130 



Three .s:ui)i)le.s of butter f;it were analyzed. The constants determined, 

 both of the fat and fatty acids. In order to secure butter fat of extreme vari- 

 ation in the chemical and physical properties. Use was made of the fact 

 that when fats are placed where the temperature is below the melting point 

 of the softer glycerides crystalization takes place, the harder glycerides sep- 

 arating from the softer. By filtration, separating the soft portion and the 

 process repeated, fractions of hard and soft fats arc obtained whose constants 

 differ widel}^ The three samples thus secured, i. e., the original butter fat 

 and the soft and hard glycerides when analyzed gave the constants as enumer- 

 ated in Table I. 



Table I. 



Soft Haul 



Butler fill. Portion. Portion. 



Reuchert-Meissl 30.00 33.85 24.66 



Iodine Value 39.82 43.55 33.08 



Saponification Value 230.1 232.78 226.4 



Mean Molecular Wt. Calc 732. 723. 744.9 



. , , [44. 44.8 43. 



Refractive Index' ■'■ 



[ 1.4552 1.4558 1.4545 



Melting Point 32.5 13.2 38.1 



Insoluble Acid- 87.54 86.67 88.64 



Soluble or Volatile Acids^ 6.9 6.90 5.17 



Constants of the fnsoluhle Acids of the Samples in Table I. 



Iodine Value 42.14 46.2 35.66 



Saponification Value 220.53 221.6 218.7 



Melting Point 39.2 35.3 42.4 



[33.75 34.2 32.7 



Refraction Index' , „„ , , ,-, 



1.4479 1.4482 1 4471 



Mean Molecular Wt. Calc 254 . 8 253 . 2 256 . 6 



IV. 



V()L.\TU.K .veins. 

 The higli per cent, of volatile acid in hutti-r fat is one of its chief char- 

 acteristics. By means of this fact it is possible to difTcrentiate it from all 

 other animal and vegetable fats, and it is natural that great importance is 

 attached to the determination of volatile acids or Hcichcrt-Meissl value. 



'ButyiofactcmetiT rc;i(linii at 40°C. 

 'Or Hehnpr value. 

 •Calfuhitod as hiilyric acid. 



