THE FAT OF THE EGG OF THE COMMON FOWL 



BY 



T. E. THOKPE. 



The yolk of the egg of the common fowl contains in addition to 

 water and proteids, a small quanti ty of cholestérol, a yellow colonring 

 matter having the spectroscopic characters of lutein (Hoppe-Seyler), a 

 minute quantity of a sugar and a considérable amount of fat. 



The average composition of the yolk of the fresh egg lias been stated 

 as folio ws (Parkes) : 



Water 47,19 



Proteids 15,63 



Lecithin 10,72 



Pat 22,84. 



Cholesterin : 1,75 



Soluble salts 0,35 



Insoluble salts 0,61 



Undetermined and loss 0,91 



The relative weights of the yolk and white of the egg have been 

 variously stated by différent observers. According to Prout it is as 1 

 to 2,096; according to Lehmann as 1 to 1,48; whilst Polack gives 

 1 to 1,6 S. There can be little doubt that the ratio varies from egg 

 to egg. 



The fat is usually regarded as a mixture of olein, palmitin and 

 stearin. Aliphatic acids also occur in lecithin, which according to 

 Dtaconow is a cholin sait of distearyl-glycerin-phosphoric acid, in 

 which the stearic acid may be replacée! by palmitic and oleic acids. It 



