432 MISSOURI AGRICULTURAL EXP. STA. RESEARCH BULLETIN NO. 12 



In the solid state the pigment was insoluble in absolute alcohol but 

 readily soluble in petroleum ether absolute alcohol, from which the 

 petroleum ether readily extracted it on dilution with a little water. 

 The solid pigment was also very difficultly soluble in alcoholic potash. 

 After saponification for one half hour and extraction by ether, the 

 pigment, in the solid state, was fused with a little solid sodium 

 hydroxide and potassium nitrate in a porcelain crucible. The flux was 

 dissolved in hot water and the solution evaporated to dryness on the 

 steam bath in the presence of an excess of c. p. HNO 3 . As much as 

 possible of the residue was dissolved in hot water containing some c, 

 p. HNO S , the solution filtered and an equal volume of pure molybdate 

 solution added to the 100 c.c. of filtrate. On digestion at 60 C, for 

 several hours there was a distinct yellow precipitate of ammonium 

 phosphomolybdate. 



Returning to the slightly cloudy but yellow aqueous filtrate from 

 the dialysed solution, we found that the color could be entirely thrown 

 down; (i) by acid lead acetate as a light yellow precipitate which 

 bleached almost entirely in 12 hours, but from which petroleum ether 

 extracted a faint yellow color after soaking in alcohol for about one 

 hour; (2) by nitric acid mercuric nitrate solution as a bright yellow 

 precipitate which was very stable and gave up its color to petroleum 

 ether only after soaking in alcohol; 1 (3) by neutral ten per cent solu- 

 tion of AgNO 3 as a deep yellow precipitate which was stable although 

 darkening badly as the AgNO 3 oxidized in the light, but readily giving 

 up its color to petroleum ether on addition of alcohol to the precipitate, 

 the pigment thus extracted showing the carotin bands in CS 2 solution ; 

 (4) on saturation with (NH 4 ) 2 SO 4 in substance as a deep yellow 

 precipitate which was not soluble in water but when suspended in water 

 gave up its color to petroleum ether only after the addition of abso- 

 lute alcohol; (5) on addition of an excess of alcohol as a yellow pre- 

 cipitate which when dry gave up no color to petroleum ether alone, 

 but to alcoholic petroleum ether gave up a yellow pigment which was 

 quantitatively found in the petroleum ether on separation of the alco- 

 hol with a little water; (6) on heating the neutral solution to boiling 

 as a yellow coagulum insoluble in water and giving up no color to hot 

 alcohol or petroleum ether. 



In addition to the above observations the following may be men- 

 tioned. In working with a large number of samples of blood serum 



1. The pigment thus extracted showed the three carotin absorption bands 

 in carbon bisulphide solution; in alcoholic solution it gave a. pronounced 

 precipitate of digitonin-cholesteride on addition of hot one per cent digitonin 

 solution in ninety per cent alcohol. 



