REICHERT-WOLLNY PROCESS. 



243 



phenol-phthalein for this purpose soon became apparent to many. 



To the number of cubic centimetres of - alkali used one-tenth 

 is added. 



Reichert - Wollny Process. Wollny, in a now classic 

 memoir, studied the errors of the Eeichert-Meissl process ; these 

 are : 



(1) Error due to the absorption of carbonic acid during the 

 saponification (may amount to + 10 per cent.). 



(2) Error due to the formation of esters during saponification 

 (may amount to 8 per cent.). 



Fig. 32. Caustic Soda Apparatus. 



(3) Error due to the formation of esters during the distillation 

 (may amount to 5 per cent.). 



(4) Error due to the cohesion of the fatty acids during distil- 

 lation (may in extreme cases amount to 30 per cent.). 



