CHLOROPHYLL CORYDALIN 341 



to boiling, alcohol, and finally ether. When this process is 

 completed, a white substance remains which becomes hard 

 and horny on drying, and which is insoluble to all reagents except 

 concentrated acids, and in all other respects possesses the char- 

 acteristics of chitin. 



Chlorophyll, possibly C 10 H 20 NPO 9 . Chlorophyll may be 

 extracted from the chloroplasts by means of strong alcohol. 

 When this extract is shaken up with benzole and a few drops 

 of water, and allowed to stand for a short time, the benzol 

 which rises to the top will contain two pigments, amorphous 

 chlorophyll-green and carotin; while the lower stratum of alco- 

 hol will contain a crystallizable chlorophyll-green and xantho- 

 phyll. The amorphous and the crystallizable chlorophyll- 

 green differ in the character of their spectra and in their solu- 

 bility in different reagents. The amorphous form is soluble 

 in alcohol, petroleum ether, carbon bisulphide and benzine; 

 while the crystallizable is soluble only in the alcohol. 



Coffee-tannin, C 15 H 18 O 8 . This occurs in the endosperm 

 of the coffee-bean. Its presence is indicated when sections 

 give an abundant precipitate with lead acetate, a deep yellow 

 color with ammonia and caustic potash, and a dark green color 

 with ferric chloride. 



Colchicine, C 22 H 25 NO 6 . This occurs in a few rows of cells 

 immediately surrounding the vascular bundles of the corm of 

 Colchicum autumnale. Treated with a mixture of i part of 

 sulphuric acid and 3 parts of water colchicine is colored yellow, 

 and this color is changed to a brownish-violet by the addition of 

 a crystal of potassium nitrate. Iodine stains it brown, and 

 potassic-mercuric iodide and hydrochloric acid produce with it 

 a yellow precipitate. 



Coloring Matters. See under Anthochlorin, Anthocyanin, 

 Anthoxanthin, Berberin, Carotin, Crocin, Frangulin, Indican, 

 Lipochromes, Pezizin, Phycoerythrin, Phycocyanin. Phyco- 

 phaein, Ruberythric Acid, Rutin, Santalin, Xanthine. 



Corydalin, C ?2 H, 7 NO 4 . This is an alkaloid which is found 

 in the idioblasts of the Fumariaceae. When corydalin is present, 



