232 PHYSIOLOGICAL CHEMISTRY. 



the absorption theory there is a still greater contrast between 

 former and present views, the latter inclining to the theory that 

 absorption is a process connected with the vital properties of the 

 cells. Investigations in this direction have been made by HEIDEN- 

 HAIK and his pupils, KOHMANN and GUMILEWSKY; and these 

 investigations have shown that the cells take an active part in the 

 absorption, and that this action is independent of the processes 

 caused by an unequal diffusibility of the different bodies. For 

 example, in a solution which contains equal quantities of grape- 

 sugar and sodium sulphate the sugar will be almost completely 

 absorbed in a certain time, while the salt, which has the greater 

 diffusibility, still remains in considerable amounts in the intestine. 

 Certain coloring matters are not absorbed, and the cells seem to 

 have the property of discriminating between the different sub- 

 stances. The absorption of dissolved bodies seems to be connected 

 with a specific activity of the living cell, the living protoplasm. 



In the absorption of bodies not dissolved, of the emulsified fats 

 forces take part which are not known. That the bile performs 

 the most important part in the absorption of fats is very generally 

 admitted, but how the bile acts in this process is not yet deter- 

 mined, v. WISTINGHAUSEN has found that fat rises higher in a 

 capillary tube when it has been moistened with bile than when 

 with water, and further that fluid fat filters more easily through a 

 dead membrane dipped in bile than when dipped in water. From 

 these observations, whose correctness has lately been disputed by 

 GAD and GROPER, the inference has been drawn that bile facilitates 

 the capillary attraction and thereby accelerates the absorption of the 

 fats. The epithelium layer of the intestinal mucous membrane 

 cannot be compared with a dead membrane soaked in water, and it 

 is therefore doubtful if the above-mentioned action of bile can have 

 any influence on the absorption of fats in the intestine. That the 

 absorption of fats is caused by the lymphoidal migratory cells 

 (ZAWARYKIN, SCH^FFER) is disputed by GRUENHAGEK and 

 HEIDENHAIN. According to them, the fat takes its way chiefly 

 through the epithelium cells. How these last act is, like the 

 nature of the action in absorption, enveloped in darkness. 



