CAROTIN, THE PRINCIPAL YELLOW PIGMENT OF MILK FAT 407 



ether, or ether, but seemed to be partly thrown down by lead acetate 

 and by saturation of a dilute alcoholic solution with (NH 4 ) 2 SO 4 . 

 Acid mercuric nitrate solution decolorized the alcoholic solution at 

 the same time throwing down a white precipitate. 



The only conclusion that can be drawn from this experiment 

 is that the blood serum of the new-born calf is free from carotin. 

 A small amount of an unknown pigment was present which was 

 readily soluble only in alcohol, and insoluble in water, ether, carbon 

 bisulphide, and petroleum ether. 



There was practically no fat on the body except a little around 

 the kidneys and in the tissue of the caul apron. In the body the 

 latter tissue had a slight brownish color. All the fat tissue that 

 could be obtained was ground up, rendered and filtered. About 40 

 grams in all was obtained. The rendered fat had a slight yellow 

 color giving a tintometer reading in i-inch layer of 4 yellow and 

 .3 red. When solid the fat had a greenish -yellow tint. Thirty grams 

 of the fat was saponified with alcoholic potash and the soap extracted 

 with ether. It was possible to differentiate the small amount of 

 pigment thus obtained so that it was about equally divided between 

 petroleum ether and 80 per cent alcohol. In carbon bisulphide solu- 

 tion these portions showed their relation to carotin and xanthophyll 

 both in the spectroscope and chromotogramm. Both portions showed 

 two beautiful bands which measured as follows: 



Body Fat Carotin Body Fat Xanthophyll 



(In CS 2 ) (In CS 2 ) 



Band I 225 244 Band I 235 250 



Band II 263280 Band II 270285 



The results of this experiment show that a small amount of 

 carotin and xanthophyll are present in the body fat of the new-born 

 Jersey calf. The results present the apparent anomaly, however, of 

 the presence of the pigments in the body fat and their absence in 

 the blood. In explanation of this it may be said that the body fat 

 of the new-born calf, the amount of which is very small indeed, 

 probably arises from the fat of the mother, being transferred to the 

 foetus a very small quantity at a time. The small quantity which 

 would be present in the blood stream under these conditions, i. e., 

 dissolved in fat, would not have been detectable by the method used 

 for the investigation of the pigments of the blood serum. It is abso- 

 lutely certain that there were none of these pigments present in 

 the blood serum in the way in which they are normally found in the 

 mature animal. 



