CHAPTER III 



CHEMICAL ANALYSIS 



WITH regard to the chemistry of tea, the most impor- 

 tant constituents from the point of view of the quality 

 of the beverage are an essential oil, tannin, and an 

 alkaloid known as theine^ The flavour of the tea is 

 largely due to the essential oil, but the remarkable 

 stimulating and refreshing qualities of the beverage 

 are due to the theine, which is also found in coffee, 

 Paraguay tea, or mate, and the kola nut ; a closely 

 allied alkaloid is also present in cacao. Experiment 

 has shown that an infusion of the leaf for ten minutes 

 is sufficient to extract all the valuable theine, and a 

 longer period merely results in an accumulation of 

 tannin which in excess, is well known to seriously 

 impede digestion. 



The mean of sixteen analyses quoted by Konig gives 

 the following result : 



Water 11'49% 



Nitrogenous Substances . . 21*22 



Theine 1'35 



Ethereal Oil *67 



Fat, Chlorophyll . . . . 3*62 

 Gum and Dextrin . . . . 7* 13 



Tannin 12*36 



Other Nitrogen free matter . . 16*75 



Woody fibre 20*30 



Ash , .. 5*11 



100*00 



