14 History of Pathology. 



observation, physiological experimentation and anatomical dissec- 

 tion grew more and more toward a plane of real excellence, af- 

 fording an increasing clearness of insight into the processes which 

 obtain in both healthy and diseased bodies. The anatomical 

 changes shown in necropsies directed attention to the topography 

 of disease. Morgagni (1682-1771). a teacher of anatomy in 

 Padua, in his work, "Dc Scdibus ct Causis Morbontin" (1761), 

 outlined the first comprehensive and system.itic exposition in this 

 direction and came to be regarded as the founder of pathological 

 anatomy. From efforts to correlate manifestations of disease of 

 the various organs with the presence of anatomical changes, arose 

 the school of Pathological-anatomical Diagnosis, to which is due 

 the discovery of a number of valuable methods of diagnosis (per- 

 cussion, thermometry, the microscope, chemical analysis), and 

 which had as its founders men like Bichat, Pinel, Corvisart, 

 Dupuytren, Auenbriigger, Laennec and Rokitansky. 



The advances in physiology inaugurated bv Johannes Miiller 

 (1801-1858) and the cellular theory formulated by Th. Schwann, 

 along with the development of microscopic anatomy, are respon- 

 sible for an important change from the older conceptions of dis- 

 ease, giving us as a basis for our ideas of morbid processes a 

 cellular pathology, first proposed by Rudolph Virchow (1858), 

 who referred the real seat of disease to the individual cells and 

 the tissues, and regarded disease as depending upon the reaction 

 of these to harmful influences. Although it is but about fifty 

 years ago that Schonlein's school looked on disease as some sort 

 of living thing of extra-corporeal origin, entering the bodies of 

 men and animals like a parasite and expelled by our therapeutic 

 measures ; yet in the interim the study of Aitiology has developed 

 the definite view that disease is but the manifestation of mor- 

 phological, chemical and functional changes which are induced by 

 the most varied harmful influences upon the cells and tissues, 

 chemical or physical ; and thus to-day, through uniform and ex- 

 act methods of objective research, clear conceptions and positive 

 knowledge are in hand relative to most diseases. 



As far as comparative pathology is concerned, it too was com- 

 pletely dormant from the fourth until the eighteenth century, at 

 first because of the general depression in science, later because 

 medical practitioners had but little interest in the diseases of ani- 

 mals when human medicine was developing along these newer 

 lines, but especially because of the aversion which men came to 



