268 PHYSIOLOGICAL CHEMISTRY 



Acidify with hydrochloric acid and allow to stand, warming if 

 necessary. What is the precipitate? 



15. The choline portion of the molecule also may be recognized 

 by appropriate tests. 



16. Dissolve 0.5 gm. stearic, palmitic or oleic acid in about 

 20 c.c. warm alcohol. (Be careful of fire.) Add a few drops of 



N 

 phenolphthalein and titrate with alcoholic NaOH. Calculate 



the purity of the fatty acid used. 



