242 Testing Milk and Its Products. 



added to the soap solution to decompose the soap into 

 free fatty acids and glycerol. A few pieces of pumice 

 stone (prepared by throwing the pieces at white heat 

 into distilled water and keeping them under water until 

 used) are added, the flask connected with a glass con- 

 denser, heated slowly till boiling begins, and the con- 

 tents then distilled at such a rate as will bring 110 cc. 

 of the distillate over in as nearly thirty minutes as pos- 

 sible. 



The distillate is mixed thoroughly and filtered 

 through a dry filter; 100 cc. of the filtrate are poured 

 into a 250 cc. beaker and titrated with a deci-normal 

 barium-hydrate solution, half a cubic centimeter of phe- 

 nolphtalein solution being used as an indicator. A blank 

 test is made in the same manner as described, and the 

 amount of alkali solution used deducted from the re- 

 sults obtained with the samples analyzed. The number^ 

 of cubic centimeters of barium-hydrate solution used is 

 increased by one-tenth, and the so-called Reichert or 

 Reichert-Meissl niimher thus obtained. 



The Eeichert number for pure butter fat will ordi- 

 narily come above 24 cc. and may go over 30 ec; butter 

 fat from stripper cows will have a low Reichert num- 

 ber. Pure oleomargarine will have a Reichert number 

 of 1 to 2 cc. ; and mixtures of artificial and natural but- 

 ter will give intermediate numbers. 



Tests foe the Detection of Oleomargarine or Reno- 

 vated Butter. 

 283. The boiling test.^ A piece of butter of the size 

 of a small chestnut is melted in an ordinary tablespoon 



' Patrick, Household tests for the detoction of oleomargarine and 

 renovated butter, Farmer's Bulletin, No. 131. For detection and 



