2O4 PHYSIOLOGICAL CHEMISTRY. 



obtained are higher than those from the ordinary process and the time 

 required for extraction much shorter. But it is not easy to obtain in this 

 way enough fat for further study, as not much more than 10 gm. can be 

 easily worked. 



The amount of crude fat in the dry feces is variable but may 

 make up in the mean about 25 per cent. Much of it under 

 normal conditions must be derived from other sources than the 

 unutilized original fat of the foods ; a portion is always de- 

 rived from residues from some of the intestinal secretions, and 

 from organized elements thrown off from the walls of the in- 

 testines. The extent of the utilization of the food fat depends 

 largely on its physical character, especially its melting point. 

 The solid fats with high melting point are but poorly utilized 

 as the following figures illustrate, in which the amount of 

 loss in the feces from different kinds of fat is given, (v. 



Noorden.) 







Melts. Loss. 



Olive oil liquid 2.3 per cent. 



Goose fat 25 2.5 



Lard 34 2.5 



Bacon 43 2.6 



Mutton tallow 49 7.4 



Stearin plus almond oil 55 10.6 



Pure stearin (and palmitin) 60 90.0 



The free fatty acids do not appear to be as well absorbed as 

 are the neutral fats, and in general from mixed vegetable 

 foods the fat loss in the feces is much greater than from the 

 animal foods. 



Pathologically there may be a very great increase of fat in 

 the feces, so great in fact as to be readily recognizable by the 

 eye. This is especially 'true in cases where the flow of bile 

 into the intestine is diminished or altogether hindered. The 

 fat in the dry feces may then amount to 50 per cent of the 

 whole. Any derangement of the normal pancreatic functions 

 leads also usually to an increase of fat in the feces. In the 

 last case protein and carbohydrates would suffer also in 

 absorption. 



