86 MILK PRODUCTS 



excess of sulfuric acid, distilling a definite portion 

 of the liquid, and titrating the distillate with 

 ^/lo alkali. The number of c.c. of this solution 

 required to overcome the acidity of the distillate 

 is called the Reichert number. E. Meissl sug- 

 gested the use of s grams, and the number so 

 obtained is called the Reichert-Meissl number. 

 Alcoholic solution of potassium hydroxid was 

 originally used for saponification, but the solu- 

 tion devised by Leffmann & Beam, namely, 

 sodium hydroxid in glycerol, is more satisfactory. 

 This procedure is now official in the U. S. and 

 several European countries. The reagents and 

 operation are as follows: 



Glycerol-soda. — loo grams of good sodium 

 hydroxid are dissolved in loo c.c. of distilled 

 water and allowed to stand until clear. 20 c.c 

 of this solution are mixed with 180 c.c. of pure 

 concentrated glycerol. The mixture can be con- 

 veniently kept in a capped bottle holding a 10- 

 c.c. pipet, with a wide outlet. 



Sulfuric Acid. — 20 c.c. of pure concentrated 

 sulfuric acid, made up with distilled water to 

 100 c.c. 



Sodium Hydroxid. — An approximately ^/m, 

 accurately standardized, solution of sodium 

 hydroxid. 



Indicator. — Solution of phenolphthalein. 



A 300-c.c. flask is washed thoroughly, rinsed 



