AUTOLYSIS IN PATHOLOGICAL PROCESSES 95 



duced by bacterial infection also seem to possess the properties 

 above described. Galdi 1 found autolysis greater in exudates 

 than in transudates, but observed no constant relation between 

 the number of leucocytes, or the amount of chlorides, and the 

 rate of autolysis. 



Knapp 2 holds that in pus the cocci and the enzymes they 

 produce are responsible for much of the digestion. Pus cells 

 alone do not undergo digestion so rapidly as when bacteria are 

 present, and digestion is more rapid if the bacteria are alive 

 than when inhibited or killed by antiseptics. Streptococcus is 

 almost inactive, staphylococcus is quite active, and B. coli still 

 more so. He could find no relation between the autolytic 

 power of the pus and the severity of the infection from which 

 it resulted. (See also the discussion of the " Chemistry of Pus, " 

 Chap, x.) 



Pneumonia. In the stage of resolution lobar pneumonia 

 presents a striking example of autolysis. The often-remarked 

 phenomenon that the lung tissue itself is not in the least affected, 

 while the dense contents of the alveoli are rapidly dissolved and 

 removed is explained by the invariable immunity of living 

 cells to digestive enzymes. Except for some slight possible 

 assistance by the alveolar epithelium and the enzymes of the 

 serum, the enormous and rapid digestion of pneumonic exudates 

 is accomplished by the leucocytic enzymes. The rapid rate of 

 digestion may be accounted for by the absence of circulation 

 within the alveolar contents, which permits the leucocytes to 

 act unimpeded by the anti-bodies of the blood plasma. Diges- 

 tion of the exudate continues after death, accounting for the 

 marked diffuse softening observed in pneumonic lungs in bodies 

 kept some days before autopsy. As long ago as 1888, Kossel 3 

 mentioned that Fr. Miiller had found that glycerin extracts of 

 purulent sputum exhibited a digestive action upon fibrin and 

 coagulated proteid, whereas non-purulent sputum did not possess 

 this property. In 1877 Filehne extracted ferments in the same 

 way from the sputum in gangrene of the lung ; Stolniknow in 

 1878, found a similar ferment in pneumonic sputa, and Esche- 

 rich in 1885 showed that the proteolytic action of tuberculous 

 sputum was independent of putrefaction. Other early observa- 

 tions of similar nature are reviewed by Simon, 4 who demonstrated 

 the presence of leucin and tyrosin in the autolyzed lungs. In 

 a later work Miiller reports finding three grams of leucin and 



Folia Hemat, 1905 (2), 529. 



2 Zeitschr. f. Heilk., 1902 (23, Chir. Abt), 236. 



3 Zeit. f. klin. Med., 1888 (13), 149. 

 4 Deut. Arch. klin. Med., 1901 (70), 604. 



