LABORATORY MANUAL OF PHYSIOLOGY. 



has solution of the fibrin taken place ? At the end of an hour, what 

 is the condition of the fibrin in the various tubes ? 



In those tubes in which digestion of the fibrin has taken place, 

 what difference can be made out, by direct observation, between 

 the action of pancreatic and gastric juice in their attack upon pro- 

 teids? 



Filter the contents of those tubes which have shown digestive 

 change and test for albumins, proteoses, and peptones. 



Place some of the filtrate in a dialyzer, and the following day test 

 the fluid surrounding the dialyzer for proteoses and peptones. 



5. Amylolytic Action of Pancreatic Juice. (a) Make up 

 some starch paste. Test it with Fehling's solution to make sure of 

 the absence of a reducing sugar. Mix some of this paste with dilute 

 pancreatic extract of neutral reaction. Label this tube A. 



In a second tube of starch paste, B, place pancreas extract of al- 

 kaline reaction. 



To a third tube of starch paste add pancreas extract made acid 

 with o.i-per-cent HC1. Label this tube C. 



To a fourth portion of starch paste add o.i-per-cent HC1 

 alone. Label D. 



To a fifth portion add strong hydrochloric acid. Label E. 



To a sixth portion add o.i-per-cent sodium-carbonate solution. 

 Label F. 



Place all these tubes in the water-bath at 38 C. In ten or fifteen 

 minutes test for reducing sugar in all the tubes, first carefully neu- 

 tralizing those of an acid reaction. Record results. In which 

 tubes has starch digestion taken place ? What is the starch-digest- 

 ing enzyme of the pancreatic secretion ? What is the optimum re- 

 action of the digesting medium ? 



(b) Mix some starch paste with pancreatic extract which has 

 been previously boiled. Place in the warm water-bath and note 

 results. W 7 hat is the effect of high temperature on the enzyme ? Is 

 this effect common to all enzymes ? 



6. Lipolytic Action of Pancreatic Juice. Mix a small quan- 

 tity of fresh butter in a test-tube with glycerin extract of pancreas 



