178 LABORATORY GUIDE IN PHYSIOLOGY. 



HC1, and 1 c.c. glyc. ext. of pepsin; put the mix- 

 ture into a test tube; label: NaCl sub. saturated. 

 Drop in a bit of fibrin and put into the incubator. 

 Take six test tubes, provide each with a bit of 

 fibrin; label and fill each as follows: 



() | Sat. NaCl : 5 c.c. artif. gast. juice + 5 c.c. 

 NaCl sat. 



(c) J Sat. NaCl : 6 c.c. artif. gast. juice -f 2 c.c. 

 NaCl sat. 



(dT) | Sat. NaCl : 5 c.c. artif. gast. juice -(- 5 c.c. 

 NaCl i sat. 



O) T V Sat. NaCl : 6 c.c. artif. gast. juice + 2 c.c. 

 NaCl i sat. 



(/) sV Sat - NaC1 : 5 c - c - artif - S ast - J uice + 5 c - c - 

 NaCl T \ sat. 



() ^V ^ a *- NaCl : ti c.c. artif. gast. juice -{-2 c.c. 

 NaCl T V sat. 



What fraction of saturation with table salt stops 

 proteid digestion ? Explain its action. How 

 much NaCl per litre would that represent? Has 

 this any hygienic bearing? 



(11) The effect of mechanically confining the fibrin to pre- 

 vent its swelling. Tie a small mass ot fibrin rather 

 tightly with several turns of white thread; drop it into 

 a test tube containing artificial gastric juice; put the 

 tube into the incubator and watch results. 



How long a time is required to digest the fibrin? 

 Has this any hygienic significance ? 



(12) The influence of division upon the time required to 

 digest proteids. Boil an egg five to ten minutes; cool 

 quickly; separate the hard coagulated white from yolk 

 and envelopes. 



