FERMENTATION 261 



quantity absorbed will be less than in the living 

 animal 



3. Kepeat Experiment 2, using an emulsion of 

 commercial olive oil and 0.25 per cent solution of 

 sodium carbonate. 



Absorption will be increased by the giving of 

 the fat in an emulsion. 



Absorption of Fat Acids. Place in the pharynx 

 of a frog a pill of pure palmitic acid made with a 

 few drops of glycerine. After about twenty-four 

 hours examine as before. 



Numerous drops of fat will be found in the in- 

 testinal epithelium. These globules are not free 

 fat acid absorbed as emulsion, for miscrocopic 

 examination of the contents of the intestine 

 shows no emulsion. Moreover, palmitic acid 

 must be liquid to be emulsified, and as its melt- 

 ing-point is 62 C. it could not melt in the 

 intestine of a cold-blooded animal at room tem- 

 perature. 



Absorption of Fat Acid as a Soap. 1 Feed a 

 frog with palmitin soap containing a few drops of 

 glycerine. After about twenty-four hours exam- 

 ine the intestine for fat, as before. 



1 Preparation of Palmitin Soap. Dissolve ten grams pure 

 palmitic acid in hot alcohol. Add enough 5 per cent potassium 

 hydrate to combine with the fat acid. Drive off the alcohol 

 by heating on a water-bath. Dilute with water and add a few 

 drops of glycerine. 



