DIGESTION AND ABSORPTION, 179 



(a) Cut out a one centimeter cube and put it into a 



beaker with 40 c c. artificial gastric juice. 

 () Put into a second beaker of 40 c.c. gastric juice 

 a centimeter cube which has been divided into 

 eight half-centimeter cubes. 



(c) Prepare another beaker in which are 16 quarter 

 centimeter cubes in 10 c.c. of artificial gastric juice. 

 (</) Into another beaker with 10 c. c. artificial gastric 

 juice put J of a cubic centimeter of the egg albu- 

 min which has been finely divided by pressing 

 through a fine sieve. 



Note time required in each case to completely 

 digest the albumen. 



Has this any hygienic bearing ? 



(13) The influence of temperature upon the time required to 

 digest proteids. Prepare five tubes by first providing 

 each with 5 c.c. of artificial gastric juice; treat the 

 several tubes as follows: 



(a) Bring to 60C. in water bath; add fibrin; note 



time. 

 (/) Bring to 50C. in water bath; add fibrin; note 



time. 

 (/) Bring to 30C. in incubator; add fibrin; note 



time. 



(//) Leave at room temperature (20C.); note time. 

 (e} Bring to 0C. in ice water; add fibrin; note time. 

 What is the optimum temperature? 

 Is the progress of digestion materially retarded 

 by a reduction of the temperature ? 



Would the temperature of the stomach contents 

 be essentially lowered by the occasional sipping 

 of an iced beverage during a meal? 



What is the hygienic significance of the experi- 

 ment ? 



