DIGESTION AND RESORPTION 95 



solution. This is not true for the quantity ioo cc. 

 from which a quantity greater by about 20 per cent 

 is taken up than the proportionality demands. 



The proportionality of the resorbed quantity to 

 the square root of the concentration indicates that 

 the process is not a question of a simple diffusion, 

 but that the resorbing action of the intestinal wall 

 is excited by the food-stuffs in the moistening fluid. 

 It seems very noteworthy that the exciting influence, 

 just as in the case of the secretion of stomachical or 

 pancreatic juice, is proportional to the square root 

 of the quantity of the exciting substance. Even the 

 quantity of enteric juice secreted is nearly propor- 

 tional to this square root. 



Another experiment of London concerns a carbo- 

 hydrate, amylodextrin, which must be digested 

 before its resorption. A solution containing 4-8 

 grammes of amylodextrin was introduced through an 

 upper fistula and carried through to a lower fistula in 

 a certain time, from 8 to 240 minutes. The longer 

 the time the solution remained in the intestine, the 

 smaller the part of it remaining undigested and 

 consequently unresorbed. The quantity of amylo- 

 dextrin remaining undigested and also unresorbed 

 was determined. The undigested amylodextrin 

 does not reduce a Fehling solution as the digested 

 parts of this carbohydrate do. As is generally true 

 for the digestion of small quantities, that of amylo- 

 dextrin obeys the monomolecular formula. This is 

 seen from the diagram, Fig. 25 (the lower curve), 

 in which the logarithm of the undigested quantity 



