CHAPTER IV 

 PROTEOLYTIC AND PEPTOLYTIC TISSUE FERMENTS 



AUTOLYSIS 



AFTER the consideration in the previous chapters of the 

 processes of protein digestion in the stomach and intestine, 

 and with the future consideration of the fate of the final 

 nitrogenous cleavage products in the intermediate metab- 

 olism before us in succeeding ones, the present discus- 

 sion may very properly be devoted to the protein- 

 digesting tissue ferments. At this point study of that mys- 

 terious change which is inclusively spoken of as "autolysis" 

 may serve in part to bridge the great gap, or perhaps in 

 more exact verbiage to conceal it, between the two phases of 

 the metabolic process. It has been pointed out that the prod- 

 ucts of cleavage of the protein molecule are lost sight of at 

 the very moment when they are res orbed through the wall of 

 the bowel; and their first traces reappear when the end- 

 products of metabolism begin to escape from the body. That 

 which lies between is the unexplored and completely un- 

 known field of the intermediate metabolism. The hope of 

 throwing some light from a single point of view upon a little 

 part of this field, as with the light-cone of a projection lamp, 

 lends special interest to the study of the phenomena of 

 autolysis. Even if these expectations, at best provisional 

 ones, fail of fulfilment, the enigmatic process is in itself suf- 

 ficiently interesting to temporarily hold our attention. 



As early as 1890 Ernst Salkowski recorded the occur- 

 rence of post mortem self -digestion ("autodigestion") in 

 animal tissues. He noted, for example, that in a pulp- 

 like suspension of tissue in chloroform water autodigestive 

 processes take place, with disappearance of coagulable 

 albumins to give place to their cleavage products. Then 

 ten years later in Hofmeister's laboratory Martin Jacoby * 



X M. Jacoby (F. Hofmeister's Lab., Strassburg), Zeitschr. f. physiol. Chem., 

 SO, 149, 174, 1900. 



