174 THE PROCESSES OF DIGESTION ASD RESORPHON. 



foreign material. The same indeed holds good of the albumoses, 

 and both are known to be distinctly toxic. This fact in itself shows 

 that after the stage of denaturization has been passed a direct resorp- 

 tion of the resulting products of digestion cannot take place by 

 simple osmosis, and that certain changes must occur in the gastro- 

 intestinal walls whereby these products are deprived of their 

 toxicity. Ludwig and Salvioli, moreover, have shown that by sub- 

 stituting an artificial circulation in an isolated intestinal loop for 

 the normal, no peptones or albumoses could be found either in the 

 blood returning from the loop nor after some time in the gut itself, 

 although an abundant amount had been previously introduced. The 

 same result may be demonstrated by finely hashing a piece of care- 

 fully cleansed and perfectly fresh intestine, and placing this in a 

 solution of peptone in the defibrinated blood of the same animal. 

 It can then be demonstrated that after a relatively short time already 

 a considerable amount of the peptones has disappeared, and is, 

 moreover, not stored as such in the tissue. 



While it is thus definitely proved that albumoses and peptones 

 are transformed into material which the body can utilize for pur- 

 poses of nutrition, we know absolutely nothing of the manner in 

 which this transformation is effected, nor of the products which thus 

 result. According to some observers, a further decomposition of the 

 albuminous molecule into smaller atomic groups takes place, but 

 thus far no substances have been found in the tissues and fluids of 

 the body in sufficient amount to favor such an explanation. On the 

 other hand, it is possible, as in the case of the carbohydrates, that 

 a polymerization of peptone radicles occurs, and that albumins again 

 result which are comparable to those from which they are derived. 



As I have stated, there can be no doubt that the epithelial cells 

 which line the gastro-intestinal tract are capable of effecting the 

 transformation of syntonin, and possibly even of native albumins 

 into forms which can be utilized by the body directly ; but under 

 normal conditions it appears that the action of the epithelium 

 scarcely begins before the albumins have been digested by the fer- 

 ments to the stage of albumoses. We have seen that in the stomach 

 the process of digestion scarcely goes further than the formation of 

 the primary albumoses, and the question naturally suggests itself: 

 Are the primary albumoses resorbed in the stomach already or is it 

 necessary that they be further exposed to the action of the pan- 

 creatic juice? To this question an ultimate answer cannot be given, 

 but it is likely that resorption takes place in the stomach to a limited 

 extent only, and that the greater portion of the primary albumoses 

 is further decomposed in the small intestine, where the resorption 

 processes are most active. Much work remains to be done in this 

 direction. 



2. Tryptic Digestion of the Native Albumins. Upon enter- 

 \ng the small intestine the acid gastric contents are rendered alkaline, 

 the pepsin is destroyed, and tryptic digestion begins. 



