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



piece of cotton is placed in the small end of the tube and the per- 

 fectly dry CaCO 3 poured in and firmly tamped down to a homogenous 

 texture. The chromotographic apparatus may now be arranged accord- 

 ing to Figure I, and the filter flask attached to the suction pump. The 

 CaCO 3 is now moistened with a little of the solvent to be used, (this 

 is very necessary) and a certain amount of the liquid which is to be 

 studied poured on the CaCO 3 . A stream of pure solvent is subse- 

 quently established and the different adsorption zones will then spread 

 out and reach their definite maximum differentiation. All unadsorbed 

 substances will be completely washed away and, "Substances which 

 form truly dissociable adsorption compounds with the CaCO 3 pass 

 slowly, 'ringwise' through and can be taken up each by itself at the 

 mouth of the tube." 



Carotin and Xanthophyll of Green Plants. 



After selecting the methods of differentiation and characteriza- 

 tion to be applied to the milk fat pigment, it was considered desirable 

 to ascertain whether they were sufficiently characteristic for a com- 

 plete identification, should the milk fat pigment be found to be either 

 a carotin or a xanthophyll. The following experiment was accord- 

 ingly carried out. 



About fifteen grams of air dry and finely divided alfalfa hay 

 which had a deep green color, was let stand for several days, with 

 shaking, under pure carbon bisulphide. The resulting deep olive brown 

 fluid was concentrated to about 25 c. c. at a low temperature. A 

 glass tube about eight inches long and one-half inch in diameter, 

 the last two inches of which were drawn out to a small opening, 

 was now filled and packed with pure CaCO 3 , which had been pre- 

 viously dried for two hours at 150 C. The CaCO 3 was tamped 

 in a small portion at a time by means of a small cotton wad and a 

 heavy glass rod. The small end of the tube was now inserted through 

 a one hole rubber stopper and fitted tightly into a side neck test tube. 

 The apparatus was then attached to a suction pump. A stream of pure 

 carbon bisulphide was passed through the column. When the CaCO 3 

 had become thoroughly moistened, 2 to 3 c. c. of the alfalfa extract was 

 poured into the top of the column, vigorous suction being maintained 

 all the time. When the extract had passed entirely into the CaCO 3 

 and occupied about one inch of the column, a stream of pure carbon 

 bisulphide was run through. As the pigment passed through it dif- 

 ferentiated itself into a number of green and yellow zones, the least 



