DIGESTION AND ABSORPTION. 167 



Dialyzer (f) contains products of peptic digestion 

 of proteids principally albumin. The progress of 

 digestion was suspended at a stage when there were 

 present not only peptone but mid-products albu- 

 moses; or, to use the general term, proteoses 



The problem which confronts us is to determine 

 whether or not proteoses are diffusible. 



(a) If peptone is diffusible the diffusate will cer- 

 tainly contain peptone. Do peptone and the pro- 

 teoses respond alike to all the general tests for 

 proteids? 



(b.) How may peptone be separated from the pro- 

 teoses ? 



What single reagent is indicated in the case? 

 (8) Demonstrate the diffusibility of peptone. 

 b. Milk. 



1. Materials. One liter of fresh whole milk; one liter of 

 milk for the preparatory steps of the demonstration. 



2. Preparation. 



(1) On the day before the demonstration fill a 500 c. c. 

 open mouthed cylinder with milk and put it in a cool 

 place. 



(2) Two days before the demonstration weigh out 10 

 gm. to 50 gm. of whole milk in a platinum dish or in 

 a thin porcelain dish. Place it in a drying oven at 

 90-95C, and dry to constant weight. Record the dry 

 weight. 



(3) Before the hour of the demonstration burn the resi- 

 due by bringing the dish which contains the dry solids 

 to a red glow in a Bunsen flame, allowing ample access 

 of oxygen. After the dish and the white ashes have 

 cooled in a desiccator take the weight. All of these 

 weights should, of course, be taken upon an analytical 

 balance. 



