144 ADULTERATION AND DETECTION. 



This analysis is especially important, inasmuch as the 

 tea which furnished the ash was of guaranteed purity, so 

 that no question of the possibility of its sophistication 

 could arise. On examining this analysis it will be 

 observed that tea-ash contains a quantity of iron, also 

 some manganese, the presence of manganese being so 

 marked in tea-ash that on subsequent treatment of the 

 ash with water a deep-green solution of manganate is 

 obtained. Owing to this presence of manganese in tea- 

 ash it also invariably evolves chlorine very perceptibly 

 when it is treated with hydrochloric acid. 



If the analysis of the tea-ash is referred to it will be 

 noted that more than one-half of it should be soluble in 

 water, so that for all practical purposes a complete 

 analysis is not requisite, a determination of the ratio of 

 soluble to insoluble parts of the ash being sufficient. Such 

 a determination is made by boiling the ash several times 

 with a little water, filtering and washing the residue in 

 the filter, drying the precipitate, igniting and weighing it. 

 The weight of the insoluble part of the ash may then be 

 subtracted from the weight of the entire ash, in which 

 manner both the percentage of the soluble and insoluble 

 ish will be conveniently arrived at, in which case the fol- 

 lowing determination of the percentage of " soluble " and 

 "insoluble ash" in 100 parts of spurious leaves and pure 

 tea when completely dried will be of interest here : 



Kind of Leaf. Soluble Ash. Insoluble Ash. 



Ash, 3.19 7.48 



Plum, 5.66 4 24 



Willow 4.16 5.18 



Teas of commerce, 3.55 2.47 



Proving that in spurious leaves the ratio of soluble or 

 insoluble ash is very different from what it is in genuine 

 tea-leaves, and that an ash of such composition cannot 

 be very soluble in water. 



