechanical Factors in Lymph Production,” Journ. of Physiol. (1894), xvi. 224, also a number of other papers bearing upon lymph-production, in same; Thorne, “Endothelia as Phagocytes,” Arch. f. mik. Anat. (1898), lii. 820; Thoma, Lehrbuch d. allg. Path. (1894), also vol. i. (Eng. trans., London, 1896); Trambusti, “On Structure and Division of Sarcoma Cells,” Beitr. z. path. Anat. u. z. allg. Path. (1897), xxii. 88; Verworn, General Physiology (Eng. trans., London, 1899); Weismann, Essays upon Heredity (Eng. trans., Oxford, 1891); also, The Germ Plasm (London, 1893); Welch, “Oedema of Lung,” Arch. f. path. Anat. (1878), lxxii. 375; Wilson, The Cell in Development and Inheritance (London, 1896); Ziegler, “Entzündung,” in Eulenburg’s Real Encyclopädie, also Text-Book of Special Pathological Anatomy (Eng. trans., New York, 1897). (D. J. H.; R. Mr.*)