364 MISSOURI AGRICULTURAL EXP. STA., RESEARCH BULLETIN NO. IO 



are shown in Table 10. The observations were not made by observing 

 all the pigments in the same volume but the volumes were adjusted 

 in each case to give the best possible bands. 



It will be noticed that with the exception of Zone I, all the xan- 

 thophylls showed the three normal xanthophyll bands to some degree of 

 intensity. Similarly hydrochloric acid had no effect on any of these so- 

 lutions or on the bands. Nitric acid had the same effect on the pigments 

 of Zones II, VII, and VIII causing the solutions to fade with the disap- 

 pearance of the bands. The effect of nitric acid on the pigments of 

 Zones III and IV was somewhat different. In these two cases a fourth 

 well-developed band appeared before the solution lost its color and 

 the three normal bands faded. The pigment of Zone I was entirely 

 different from any of the others. The normal first band of the 

 xanthophylls was entirely missing and the alcoholic solution turned 

 a distinct bluish green on the addition of a little concentrated hy- 

 drochloric acid. This color persisted for 24 hours, long after the 

 absorption bands had disappeared. This was evidently the xanthophyll 

 B of Tswett and the xanthophyll B of C. A. Schunck. 



TABLE No. 10. 



SPECTROSCOPIC PROPERTIES OF THE XANTHOPHYLLS OF THE 

 CARROT. 



THE FEEDING EXPERIMENTS. 



The foregoing studies indicated that the foods best adapted 

 for non-pigmented rations were bleached hays and cottonseed hulls 

 for roughages and white corn and cottonseed meal for grains. To 

 study the variation in the color of butter fat, the ration of various 

 cows was changed to one containing the smallest possible amounts 

 of carotin and xanthophylls, and the butter fat studied colorimetrically 

 during this time. The procedure for the butter fat was in each case 

 as follows : The milk of one or two milkings was separated by means 

 of a centrifugal hand separator and the cream churned by hand in 



