[ 455 ] 



tion. The greater part of the albuminoid being in the form 

 of an alkali-albumen, called legumin, which has properties 

 very similiar to those of case-in in milk, is precipitated like 

 case-in on the acidification of its solution. This reaction is 

 an undesirable one, as legumin (to which the nutritive value 

 of pulses is due) is a valuable food-material. The following 

 is an analysis of the tea leaf made by Mr. Bamber, the tea- 

 chemist : 



Essential oil ... ... ... *S % 



Fixed oil ... ... ... "50 ,, 



Thein ... ... ... 4'fo ,, 



Volatile alkaloid ... ... Trace. 



; Tannin ... ... ... 18-15 



Boheic acid ... ... ... 2^34 ,, 



Gallic acid ... ... ... '83 



Legumin ... ... ... 24-00 



Albumin and Globulin ... ... 1*00 ,, 



Waxes and Gums ... ... 2'88 ,, 



Pectin, Pectoses &c. ... ... i2'6o 



Amides ... ... ... Trace. 



Cellulose, fibre &c. ... ... 21^20 ,, - 



Phlobaphine, resins &c. ... ... 7,85 ,, 



Mineral matter ... ... 4*60 ,, 



100 



714. Black tea has less tannin than green tea, as the 

 withering process which is allowed to go on much longer in 

 the former case results in saccharine fermentation, the tannic 

 acid being replaced by sugar by the absorption of oxygen, 

 while the green resinous matter is converted into a red or 

 brown colouring matter which gives rise to the red infusion 

 characteristic of black tea. Starch is also converted into 

 sugar during the manufacturing process of tea by the absorp- 

 tion of oxygen. 



