ADULTERATION AND DETECTION. 149 



of the suspected tea and boil with about ten times its 

 weight of water in a porcelain dish or beaker. This boil- 

 ing will wash the sand off the leaves and sink to the 

 bottom, the leaves floating in the liquid. When the 

 liquid has cooled sufficiently, the leaves may be removed 

 with the hand, the liquid and sand being poured into a 

 filter. The sand is then washed, dried and ignited in a 

 platinum plate and weighed, in which manner the amount 

 of sand yielded by 50 or 100 grams of tea may be 

 actually weighed and ascertained. On examining the 

 analysis it will be found that tea-ash contains a quantity 

 of iron and some manganese, the presence of the latter 

 being so marked in tea-ash, that on subsequent treatment 

 of the ash with water a deep green solution of the man- 

 ganate is obtained. Owing to the presence of this 

 chemical, tea-ash also evolves chlorine very perceptibly, 

 particularly when treated with hydrochloric acid. If 

 the sample of tea treated yield only the normal percentage 

 of ash at the same time contains a considerable quantity 

 of silica, such a combination would afford the strongest 

 evidence of adulteration. This will be apparent from 

 the fact that tea-ash is an essential part of the tea, and if 

 a part of the tea-ash be absent, the sample must have 

 been deprived of at least the corresponding quantity of tea. 

 Spent leaves contain less ash than genuine tea, the aver- 

 age being about 3.06 of ash in 100 parts of dried spent 

 leaves, and when the ash is deficient, the explanation is 

 that the genuine tea has been more or less replaced by 

 spent or exhausted leaves. But for all practical purposes 

 a complete analysis of tea-ash is not necessary, a deter- 

 mination of the ratio of soluble to insoluble portions of 

 the ash answering the purpose as well. Such a deter- 

 mination is made by boiling the ash several times with a 

 little water, filtering and washing the precipitate in the 



