86 MILK PRODUCTS 
excess of sulfuric acid, distilling a definite portion 
of the liquid, and titrating the distillate with 
N/,, 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 5 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.—1oo grams of good sodium 
hydroxid are dissolved in 100 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.—2o0 c.c. of pure concentrated 
sulfuric acid, made up with distilled water to 
100 C.c. 
Sodium Hydroxid.—An approximately /,,, 
accurately standardized, solution of sodium 
hydroxid. 
Indicator.—Solution of phenolphthalein. 
A 300-c.c. flask is washed thoroughly, rinsed 
