466 APPENDIX. 



3. With Platner's bile and the isolated acids perform Petten- 

 kofer's test (page 161). 



4. Isolate taurin from the sheep-bile and identify it (page 169). 



5. With the fresh sheep-bile, somewhat diluted, perform Gmelin's 

 test, Huppert's test, and Smith's test (page 173). 



6. Isolate the biliary mucin from ox-bile (page 159). 



7. Procure some human bile (at autopsy) and examine into the 

 presence of true mucin (page 159). 



8. Procure some gall-stones (preferably cholesterin stones) ; isolate 

 the cholesterin in pure form and perform the Liebermann-Burck- 

 hard and Salkowski tests (page 177). 



Exercise XX. Carbohydrate digestion (see Exercise XIII.). 



Exercise XXI. 1. Digest 100 grammes of fresh fibrin with 

 pepsin-hydrochloric acid and isolate the various fractions as de- 

 scribed on page 195. If fibrin preserved in chloroform is only avail- 

 able, heat this in a 2 per cent, solution of hydrochloric acid until it 

 swells and assumes a jelly-like appearance. 



Exercise XXII. Digest 100 grammes of fibrin with pancreatin 

 and isolate the various albumoses as described on page 196. 



Exercise XXIII. From a fibrin-pancreatin digestive mixture 

 that has stood for a week well guarded against putrefactive changes 

 with toluol (2 cm. of toluol should stand above the mixture), isolate 

 (a) the anti-peptone fraction. Demonstrate that this contains a 

 fraction which can be precipitated with phosphotungstic acid and 

 one which remains in solution (page 201). (6) Use this same mix- 

 ture to demonstrate the presence of leucin and tyrosin (page 205), 

 aspartic acid and glutaminic acid (page 207). (c) In the same 

 mixture demonstrate the presence of tryptophan (page 209). 



4. To demonstrate glycocoll as a decomposition-product, of the 

 albumins it is best to start with gelatin. This is conveniently 

 hydrolyzed with 25 per cent, sulphuric acid (page 208). Use about 

 100 grammes of gelatin, 1000 c.c. of dilute acid, and boil for twenty- 

 four hours. 



Exercise XXIV. Hash 100 grammes of liver-tissue ; suspend in 

 1000 c.c. of water ; add an abundance of toluol, shake well (the toluol 

 should form a layer 1 cm. deep on the surface), and keep at a tem- 

 perature of 40 C. for three to four weeks. Then examine for 

 albumoses, tyrosin, leucin, etc., as above. 



Exercise XXV. Hash 100 grammes of pancreas ; suspend in 

 1000 c.c. of water ; place in an incubator at 40 C. for a week, and 

 then examine for indol, skatol, and phenol (page 221). 



Exercise XXVI. 1. Collect the urine of twenty-four hours 

 from an individual. Measure the amount, note the color, odor, re- 

 action, and specific gravity (pages 224 to 229). 



2. Determine the degree of acidity (page 229). 



3. Estimate the mineral ash (page 233). 



Exercise XXVII. Estimate the chlorides of the urine (use the 



