LUTEINE. 



147 



form, carbon disulphide, and hot glacial 

 acetic acid. 



b. To a small quantity of the crystals add nitric 

 acid ; a blue colour, turning rapidly yellow, 

 is produced. The acetic acid solution gives 

 the same reaction. 

 6. Reactions of Chloroform /Solution. 



a. Dry the solid residue of the corpora lutea, 

 and extract with chloroform. Test the solu- 

 tion as follows : 



b. Examine with spectroscope with lime light. 

 Two bands in blue will be shown. 



AaBO 



D 



Eb 



HH' 



Spectrum of chloroform solution of corpora lutea. 



c. Add nitric acid ; the solution will become 

 colourless. 



d. Evaporate the solution in a current of air. 

 A peculiar odour will be noticed, and a 

 yellow residue left. To the residue add 

 sulphuric acid ; a dirty green colour will 

 appear. Add a little sugar; no purple 

 colour will ensue. 



II. Ovo-luteine, or luteine from egg-yelks. 



1. Alcohol extract. Boil the yelk with 85% al- 

 cohol, filter, and allow to stand till clear. It 



