VEGETABLE PRODUCTS. 157 



and alcohol. The coloring matter of the yellow series is mther 

 resinous, and is colored blue by sulphuric acid. They are un- 

 doubtedly modifications of chlorophyl. 



Alizarin and Purpurin, Cgo, Hio, 0,o, are the coloring matter 

 of Madder, from the root of the Rubia tinctoria. Alizarin is 

 soluble in boiling water. Takes various colors in varied cir- 

 cumstances, but is used in dyeing red. The Turkey- red pro- 

 duced on cotton is produced by alizarin. With alumina it 

 forms Madder-laJce. Animals with madder taken in their food 

 have their bones colored red. 



Anchusin, a red, resinous coloring matter, is from the An- 

 chusa tinctoria. It assumes a great variety of colors, under 

 ditierent circumstances. 



Carthamin, from the Carthamus tinctorius. A red and yellow 

 coloring matter is obtained from it. 



Hcematoxylin is the coloring matter of Logwood. The ex- 

 ti-?ict by ether is yellow. Ammonia changes it to a dark red ; 

 Potassa, to a violet ; Hydrates of the earths, oxides of zinc, and 

 Bismuth, to purple; Iron, to black. 



Cucurmin, turmeric, is from the root of the Cucurma longa ; 

 Dragon's-blood, from the Dracaena draco. Various lichens give 

 peculiar coloring matters, from one of which our Litmus comes. 



Whence alizarin and purpurin t 

 lin 1 Turmeric ? Dragon's-blood i 



Anchusin ? Carthamin ? IJBematoxv- 

 Litmus ? 



