110 PATHOLOGY 



scale of two biological sciences in the study of pathology, namely the 

 physiological or study of function and the anatomical or study of 

 structure. Morgagni's conception of disease as inseparably con- 

 nected with structural changes in the organs was designated happily 

 by Virchow as the anatomical idea in medicine, and this idea the 

 greatest gift of anatomy to medicine proved of incalculable 

 service in turning the minds of physicians away from speculation to 

 careful, objective study of disease during life as well as after death. 

 We catch an interesting glimpse of Morgagni's own point of view in 

 the following quotation from his writings: "The various steps in 

 progress ought not to be disregarded, for, in difficult research, we 

 derive encouragement from the recollection that although the exer- 

 tions of an individual may not advance philosophy in any perceptible 

 degree, yet, owing to the power of experiment and the successive 

 influence of opinion, the most obscure and apparently unsuccessful 

 inquirer may prove the first or the connecting link in a series of most 

 valuable discoveries." 



The Cell Doctrine 



The next advance was the result of Bichat's introduction of minute 

 anatomy and the demonstration that the organs consist of tissues to 

 which the seat of disease now was referred. Before long came the 

 epochal development in botany under the influence of Schleiden of 

 the cell doctrine, which was applied by Schwann to normal animal 

 histology, and by Virchow in 1858 to pathology, the direct outgrowth 

 being the justly celebrated cellular pathology beginning an era during 

 which medicine has made greater progress than in all preceding time. 



Physiological and pathological processes were traced to the 

 elementary morphologic constituents of living organisms the 

 cells. The famous phrase "omnis cellula e cellula" completed the 

 liberation of medicine from abstract speculation already begun by 

 Morgagni. "The physician grew from a schoolman into a scientific 

 observer, and the surgeon, who appeared on the scene in livery and 

 without learning, grew from a handicraftsman to be a man of 

 science." Pathology became a natural science. What rich new 

 fields were now open for investigation! A vast amount of material 

 was accumulated from careful clinical and morphologic study of 

 individual cases and the basis thus laid for the construction of gen- 

 eral laws and fruitful theories of disease. During the earlier part 

 of this period attention was confined largely to man, but it also 

 was often turned in the direction of animals in the effort to pene- 

 trate deeper into morbid processes; the experimental method was 

 used to interpret correctly observations made in the clinic and in the 

 post-mortem room. 



