28 
RESEARCHES ON THE MANUFACTURE 
case of green tea are Prussian blue and soap-stone, these are 
mixed in various proportions, so as to produce different shades 
of blue and green. Such mixtures as I know to be employed 
in some tea refiring factories consist of the following propor¬ 
tions. 
Mixture. Prussian blue. 
No. I 13 grs. 
>! 2 9 >> 
>> 3 ® >! 
>) 4 4 !! 
>> 5 3 u 
For measuring the mixture, spoons of various sizes are used, 
a spoonful of the largest being about 10 grs., whilst that of the 
smallest is only 1 gr. Generally a spoonful of the mixture is 
added to 5 English pounds of tea, so that the maximum quantity 
of the admixture amounts on 0,4%, corresponding to 0,001% of 
Prussian blue. For black tea, a small quantity of graphite is 
mixed, which imparts to the tea an uniform smooth and glossy 
appearance. Owing to the minute quantity of the admixture 
used for facing tea, some regard it as an admissible or even as 
a legitimate practice. Indeed, facing thus conducted is of no 
great consequence to public health, but this can not be taken 
as the ground for declaring the practice legitimate or even ad¬ 
missible. Facing and colouring ought to be most emphatically 
condemned not because of their injury to health, but because 
of their fraudulent intent. Various other kinds of adulteration, 
such as the addition of sand and clay, the admixture of foreign 
and exhausted leaves, etc. were formerly resorted to in this 
country, when the demand for tea exceeded the supply in con¬ 
sequence of the sudden opening of the trade with foreign coun¬ 
tries. But owing to the gradual reduction of the price of tea, 
such adulterations take place at present but very rarely. 
Thus, although nearly all export tea is more or less faced, 
that consumed at home is never dyed. But we have a number 
of plants the leaves of which are sometimes used as surrogates 
Soap-stone. 
5 °° g rs - 
ff 
> > 
> ? 
