464 APPENDIX. 



egg-albumin, and albumoses (Witte's peptone), also a dilute saline 

 solution of serum-globulin, and perform the various qualitative 

 tests outlined on page 34. Repeat the tests with an albuminous 

 urine. Remove all albumins from one of the albuminous solutions 

 with ferric chloride as described, filter, and demonstrate the absence 

 of albumin in the filtrate with potassium ferrocyanide and acetic 

 acid. 



Exercise V. Perform the albumin color- tests with various 

 albumins (egg-albumin, serum-albumin, casein) either in solution or 

 in substance, as directed on page 35. Note the negative Molisch 

 reaction in the case of casein, and the relative amount of sulphur 

 in serum-albumin as compared with casein. 



If no glyoxylic acid is available, use glacial acetic acid in the 

 Adamkiewicz reaction ; if the reaction is negative, add a small 

 amount of a solution of oxalic acid which has been previously 

 treated with sodium amalgam. 



Exercise VI. Examine solutions of different albumins with the 

 polarimeter ; note the degree of Ia3vorotation. 



Exercise VII. Place 100 grammes of dry egg-albumin in a 

 flask holding about 1 liter ; add 500 c.c. of concentrated hydro- 

 chloric acid and boil for twelve hours. Let cool ; add strong caustic 

 alkali solution until the reaction is feebly acid ; boil with much 

 animal charcoal for about one-half hour and filter. In the filtrate 

 look for leucin, tyrosin, glutaminic acid, asparaginic acid, etc., as 

 described in Exercise XXIII. 



Exercise VIII. See exercises on serum-albumin and serum- 

 globulin, Exercise XLVI. 



Exercise IX. Suspend a small amount of casein (0.5 gramme) 

 in 25 c.c. of water and dissolve it by the careful addition of dilute 

 caustic alkali solution (1 : 10), then precipitate the casein with acetic 

 acid and wash with water ; this is to remove any adherent phos- 

 phates. Now fuse the purified and dried casein with soda and 

 saltpeter and test for alkali phosphate. 



Exercise X. See Exercise XXXVI. 



Exercise XI. Make a little starch paste ; boil with 25 per 

 cent, hydrochloric acid for ten minutes ; filter ; render the filtrate 

 strongly alkaline with caustic soda solution and test for glucose. 

 (See Exercise XXXVI.) 



Exercise XII. Prepare a 90 per cent, solution of alcohol 

 (100 c.c.), add 25 c.c. of a concentrated solution of caustic soda, 

 melt about 50 grammes of lard, and pour all into a half liter flask. 

 Heat on a water-bath and shake the mixture frequently as soon as 

 the alcohol begins to boil. When saponification is complete, which 

 occurs very rapidly if the experiment is conducted as just outlined, 

 a small amount of the solution on being poured into distilled water 

 should give rise to no turbidity. The resulting solution contains 

 soap and glycerin, which can be demonstrated according to the usual 

 methods. 



