26 FATS, OILS, AND WAXES 



(fe) Semi-Drying Oils — 



Beech-nut oil ... 



Cotton-seed oil . . . 



Sesame ..... 

 Rape oil (colza) 



(c) Non-Drying Oils — 

 Almond oil . 



Olive oil .... 



Grape-seed oil . . . 



Castor oil .... , 



{d) Vegetable Fats — 



Cacao butter .... 

 Palm-kernel oil * . 

 Coco-nut oil * 



(5) The Reichert Meissl Value. 



This represents the number of cubic centimetres of N/lO, 

 caustic potash required for neutralizing the volatile acids 

 liberated from 5 grams of a sample of fat under certain special 

 conditions. 



The determination is carried out as follows : Five grams 

 of the sample are weighed into a 200 c.c. flask and saponified 

 by warming with 70 c.c. of 10 per cent alcohol and 2 grams 

 of caustic potash. The excess of alcohol is then evaporated 

 off and the residue, after dissolving in lOO c.c. of water, is 

 acidified with 40 c.c. of sulphuric acid (l : 10) ; a few chips of 

 asbestos are then dropped into the flask and the liquid is dis- 

 tilled through a Liebig condenser at such a rate that exactly 

 no c.c. of distillate pass over in an hour ; 100 c.c. of the dis- 

 tillate remaining after filtration are titrated with N/io caustic 

 potash in the presence of phenolphthalein. Appended are the 

 numbers obtained for several different fats : — 



The determination of the Reichert Meissl value is of 

 considerable value for the detection of adulteration in butter, 

 since any adulterant will at once lower the value. 



* Though described as oils, these substances are both solid at ordinary 

 temperatures, melting at about 25°. 



