CAROTIN, THE PRINCIPAL YELLOW PIGMENT OF MILK FAT 



421 



Analyzed by means of a chromotogramm the solution showed 

 only a wide, quickly filtering, unadsorbed, rose-colored zone. 



The 80 per cent alcohol soluble pigment was transferred to ether 

 and then to carbon bisulphide, giving in the latter an orange-yellow 

 solution showing one band and much end-absorption. In the chromo- 

 togramm it showed 2 zones close together, an upper orange zone and 

 a lower canary yellow zone. The carbon bisulphide solution of the 

 orange zone showed 2 absorption bands and end-absorption. The 

 measurements are given in Table No. 2. 



TABLE No. 2. SPECTEOSCOPIC ABSORPTION BANDS OF BLOOD SERUM CAROTIN AND 



XANTHOPHYLLS. 



DISCUSSION OF EXPERIMENTS. 



It must be concluded from the above experiments that the princi- 

 pal lipochrome of the blood serum of the cow is identical with that 

 of the milk fat, body fat, and corpus luteum, and as in the case of 

 these pigments, with the carotin of green plants. 



It appears also from the above investigations that a small portion 

 of the blood lutein pigment is composed of xanthophylls. It was found 

 to be much more difficult to show their presence in the blood serum 

 than in the body fat or butter fat. The reason for this is not perfectly 

 clear but a close study of the investigations throws some light on the 

 question. It will be noticed that it required complete extraction of 



